NEAT!2 Sedentary Behavior Reduction Intervention for Individuals With Past or Present Knee Symptoms, Injuries, or Surgeries
Phase: NA
Conditions: Sedentary Lifestyle, Knee Osteoarthritis, Knee Injuries, Knee Pain Chronic
Sponsor: University of South Carolina

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Version 3 – 5/22/19 
 
Study Title: NEAT!2 Sedentary Behavior Reduction Intervention for Individuals with 
Past or Present Knee Symptoms, Injuries, or Surgeries* 
 
Principal Investigator Name:  Christine A. Pellegrini, PhD 
 
NCT: 03987932 
 
*Study stopped due to COVID-19 pandemic 
 
 

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A. SPECIFIC AIMS 
 
The purpose of this proposed project is to conduct a randomized controlled trial 
to evaluate the effect of an mHealth sedentary reduction program (NEAT!2) over a 6 
month period of time in adults with past or present knee symptoms, injuries, or 
surgeries. The specific aims of the project are: 
 
 
Aim 1: To compare the change in sedentary behavior from baseline to 1 and 3 
months between a smartphone app delivered sedentary reduction intervention with 
(NEAT!2+Calls) or without (NEAT!2) coaching calls and a delayed control (Delayed 
NEAT!2) in adults with past or present knee symptoms, injuries, or surgeries. 
 
 
Aim 2: To examine the changes in physical function after participating in the 
NEAT!2 or NEAT!2+Calls mHealth sedentary reduction interventions as compared to 
control from baseline to 1 and 3 months in adults with past or present knee symptoms, 
injuries, or surgeries. 
 
 
Aim 3: To examine the maintenance in changes in sedentary behavior and 
physical function during the follow-up period between 3- and 6- months with no 
intervention contact in those who were initially randomized to NEAT!2 or NEAT!2+Calls. 
 
B. BACKGROUND AND SIGNIFICANCE 
Sedentary behavior is defined as “any waking behavior characterized by an energy 
expenditure of ≤ 1.5 metabolic equivalents (METs) while in a sitting, reclining, or lying 
posture.”1 Excess sedentary behavior is associated with numerous health 
consequences2-4 including poor physical function.5 Older adults with symptomatic knee 
pain spend the majority of waking hours engaged in sedentary behaviors.5 To reduce 
the risk of disability, improve quality of life, and prevent deterioration in physical 
function,6,7 it is critical to develop ways to decrease sedentary time. Several studies 
have started to explore preliminary ways to reduce sedentary time in older adults,8-10 
however, to our knowledge, few studies have been done in older adults with current or 
past knee symptoms. Smartphone ownership among older adults is increasing and may 
provide a scalable opportunity to disseminate a sedentary reduction intervention. 
Therefore, this study aims to evaluate and compare changes in sedentary behavior 
between an mHealth sedentary reduction, mHealth intervention plus coaching, and 
delayed control group.  
 
C. PRELIMINARY STUDIES 
Using data obtained from the Osteoarthritis Initiative, we evaluated physical activity 
levels and sedentary behavior in adults with or at risk of developing knee osteoarthritis 
(KOA). Adults with KOA spend at least 2/3 of waking hours in sedentary behaviors.11 
We have found that greater amounts of time engaged in sedentary behaviors are 
associated with functional decline, lower quality of life, and weight gain.7,11,12 We have 
previously identified barriers and facilitators to physical activity in adults with KOA prior 
to having knee replacement. Barriers for activity included pain, physical limitations, and 
lack of motivation, whereas facilitators included having motivation to improve knee 
symptoms/outcomes, personal commitment to activity, and monitoring activity levels.13 

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Although this population is interested in being active, they are limited by knee pain. It is 
unclear how willing this population would be to decrease sedentary time, which may be 
a more feasible approach for those with knee pain. Additionally, those with end-stage 
KOA who recently had knee replacement are engaging in sedentary behavior ~69% of 
the day (manuscript in preparation). 
 
Nine adults (53.1±10.7 years, BMI 37.4±9.9kg/m2) with diabetes used the NEAT! app on 
21.9±8.0 days/month. NEAT! interrupted continuous bouts (≥20 minutes) of sitting by 
providing prompts on the smartphone to engage in light-intensity activity for ≥2 minutes. 
Prompts to interrupt sedentary time were given 5.8±3.5 times/day. Participants reduced 
their sedentary time by 8.1±4.5% (156.4±75.0 min/day)  between baseline and 1 
month.14 Nearly 88% of participants indicated they would use NEAT! again in the future, 
suggesting high acceptability of the first iteration of the technology. 
 
