Assessing the Response Results of an mHealth-Based Patient Experience Survey Among People Receiving HIV Care in Lusaka, Zambia: Cohort Study

Background: This pilot study evaluates the effectiveness of mobile talk-time incentives in maintaining participation in alongitudinal mobile health (mHealth) data collection program among people living with HIV in Lusaka, Zambia. While mHealthtools, such as mobile phone surveys, provide vital health feedback, optimal incentive strategies to ensure long-term engagementremain limited. This study explores how different incentive levels affect response rates in multiple survey rounds, providinginsights into effective methods for encouraging ongoing participation, especially in the context of Zambia's prepaid mobile systemand multi-SIM usage, a common practice in sub-Saharan Africa.Objective: This study aimed to assess the response rate success across multiple invitations to participate in a care experiencesurvey using a mobile phone short codes and unstructured supplementary service data (USSD) model among individuals in anHIV care setting in the Lusaka, Zambia.Methods: Participants were recruited from 2 study clinics-1 in a periurban setting and 1 in an urban setting. A total of 2 roundsof survey invitations were sent to study participants on a 3-month interval between November 1, 2018, and September 23, 2019.Overall, 3 incentive levels were randomly assigned by participant and survey round: (1) no incentive, (2) 2 Zambian Kwacha(ZMW; US $0.16), and (3) 5 ZMW (US $0.42). Survey response rates were analyzed using mixed-effects Poisson regression,adjusting for individual- and facility-level factors. Probability plots for survey completion were generated based on language,incentive level, and survey round. We projected the cost per additional response for different incentive levels.Results: A total of 1006 participants were enrolled, with 72.3% (727/1006) from the urban HIV care facility and 62.4% (628/1006)requesting the survey in English. We sent a total of 1992 survey invitations for both rounds. Overall, survey completion acrossboth surveys was 32.1% (637/1992), with significantly different survey completion between the first (40.5%, 95% CI 37.4-43.6%)and second (23.7%, 95% CI 21.1-26.4) invitations. Implementing a 5 ZMW (US $0.42) incentive significantly increased the adjusted prevalence ratio (aPR) for survey completion compared with those that received no incentive (aPR 1.35, 95% CI1.11-1.63). The cost per additional response was highest at 5 ZMW, equivalent to US $0.42 (72.8 ZMW [US $5.82] per 1%increase in response).Conclusions: We observed a sharp decline of almost 50% in survey completion success from the initial invitation to follow-upsurvey administered 3 months later. This substantial decrease suggests that longitudinal data collection potential for a careexperience survey may be limited without additional sensitization and, potentially, added survey reminders. Implementing amoderate incentive increased response rates to our health care experience survey. Tailoring survey strategies to accommodatelanguage preferences and providing moderate incentives can optimize response rates in Zambia.