Appointment reminders to increase uptake of HIV retesting by at-risk individuals: a randomized controlled study in Thailand

Abstract

Introduction: Frequent HIV testing of at-risk individuals is crucial to detect and treat infections early and prevent transmissions. We assessed the effect of reminders on HIV retesting uptake.

Methods: The study was conducted within a programme involving four facilities providing free-of-charge HIV, syphilis and hepatitis B and C testing and counselling in northern Thailand. Individuals found HIV negative and identified at risk by counsellors were invited to participate in a three-arm, open-label, randomized, controlled trial comparing: (a) "No Appointment & No Reminder" (control arm); (b) "No Appointment but Reminder": short message service (SMS) sent 24 weeks after the enrolment visit to remind booking an appointment, and sent again one week later if no appointment was booked; and (c) "Appointment & Reminder": appointment scheduled during the enrolment visit and SMS sent one week before appointment to ask for confirmation; if no response: single call made within one business day. The primary endpoint was a HIV retest within seven months after the enrolment visit. The cost of each reminder strategy was calculated as the sum of the following costs in United States dollars (USD): time spent by participants, counsellors and hotline staff; phone calls made; and SMS sent. The target sample size was 217 participants per arm (651 overall).

Results: Between April and November 2017, 651 participants were randomized. The proportion presenting for HIV retesting within seven months was 11.2% (24/215) in the control arm, versus 19.3% (42/218) in "No Appointment but Reminder" (p = 0.023) and 36.7% (80/218) in "Appointment & Reminder" (p < 0.001). Differences in proportions compared to the control arm were respectively +8.1% (95% CI: +1.4% to +14.8%) and +25.5% (+17.9% to +33.2%). The incremental cost-effectiveness ratios of "No Appointment but Reminder" and "Appointment & Reminder" compared to the control arm were respectively USD 0.05 and USD 0.14 per participant for each 5% increase in HIV retesting uptake within seven months.

Conclusions: Scheduling an appointment and sending a reminder one week before was a simple, easy-to-implement and affordable intervention that significantly increased HIV retesting uptake in these at-risk individuals. The personal phone call to clients probably contributed, and also improved service efficiency.

Keywords: appointment; cell phone; reminder; retesting; testing; text messaging.

© 2020 The Authors. Journal of the International AIDS Society published by John Wiley & Sons Ltd on behalf of the International AIDS Society.

Figures

Figure 1

CONSORT diagram of the disposition of participants.

Figure 2

Participants retested for HIV within (a) seven months (b) twelve months by arm. “No Appointment & No Reminder”: clients encouraged to present for HIV retesting within three to six months or even within less than three months if the perceived risk was high, then no further contact made; “No Appointment but Reminder”: short message service (SMS) sent 24 weeks after the enrolment visit to remind booking an appointment, and sent again one week later if no appointment was booked; “Appointment & Reminder”: appointment scheduled during the enrolment visit and SMS sent one week before appointment to ask for confirmation; if no response: single call made within one business day. Bars represent 95% confidence intervals calculated using the Clopper–Pearson method. The overall two‐sided type I error for the final analysis was set to 0.049 for pairwise comparisons between the control arm and each experimental arm, that is, 0.0248 per comparison using Sidak correction. p‐values were derived from two‐sided Fisher’s exact tests. In a post hoc analysis, the p‐value for the comparison between the two experimental arms was <0.001 (a) 0.002 (b).