A Large-Scale Randomized Control Trial to Determine the Effects of Dress by Adolescents on Electronic Cigarette Retailer Behaviors in Regulation Compliance in China
Phase: NA
Conditions: Regulation Compliance, Electronic Nicotine Delivery Systems
Sponsor: Peking University

 
 
1 
Study Protocol 
 
A Large-Scale Randomized Control Trial to Determine the Effects of 
Dress by Adolescents on Electronic Cigarette Retailer Behaviors in 
Regulation Compliance in China 
 
Registered ID: NCT05962411 
Version Date: July 27th, 2023 
 
Principal Investigator: 
Yang Wang, Assistant Professor, China Center for Health Development Studies, Peking 
University, E-mail: yang.wang@hsc.pku.edu.cn 
Hai Fang, Professor, China Center for Health Development Studies, Peking University, 
E-mail: hfang@hsc.pku.edu.cn 
 
Funding Sources: 
The China Medical Board (in the United States)

 
 
3 
Study Synopsis 
Lay Title 
Effects of Dress by Adolescents on Electronic Cigarette 
Retailer Behaviors in China 
Official Title 
A Large-Scale Randomized Controlled Trial to Study the 
Effects of Adolescents' Attire on Electronic Cigarette Retailer 
Behaviors in Regulation Compliance in China 
Registered ID 
NCT05962411 
Study type and phase Non-CTIMP 
Study design 
a two-armed cluster randomized controlled trial 
Chief investigators 
Professor Yang Wang, Peking University;  
Professor Hai Fang, Peking University 
Indication 
under 
investigation 
Retailers’ compliance-related behavior: illegal sales of e-
cigarettes to minors 
Study objectives 
Primary objective: To measure the effect of adolescents 
dressing in school uniforms (compared to casual attire) on 
regulation compliance-related behaviors of e-cigarette 
sellers, specifically focusing on age verification and 
underage cigarette sales. 
Secondary objectives: (1) To determine the impact of the 
type of attire worn by adolescents on in-store communication 
between sellers and customers, specifically in terms of 
dissuading use. (2) To discern the differences in regulation 
compliance-related behaviors between e-cigarette and 
cigarette retailers. 
Study subjects 
e-cigarette stores and cigarette stores 

 
 
4 
Study groups 
Intervention/Control, cluster-randomized 
Study locations 
36 major metropolitan areas across mainland China 
(including 4 municipalities directly under the Central 
Government, 27 provincial capitals, and 5 cities specially 
designated in the national plan) 
4 municipalities directly under the Central Government: 
Beijing, Shanghai, Tianjin, Chongqing. 
27 provincial capitals: Shijiazhuang (Hebei Province), 
Taiyuan (Shanxi Province), Hohhot (Inner Mongolia 
Autonomous Region), Shenyang (Liaoning Province), 
Changchun (Jilin Province), Harbin (Heilongjiang Province), 
Nanjing (Jiangsu Province), Hangzhou (Zhejiang Province), 
Hefei (Anhui Province), Fuzhou (Fujian Province), 
Nanchang (Jiangxi Province), Jinan (Shandong Province), 
Zhengzhou (Henan Province), Wuhan (Hubei Province), 
Changsha (Hunan Province), Guangzhou (Guangdong 
Province), Nanning (Guangxi Zhuang Autonomous Region), 
Haikou (Hainan Province), Chengdu (Sichuan Province), 
Guiyang (Guizhou Province), Kunming (Yunnan Province), 
Lhasa (Tibet Autonomous Region), Xi'an (Shaanxi 
Province), Lanzhou (Gansu Province), Xining (Qinghai 
Province), Yinchuan (Ningxia Hui Autonomous Region), 
Urumqi (Xinjiang Uygur Autonomous Region). 
5 cities specially designated in the national plan: Dalian 
(Liaoning Province), Qingdao (Shandong Province), Ningbo 
(Zhejiang Province), Xiamen (Fujian Province), Shenzhen 
(Guangdong Province). 

 
 
5 
Eligibility 
criteria 
(inclusion) 
l 
Identified from the AutoNavi Map through keyword 
searches 
l 
Have reachable contact information 
l 
Only one will be randomly included if multiple stores 
have the same contact information listed 
l 
Claim to be open for business on a regular basis when 
contacted  
Eligibility 
criteria 
(exclusion) 
l 
Not located in main districts of the metropolitan areas. 
l 
 Closed when arriving or located in venues that are 
inaccessible to the public, such as office buildings that 
require membership access 
l 
Cannot be located based on the AutoNavi map 
information 
l 
Simulated buyers perceived potential danger at the 
surroundings 
Target 
number 
of 
participants  
1080 e-cigarette stores nation-wide 
Interventions 
(treatment 
and 
control groups) 
Each e-cigarette store will be visited by a simulated buyer 
(also serving as a data collector) who is 18-19 years old, 
wears a specific type of attire (including carried accessories), 
and attempts to buy e-cigarette products. If necessary, the 
simulated buyer will claim that (1) he or she is an adult but 
will not show any age proof; (2) he or she has never tried any 
tobacco products; and (3) he or she wants to buy e-cigarettes 
out of curiosity because his or her friends are using the 
products.  
The sellers’ behaviors and claims will be documented 
immediately after the simulated buyer leaves the e-cigarette 
store. The primary difference between the treatment group 
and control group is the attire that the simulated buyer wears: 

 
 
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school uniforms vs. casual attire.  
Treatment Group: The e-cigarette stores will receive a 
simulated buyer of randomly assigned sex who will wear a 
school uniform, carry a school bag, and attempt to purchase 
e-cigarette products. The seller in the e-cigarette stores will 
not be aware of this study and will assume that the simulated 
buyer is a real buyer of e-cigarette products. 
Control Group: The e-cigarette stores will receive a 
simulated buyer of randomly assigned sex who will wear 
casual attire, carry a business-style bag (backpacks for males 
and handbags for females), and attempt to purchase e-
cigarette products. The seller in the e-cigarette stores will not 
be aware of this study and will assume that the simulated 
buyer is a real buyer of e-cigarette products. 
1:1 Matching: After mystery shopping and point-of-sale 
auditing in an e-cigarette store, adolescent simulated buyers 
will search for the nearest store where traditional cigarettes 
can be purchased and conduct a similar visit intervention. The 
seller in the cigarette stores will not be aware of this study 
and will assume that the simulated buyer is a real buyer of 
cigarette products. 
Outcome measures 
The primary outcome: The sales of e-cigarettes to the 
simulated buyers (school uniforms vs. casual attire), 
measured by the incidence of adolescent buyers successfully 
purchasing e-cigarette products from the stores without 
showing any age proof. 
 
Secondary outcomes include: 
l 
Sellers verbally inquiring about the buyer’s age 
l 
Sellers requesting ID cards from buyers for age 
verification 
l 
Sellers dissuading buyers from using e-cigarettes 

 
 
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Other Outcome Measures include: 
l 
Illegal flavored products being sold 
l 
Online contact 
l 
Delivery service offered 
l 
Marketing claims 
Statistical 
analysis 
plan 
Summary statistics will be presented for both the treatment 
and control groups. The significance level for comparisons 
between the groups is set at α=0.05 (two-sided). A p-value of 
less than 0.05 will be considered statistically significant. All 
analyses will be performed using Stata MP 17. 
For primary and secondary outcomes, Chi-square tests will 
be used to determine if there are statistically significant 
differences between the treatment group and control group. 
Multivariate logistic regression models will be further 
employed to analyze the treatment effect, adjusting for 
covariates. 
National maps depicting the geographic variations in the 
outcomes 
will 
be 
created 
using 
the 
R 
package 
DrawChinaMap. 
Sources of funding 
The China Medical Board in the United States 
Start date 
July 28, 2023 
Anticipated finished 
date 
September, 2023 
 
 
 

 
 
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Table of contents 
Study Synopsis ............................................................................................................... 3 
Table of contents ........................................................................................................... 8 
Study Glossary ............................................................................................................. 11 
1. Introduction .............................................................................................................. 12 
1.1. Background ................................................................................................... 12 
1.2. Rationale and justification for the study ....................................................... 13 
2. Hypothesis and Objectives ....................................................................................... 14 
2.1. Hypothesis ..................................................................................................... 14 
2.2. Primary objective .......................................................................................... 14 
2.3. Secondary objectives .................................................................................... 14 
2.4. Exploratory objectives .................................................................................. 14 
3. Study Design ............................................................................................................ 16 
4. Study subjects .......................................................................................................... 18 
4.1. Study setting and locations ........................................................................... 18 
4.2. Number of subjects to be enrolled ................................................................ 18 
4.3. Eligibility criteria .......................................................................................... 19 
4.3.1. Inclusion criteria ................................................................................ 20 
4.3.2. Exclusion criteria ............................................................................... 20 
4.4. Subject replacement ...................................................................................... 21 
4.5. Subjects for comparison ................................................................................ 21 
5. Study treatments ....................................................................................................... 22 
5.1. Treatment and control ................................................................................... 22 
5.2. Treatment procedures .................................................................................... 22 
5.3. Design and selection of the uniforms ............................................................ 23 
6. Outcome Measures ................................................................................................... 25 
6.1. Primary outcome measure ............................................................................. 25 
6.2. Secondary outcome measures ....................................................................... 25 
6.3. Other outcome measures ............................................................................... 25 

 
 
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6.4. Design of the assessing tool .......................................................................... 25 
7. Study procedures ...................................................................................................... 27 
7.1. Subject enrollment and randomization ......................................................... 27 
7.1.1. Screening and enrollment .................................................................. 27 
7.1.2. Informed consent ............................................................................... 27 
7.1.3. Randomization ................................................................................... 28 
7.1.4. Blinding .............................................................................................. 28 
7.2. Pilot study ..................................................................................................... 29 
7.3. Data collector recruitment ............................................................................. 29 
7.4. Training data collectors ................................................................................. 30 
7.4.1. Course Training .................................................................................. 30 
7.4.2. Field training ...................................................................................... 31 
7.5. Randomization .............................................................................................. 31 
7.6. Study visits and treatment procedures .......................................................... 31 
8. Statistical Analyses .................................................................................................. 34 
8.1. General statistical methods ........................................................................... 34 
8.2. Analysis of primary outcome ........................................................................ 34 
8.3. Analysis of secondary outcomes ................................................................... 34 
8.4. Analysis of other outcomes ........................................................................... 35 
8.5. Subgroup analysis ......................................................................................... 35 
8.6. Sample size considerations ........................................................................... 35 
8.7. Missing data .................................................................................................. 36 
9. Quality control ......................................................................................................... 37 
9.1. Design phase of the protocol ......................................................................... 37 
9.2. Implementation phase of the protocol ........................................................... 37 
9.3. Analysis phase of the protocol ...................................................................... 37 
10. Ethics ...................................................................................................................... 38 
10.1. Ethical approval and informed consent ....................................................... 38 
10.2. Legality ....................................................................................................... 38 
10.3. Follow-up processing .................................................................................. 38 