To inform the development of our NEAT!2 sedentary reduction intervention and update 
the NEAT! smartphone application, we surveyed 42 participants (61.8±7.6 years, 67% 
female) on their beliefs about sedentary behavior and preferences for participating in a 
sedentary behavior reduction program. Nearly 80% of participants were located within the 
Columbia, SC region. Additionally, 88% of participants own a smartphone and 80% 
indicated they would be interested in participating in a sedentary reduction program.  
 
D. RESEARCH DESIGN AND METHODS AND DATA ANALYSIS  
Design Overview: This study is a three-group randomized controlled trial comparing 
changes in sedentary behavior between the NEAT!2 intervention with or without 
coaching calls and a control group in adults with past or present knee symptoms, 
injuries, or surgeries. A total of 90 participants will be randomized into one of three 
groups 1) NEAT!2 2) Delayed NEAT!2 or 3) NEAT!2+Calls. Data will be collected at 
baseline and months 1, 3, and 6.  
 
Screening: Potential participants will complete an online screener to assess initial 
eligibility. Eligible patients will be invited to an in-person session where staff will review 
full details of the study and answer any questions. An equipoise induction will be 
conducted to review the pros and cons of being randomized to either condition to help 
prevent differential attrition.15 Interested and eligible participants will provide informed 
consent, approved by the University of South Carolina’s Institutional Review Board. 
Participants will complete the baseline assessment and wear an accelerometer for 7 
days. Participants will need to have 4 valid days of accelerometer data to be eligible for 
randomization. They will not receive any feedback on sedentary time and will be 
encouraged to engage in typical behavior during this period. In addition, to ensure 
compatibility and eliminate the potential of technological issues following randomization, 
all participants will download a test version of NEAT!2 app on their phone. The test 
version of NEAT!2 app will remain idle, and participants will not receive notifications 
about their sedentary time until after randomization.  
 
Randomized Conditions: 

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1) NEAT!2: NEAT!2 is guided by the Dual-Process Theory16 and targets both 
automatic and controlled processes.17 Participants randomized to NEAT!2 will 
have their NEAT!2 app turned on after randomization. Using the smartphone’s 
internal accelerometers, NEAT!2 detects periods of movement vs. non-
movement. When 30 minutes of continuous non-movement or sedentary time is 
detected, the NEAT!2 app will initiate a reminder notification via vibration or audio 
as well as display a reminder on the phone’s lock/home screen. This novel 
approach will take advantage of the frequent number of times an individual looks 
at his/her phone.18 If and when the app detects activity/movement, the 30-minute 
timer will restart; thus, the app will only provide notifications when prolonged 
bouts of inactivity are objectively detected. Further, the app will only trigger 
notifications during participants waking hours. Each notification will consist of a 
different message. Participants will be asked to use the app for the 3 months of 
the intervention. Participants will be given an initial goal to reduce total sedentary 
time by 30 minutes/day, ultimately progressing to a 90 minute/day reduction by 3 
months. After the 3-month assessment, participants randomized to NEAT!2 will 
have the option to continue using the app until 6 months. 
 
2) Delayed NEAT!2: Participants randomized to the delayed control condition will 
not receive any contact or app between baseline and 3 months. However, after 
completing the 3-month assessment, participants in the delayed condition will 
receive the NEAT!2 application. Participants will then have the option to use the 
app between 3 and 6 months.  
 
3) NEAT!2+Calls: NEAT!2+Calls participants will have their NEAT!2 app turned on 
after randomization. In addition, to receiving the identical app and given the same 
goals as participants randomized to NEAT!2, NEAT!2+Calls participants will 
receive bi-weekly coaching calls. Coaching calls will be completed by trained 
coaches, be semi-scripted, and last approximately 10-15 minutes. During calls, 
coaches will use motivational interviewing techniques, discuss goal progression 
and educational handouts, problem solve, and set a SMART (specific, 
measurable, attainable, realistic/reward, timely) goal related to reducing 
sedentary time. All calls will be recorded and timed to allow the assessment of 
treatment fidelity. After the 3-month assessment, participants randomized to 
NEAT!2+Calls will have the option to continue using the app until 6 months. 
During this time, participants will not receive any coaching calls. 
 
