Cash Payment and Counseling for Quitting Smoking During Pregnancy
Phase: NA
Conditions: Smoking Cessation, Pregnancy Related, Incentives
Sponsor: University Medicine Greifswald

 
 
 
 
 
 
 
 
 
 
 
 
MARS – Cash payment and counseling during 
pregnancy 
 
MARS 
 
Study protocol 
 
 
 
 
 
 
 
 
Number of the Ethical Approval: BB 154/20 
AUGUST 7, 2020 
 
 
 
 
 

 
1. Background  
 
Smoking constitutes a risk of disease regardless of the dosage. Nevertheless, smoking is 
common among women in childbearing age and especially among those with a lower socio-
economic status. Meta-analyses have shown that psychosocial interventions for quitting 
smoking have positive effects on both mother and child. Further, there is evidence from 
international studies on the efficacy of rewards in combination with psychosocial counseling. 
However, there is a lack of German studies on incentives to achieve smoking cessation 
among pregnant women. Therefore, in our current study, we ask how rewards are most 
effective in supporting smoking cessation in pregnancy.  
 
 
2. Objectives  
 
The primary outcome of this pilot study is the adherence of initially smoking pregnant 
women to the monitoring of the smoking status up to the birth of the child / children. 
Secondary outcomes are (1) differences in number of cigarettes per day by self-report, (2) 
number of attempts to stop smoking by self-report, (3) number of attempts to stop smoking 
by carbon monoxide measurement. All outcome data are collected between baseline and up 
to pregnancy week 36. 
 
3. Methods/ Study design  
 
The study region is Schwerin, a city with approximately 95.000 inhabitants in Northeast of 
Germany. MARS is a pilot study consisting of up to three assessments for the completion of a 
standardized survey at three time points (baseline, pregnancy week 36 , and 8 weeks after 
the delivery, as well as participation in the evaluation of the smoking status twice a week 
using breath carbon monoxide (CO) monitor piCObaby™ Smokerlyzer (Bedfont Scientific). 
After an initial survey, the participating women are scheduled twice a week for counseling 
and evaluation of the smoking status.They will receive cash payment of 25 Euro if her CO 
reading does not exceed value "3" on two consecutive dates per week.  
 

Study population  
The study population consists of pregnant women who meet the following inclusion criteria:  
(1) Current pregnancy between pregnancy week 15 and 23,  
(2) Current smoking of at least one cigarette per day 
 
Recruitment  
Pregnant women will be recruited by the staff of a counseling center for pregnant women in 
Schwerin. A short personal screening is performed to assess the inclusion criteria. For 
women who meet the inclusion criteria, an initial survey is conducted and data on socio-
demographic variables (age, partnership, number of children, education), current pregnancy, 
smoking, alcohol consumption, physical activity, fruit and vegetable consumption are 
collected. The participating women are scheduled twice a week for counseling and 
evaluation of the smoking status. They will receive cash payment of 25 Euro if their CO 
reading does not exceed value "3" on two consecutive dates per week. A second survey will 
be conducted in pregnancy week 36 and a third survey, eight weeks after the delivery. 
 
Documentation, data storage, and data security  
All participants receive a study ID at the first visit in the examination center to ensure their 
correct assignment over time. Data from the self-administered questionnaire and data from 
the breath carbon monoxide examination will be stored in a central data base. Personal data 
(name, address, telephone number) will not be entered in the data base. The data storage is 
managed according to the standards for data security and data privacy. Only the staff 
members of the project team have access to personal data during the study.  
 
Data analysis  
Adherence to the study protocol will be investigated using drop-out analysis. Descriptive 
statistics of (1) differences in number of cigarettes per day by self-report, (2) number of 
attempts to stop smoking by self-report, and (3) number of attempts to stop smoking by 
carbon monoxide measurement will be calculated. The software package STATA (version 
15.1) will be used.