 
 
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11. Data processing and storage ................................................................................... 39 
12. Study Timeline ....................................................................................................... 40 
13. Role of funding source ........................................................................................... 41 
14. Declaration of interests .......................................................................................... 42 
15. Reference ............................................................................................................... 43 
16. Appendix ................................................................................................................ 46 
Appendix 1 Specific Administrative Districts Included in 36 Major 
Metropolitan Areas of Mainland China ........................................................... 46 
Appendix 2 Communication script in the e-cigarette store ............................ 49 
Appendix 3 Pictures for models wearing school uniforms and casual attire 52 
Appendix 4 Assessing tool ................................................................................. 56 
Appendix 5 Telephone protocol ........................................................................ 74 
Appendix 6 Recruitment poster for simulated buyers .................................... 77 
Appendix 7 Interview process for simulated buyers ....................................... 79 
Appendix 8 Survey sequence of the metropolitan areas for three teams ...... 80 
Appendix 9 Code for web crawling .................................................................. 81 
 
 
 

 
 
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Study Glossary 
Abbreviation or Term 
Definition/Explanation 
E-cigarette 
Electronic cigarette 
RCT 
Randomized controlled trial 
ID 
Identification card 

 
 
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1. Introduction 
1.1. Background 
Electronic cigarettes (e-cigarettes) are battery-powered devices that heat a reservoir of 
liquid that commonly contains nicotine, flavorings and other chemicals, which are 
vaporized and inhaled by the users. The use of e-cigarettes in young generations has 
climbed significantly over the past decade globally. In the United States, the prevalence 
of current e-cigarette use increased from 1.5% to 19.6% among high school students 
during 2011-2020.1,2 A meta-analysis of data from 69 countries and territories, 
published in 2021, showed that the pooled prevalence of ever and current e-cigarette 
use in those younger than 20 years old reached 17.2% and 7.8%, respectively.3  
Laboratory and epidemiological studies have both suggested that e-cigarettes pose 
harms to respiratory and cardiovascular systems,4,5 though the long-term health impacts 
remain unclear. Moreover, previous longitudinal studies showed that e-cigarette use 
among adolescents may act as a gateway to combustible cigarette and other substance 
use.6 These evidence have raised major concerns about adolescent e-cigarette use and 
encouraged policymakers to introduce strict regulations, including the minimum age 
restriction of e-cigarette sales, in many countries.  
Until 2023, over 50 countries/jurisdictions have implemented the age restriction for e-
cigarette sales. However, a few studies have uncovered that such policy interventions 
failed to significantly reduce adolescent e-cigarette use prevalences.7-9 One important 
explanation is that e-cigarette sellers were not fully compliant with the regulation.10 
They sell e-cigarettes to customers who are clearly underage without any age checks. 
Furthermore, minors may avoid possible inspections by disguising themselves as 
adults.11 Therefore, advancing the understanding of seller compliance behaviors with 
age restriction and identifying associated factors are critical to the market regulation.  
In China, the prevalence of current e-cigarette use among adolescents increased from 
2.7% in 2019 to 3.6% in 2021, and 16.1% of middle school students had experimented 
with the products.12 The Chinese Minors Protection Law prohibits the sales of cigarettes 
to minors under 18 years old, verified through ID checks when necessary, which has 
also applied to e-cigarettes since 2018.13 Followed by this, the Chinese State Tobacco 

 
 
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Monopoly Administration and the Chinese State Administration for Market Regulation 
have launched multiple national campaigns and conducted specific inspections of 
points of sales and advertisements to enforce the national laws.13 Despite lack of 
investigations regarding e-cigarette sales to minors in China, a prior study has shown 
that sellers’ compliance with posting 'no sales to minors' signs is still low,14 suggesting 
the illegal practice of selling e-cigarettes to adolescents may be widespread.  
The practice of requiring students enrolled in school to wear a uniform varies globally, 
with diverse practices across the US and European Union, and widespread adoption in 
the United Kingdom and in Asian countries such as China, Japan, and South Korea.15 
Since 1993, some Chinese middle schools have been requiring students to wear school 
uniforms while attending classes, which has later become the consensus.16 This renders 
it convenient to determine that a person is a middle or high school student based on the 
wearing of a school uniform, and thus must be an adolescent. While some studies have 
reported negative impacts on physical and psychological health,17 others have 
suggested that school uniforms can lead to better discipline, academic performance, and 
class involvement.18,19 Few research studies the effect of school uniforms on reducing 
illegal sales to minors. 
1.2. Rationale and justification for the study 
In the absence of strict regulatory enforcement, e-cigarette sellers make decisions on 
whether they should sell the products to customers mostly based on their judgment on 
the youthfulness of the customer's appearance. As a result, sellers tend to sell products 
to adolescents who look mature or dress as adults without checking their IDs. Even 
worse, some unscrupulous sellers dare to sell e-cigarettes to minors, even if they know 
that it is illegal. However, by allowing sellers to identify school aged adolescents more 
easily, uniforms may reduce illicit sales of tobacco and nicotine products. Current 
knowledge on the regulation compliance of e-cigarette retailers in China remains sparse. 
It is also unclear regarding the effects of adolescents dressing school uniforms 
(compared to casual attire) on the sellers’ compliance behaviors.  
 

 
 
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2. Hypothesis and Objectives 
2.1. Hypothesis 
We hypothesize that dressing in school uniforms (compared to casual attire) * by 
adolescents will significantly increase the likelihood of e-cigarette sellers verifying the 
age of buyers in stores and reduce the probability of their illegal sales to minors. 
The corresponding null hypothesis that will be tested is that dressing by school uniforms 
by adolescents will have no effect upon e-cigarette selling behaviors in regulation 
compliance.  
2.2. Primary objective 
To measure the effect of adolescents dressing in school uniforms (compared to casual 
attire) on regulation compliance-related behaviors of e-cigarette sellers, specifically 
focusing on age verification and underage cigarette sales. 
2.3. Secondary objectives 
l 
To determine the impact of the type of attire worn by adolescents on in-store 
communication between sellers and customers, specifically in terms of dissuading 
use.  
l 
To discern the differences in regulation compliance-related behaviors between e-
cigarette and cigarette retailers. 
2.4. Exploratory objectives 
l 
To describe the regulatory compliance of e-cigarette and cigarette sellers across 
mainland China. 
l 
To document the marketing and communication strategies adopted by e-cigarette 
and cigarette sellers, e.g. store location, advertisements, decorations, and online 
 
* The setting of the intervention and control in the protocol and manuscript was reversed from the time of registration, 
which aimed to provide readers with a better understanding of the impact of adolescents' clothing (appearance) on 
retailers' compliance and highlighted the protective effect of school uniforms. This would actually not influence the 
implementation or results of trial.  

 
 
15 
delivery service, across mainland China.

 
 
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3. Study Design 
This study is a two-armed, national-level, open-label cluster RCT conducted among e-
cigarette stores located in 36 major metropolitan areas (including 4 municipalities 
directly under the Central Government, 27 provincial capitals, and 5 cities specially 
designated in the national plan) across mainland China. This RCT will adopt the 
mystery shopping approach to measure the effect of adolescent buyers’ type of attire 
(school uniforms vs. casual attire) on the likelihood of sellers’ compliance of the 
minimum age restriction of e-cigarette sales, defined by both age verification and sales. 
The e-cigarette stores in clusters will be randomly assigned to the intervention group 
(school uniform) or control group (casual attire) at the ratio of 1:1. Each store in the 
intervention group will receive a mystery buyer dressed in a school uniform, while each 
store in the control group will receive a mystery buyer dressed in casual attire. The 
adolescent buyers will attempt to purchase products and record the behaviors and 
marketing claims of the sellers, as well as the internal and external characteristics of the 
store. 
Eligible stores as study subjects will be identified from the AutoNavi Map through 
keyword searches. Stores are eligible for enrollment if they have reachable contact 
information and claim to be open for business on a regular basis when contacted. The 
expected number of stores sampled in each metropolitan area is approximately 32, if 
the number allows, for a minimum expected total enrolment of approximately 1080 
sellers nationwide. In addition, we plan to conduct the same trial for cigarette stores and 
perform a 1:1 match with e-cigarette stores. This will allow us to compare sellers' 
behaviors between the two attire groups in both cigarette and e-cigarette stores. 
The overall study design is described by a flow chart as follows (Figure 1): 

 
 
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Figure 1 Flow Chart of Study Design 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
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4. Study subjects 
4.1. Study setting and locations 
This study will be conducted across 36 metropolitan areas in mainland China (including 
4 municipalities directly under the Central Government, 27 provincial capitals, and 5 
cities specially designated in the national plan). All major metropolitan areas in 
mainland China are included as listed below:  
4 municipalities directly under the Central Government: Beijing, Shanghai, Tianjin, 
Chongqing. 
27 provincial capitals: Shijiazhuang (Hebei Province), Taiyuan (Shanxi Province), 
Hohhot (Inner Mongolia Autonomous Region), Shenyang (Liaoning Province), 
Changchun (Jilin Province), Harbin (Heilongjiang Province), Nanjing (Jiangsu 
Province), Hangzhou (Zhejiang Province), Hefei (Anhui Province), Fuzhou (Fujian 
Province), Nanchang (Jiangxi Province), Jinan (Shandong Province), Zhengzhou 
(Henan Province), Wuhan (Hubei Province), Changsha (Hunan Province), Guangzhou 
(Guangdong Province), Nanning (Guangxi Zhuang Autonomous Region), Haikou 
(Hainan Province), Chengdu (Sichuan Province), Guiyang (Guizhou Province), 
Kunming (Yunnan Province), Lhasa (Tibet Autonomous Region), Xi'an (Shaanxi 
Province), Lanzhou (Gansu Province), Xining (Qinghai Province), Yinchuan (Ningxia 
Hui Autonomous Region), Urumqi (Xinjiang Uygur Autonomous Region). 
5 cities specially designated in the national plan: Dalian (Liaoning Province), 
Qingdao (Shandong Province), Ningbo (Zhejiang Province), Xiamen (Fujian Province), 
Shenzhen (Guangdong Province). 
4.2. Number of subjects to be enrolled 
The expected number of study subjects sampled from each metropolitan area is 
approximately 32 e-cigarette stores, if the number allows, for a minimum expected total 
enrollment of approximately 1,080 e-cigarette stores. Some metropolitan areas may 
have fewer than 32 e-cigarette stores, so more e-cigarette stores will be included from 
other metropolitan areas to reach the study's total. 