Treatment Fidelity:  Telephone sessions will be audiotaped, and a 15% sample rated for 
treatment fidelity on a quarterly basis. If fidelity falls below 80%, coaches will be 
retrained. Fidelity checklists will assess intended session content (e.g., app usage, 
SMART goal setting). Dr. Pellegrini will train the coaches on the intervention and will 
oversee the fidelity evaluation. Coaches will meet with Dr. Pellegrini once a month to 
review treatment delivery. 
 
Assessments: Participants will be asked to complete four in-person assessments at 
baseline, 1 month, 3 months, and 6 months. All in-person assessments will take place 

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at the TecHealth Center at the University of South Carolina (915 Greene Street, Suite 
403) and each session will be last approximately 45 minutes in length. Table 1 provides 
an overview of what outcomes will be assessed, how they will be assessed, and at what 
time points. 
 
 
Table 1. Study Outcomes and Measures 
 
Concept 
Variable 
Measure 
Data Collection 
Time 
Points 
Aim 1 Outcomes  
 
Sedentary 
Behavior 
 
 
 
 
Objectively 
measured 
sedentary 
behavior 
 
Daily diary 
 
Sitting minutes/day and 
Sitting bouts >30 minutes 
during waking hours 
 
 
Times monitor on/off, 
awake/sleep 
ActivPal worn on 
thigh for 7 days for 
24 hours/day 
 
 
Paper log for 7 days 
 
0, 1, 3, & 6 
months 
 
 
 
0, 1, 3, & 6 
months 
Aim 2 Outcomes 
 
Physical 
Function 
Objectively 
measured 
physical 
function 
Timed up and go; 30-
second chair stands, 6-
minute walk test based on 
OARSI recommended 
procedures19 
In-Person 
Assessment 
0, 1, 3, & 6 
months 
Demographic, Health Status, and Process Variables 
 
Demographics 
Age, Sex, 
Race, 
Ethnicity, 
Marital Status, 
Education 
Demographic 
Questionnaire 
REDCap survey 
0 (baseline) 
Health Status 
 
 
 
 
 
 
Knee Symptoms 
 
 
 
 
 
 
 
 
Habit Strength 
 
Domain specific 
sedentary 
behavior 
 
 
Behavioral 
Beliefs 
Height, Weight, 
Waist 
Circumference 
BMI 
 
Medical History 
 
Self-reported 
knee 
symptoms 
 
Pain intensity, 
pain 
interference, & 
mobility 
 
Self-reported 
habit strength 
Self-reported 
 
 
 
 
Self-reported 
beliefs on 
Stadiometer, electric 
scale, and tape measure 
 
 
 
Brief medical history 
 
Knee injury and 
Osteoarthritis Outcome 
Score (KOOS)20 
 
Patient-Reported 
Outcomes Measurement 
Information System 
(PROMIS)21,22 
 
Adapted Self-Report Habit 
Index23 
Total sitting time and 
domain specific sitting 
time 
 
 
TPB Survey24 and 
Elicitation Interview25  
In-Person 
assessment 
 
 
 
REDCap Survey 
 
REDCap Survey 
 
 
 
REDCap Survey 
 
 
 
 
REDCap Survey 
 
SIT-Q26 and the 
Sedentary Behavior 
Questionnaire27 
 
 
0, 1, 3, & 6 
months 
 
 
 
0 (baseline) 
 
0, 1, 3, & 6 
months 
 
 
0, 1, 3, & 6 
months 
 
 
 
0, 1, 3, & 6 
months 
0, 1, 3, & 6 
months 
 
 
 
0,1,3, & 6 
months 

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Personal 
Environment 
Changes 
 
physical 
activity and 
sedentary 
behavior 
 
Self-reported 
change in use 
of activity 
monitor 
 
 
 
 
 
Physical Activity Monitor 
Changes Questionnaire 
REDCap Survey 
and In-Person 
Interview 
 
 
 
 
REDCap Survey 
(interview 
only 0 
months) 
 
 
1, 3, & 6 
months 
 
 
 
 
Primary Outcomes:  
• Sedentary behavior will be measured using ActivPALTM (PAL Technologies Ltd, 
Glasgow, UK), a small lightweight (15 g) uni-axial accelerometer. The time spent 
sitting/lying, standing, and stepping. The ActivPAL summarizes data in 15 
second intervals over 24 hours at a sampling frequency of 10 Hz.24 During 
assessments, participants will be asked to wear the ActivPAL on their thigh for 7 
days. The monitor will be secured to the participants leg with medical grade 
waterproof adhesive tape. Participants will also be asked to complete a log 
indicating times the ActivPAL was worn and taken off over the 7-day assessment 
period in addition to what times they went to sleep and woke up.  
 
