Mobile Motivational Physical Activity Targeted Intervention (MobMPATI) to Improve Sleep in Older Adults With Osteoarthritis
Phase: NA
Conditions: Osteoarthritis
Sponsor: University of Washington

Cover page 
Official Title: Mobile Motivational Physical Activity Targeted Intervention 
NCT number: NCT03160287 
Document Date: 05/18/2017 

Study Design 
This was a prospective one group pre-posttest study to test the feasibility and efficacy of 
a multidimensional intervention, the components of which were wearable activity 
tracking devices, personalized texts, and motivational interviews.  Participants received 
a Fitbit Charge 2 device [Fitbit, San Francisco, CA]) and were given access to the Fitbit 
mobile app to facilitate their self-monitoring. The study occurred over 19-weeks.  
Participants 
Study participants were recruited through direct mailings, presentations, and flyers in 
retirement communities and other places frequented by older adults in Seattle, WA. 
Eligibility criteria included: a) being age 65 years and older, b) having a diagnosis of 
osteoarthritis, c) having a smartphone, d) having physical activity levels below the U.S. 
Department of Health and Human Services recommended guidelines evaluated using 
the Rapid Assessment of Physical Activity scale, and e) having Insomnia Severity Index 
score >12. Exclusion criteria included: a) having an acute injury associated with hip or 
knee pain, b) inability to stand up without assistance, c) having a Memory Impairment 
Screen for Telephone score of <4, d) having severe hearing or visual impairment, and 
e) an acute episode or change in the treatment of psychiatric problems within the past 3
months.  
Intervention Components  
Wearable Activity Tracking Devices  
The Fitbit Charge 2 is a heart rate and fitness wristband used to deliver the intervention 
and measure daily step counts. This device was selected because  1) it can accurately 
sense step count in older adults; 2) it has an optical heart rate sensor that monitors and 

documents heart rate over time, thus allowing for collection of objective wear time; and 
3) its technology permitted the retrieval of near real time information exchange between 
the Fitbit app and the iCardia research platform. 
Personalized Texts  
The adaptive personalized intervention was informed by Control Theory framework. 
Following a formative process that included an expert panel, end users, and literature 
review, the study team developed targeted behavioral change text messages that 
provided information and motivational reinforcement with regard to participant’s past 
and concurrent physical activity progress.  Participants received weekly targeted and 
personalized text messages that provided motivational feedback according to their 
adaptive step count attainment.  
Motivational interviews 
 In addition to text messages, three phone calls at weeks 1, 5, and 9 that were informed 
by motivational interviewing principles were scheduled with participants to discuss their 
goals and debrief strategies for facilitating behavioral change.  
Remote and self-monitoring 
The iCardia research platform was used to retrieve data from the Fitbit cloud server, 
present these data on a user-friendly dashboard, and send personalized text messages 
to the end user smartphones. In addition to motivational messages, reminders to sync 
the Fitbit and charge its battery were sent when participants failed to sync for more than 
3 days and/or tracker battery was low.  
Data Collection Procedures  

A study coordinator (SC) collected data during one-on-one interviews and remotely 
using standardized procedures at three-time points. At the baseline in-person 
assessment, the SC administered clinical and demographic questionnaires and 
provided actigraphs. The second and third assessments at weeks 14 and 19 occurred 
either in-person or remotely by using Research Electronic Data Capture (REDCap) 
online survey feature. During the second and third data collection points, participants 
were also provided with actigraphs, which they were instructed to wear for one week 
and mail back to the research office.  
Statistical Analyses 
De-identified data from RedCap and iCardia were exported and analyzed using Stata 
15.0 in two phases. First, univariate analyses were conducted to summarize 
participants’ baseline characteristics and follow-up measures. Mixed effect models were 
utilized next because of the time repeated structure of the data. Data collection 
occasions were also entered in the models to account for change over time. The 
adjusted main effects for time for each of the variables were tested for significance and 
reported as estimates and 95% confidence intervals (CI).