 
 
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4.3. Eligibility criteria  
Due to lack of officially-released information of licensed e-cigarette stores, the list of 
brick-and-mortar stores and their detailed information (including address and phone 
number) will be compiled from the most popular Chinese navigation tool AutoNavi 
Map through keywords searching using the application programming interface service.  
Search keywords include general terms, such as e-cigarette and vape, as well as popular 
brands. The keywords were determined based on the results of searches for “电子烟店” 
(electronic cigarette store in Mandarin Chinese) in Beijing through AutoNavi 
application on June 27, 2023, and we took the first 200 records as the reference for 
deciding the keywords. Top brands of e-cigarettes were identified according to both the 
initial search results and the annual production scale of e-cigarette companies in China 
in 2022.20 The search terms used will be in Mandarin Chinese, and the English names 
of these brands will also be included (see Table 1).   
The detailed information to be compiled should include store ID, store name, address, 
longitude and latitude, city, specific district or area, and telephone number. 
 
Table 1 Search terms 
Mandarin (used) 
"电子烟店", "电子烟零售店", "电子烟体验店", "电子烟集合
店", "电子烟专卖店", "电子烟直营店", "雾化", "蒸汽烟", 
"vape", "电子烟旗舰店", "悦刻", "魔笛", "雪加", "小野", "铂
德", "柚子电子烟", "徕米", "MR 迷睿", "VTV", "福禄
FLOW", "RELX", "MOTI", "YOOZ", "snowplus", "vvild", 
"Boulder", "LAMI" 
English 
translation 
"e-cigarette store", "e-cigarette retail store", "e-cigarette 
experience store", "e-cigarette collection store", "e-cigarette 
exclusive 
store", 
"e-cigarette 
directly-operated 
store”, 
“vaporized", "vapor cigarettes", "vape", "e-cigarettes flagship 
store", "Yueke", "Modi", "Xvejia", "Xiaoye", "Bode", "Yozi e-
cigarettes", "Lami", "MR Mirui", "VTV". "Fulu Flow", 
"RELX", "MOTI", "YOOZ", "snowplus", "vvild", "Boulder", 

 
 
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"LAMI" 
 
4.3.1. Inclusion criteria  
The e-cigarette stores will be eligible to be sampled in this study if they meet all of the 
inclusion criteria:  
l 
Identified from the AutoNavi Map through keyword searches 
l 
Have reachable contact information 
l 
Only one will be randomly included if multiple stores have the same contact 
information listed 
l 
Claim to be open for business on a regular basis when contacted (pre-selected 
stores will be called ahead of investigation to inquire about their business status) 
4.3.2. Exclusion criteria  
Stores will not be eligible for the study if they meet one of the exclusion criteria:  
l 
Not located in main districts of the metropolitan areas. Given the fact that most e-
cigarette stores in China are located in economically developed areas with high 
population density,21 this trial will only include stores in these metropolitan areas. 
The definition of main districts for each metropolitan area can be seen in Appendix 
1. 
l 
Closed when arriving or located in venues that are inaccessible to the public, such 
as office buildings that require membership access. 
l 
Cannot be located based on the AutoNavi map information. 
l 
Data collectors (simulated buyers) perceived potential danger at the surroundings. 
This usually means that the store is located in a long alley with no pedestrians in 
the neighborhood. Training will be given to the simulated buyers prior to the formal 
survey to facilitate their judgement, but whether or not to exclude trial subjects will 
require an instant online discussion between the simulated buyers and the study 
coordinators via an App in their cell phones. 

 
 
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4.4. Subject replacement 
Given that whether an e-cigarette store will be ultimately included and audited in this 
study cannot be determined until simulated buyers arrive at it, we will randomly select 
40 e-cigarette stores in total (8 for replacement if needed), rather than 32, for each 
metropolitan area in case that the final number of the subjects cannot reach the 
minimum sample size required for data analysis due to the exclusion criteria. 
Simulated buyers with school uniforms and casual attire will be randomly assigned to 
buy e-cigarettes in 32 e-cigarette stores for each metropolitan area. When an e-cigarette 
store is excluded from the trial because it is not in business or cannot be found, the 
simulated buyer will go to visit the nearest store from the replacement list with the study 
coordinator’s permission.  
If too many stores are excluded for failing to meet the criteria in a metropolitan area, 
the simulated buyers will report the excluded ones to the study coordinator and search 
for the nearest eligible stores using the AutoNavi APP. The study coordinator will also 
provide assistance in this process, including making phone calls to confirm that the 
alternative e-cigarette stores are open and ensuring that they are not the ones that have 
already been audited.  
4.5. Subjects for comparison 
This study will include cigarette stores for comparisons with e-cigarette stores. For each 
e-cigarette store, one cigarette shop nearby will be conveniently selected for matching, 
because cigarettes are widely available in convenience stores, supermarkets, and 
tobacco and liquor shops, and thus these stores are impossible to systematically be pre-
identified. 

 
 
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5. Study treatments 
5.1. Treatment and control 
Each e-cigarette store will be visited by a simulated buyer (also serving the role of a data 
collector) who aged 18-19 years old and wear a certain type of attire, including carried 
accessories. If necessary, the buyers will claim that (1) they are adults but will not show 
any age proof; (2) they have never tried any tobacco products; (3) they want to buy e-
cigarettes out of curiosity because their friends are using the products.  
The sellers’ behaviors and claims will be documented immediately after the simulated 
buyers leave the stores. The primary difference between the treatment group and control 
group is the attire that buyers wear: school uniforms vs. casual attire.  
Treatment group: The e-cigarette stores will receive a simulated buyer of a randomly 
assigned sex who will wear a school uniform, carry a school bag, and attempt to purchase 
e-cigarette products. 
Control group: The e-cigarette stores will receive a simulated buyer of a randomly 
assigned sex who will wear casual attire, carry a business style bag (backpacks for males 
and handbags for females), and attempt to purchase e-cigarette products. 
1:1 matching: After mystery shopping and point-of-sale auditing in an e-cigarette store, 
simulated buyers will search for the nearest store where traditional cigarettes can be 
purchased and conduct a similar visit intervention.  
Note: The simulated adolescent buyer (also the data collector) will role-play a minor under 
18 years old who attempt to buy e-cigarettes. Only adolescents aged 18 or 19 years old will 
be recruited in this study because it is theoretically difficult to distinguish whether they are 
under or above 18 years old from the facial features. This trial will not recruit minors who 
are younger than 18 years old because it is illegal for them to purchase e-cigarette products 
in China.  
5.2. Treatment procedures 
Before entering a store, the simulated buyers will observe and record the location and 

 
 
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exterior advertising from a hidden corner.  
After that, the simulated buyers will enter the store and attempt to buy e-cigarette products. 
If the seller asks about their age, they will tell the seller that they are adults (18 years old 
or above) but will not show their ID cards or give any proofs to mimic the real-world 
situation. If the seller asks about buyer’s smoking status, the buyer will claim that he/she 
has never tried any tobacco products including both e-cigarettes and cigarettes, and wants 
to buy e-cigarettes out of curiosity because his/her friends are using these products. The 
buyer will ultimately attempt to buy the cheapest e-cigarette product in the store for the 
budget reason, but he or she will not reveal this before asking about the price. To reduce 
potential biases caused by adolescent buyers’ personalities and communication skills, a soft 
script will be developed to standardize the in-store interactions as much as possible (see 
Appendix 2).  
After the assessment (approximately 10-15 minutes), simulated buyers will immediately 
leave the store and complete the rest of data entry to optimize retention. They will note the 
seller’s responses during the visit, including whether or not inquiring about age, checking 
ID card, dissuading uses, and ultimately selling products. In addition, they will document 
the seller’s demographic characteristics, marketing messages, interior decorations and 
signs. The detailed information about outcome measures is shown in Section 6. Data will 
be inputted via a self-developed instrument embedded in the online survey platform called 
Questionnaire Star accessed by smart phones.  
After leaving the e-cigarette store, simulated buyers will search for the nearest cigarette 
shop and conduct a similar visit intervention. They will firstly observe the store’s location 
and exterior advertising. Then, they will enter the shop and attempt to purchase a pack of 
cigarettes. If cigarette seller asks, they will answer that they are adults now and have never 
smoked. The adolescents will similarly record the behaviors and claims of the sellers in 
cigarette stores. The detailed information about outcome measures is shown in Section 6.  
5.3. Design and selection of the uniforms 
In 2015, China’s Ministry of Education, together with multiple departments including the 
National Standardization Committee, issued a directive titled ‘Opinions on Further 
Strengthening the Management of School Uniforms for Primary and Secondary School 

 
 
24 
Students’.16 The policy, although not legally mandated, encourages students to wear school 
uniforms on weekdays. The decision on school uniforms is jointly made by the schools and 
committees of students’ parents. However, once established in a school, it in reality 
becomes mandatory for all students to adhere to. Due to the fact that wearing school 
uniforms by secondary school students has become a social consensus, those wearing 
uniforms are naturally perceived as minors in China, especially when he/she looks young.  
This study chooses school uniforms and casual attire as the indicator of being potential 
minors and adult buyers, respectively. The school uniform chosen is the most common 
style of middle/high schools in China, as the study will be conducted in thirty-six major 
metropolitan areas across mainland China. The casual attire style chosen is the most 
commonly seen in China. Appendix 3 shows pictures for adolescent models with pre-
selected school uniforms and casual attire.  
The same styles of school uniforms and casual attire with corresponding accessories, 
including school bags (adolescents), backpacks (male adults), and handbags (female 
adults), will be ordered and provided to simulated buyers free of charge. 
 
