Feasibility and Convergent Validity of an Activity Tracker in a Clinical Study of Low Back Pain (Preprint)
BACKGROUND Low back pain (LBP) is a highly prevalent condition affecting individuals of all ages. To manage the symptoms and prevent recurrences and flare-ups, physical activity in conjunction with self-management education is recommended. Tools such as diaries and questionnaires have been the gold standard for tracking physical activity in clinical studies. However, there are issues with consistency, accuracy, and recall with the use of these outcome measures. Given the growth of technology in today’s society, consumer-grade activity monitors have become a common and convenient method of recording physical activity data. OBJECTIVE To test the feasibility and convergent validity a Garmin Vivo 3 activity tracker in evaluating physical activity levels in a clinical trial of LBP patients. METHODS We recruited 17 individuals with non-specific LBP referred from health care professionals or self-referred through advertisements in the community. The participants entered into a 12-week physical activity and self-management program. Physical activity was assessed using a self-reported questionnaire and the Garmin activity tracker. Activity tracker data (e.g. steps taken, distance walked, intensity minutes, etc.) were extracted weekly from the Garmin Connect online platform. Outcomes of pain and activity limitation were assessed weekly using a mobile app. Linear regression was conducted to evaluate if demographic factors (i.e. age, gender, pain level) affected the adherence rates to the activity monitor. We also used Pearson’s correlations to evaluate the convergent validity of the Garmin activity tracker with the physical activity questionnaire. RESULTS The daily adherence rate for activity monitors was 70% (SD 31%) over the 26 weeks of study. The daily response rate for the text messaging system over the first 12 weeks of the study was 81% (SD 28%). The response rate for the weekly physical activity measures using REDCap was 91% (SD 17%). None of the hypothesized variables or questionnaires were predictors of response rate. CONCLUSIONS No correlations were found between the International Physical Activity Questionnaire Short Form (IPAQ-SF) and the activity monitor. Demographic factors were not found to be predictors of adherence to wearing the device. However, the majority of participants were compliant with wearing the tracker and thus, activity monitors may still be a useful tool in scientific research.