Secondary and Exploratory Outcomes: 
• Physical function measures will include the chair stand, timed up and go, and 6- 
minute walk test. All physical function tests will be completed following 
Osteoarthritis Research Society International (OARSI) recommendation 
procedures.19 During the chair stand test, patients are asked to complete as 
many chair stand repetitions as possible during a 30-second period. The Timed 
Up and Go Test assesses the time in seconds taken to rise from a chair, walk 3-
meters, turn, walk back to the chair, and sit down. The Six Minute Walk Test 
evaluates the maximal distance a patient can cover during a 6-minute period. 
• Knee symptoms will be assessed using the Knee Injury and Osteoarthritis 
Outcome Score (KOOS).20 Participants will self-report on symptoms, stiffness, 
pain, daily function, and active function of their knee from the past week.  
Patient-Reported Outcomes (pain intensity, pain interference, and mobility) will 
be assessed using Patient-Reported Outcomes Measurement Information 
System (PROMIS).21 PROMIS utilizes a computer adaptive test via RedCap.25  
• Adapted Self-Report Habit Index23 assesses habit strength related to sitting. 
Participants answer the questions on a 1-7 Likert scale ranging from “Strongly 
Disagree” to “Strongly Agree”. 
• Sedentary behavior will also be assessed with the SIT-Q.26  This will be 
assessed as part of the web screening to estimate how many hours individuals 
spent sitting on an average day. The survey assesses time spent sleeping and 
sitting time during multiple domains (e.g., meals, transportation, work, leisure). 
The survey will also be administered at each assessment to explore changes in 
domain specific sedentary time. The Sedentary Behavior Questionnaire27 will 
also be assessed to examine specific activities done while sitting (9 behaviors 
such as TV watching, reading, and using the phone on weekends vs. weekdays).  

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• Participants’ control, normative, and behavioral beliefs toward sedentary 
behavior and physical activity will be assed with (1) a modified Theory of Planned 
Behavior (TPB) survey24 - The survey includes 37 questions about the 
participants beliefs towards sedentary behavior and physical activity utilizing a 1-
7 Likert scale. (2) An elicitation interview modified from Speed-Andrews et al.25 
will be administered at baseline. The interview contains 12 open-ended questions 
and elicits participants beliefs related to sedentary behavior and physical activity.  
• Waist Circumference will also be assessed as a predictor of abdominal visceral 
fat. Measurement will be done twice during expiration, taking the average for 
analyses, by positioning an anthropometric tape midway between the palpated 
iliac crest and the palpated lowest rib margin in the mid-axillary lines (smallest 
part of the waist). 
 
Evaluation: Following completion of the 3 or 6 month assessment, participants will be 
asked to complete a short evaluation form asking about their feelings and attitudes 
regarding the NEAT!2 program and the NEAT!2 application. The evaluation will aid in 
future research utilizing the NEAT!2 application or research directed at reducing 
sedentary behavior in this population. 
 
Statistical Analysis: Baseline participant characteristics will be described. Mixed 
ANCOVA’s will be conducted to examine differences in sedentary behavior, physical 
function, and patient-reported outcomes across time by group. Additionally, we will 
control all sedentary time analyses for moderate intensity physical activity.  All analyses 
will be performed using SAS 9.2 and SPSS. 
 
E. PROTECTION OF HUMAN SUBJECTS 
 
1. TARGET POPULATION: 
We will aim to recruit 90 participants from Columbia, SC and surrounding areas. The 
target population will consist of adults over the age of 40 who identify with past or 
present knee pain, injury, or surgery.   
 