 
 
 
 
 
 
 
 
 

 
 
25 
6. Outcome Measures 
6.1. Primary outcome measure 
The primary outcome is the sales of e-cigarettes to simulated buyers, as adolescents 
successfully purchase e-cigarette products from the stores without showing any age proof.  
6.2. Secondary outcome measures 
Secondary outcomes include: 
l 
Sellers’ verbally inquiring about buyer age 
l 
Sellers’ requesting ID cards from buyers for age verification 
l 
Sellers’ dissuading buyers from using e-cigarettes (added after the pilot study) 
6.3. Other outcome measures 
Other outcome measures primarily include: 
l 
Illegal flavored products being sold 
The simulated buyers will report if sellers mention that flavored (not allowed in China) 
e-cigarette products are available in the stores.  
l 
Online contact 
The simulated buyers will report if WeChat account information is publicly displayed 
for adding contacts. 
l 
Delivery service offered 
The simulated buyers will report if sellers mention that products ordered online can be 
delivered to them. 
l 
Marketing claims 
The simulated buyers will record the marketing claims of sellers to promote the 
products 
6.4. Design of the assessing tool 
The assessing tool will be used by simulated buyers to check whether all information is 

 
 
26 
recorded after leaving the store, and all data will be inputted.  
The assessing tool is designed primarily based on the Vape Shops Standardized Tobacco 
Assessment for Retail Setting (V-STARS)22 and Tobacco Advertising, Promotion and 
Sponsorship (TAPS) bans compliance guide23, and published articles14. It will be further 
adapted by investigators who are familiar with Chinese e-cigarette retailers and laws and 
have observed store characteristics, to the Chinese context to collect information mainly 
on store internal/external environmental features (e.g., location, advertising, warning signs, 
and licensing), product availability, and seller behaviors. 
After the initial version of the assessing tool is finished, a pilot investigation will be 
conducted to further revise and finalize this instrument. The pilot trial will be conducted 
by two simulated buyers (18-19 years old, see the requirements in Section 7.3), 
accompanied with coordinators, in 2 metropolitan areas: Beijing and Shijiazhuang (the 
capital city of Hebei Province). Each simulated buyer will conduct mystery shopping and 
point-of-sale auditing in 10 e-cigarette stores. After data collection is complete for each 
store, coordinators will discuss with simulated buyers encountered problems and possible 
solutions, as well as further refine the research process and assessing tool. Detailed 
information can be seen in Section 7.2. The final assessing tool can be seen in Appendix 4.  
 
 
 
 
 
 
 
 
 

 
 
27 
7. Study procedures  
The trial will be registered at ClinicalTrials.gov, and will be conducted after getting 
permission or exemption from the ethical review from Peking University Institutional 
Review Board (IRB).  
7.1. Subject enrollment and randomization 
7.1.1. Screening and enrollment 
First, after obtaining a list of e-cigarette stores through keyword searching, we will remove 
e-cigarette stores without contact information based on the eligibility criteria. Stores not 
located in main districts of the metropolitan areas (see Appendix 2) will be then removed 
with Excel filter function, and investigators will further manually delete those that are 
judged to be non-e-cigarette shops. In this way, a pool for the sampling of trial subjects 
will be generated.  
Second, using R software, each store will be assigned a random number and all the stores 
in the list will be ordered by the random number from smallest to largest, so that each store 
with a phone number will have an equal probability of being enrolled in this study. 
Subsequently, as each selected store needs to be contacted for confirming their opening, 
this trial will further exclude those stores which have the same contact information as the 
other store. If more than one store with the same telephone number exists, only the first 
one will be kept.  
Finally, e-cigarette retailers will be called in the ascending order of random numbers for 
inquiring about their operating status and verifying that their address is correct, until 40 
stores are confirmed to be still in business for each metropolitan area (if the number allows). 
A telephone protocol (Appendix 5) will be used to standardize communication process to 
collect relevant information. Callers will pretend to be potential buyers who may be visiting 
the store shortly, and each store will be contacted once again on the second day if not 
answered. 
7.1.2. Informed consent 
This study uses the mystery shopping approach and all the e-cigarette store owners and 
sellers will not be informed that they are enrolled in this trial.24-26  

 
 
28 
7.1.3. Randomization 
Prior to the randomization of subjects, all the eligibility criteria must be met. 
l 
Generating clusters to which the stores belong: Considering traveling time and the 
efficiency of data collection, this trial will use a cluster randomization approach, rather 
than simple randomization. Investigators will firstly map all the 40 selected stores 
within each metropolitan area, then divide them into clusters that contains the same 
number (usually 4 stores) considering their locations and public transportation. Then 
each cluster will be digitally labeled, from area 1 to area 8. The labeling of the clusters 
follows the principle of from top to bottom, from left to right on the map.  
l 
Assigning clusters to treatment: Each cluster will be randomly assigned to one 
simulated buyer, and the attire (school uniforms or casual attire) he/she wears on a 
specific day will also be random. In this way, the e-cigarette stores will finally be 
allocated at a 1:1 ratio to either the intervention or control group.  
(1) Specifically, the simulated buyers (data collectors) to be recruited are 18 to 19 years 
old, with a 1:1 ratio of males to females. To reduce bias associated with personal 
characteristics of simulated buyers, they will be randomly assigned a new digital 
number for each metropolitan area, which is used for matching the clusters.  
(2) The type of attire wore by each adolescent on a specific day will be pre-determined 
using the Excel’s random number generator within each sex, and each adolescent 
will have an equal probability to wear school uniforms and casual attire during the 
entire study.  
7.1.4. Blinding  
It will be impossible to blind study subjects regarding the assignment to the intervention 
or control group, as letting sellers in the e-cigarette stores see the buyers’ attire is part of 
the treatment. However, sellers will not be aware of the participation in this trial because 
of the mystery shopping approach adopted. 
The trial team, consisting of both data collectors and coordinators collecting outcomes, will 
also not be blind to e-cigarette stores in the intervention and control groups, because there 
is no way to not let them know the e-cigarette stores with simulated buyers with school 
uniforms or casual attire on each day. 

 
 
29 
The statistician conducting analyses will have no direct contact with e-cigarette stores but 
will not be blind to the treatment allocation. 
7.2. Pilot study 
Aim: To refine the treatment procedures and improve the assessing tools 
Subjects: 20 e-cigarette stores, including 10 in Beijing and 10 in Shijiazhuang (the capital 
city in Hebei Province). These 20 e-cigarette stores will be selected from the list we 
complied, and will not be revisited in the formal trial. 
Time: After subject enrollment but prior to data collector training 
Data collectors (simulated buyers): two adolescents aged 18 or 19 years old, including 
one male college student and one female college student. The requirements for them are 
same as the that for the formal trial. For each adolescent, a coordinator will accompany 
him/her for any necessary help and further discussion for the treatment procedures.  
Treatment: 10 stores will receive an adolescent buyer wearing casual attire and the other 
10 stores will receive a simulated buyer wearing school uniforms. All the treatment 
procedures will be same as the formal trial, which can be seen in Section 5. 
Evaluation after the pilot trial: After the data collection of 20 polit e-cigarette stores, the 
research team will discuss the problems encountered and possible solutions with each 
simulated buyer, as well as further refine the research process and the assessing tool. 
7.3. Data collector recruitment 
We plan to recruit 25 college students in Beijing through social media in June-July 2023, 
including 12 males and 13 females, where the one additional female data collector will be 
recruited considering that females may need to take some days off during the fieldwork 
due to health-related reasons. This way, a gender-balanced sample will be more likely to 
be achieved. 
Requirements including:  
l 
Aged 18 or 19 years old (according to the WHO standard, adolescents are defined 
to less than 20 years old) 
l 
Having never used any tobacco products including e-cigarettes and cigarettes 

 
 
30 
l 
No apparent dyed hair 
l 
No tattoos being seen 
A poster will be designed and posted in WeChat Moments and online forums to recruit the 
simulated buyers in Beijing. It also will be shared among faculty, staff, and students at 
several universities in Beijing. The poster will contain the following information, including 
study title, location, time of the investigation, requirements, compensation, and contact 
information. Considering the need to keep the study confidential from Chinese e-cigarette 
retailers, the investigators will avoid mentioning too many details in the recruitment poster 
and only inform adolescents of more specific information in the subsequent interview 
sessions.  
The coordinator will create a WeChat group of the adolescents who sign up. In July 2023, 
an online interview will be performed to communicate with those who are willing to take 
part in, providing them with more details about the trial, and check whether they are eligible 
for the investigation. 
Each simulated buyer will receive CNY 350 (approximately USD 50) per day as payment 
and all accommodation and transportation costs will be covered by the study.  
7.4. Training data collectors 
7.4.1. Course Training 
After recruiting the adolescents participating in the trial, the investigators will arrange a 
one-day on-site training. The training will be conducted in the form of PowerPoint 
presentations and lectures by investigators and coordinators. The training date is set within 
seven days prior to the formal investigation.  
The training content will include the study background, purpose, process, time schedule, 
precautions in the fieldwork, etc. Investigators will make sure that simulated buyers 
understand the roles they play. Coordinators will show them the pictures of retail stores, 
product advertisements, and warning signs to help them quickly and accurately identify the 
details they need to record in the study. At the end of the lecture, the coordinator will role-
play the seller in one (or more) simulated interactions with simulated buyers to help them 
better perform in real-life possible scenarios.  

 
 
31 
An investigation manual will be provided by the coordinator to the simulated buyers to 
guide them in the proper conduction of the survey and completion of the questionnaire. 
The manual will include training contents, detailed explanations of the questionnaire items, 
special situations handling strategies, and how to communicate with sellers in a 
standardized manner (without making them suspicious). 
7.4.2. Field training 
On the second training day, simulated buyers will practice fieldwork at nearby e-cigarette 
stores with coordinators accompanying them. The goal of the field training is to further 
enhance the simulated buyers' understanding of the process, proficiency in memorizing 
details, and ability to complete the questionnaire 
The practice in the field will be conducted by a single simulated buyer, and the process will 
be exactly the same as the formal trial. Sellers in the e-cigarette stores will not be aware 
that they are being studied, and the physical environment will be recorded by the 
coordinators beforehand. During the field training, the coordinator will wait outside e-
cigarette stores and discuss the difficulties and problems encountered after the survey is 
completed, to help them effectively develop skills for data collection. Each simulated buyer 
will try several stores until they are familiar with the entire process and get more than 90% 
of the objective items in the questionnaire correct. Otherwise, they will be taken to the next 
e-cigarette store to continue their field practice. The entire training will last 3-5 days. 
7.5. Randomization  
Each simulated buyer will be assigned with a random number and the clusters of e-cigarette 
stores will be randomly allocated to the intervention group or the control group before the 
visits. Details on randomization can be found in Section 7.1.3. Randomization and 
assignment of all simulated buyers and e-cigarette stores will be completed before the start 
of the formal survey. 
7.6. Study visits and treatment procedures  
The formal study will begin in July 2023. The simulated buyers and coordinators will be 

 
 
32 
divided into three teams, each including eight simulated buyers† (18-19 years old) and two 
coordinators (graduate students). Each team will travel from Beijing to all the metropolitan 
areas across mainland China (Appendix 8). 
Simulated buyers will travel to new metropolitan areas by train or air and change into the 
prepared attire at the hotel (the type of attire worn on that day will be pre-determined by a 
random number). The team coordinator will then assign a list of pre-specified e-cigarette 
stores to each simulated buyer. Using the assistance of the AutoNavi Map, simulated buyers 
will travel by public transportation according to the geographic information on the list to 
the e-cigarette stores to conduct the survey. Each simulated buyer will visit 4-5 e-cigarette 
stores per day if possible. 
The simulated buyers will take on the role of an adolescent who attempt to buy e-cigarette 
products, go into a store, talk to the seller, and try to make the purchase. They will record 
all the information using Questionnaire Star (an App) on their smart phone after the visit is 
completed. Upon the arrival, the simulated buyers will first observe the external 
environment of the store out of sight of the seller and fill in the related information. They 
will then enter the store, purchase e-cigarette products, and record seller responses and the 
internal environment of the store. After memorizing the information, they will leave the 
store, complete, and submit the data collection form online. The same simulated buyer will 
conduct a similar trial in one of the nearest cigarette stores, which serves as a match to the 
e-cigarette store that he or she just visited. After completing the visit, they will then travel 
to the next e-cigarette store. Survey details and measurements can be seen in Section 5 and 
Section 6. 
The coordinators will provide them with necessary help and answers to their queries during 
the fieldwork. If any of the included stores happen to be closed or unavailable, the 
coordinators will direct them to the nearest alternative e-cigarette store from the 
replacement list. If the number of inaccessible stores is too high, the coordinators will 
search for available e-cigarette stores nearby the simulated buyers and confirm their 
operating status at that time by phone, and then assign simulated buyers to go to survey 
them when possible. 
 
