4.4. Limitations, Strengths, and Future Directions
PA behaviors
RECRUITMENT, BLIND
The study’s findings are encouraging, but it is important to recognize potential limitations. The primary focus for this stage of intervention development was on feasibility and acceptability of the smartphone-delivered intervention, rather than efficacy testing. Accordingly, when interpreting PA, cardiometabolic, and psychosocial outcomes, we focused on examining magnitudes of effect, rather than statistical significance. Results for these outcomes (and our subsequent discussion of them) should be interpreted as suggestive, rather than definitive. Additionally, the multi-component nature of the intervention limits our ability to determine if one component of the intervention may have been more strongly related to changes in PA behavior than another. To properly address this type of question, a design that can examine component-specific effects is needed (e.g., factorial or multiphase optimization strategy [MOST] designs). A third limitation was that although efforts were made to blind research technicians conducting cardiorespiratory fitness tests to participants’ study group allocation at 4- and 8-month follow-up assessments, this was not always possible. Standardized testing procedures were used to limit this potential bias. Other limitations include recruiting participants from single geographical area (i.e., Phoenix, Arizona), using community-based recruitment methods, and providing compensation for participation (although this compensation was nominal compared to study time commitments). These considerations may limit generalizing results to AA women outside of the Phoenix metropolitan area and likely reflect a sample with increased motivation to adopt healthy lifestyle behaviors. Finally, restrictions on data collection related to the COVID-19 pandemic had serious impacts on conclusions that could be drawn from analyses of several 8-month outcomes. The lack of 8-month physiological study assessments for approximately 1/3 of our sample resulted in untrustworthy estimates from analyses of multiply imputed datasets, limiting us to complete-case analyses of cardiometabolic outcomes at 8 months. These restrictions also likely influenced PA behaviors and psychosocial outcomes among participants who were completing the study during the early stages of the pandemic.Despite limitations, numerous strengths of the study should also be noted. This is one of the first studies to examine the effects of a culturally tailored smartphone-delivered PA intervention among AA women, research necessary to advance e- and mHealth research on PA promotion. Second, we addressed several design limitations of previous studies [Future directions for this program of research include refining the 