Inclusion criteria: Eligible participants will 1) be at least 40 years of age, 2) own an 
Android or iOS smartphone, 3) have their smartphone near them (in their pocket, in their 
hand, or within 10 feet of them for >50% of their waking day 4) be willing to download 
the study application on their smartphone and have the application be compatible with 
their device, 5) spend at least 7 hours/day sitting, assessed by the SIT-Q, 6) have at 
least 4 days of valid accelerometer data at baseline, 7) have knee pain (at least one 
knee with pain, aching, or stiffness on most days for one month of the last 12 months), 
knee injury, or knee replacement within the last 5 years, and 8) read, speak, and 
understand English.  
 
Exclusion criteria: Participants will only be excluded if they 1) have any 
contraindications to activity, 2) have a mobility limiting comorbidity (e.g. spinal stenosis), 
or 3) have a scheduled surgery (i.e., total knee replacement) within the next 6 months. 
 

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2. RECRUITMENT PLANS: 
We will target recruitment channels including: 1) promotions in publications with low or 
no advertising cost (i.e., Craig’s List); 2) electronic and social media recruitment blurbs 
(i.e., Facebook, Twitter, website, email newsletter, electronic billboard, etc.); 3) posting 
flyers around USC campus area and local Columbia businesses, health centers, 
rehabilitation or orthopedic centers; 4) word of mouth; and 5) emails to individuals from 
previous studies who expressed interest in participating in future trials.  
 
All recruitment material will list study eligibility criteria and requirements and include a 
phone number, email address, and website where participants can reach staff if they 
have any general questions regarding study participation.  
 
3. EXISTING DATA/SAMPLES:  
Not applicable 
 
4.  CONSENT/ASSENT: 
Written informed consent will be obtained in person. Full disclosure will be made of the 
nature and potential risks of participating in the study. Prior to starting, all participants 
will be asked if they have any questions about their participation to ensure they 
understand the procedures. The consent form has been developed according to the 
requirements of the University of South Carolina Institutional Review Board. All 
participants will receive a copy of their signed consent form. A copy of all signed IRB-
approved consent forms will be kept in a locked file. 
 
5.  POTENTIAL RISKS: 
Risks associated with interrupting sedentary time with brief bouts of light-intensity 
physical activity such as standing or light ambulation are minimal. Participants may 
experience skin irritation from wearing the activPAL accelerometer for 7 days at each 
assessment. In the event the participant experiences skin irritation, we will ask the 
participant to remove the device. We will provide them with additional tape, with multiple 
options available to accommodate individual reactions and preferences to medical 
grade tape, to reaffix to the other leg.  
 
6.  POTENTIAL BENEFITS: 
Participants may or may not directly benefit from participating in this study, however the 
risks of participating in either randomized group are considered minimal. Participants 
may gain skills and knowledge regarding how to decrease sedentary behavior. 
Participants who are adherent to the intervention and reduce sedentary time may have 
greater reductions in pain and improvements in physical function. If the intervention is 
acceptable, safe, and effective, it may provide an innovative approach to reduce 
sedentary time among adults with previous or past knee symptoms, injuries, or 
surgeries. 
 
7.  CONFIDENTIALITY 
A number will be assigned to the participant who agrees to be a part of the study. This 
number will be used on the project records rather than their name, and no one other 

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than the researchers will be able to link the data with the name. Study records/data will 
be stored in locked filing cabinets and protected computer files at the University of 
South Carolina.   
 
8. COMPENSATION:   
Participants will be given two raffle tickets for completing the assessments at 1, 3, and 6 
months.  They will receive 1 ticket for the in-person assessment; 1 ticket for wearing the 
activPAL. These tickets will be placed into a bi-monthly drawing. Every two months of 
the study, 2 winners will be drawn and receive a $25 prepaid Visa debit card. 
  
9.  WITHDRAWAL: 
Participants will be informed they can leave the research at any time without penalty. If 
a participant decides to withdraw, no more information will be collected. The participants 
will be made aware of this during the consent process.  
 
Any data collected during your participation in this research study prior to the date the 
participant chooses to withdraw consent may continue to be used by the investigators 
for the purposes described above.   
 
Choosing not to be in the study will not result in any penalty or loss of benefit to which 
participants are entitled. Specifically, the choice not to be in this study will not negatively 
affect a participant’s right to any present of future medical treatment or his/her present 
or future employment (for employees at USC or its affiliates).  
 
 

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