† One team will include 4 male and 5 female adolescent buyers due to the inclusion of an extra female data collector. 

 
 
33 
Each team will need at least one day to complete the survey in one metropolitan area, and 
the survey is expected to last between 3 and 5 weeks, considering the long distances 
between study sites (metropolitan areas), uncertain weather conditions, delayed 
transportation, and illness of personnel. The survey is scheduled to be fully completed by 
September 2023 for the data collection in all 36 metropolitan areas across mainland China. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
34 
8. Statistical Analyses 
8.1. General statistical methods  
Summary statistics will be presented for both the treatment and control groups. Continuous 
variables will be summarized by the number of observations, mean, standard deviation, 
median, minimum, and maximum. Categorical variables will be summarized using 
frequency counts and percentages. Descriptive analyses of the distributions of the e-
cigarette seller behavior outcomes between two types of attire (treatment and control 
groups), including successful purchases, inquiring about buyer age, requesting ID cards for 
age verification, and dissuading buyers from use, as well as store environment features, 
and sellers’ demographic characteristics, will be conducted with t-tests and chi-square tests 
detecting statistically significant differences. 
The significance level for comparisons between the two groups is set at 𝛼=0.05 (two-sided). 
Differences between the study groups will be considered statistically significant if the p-
value is less than 0.05. All analyses will be performed using Stata MP 17. 
8.2. Analysis of primary outcome 
For the primary outcome, successful purchase rates will be analyzed using Chi-square tests 
to determine if the differences between the treatment group and the control group are 
statistically significant. Multivariate logistic regression models will be further employed to 
analyze the treatment effect, adjusting for covariates. 
A national map depicting the geographic variations in the outcomes of successful purchase 
rates will be created using the R package DrawChinaMap. 
8.3. Analysis of secondary outcomes 
Secondary outcomes, including inquiring about the buyer's age, requesting ID cards for age 
verification, and dissuading buyers from use, will be analyzed in a similar manner to the 
primary outcome. Chi-square tests will be used to detect the statistical significance of 
differences between the two study groups, and logistic regression models, adjusted for 
covariates and appropriate for the distribution of the outcomes, will be employed. 
Additionally, similar national maps describing geographic variations will be generated. 

 
 
35 
8.4. Analysis of other outcomes 
Other outcomes, including illegal flavored products, online contact, and delivery service 
offered, will be analyzed in a similar way as the primary outcome. Chi-square tests will be 
used to detect statistical significance in differences between the two groups, and logistic 
regression models appropriate for the distribution of the binary outcomes with covariate 
adjustments will be employed. Similar national maps describing geographic variations will 
be generated as well. For marketing claims and strategies, we will further employ thematic 
framework analysis to qualitatively analyze and describe the marketing methods and tactics 
of e-cigarette stores. 
8.5. Subgroup analysis 
For matched e-cigarette and cigarette stores, we will employ McNemar’s tests to assess the 
distinctions in the outcomes between e-cigarette stores and cigarette stores. Rates of 
successful e-cigarette purchases stratified by age checking behaviors and buyer attire will 
also be reported. Planned subgroup analyses are intended to explore potential effect 
modifications of gender, age, metropolitan area and store types. 
8.6. Sample size considerations 
Successful purchase rates of e-cigarette products for the school uniform group and the 
casual attire group will be derived from the pilot study. Other parameters required for the 
cluster-RCT sample size calculation are as follows: 
l 
Randomization in a 1:1 ratio 
l 
α = 0.05 (two-sided) 
l 
power = 0.85 
l 
cluster size = 4 (both for intervention group and control group) 
l 
inter-cluster correlation coefficient = 0.5 (default) 
However, considering the primary goal of this study is to characterize e-cigarette seller 
behaviors at a national level, we decide to set the final sample size to be approximately 
1,080, which may be far more than the minimum sample required (about 3 times) for testing 
the effect of buyer attire on e-cigarette sales to adolescents. 

 
 
36 
8.7. Missing data 
Since simulated buyers use the instrument embedded in an online survey platform to fill 
out the collected information, there is no chance that they will miss any questions as the 
system will remind them of any potential missing values. The pilot survey will help us 
confirm which questions can be filled in, considering the possibility that the adolescents 
may be asked to leave by the sellers for not being able to show proof of age as soon as 
he/she enters the store. While filling in questions regarding the store external environment, 
simulated buyers can select "Unable to observe" and skip questions that cannot be 
answered. Missing data on the store internal environment due to the reason of being asked 
to leave will not affect our main analysis. For the in-store environmental characteristics, 
only subjects with available data will be included in the analyses. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
37 
9. Quality control 
9.1. Design phase of the protocol  
l 
Provide trainings to simulated buyers with a study manual and effective 
communication skills to ensure the quality of research in the fieldwork;  
l 
Prior to study implementation, a pilot survey will be carried out using the designed 
assessing tool. Subsequently, we will modify the tool based on seller responses and 
preliminary results to improve its operability and accuracy of information collected. 
l 
Data input will be completed an online self-developed assessing tool, eliminating the 
possibility of missing critical items. 
9.2. Implementation phase of the protocol 
l 
The inclusion criteria for study subjects will be strictly followed; 
l 
The randomization of the e-cigarette stores will be strictly carried out using random 
numbers. 
l 
Two staff members will accompany the team to each surveyed metropolitan area and 
provide implementation assistance to simulated buyers and answers to their questions 
whenever needed. 
9.3. Analysis phase of the protocol 
Two analysts will conduct independent data cleaning and logical error correction of data 
(e.g., range checks for data values). Any discrepancies uncovered will be resolved by the 
principal investigators. 
 
 
 
 

 
 
38 
10. Ethics 
10.1. Ethical approval and informed consent 
According to previous literature24-27, this study does not involve human subject research or 
collect any private information. Prior to the study, the investigators will submit the protocol 
to the Institutional Review Board at Peking University, which may exempt this trial from 
ethical review. 
Following prior research, this trial uses the mystery shopping approach, and all the study 
subjects (e-cigarette stores and cigarette stores) will not be informed that they will be 
enrolled in this trial.24-26  
10.2. Legality 
Purchase of e-cigarette products by adolescent buyers (age >=18) is legal in China. This 
study does not involve the collection of private personal information from sellers. 
10.3. Follow-up processing 
For the purchased e-cigarette and cigarette products, some will be given to scientific 
research institutions for academic purposes, and others will be sent to tobacco control 
associations as samples for educational purposes. 
 
 
 
 
 
 
 
 
 

 
 
39 
11. Data processing and storage 
The data will be collected through the self-developed instrument embedded in the 
Questionnaire Star platform (an App on smart phones), downloaded by the investigators at 
the end of the survey and saved on the principal investigator's computer located in the 
office. Statisticians will create the database in a timely manner, and the data will then be 
backed up and locked with passwords by investigators and research assistants after it has 
been thoroughly reviewed. To ensure data security, a non-permitted person cannot modify 
the data. All related analyses will be conducted on the principal investigator's computer. 
Staff who have access to the information of the trial subjects will sign confidentiality 
agreements. All the data in the study will be available to principal investigators, who have 
ultimate authority for the decision on data. The information shall not be disclosed to any 
third party (other than persons or institutions directly involved or required to know by law) 
without the prior consent of principal investigators. The investigators must take all 
appropriate precautions to avoid disclosing the information to third parties or the public by 
any staff or institutions. 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
40 
12. Study Timeline 
We plan to complete the preliminary recruitment of adolescents who will work as simulated 
buyers and data collectors, store sampling, and pilot survey from June 2023 to July 2023. 
In July 2023, we will train the simulated buyers and conduct the randomization of 
simulated buyers and e-cigarette stores. From July 2023 to September 2023, we will divide 
the data collectors into three teams and carry out the trial investigation. Data cleaning and 
analysis will be conducted after September 2023. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
41 
13. Role of funding source 
This study is funded by the China Medical Board in the United States. The funder will have 
no role in the study design, data collection, analysis, interpretation, or writing of the paper. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
42 
14. Declaration of interests 
There are no financial or other competing interests for the principal investigators in the 
overall trial or at each study site. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
43 
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16. Appendix  
Appendix 1 Specific Administrative Districts Included in 36 Major Metropolitan 
Areas of Mainland China 
Metropolitan 
area  
Administrative districts included 
Beijing 
(Beijing 
Municipality) 
Dongcheng, Xicheng, Haidian, Chaoyang, Shijingshan, Fengtai 
Changchun 
(Jilin Province) Nanguan, Kuancheng, Chaoyang, Luyuan, Erdao 
Changsha 
(Hunan 
Province) 
Furong, Tianxin, Kaifu, Yuelu, Yuhua 
Chengdu 
(Sichuan 
Province) 
Jinjiang, Qingyang, Wuhou, Chenghua, Jinniu 
Chongqing 
(Chongqing 
Municipality) 
Jiangbei, Nan'an, Yuzhong, Shapingba, Jiulongpo 
Dalian 
(Liaoning 
Province) 
Zhongshan, Xigang, Shahekou, Ganjingzi 
Fuzhou (Fujian 
Province) 
Cangshan, Gulou, Jin'an, Taijiang 
Guangzhou 
(Guangdong 
Province) 
Liwan, Yuexiu, Tianhe, Haizhu, Baiyun, Huangpu, Panyu 
Guiyang 
(Guizhou 
Province) 
Nanming, Yunyan, Baiyun, Guanshanhu, Huaxi, Wudang 
Haikou 
(Hainan 
Province) 
Xiuying, Qiongshan, Longhua, Meilan 
Hangzhou 
(Zhejiang 
Province) 
Shangcheng, Gongshu, Binjiang, Linping, Qiantang, Xihu 
Harbin 
(Heilongjiang 
Province) 
Nangang, Daoli, Daowai, Xiangfang, Pingfang, Songbei 

