Overall Retention and Characteristics Associated With Longitudinal Completion of Remote Patient-Reported Outcome Questionnaires in a Representative, General Population Cohort Study: The Project Baseline Health Study

OBJECTIVES: Remote, digitally-supported longitudinal cohort studies are promising for research due to their potential for participant-centered, convenient, cost-efficient, scalable, and secure data collection that may increase participation and representativeness. However, it is well-recognized that longitudinal compliance is challenging for remote studies. The Project Baseline Health Study (PBHS), a hybrid in-person and virtual study, offers a unique opportunity to evaluate aspects of remote engagement over time.

METHODS: We summarized overall four-year retention in PBHS and rates of longitudinal remote survey completion. We also investigated associations of demographic, social determinants of health, physical, and mental health characteristics with quarterly remote survey completion using regression models.

RESULTS: A total of 2502 participants enrolled in PBHS; 94% remained enrolled after 4 years and 60% of participants completed all 4 annual follow-up visits. There were 2490 participants enrolled in PBHS for at least one quarter. The median (IQR) number of remote electronic survey sets completed was 8 (3-12) of a possible 16. Age was positively associated with remote survey completion. Black (OR: 0.70; 95% CI: 0.59-0.84) and Hispanic (OR: 0.75; 95% CI: 0.62-0.92) participants had lower odds of completion versus White and non-Hispanic counterparts, respectively. Income and education were positively associated with remote survey completion. Those with at least mild symptoms of depression (OR: 0.87; 95% CI: 0.81-0.93) or anxiety (OR: 0.83; 95% CI: 0.77-0.89), reported via 9-item Participant Health Questionnaire and 7-item Generalized Anxiety Disorder questionnaire, respectively, had lower odds of remote survey completion versus those without.

CONCLUSIONS: Overall, 94% of PBHS participants remained enrolled after four years. Age, race, ethnicity, income, education, and symptomatic depression and anxiety were significantly associated with longitudinal remote questionnaire completion. Understanding factors associated with remote electronic questionnaire completion may inform future longitudinal study design, promote representativeness, and provide insights into engagement strategies to maximize study engagement and data completeness.