Enhancing the Content Validity of Self-Reported Physical Activity Self-Efficacy in Adolescents: A Qualitative Study.

PURPOSE: This study's primary purpose was to enhance the content validity of a self-reported measure of self-efficacy for physical activity (PA) in adolescents. This was addressed through assessment of younger and older adolescents' understanding of the construct of self-efficacy for PA, coupled with assessment of the content coverage and comprehensibility of items derived from existing measures. METHODS: Participants completed individual semistructured and cognitive debriefing interviews as well as 3 PA self-efficacy questionnaires. RESULTS: Thematic analysis identified personal and environmental facilitators and barriers to PA self-efficacy. The major categories were physical; psychological; interaction with surroundings; support and relationships; attitudes; and services, systems, and natural environments. Cognitive interviews resulted in the retention of 52 final items: 24 for self-efficacy with perceived facilitators and 28 for self-efficacy to overcome barriers. CONCLUSIONS: This study provides a PA self-efficacy instrument with expanded content coverage that is relevant to adolescents as young as 11 years. With further validation testing in future studies, this instrument will enable pediatric physical therapists and researchers to assess PA self-efficacy and design effective intervention strategies to improve PA.

Convergent Validity of the Patient Reported Outcome Measurement Information System-Pediatric Physical Activity Instrument (PROMIS®-PA) with Wearable Devices in Adolescents.

The study was conducted mainly to examine the convergent validity of the Patient Reported Outcome Measurement Information System-Pediatric Physical Activity instrument (PROMIS®®®-PA) with step counts from wearable devices and another validated self-reported outcome measure. As a secondary aim, we explored the effect of different recall time frames (7-day, end-of-day [EoD], and ecological momentary assessment [EMA] time frames during the day) in terms of their feasibility and associations with each other and with step counts. This was a prospective cohort study that examined the associations between measures of PA in school-age children and adolescents (n = 84, aged 10-20). The participants wore Fitbit devices for 7 consecutive days, and then completed the 7-day-recall PROMIS-PA short form and Youth Activity Profile (YAP). Additional analyses were completed in a sub-sample (n = 25, aged 11-18 years) using the PROMIS-PA for the EMA at five intervals during the day (shorter form) and at the EoD. In the total sample, the PROMIS-PA results showed positive moderate correlations with the YAP and average daily steps (r = 0.533, p < 0.001 and r = 0.346, p = 0.002, respectively). In the sub-sample, the 7-day PROMIS-PA was highly correlated with the averaged EMA or EoD ratings for the week, and moderately correlated with the daily step counts. These findings support the validity of the PROMIS-PA as a measure of self-reported physical activity. Adolescents demonstrated higher compliance rates and preference for the 7-day recall and EoD assessments compared to more frequent EMA reporting.