 
 
47 
Hefei 
(Anhui 
Province) 
Shushan, Yaohai, Baohe, Luyang 
Hohhot (Inner 
Mongolia 
Autonomous 
Region) 
Xincheng, Huimin, Yuquan, Saihan 
Jinan 
(Shandong 
Province) 
Huaiyin, Lixia, Tianqiao, Shizhong, Licheng, Changqing 
Kunming 
(Yunnan 
Province) 
Wuhua, Panlong, Guandu, Xishan 
Lanzhou 
(Gansu 
Province) 
Chengguan, Qilihe, Anning, Xigu, Honggu 
Lhasa (Xizang 
Autonomous 
Region) 
Chengguan, Duilongdeqing 
Nanchang 
(Jiangxi 
Province) 
Donghu, Xihu, Qingyunpu, Honggutan, Xinjian, Qingshanhu 
Nanjing 
(Jiangsu 
Province) 
Xuanwu, Qinhuai, Jianye, Gulou, Qixia, Yuhua 
Nanning 
(Guangxi 
Autonomous 
Region) 
Xingning, Qingxiu, Xixiangtang, Jiangnan, Liangqing, Yongning 
Ningbo 
(Zhejiang 
Province) 
Haishu, Jiangbei, Beilun, Zhenhai, Yinzhou, Fenghua 
Qingdao 
(Shandong 
Province) 
Shinan, Shibei, Laoshan, Licang, Huangdao 
Shanghai 
(Shanghai 
Municipality) 
Huangpu, Xuhui, Changning, Jing'an, Putuo, Hongkou, Yangpu, Pudong 
New Area 
Shenyang 
(Liaoning 
Province) 
Heping, Shenhe, Dadong, Huanggu, Tiexi 
Shenzhen 
(Guangdong 
Province) 
Futian, Luohu, Nanshan, Yantian 
Shijiazhuang 
(Hebei 
Province) 
Changan, Qiaoxi, Xinhua, Yuhua 

 
 
48 
Taiyuan 
(Shanxi 
Province) 
Xinghualing, Jiancaoping, Yingze, Wanbailin, Xiaodian, Jinyuan 
Tianjin 
(Tianjin 
Municipality) 
Heping, Hedong, Hexi, Nankai, Hebei, Hongqiao 
Urumqi 
(Xinjiang 
Autonomous 
Region) 
Tianshan, Shayibake, Xinshi 
Wuhan (Hubei 
Province) 
Jianghan, Wuchang, Jiang'an, Hongshan, Hanyang 
Xiamen 
(Fujian 
Province) 
Siming, Huli, Haicang, Jimei 
Xi’an (Shaanxi 
Province) 
Lianhu, Xincheng, Yanta, Beilin, Baqiao, Weiyang 
Xining 
(Qinghai 
Province) 
Chengdong, Chengzhong, Chengxi, Chengbei 
Yinchuan 
(Ningxia 
Autonomous 
Region) 
Xingqing, Xixia, Jinfeng 
Zhengzhou 
(Henan 
Province) 
Jinshui, Erqi, Guancheng Hui, Zhongyuan 
 
 

 
 
49 
Appendix 2 Communication script in the e-cigarette store 
Soft script 
When the simulated buyer, acting as a customer, communicates face-to-face with the seller 
in an e-cigarette store, the main information recorded includes: successful purchases of e-
cigarette products, inquiries about age, requests to show ID cards, dissuasion from using 
e-cigarettes, price information, and marketing strategies (such as the store clerk adding you 
on WeChat). You can use the following conversational sentences to naturally gather the 
above information: 
 
Other key points: advertising area, warning slogans, decorations, product types, flavor 
recommendations, information conveyed, and discounted prices. 
 
Legal requirements: (record only) 
l 
Does the seller in the e-cigarette store ask about your age? 
l 
Have you been asked by the seller to show your ID card? 
 
1. When you walk into the store or approach the counter, first glance at the wall to see if 
there is a tobacco license. Then look at the e-cigarette products, paying attention to any 
"No use by minors" warning signs and "Smoking or vaping is harmful to health" warning 
signs. Continue to pretend you are browsing the store. 
 
2. Typically, the seller will notice you immediately and ask what you are looking for. You 
should respond with "I'm just browsing," "I'm here to learn about the products," or "My 
friend uses e-cigarettes, and I'm here to check them out." 
 
3. The seller will likely ask if you have used e-cigarettes or smoked before. You should 
respond, "I have never used them before." At this point, some sellers may advise you not 
to buy or try them. 
 

 
 
50 
4. You should ask the seller, "Do you have any recommendations?" The seller will likely 
recommend a lighter flavor product and hand it to you. You then ask, "Is this detachable?" 
or "Can this be used continuously?" to determine the type of e-cigarettes sold in the store. 
While doing this, take the opportunity to look around to see if there are disposable e-
cigarettes and open-system e-cigarettes, as well as whether protective cases and lanyards 
are sold at the counter. 
 
5. During the ongoing product viewing phase, point to the various e-cigarette cartridges on 
the counter or shelf and ask the seller about their differences. Then further inquire, "Which 
ones sell well?" or "What do people often buy?" or "Which are popular?" Take note of the 
first and second flavors mentioned by the clerk. If the seller offers you a sample, be sure to 
refuse! 
 
6. After learning about the popular flavors, express how popular e-cigarettes are around 
you by saying something like, "I have a few friends who use them," "I've seen many people 
using them," or "I've seen others using them several times while shopping." Use this to 
prompt the seller to explain why e-cigarettes are popular. They will generally actively 
market a positive image of e-cigarettes. Please note the content and order of what the seller 
says, taking down the first two to three points. 
 
7. By asking "I've smelled someone using an e-cigarette with a sweet flavor, do you have 
that?", observe whether the seller tries to sell you flavored e-cigarettes, and note the flavor. 
Be careful not to mention words like "fruit" to avoid arousing the seller's suspicion. Pay 
attention to whether the seller mentions illegal products like "milk tea cups" and record 
them, but the decoy should not bring them up proactively. 
 
8. Inquire about the prices of e-cigarettes, including the cigarette rod and cartridge. If the 
seller recommends Relx e-cigarettes, respond with, "That's a bit expensive, any discounts?" 
to record discount information. Then say, "I want to try first, do you have anything 
cheaper?" to express that it is still too expensive. Continue this until the seller explicitly 
replies that it is the cheapest product in the store. If the store only sells pod-based e-

 
 
51 
cigarettes, say, "I can use my friend's cigarette rod" to purchase only the cartridge and not 
the rod. Disposable e-cigarettes are usually cheaper than pod-based ones, and if offered by 
the seller, you can purchase them. 
 
9. When you pay, observe whether there are contact details (such as WeChat number, 
WeChat group code, phone number, etc.) on the counter. If the seller actively adds you on 
WeChat, they will likely also mention, "We offer online mailing services." If the seller does 
not actively mention online mailing, you should ask, "Why add WeChat?" and record the 
seller's reaction. 
 
10. You should observe whether there are any "free trial" signs or disposable flavor filters 
placed in the store. Pay attention to whether the seller advises you against using e-cigarettes. 
 
11. While you are in the store picking products or after making a purchase, take a moment 
to naturally browse the merchandise. Observe whether other items like tobacco, alcohol, 
or areca nuts are sold on the shelves, and whether toys and decorative ornaments are 
displayed. 
 
Handling Special Situations: 
l 
If a seller offers you to try an e-cigarette, they usually provide a disposable tool. 
Respond with, "This seems unsanitary, I won’t use it... I’d rather buy a new one/I’d 
rather use my friend’s." 
l 
The seller might claim that the e-cigarette and cartridges are sold as a set, and that a 
friend’s e-cigarette might not be compatible. You should insist on only buying the 
cartridges, "It’s fine, I remember it’s just like this one/... just buy a box of these." 

 
 
52 
Appendix 3 Pictures for models wearing school uniforms and casual attire 
School uniform, male 
     
   
 
 
 

 
 
53 
School uniform, female 
 
  
 
 
 

 
 
54 
Casual attire, male 
        
 
 
 
 
 

 
 
55 
Casual attire, female 
 
 
        
 
 
 

 
 
56 
Appendix 4 Assessing tool  
E-cigarette store survey questionnaire 
 
Basic Information 
1. Survey date [Fill in the blanks] *-------Click to confirm 
____________________________ 
2. Simulated buyer’s name [Fill in the blank] *-------Fill in the name 
____________________________ 
3. City where you are located [Fill in the blanks] *------Please fill in "Beijing" in the format, do not 
fill in "Beijing City" 
____________________________ 
4. Store ID：__________________ [fill in the blank] *------- Each store corresponds to an ID. Note 
that there may be e-cigarette stores very close to each other in practice, and the store names might 
not be easily distinguishable. Please check carefully.  
 
5. Location of store: (automatically fill the building location by the GIS function embedded in the 
Questionnaire Star) [Fill in the blank] * 
____________________________ 
 
6. The simulated buyer’s attire today [single-choice question] * 
○Student uniform 
○Casual attire 
 
Outside Store Observation 
7. Is it possible to study this store? *[Single choice question] 
○Yes; 

 
 
57 
○No, unable to locate the store based on the geographic information. You can follow the 
map navigation to the building and walk around the area to try to find it. If you still cannot 
find it, contact the study coordinator to add a new store; 
○No, possible danger in surroundings was perceived, such as remote alleys with no 
pedestrians at all; 
○No, store closed upon arrival, even though it was confirmed to be in business before. 
Note that some unopened stores can be observed, such as in pictures 1 and 2 below; 
 
 
○No, other reasons _______________ * (Please skip to the end of the questionnaire and submit 
your answer sheet). 
 
8. The type of stores is [single choice question] * 
○Open stores in shopping malls ------based on whether the counter can be accessed from 
the pedestrian area; 
 
 
○Enclosed stores in shopping malls; 

 
 
58 
  
 
○Convenience store or small supermarket on the street — not primarily selling e-
cigarettes; 
 
 
 
○E-cigarette store with independent stores on the street 
 
 
 
 
○E-cigarette store under an office building ------ [please note the distinction from an e-
cigarette store that is an independent store on the street]; 
 

 
 
59 
 
○Other type _________________ *  
 
9. Are any of the following places near the e-cigarette store (look around and within sight)? 
[Multiple choice questions] *----- [Look around twice and mentally count 5 or more stores] 
□School 
 
□Shopping mall entrance, stairs-----This refers to the e-cigarette retail store in the mall 
 
□Trendy toy store 
 
□Beverage shop 
 
□Female-only stores such as nail salons and cosmetics stores 
 
□Internet cafe 
 
□Bar 
 
□Video arcade 
     
 
 
□Mobile phone store-----primarily sells mobile phone cases, data cables, and screen 
protectors. 
 

 
 
60 
 
□Others (such as: large supermarkets, clothing stores) ___________----- （i.e. next to 
the entrance of large supermarkets） 
 
 
□None of the above 
 
  
10. In which of the following ways does the exterior decoration of the store attract the 
attention of passers-by? [Multiple choice questions] *----Brand names or store names such 
as "RELX" do not count as advertising. 
□General print advertising (posters, banners, flyers, etc.) 
   
   
 
 
□Backlit or illuminated advertising-----refers to advertising that features LED lighting, 
video, and short clips accompanied by dynamic or static text display. [Note: When not 
illuminated, it is considered standard printed advertising.] 

 
 
61 
 
□Three-dimensional advertising, such as large fixtures — refers to large e-cigarette 
installations used in e-cigarette stores for product promotion or promotional activity 
displays, including large props, dolls, etc. (see the figure below). 
   
□Other_________________ 
□No advertising 
 
 
11. Area of large billboards: [Fill in the blanks__________] *---- Note: Take the prescribed 
poster as the first figure below. There may be more than just e-cigarettes in the 
advertisements in the second figure below. If there are too many advertisements in the third 
figure below, fill in 10. [For Question #10 above, if "Others" or "No advertising" is chosen, 
please fill in 0 for Question #11.] 

 
 
62 
   
 
 
  
12. Are there any billboards with the following characteristics outside e-cigarette stores? 
[Multiple choice questions] * 
□Use of celebrity endorsements 
 
□Scenic photos, such as mountains, rivers, trees, and blue sky 
  
 
 
□Contains images of cartoon characters or animals ---- on billboards 

 
 
63 
 
□Price discounts or promotional activities-----advertisements for price discounts or 
promotions often include phrases such as 'limited-time offer,' 'X% off,' 'price reduction,' 
'buy and get xxx free,' 'grab a bargain,' or 'carnival season.' and so on. 
 
□Ads showing e-cigarette flavors, such as photos of fruit 
 
□Other_________________ 
 
Depends on options 1, 2, 3, or 4 of Question #10. 
 
13. From the perspective of pedestrians, is there a recognizable "No Use by Minors" sign 
[Single Choice Question] *----The following large warning signs or clearly visible signs 
that can be seen from the outside 

 
 
64 
○Yes 
○No 
 
 
In-store communication and records 1 
  
14. Can you enter the store to observe and record? Please select one of the following [Single 
Choice Question] * 
○Yes 
○No, the e-cigarette store is not open (please skip to the end of the questionnaire and submit 
your answer sheet) 
○No, the seller is not in the store (please skip to the end of the questionnaire and submit 
your answer) 
○No, other _______________ * (please skip to the end of the questionnaire and submit 
your answer sheet) 
 
15. Is the tobacco retail license visible [Single choice question] * 
○Yes 
○No 

 
 
65 
  
 
16. Is there a "No use by minors" slogan in the store (excluding slogans on product 
packaging) [Single-choice question] * 
○Yes 
○No 
    
 
 
17. Are there any of the following health warning signs in the store (excluding slogans on 
product packaging) [Single choice question] * 
○Yes, there is a "Smoking is harmful to health" sign 
○Yes, there is a "E-cigarettes are harmful to health" sign 
○Yes, both of the above exist 
○No 
 
18. Are there children's toys, car models, figurines, and/or other decorations placed on the 
shelves or counters? [Note that these decorations need to be targeted at teenagers.] [Single 
Choice Question] * 
○Yes, specifically _______________ *  

 
 
66 
○No 
 
19. Gender of the seller: (When there are multiple sellers, this question refers to the seller 
who communicates with the simulated buyer the most. The same applies to the questions 
below.) 
○Male 
○Female 
  
20. Age of the seller (the simulated buyer needs to estimate) [Single-choice question] * 
○18-24 years old 
○25-29 years old 
○30-39 years old 
○>40 years old 
  
21. Did the seller ask the simulated buyer if he or she was an adult? [Single Choice 
Question] * -----Questions such as "Are you an adult?" "Are you over 18?" "How old are 
you?" "Are you a student?" etc. 
○Yes 
○No 
 
22. Did the seller ask to see the simulated buyer's ID? (If the seller requires you to fill in 
identity information on the system, please select Yes.) [Single Choice Question] * 
○Yes 
 
○No 
 
 
23. Did the seller ask the simulated buyer to leave? (No sales communication) [Single 
Choice Question] * ----- If the seller does not check the age until the simulated buyer pays, 
the sales communication has been completed at this point. In this case, you should select 
"No" and continue to fill in the questionnaire. 

 
 
67 
○No 
○Yes, the seller asked you (the simulated buyer) to leave without asking about their age. 
(Please skip to the end of the questionnaire and submit your answer.) 
○Yes, the seller asked you (the simulated buyer) to leave after asking their age. (Please 
skip to the end of the questionnaire and submit your answer.) 
○Yes, the seller asked you (the simulated buyer) to leave after knowing that he or she 
did not have an ID card. (Please skip to the end of the questionnaire and submit your 
answer.) 
 
 
In-store communication and records 2 
 
24. Does the e-cigarette store sell the following types of e-cigarettes and accessories 
[Multiple choice questions] ** 
□Disposable e-cigarettes ----- Disposable e-cigarettes refer to those e-cigarettes that 
cannot be disassembled, refilled, or changed by the user and are thrown away after use. 
They can also be rechargeable. For example, the seller might describe them to you as 
"rechargeable for 1,000 puffs." 
    
 
□Reloadable e-cigarettes and/or cartridges ----- Reloadable e-cigarettes usually consist 
of two parts: a cigarette rod and a cigarette cartridge. The cigarette rod can be recharged 
and reused, while the cigarette cartridge is thrown away after use. 

 
 
68 
 
 
 
□Open e-cigarettes that the user refills with e-liquid himself or herself ----- The e-liquid 
tank of open e-cigarettes is open and refillable. It can be refilled 3-6 times for continued 
use. The atomizer has a long service life. 
 
□Auxiliary accessories for e-cigarettes, such as protective cases, lanyards, etc. 
 
□Other, _________________ 
  
25. Other items sold in the e-cigarette stores: [Multiple choice questions] * 
□No products other than e-cigarettes are sold 
□Power bank rentals 
□Addictive substances, such as tobacco, alcohol, and betel nut 

 
 
69 
  
 
□Other _________________ 
  
26. Did the seller proactively dissuade the simulated buyer from trying e-cigarettes? [Single 
Choice Question] * ----- The seller will tell you (the simulated buyer) that e-cigarettes are 
harmful, addictive, impossible to quit, don’t try them, etc., in an attempt to discourage you 
from buying them. 
○Yes 
○No 
  
27. The most popular flavor recommended to you (the simulated buyer) by the seller is [fill 
in the blank] * ----- Ask the seller, "With so many varieties, what are the differences?" and 
then, "Which one sells better?" 
  
  
_________________________________ 
  

 
 
70 
  
28. The second most popular flavor recommended to you (the simulated buyer) by the seller 
is [fill in the blank] * ----- If the seller only recommended one flavor in the previous 
question, you can fill in "none" for this question. 
_________________________________ 
  
29. Is there a "Free Trial" sign or disposable filters in the store [Single-choice question] * 
-----Pay attention to whether there are disposable filters at the cashier]  
○Yes 
○No 
  
30. Did the seller proactively mention the free trial? [Single-choice question] * ------The 
seller had a higher chance of letting you (the simulated buyer) try it, and might even 
assemble the e-cigarette and hand it over to you. 
○Yes 
○No 
  
31. Are illegal flavored e-cigarettes sold? [Single Choice Question] * ----- Usually, illegal 
flavored e-cigarettes are not placed on display, lack obvious warning slogans on the 
packaging, and the product may be labeled in English. 
○Yes 
○No 
  
 

 
 
71 
  
  
32. Does the e-cigarette store sell illegal e-cigarettes with the following flavors [Multiple 
choice questions] * 
□Fruit flavor 
□Candy flavor 
□Food or drink flavors 
□Mint flavor 
□herbal vaporizer 
□Other, _________________ 
□None of the above 
Question #32 depends on option 1 of Question #31.  
  
33. Did the seller proactively mention illegal e-cigarette products such as "milk tea cups" 
and "Coke cans" [Single-choice question] * 
○Yes 
○No 
 
 
 
 
34. Does the information delivered to you (the simulated buyer) by the seller include the 
following? (Select in order) * ----- Use "E-cigarettes are very popular recently..." to 
potentially guide the seller to describe the reasons for the popularity of e-cigarettes. 
  
[ ] None 
[ ] E-cigarettes are less harmful 

 
 
72 
[ ] E-cigarettes can be used in more places 
[ ] E-cigarettes are easily accepted by people around them 
[ ] E-cigarettes have a variety of flavors 
[ ] E-cigarettes do not produce unpleasant odors 
[ ] Other, _________________ 
  
35. Are e-cigarettes promoted in the following ways? [Multiple choice questions] * -----
Ask "Are there any promotions?" 
□ Price discounts (including coupons, limited-time activities, group purchase discounts, 
etc.) 
□Free products 
□Small gifts 
□Membership activities, points rewards 
□Others _______________ 
□None of the above 
  
36. The lowest price of e-cigarette products is: [Fill in the blanks] * ----- If the cheapest 
one is a disposable e-cigarette, buy it and fill in the price. If there are only reloadable e-
cigarettes in the store, you need to fill in the sum of the prices of the cartridges and the 
cigarette rods. 
  
_________________________________ 
  
37. Did you (the simulated buyer) successfully buy e-cigarettes [single-choice question] * 
○Yes 
○No 
  
38. Did the seller take the initiative to add your (the simulated buyer's) contact information? 

 
 
73 
[Single Choice Question] * ----- Pay attention to whether the seller took the initiative; you 
(the simulated buyer) should not take the initiative to ask. Please be sure not to agree to 
add WeChat. 
○WeChat (a mobile instant messaging software) 
○QQ mobile (a mobile instant messaging software) 
○Phone number 
○Other _________________ 
○No 
  
39. Does the seller proactively provide online shopping services in an attempt to send e-
cigarette products through social platforms? [Single Choice Question] * ----- If you were 
asked to add WeChat in the previous question, ask, "Why add WeChat?" If the seller says 
that he or she can send it to you online by adding WeChat, then select "Yes" for this question. 
Be sure to find a reason to refuse to add WeChat, such as replying, "No, I will buy it myself 
when I have time." 
○Yes 
○No 
  
40. Is the contact information (including WeChat, phone number, etc.) publicly displayed 
in the store? [Single Choice Question] * ----- Usually, this is a small sign on the checkout 
counter, or it may be a brand WeChat group. 
○Yes 
○No 
  
41. Do you (the simulated buyer) have any other notable observations that you would like 
to add? [Fill in the blanks] * 
_________________________________ 
 

 
 
74 
Appendix 5 Telephone protocol 
For training the personnel making phone calls, you are attempting to gather information about 
e-cigarette stores over the phone. You can pretend to be a buyer looking to purchase e-cigarettes. 
Once you have collected all the information about the e-cigarette stores on the list, please make 
sure to keep all of it. 
 
Soft Script: Speak cautiously, pretending that you are a buyer attempting to purchase e-
cigarettes in the store. You would like to get more information about the e-cigarette stores, such 
as location, address, and opening hours. Do not ask questions proactively to avoid raising the 
seller's suspicions. Mention other issues as little as possible to minimize mistakes. 
 
Once the call connects, ask: "Hello, is your shop still open? I want to buy some e-cigarettes." 
If they answer it's closed, lament: "Ah, why is it closed... where can I buy some now..." Pay 
attention to whether they voluntarily mention: 
• 
Having changed their type of business; 
• 
Providing other contact methods (adding their WeChat, a mobile instant messaging 
software, or recommending another merchant's phone number); 
• 
Offering online sales (rapid delivery, courier); 
• 
Mentioning illegal flavored e-cigarettes (milk tea cup, bear cup, planet cup, etc.). 
 
If the seller answers the store is closed, you can respond with, "Never mind, I'll look elsewhere." 
—> Hang up the call to end it. 
Answer 
the call 
Under 
normal 
business 
Change 
business 
Provide 
additional 
contact 
information 
Selling 
online 
Selling 
illegal 
flavors 
Key 
information 
records 
1 
0 
1 
1 
1 
1 
“Branded 
products are not 
selling well, but 

 
 
75 
milk tea cups 
have 
many 
flavors.” 
“Add 
me 
on 
WeChat and I 
will send them 
to you by local 
courier.” 
1 
0 
0 
0 
1 
0 
“The store is 
closed, but if 
you need it, add 
me on WeChat 
and 
I 
will 
contact 
my 
friends to sell it 
to you.” 
 
 
(1) For the e-cigarette stores that are open —> 
You said: "Okay, then I'll come over and see if I have time. Are you at [xxxxx] (check address)?" 
—> Hang up to end the call. 
 
(2) Record if no one answers your call: 
After dialing, wait until the voice prompt says "Sorry, the number you dialed is temporarily 
unavailable." This is considered unavailable, and you should mark 0 in Excel. 
—> Try to call again after 15 minutes. 
—> If the call is connected, follow the soft script above for communication. If still 
not connected, hang up to end the call. 
 

 
 
76 
 
(3) Record shutdown: 
—> If the call is connected, follow the soft script above for communication. If 
the phone is turned off or disconnected, hang up to end the call. 
 
Note： 
Stop calling once you have a list of 40 e-cigarette stores open in each metropolitan area. Submit 
the list of 40 e-cigarette stores to your supervisors. 
 
For various problems and situations encountered, if the issue is special or difficult to resolve, 
you can contact your supervisors at any time. Do not force the task to be completed. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
77 
Appendix 6 Recruitment poster for simulated buyers 
 
The China Center for Health Development Studies at Peking University will conduct a 
survey on the behaviors and marketing strategies of e-cigarette retail stores in several major 
metropolitan areas in China. The survey is expected to begin from July 22-25 and last for about 
three weeks. Offline training will be provided before the official start date. Scan the QR code 
to sign up, and you will gain valuable research experience and generous compensation. This is 
also a great opportunity to visit various places in China and explore local delicacies. 
 
Recruitment Criteria: 
University students aged 18 or 19 currently studying in Beijing. 
Have never used cigarettes or e-cigarettes. 
Possess good communication skills and a sense of responsibility, and can commit to the 
training and the entire survey period. 
 
Benefits: 
Accommodation and transportation fees covered, with a daily compensation of CNY 350. 
Outstanding researchers have a chance to receive a surprise gift pack! 
After the survey, the research team will verify the quality of the questionnaires and issue 
a certificate of practice. 
 
QR Code for Registration: 
We sincerely look forward to your participation! If you have any questions, feel free to 
contact us via phone or WeChat: 15010987573. 

 
 
78 
 
 
 
 
 

 
 
79 
Appendix 7 Interview process for simulated buyers 
 
The interview will be conducted online via Tencent Meeting. The interview time for each 
student (the simulated buyer) is about 10 minutes. The process is as follows: 
1. 
Self-Introduction: Please give a brief self-introduction. 
2. 
Recruitment Inquiry: How did you hear about our recruitment? Why do you want to 
participate in our research activities, and what do you hope to gain? 
3. 
Research Overview: Introduce the key content of this research. Do you have any concerns 
or difficulties about participating fully? If there are difficulties that cannot be overcome, 
we suggest not participating. 
4. 
Dress Code and Confidentiality: Additional information on dress code and confidentiality 
agreement (scientific rigor, data authenticity, innovation in research projects). 
5. 
Safety Emphasis: Finally, we emphasize safety issues. We hope everyone will cooperate 
with us, return on time in the evening, and communicate with us if you have any 
arrangements or places you need to go. 
 
 

 
 
80 
Appendix 8 Survey sequence of the metropolitan areas for 
three teams 
  
Team  
Survey sequence 
Team A 
Harbin - Changchun - Shenyang - Dalian - Qingdao - Jinan - 
Shijiazhuang - Taiyuan - Beijing - Tianjin - Hohhot - Lhasa 
Team B 
Nanjing - Shanghai - Hangzhou - Ningbo - Fuzhou - Xiamen - 
Shenzhen - Guangzhou - Nanchang - Hefei - Urumqi - Xining - 
Yinchuan 
Team C 
Zhengzhou - Wuhan - Changsha - Nanning - Haikou - Guiyang - 
Kunming - Chongqing - Chengdu - Xi'an - Lanzhou 

 
 
81 
Appendix 9 Code for web crawling 
 
#Rversion 4.04 
setwd("E:/R") 
library(xml2) 
library(rvest) 
library(dplyr) 
library(stringr) 
library(rjson) 
library(jsonlite) 
library(scales) 
library(ResourceSelection) 
library(openxlsx)#xlsx 
library(sampling) 
rm(list = ls()) 
 
# collect address and phone number using AutoNavi ----------------------------------------------------- 
key <- c("AutoNavi Key (got from AutoNavi API)") 
storedf <- as.data.frame(matrix(nrow = 0,ncol = 8))  
surveywords <- c("电子烟店","电子烟零售店","电子烟体验店","电子烟集合店","电子烟专卖店","
电子烟直营店", "雾化","蒸汽烟","vape","电子烟旗舰店",  "悦刻","魔笛","雪加","小野","铂德","
柚
子
电
子
烟
","
徕
米
","MR
迷
睿
","VTV","
福
禄
FLOW", 
"RELX","MOTI","YOOZ","snowplus","vvild","Boulder","LAMI")  
 
gGetstore <- function(keywords,city,page){ 
  url <-  paste0("https://restapi.amap.com/v3/place/text?keywords=",keywords,"&city=", 
                 city,"&citylimit=true&offset=20&page=",page,"&key=", 
                 key,"&extensions=all") 
  data <-  read_html(url, encoding='utf-8') %>% html_text() 
  datalist<- fromJSON(data) 
  address_islist <- 0 #check  
  tel_more <- 0  
  if (datalist$status=="1") { 
    if (datalist$count!="0") { 
      if(is.list(datalist$pois$address)){ 
        datalist$pois$address <- sapply(datalist$pois$address,"[",1) 
        address_islist <- 1 
      } 
      df <- cbind(datalist$pois$id, datalist$pois$name, datalist$pois$address, 
                  datalist$pois$location,datalist$pois$cityname,datalist$pois$adname, 
                  datalist$pois$typecode) 
      if(all(lengths(datalist$pois$tel)<2)){  
        tel <- sapply(datalist$pois$tel,"[",1) 

 
 
82 
      }else{tel_more <- 1}  
       
      df <- cbind(df, tel) 
    }else{df <- 0} 
  }else{df <- 1} 
  storeout  <- list(df=df, two=address_islist, three=tel_more) 
  return(storeout) 
} 
 
#run  
cityname <- c("北京")  #try each 
store_city <- data.frame() 
address_list <- rep(0,length(surveywords)) 
searchnm <- rep(0,length(surveywords)) 
storedf_class <- rep(0,length(surveywords)) 
tel_list  <- rep(0,length(surveywords)) 
for (j in 1:length(surveywords)) { 
  storedf <- data.frame()  
  for (i in 1:100) { 
    storelocation <- gGetstore(surveywords[j],cityname,i) 
    storedf2 <- storelocation$df 
    if(storelocation$two==1){address_list[j]  <- 1} 
    if(storelocation$three==1){tel_list[j] <- 1} 
    if (is.numeric(storedf2)){ 
      searchnm[j]  <- i 
      break 
    }else{ 
      storedf <- rbind(storedf,storedf2) 
    } 
  } 
  storedf_class[j] <- class(storedf) 
  store_city <- rbind(store_city,storedf) 
  if(dim(storedf)[1] !=0){ 
    colnames(storedf) <- c("id","name","address","location","city","adname","typecode","tel") 
write.xlsx(storedf,paste0("E:/e_cig/summer_survey/retailer_list/list_",surveywords[j],"_",cityname,".xl
sx"),      append=T,  overwrite=T) 
  } 
} 
write.xlsx(store_city,paste0("E:/e_cig/summer_survey/retailer_list/city2/list_",cityname,".xlsx"),overwr
ite = T) 
store_city <- unique(store_city) 
write.xlsx(store_city,paste0("E:/e_cig/summer_survey/retailer_list/city/list_",cityname,".xlsx"),overwri
te = T)