Incentivising PrEP in AGYW

Can conditional economic incentives motivate uptake and habitual use of pre-exposure prophylaxis in adolescent girls and young women?

Pre-exposure prophylaxis (PrEP) can reduce HIV infection risk by more than 90% if taken regularly and consistently (1). In 2016 South Africa rolled out the adolescent girl and young women (AGYW) PrEP programme (2). However, as of mid-2020 only 45,000 people in South Africa used PrEP (3) with AGYW knowledge of PrEP (1 in 10) and PrEP uptake (2 in 100) remaining low (4). AGYW are at a disproportionate risk of HIV (5). Predisposing factors include gender-based and intimate partner violence, age disparate sexual relationships, multiple, concurrent sexual partnerships, transactional sex, and challenges with negotiating condom use (6). 


Fear of partner disapproval, or worse – emotional abuse, physical abuse and forced sex –  can influence AGYW’s decisions and impact their ability to access and  consistently use PrEP and other HIV prevention technologies such as the vaginal ring, microbicide gel and/or condoms (7). AGYW frequently leave decision making regarding sexual matters to their partners, prioritising their relationships over HIV risk (8), especially when male partners are providing financial support. Additionally, the hassle of a daily pill, stigma and perceived side effects associated with using PrEP perpetuate reluctance to use this medication (9). For AGYW, the future benefit of HIV prevention may come with potential immediate costs related to conflict in the relationship and no other explicit immediate rewards (8). This concept in behavioural economics terms is present bias or hyperbolic temporal discounting which refers to the weighting of more immediate rewards over those in the distant future (10).



Conditional economic incentives to overcome present bias

Conditional economic incentives (CEIs) such as cash transfers, grants, food stamps, shopping vouchers, school subsidies and lotteries, can help overcome economic and behavioural barriers related to present bias (11,12). Several trials aimed at improving HIV prevention strategies successfully used CEIs. Conditional cash transfers have been effective in lowering HIV and sexually transmitted infections (STIs) in AGYW (12,13). Lottery based incentives have increased the use of dual protection in South African women, STI prevention in young adults in Lesotho, and voluntary medical male circumcision among men in Kenya (14–16). Lottery incentives have also shown efficacy in shortening the time to ART initiation among South African men, outperforming motivational text messaging in time to ART initiation and clinic registration, indicating improved engagement in care (17). While these studies are encouraging, the long-term effect of CEIs after they are removed is less clear (11). The potential lack of a sustained effect could negatively impact adherence to prevention and treatment modalities.  



Can CEIs motivate initiation in care with a view to the engagement becoming more habitual? They may very well do so, especially in resource poor settings where CEIs contribute to enabling or supporting access to health services. Engagement in sexual and reproductive health services (SRH) is key in promoting the use of HIV prevention technologies. In a large study of over 2,500 AGYW, participants primarily heard about PrEP for the first time when engaging in SRH services at a clinic participating in the research (9).  Several trials in AGYW have shown promising associations between CEIs and lower prevalence of sexually transmitted infections and HIV (13). A lottery-based incentive was found to significantly increase use of dual protection methods by women 18-40 years attending post-abortion care (15). Incentivising PrEP adherence resulted in a higher proportion of AGYW with high adherence in the incentivised group compared to the control group at a three month follow up (though not statistically significant) (18).



The question remains, even though the use of CEIs have shown promise, is their use appropriate for AGYW who are potentially disempowered and likely exposed to multiple influences? Could economic incentives diminish autonomy and exploit an already vulnerable group? The Ethics Working Group of the HIV Prevention Trials Network supports the use of incentives if used to motivate engagement in health services, overcome economic difficulties that limit access to health services and promote healthy behaviours (19). A recent study showed that AGYW who had knowledge of PrEP expressed positive sentiments for personal decision making, safety and freedom in managing HIV risk (9). Those who used PrEP consistently felt empowered and confident in their ability to act and make choices for their own sexual health with engagement in SRH services and support systems being integral to starting PrEP (9). Therefore, the benefits of using incentives to motivate engagement with health services may far outweigh the risks.



There is a growing recognition of the efficacy of combination programmes in HIV prevention and treatment tailored to suit the needs of AGYW (2,13). While effectiveness of text message reminders and youth friendly services to improve daily medication use has been established, there is less evidence for the efficacy of CEIs in adolescents and young adults (20). CEIs have potential to motivate engagement in care within these programmes but much of the evidence to date is focused on adult populations (21). Evidence for  the use of economic incentives to motivate PrEP use and continuation among AGYW living in sub-Saharan Africa is limited. In order to try and help fill this evidence gap, the Indlela team, together with Triggerise and the Institute for Health Programs and Systems (IHPS) are investigating the use of CEIs among AGYW in one of our Behavioural Insight Tests (BIT).



This BIT will evaluate the effectiveness of a lucky draw using the Triggerise Tiko mobile phone platform to increase PrEP uptake and persistence among AGYW aged 15-24 years in Mbombela, Ehlanzeni District, Mpumalanga. AGYW engaging in the IHPS combination HIV prevention programme and who are enrolled on the Tiko platform will be randomised into one of two study arms: control arm (no lucky draw) or intervention which is entry into a lucky draw with 1:20 odds of receiving 250 Tiko Miles (R250) conditional on attending each follow up visit. Tiko Miles can be redeemed via Cellbux vouchers sent to the AGYW’s mobile phones, which can be used at local retailers in the area. The intervention will measure PrEP uptake within one month of screening and PrEP persistence monthly over three months following uptake. Our aspirations are that the study provides evidence to support strategies to improve AGYW knowledge of and regular engagement in HIV prevention care. Read more about Motivating PrEP uptake and persistence amongst adolescent girls and young women in Mpumalanga, South Africa here.

By: Preethi Mistri Indlela Nudge Associate |03.03.2022

This disclaimer informs readers that the views, thoughts, and opinions expressed in the text belong solely to the author, and not necessarily to the author’s employer, organization, committee or other group or individual.


  1. Baeten JM, Donnell D, Ndase P, Mugo NR, Campbell JD, Wangisi J, et al. Antiretroviral prophylaxis for HIV prevention in heterosexual men and women. N Engl J Med. 2012;367(5):399–410. 
  2. National Department of Health. South African Guidelines for the Provision of Pre-exposure Prophylaxis (PrEP) to Persons at Substantial Risk of HIV Infection. 2020; Available from:
  3. Bekker L-G, Brown B, Joseph-Davey D, Gill K, Moorhouse M, Delany-Moretlwe S, et al. Southern African guidelines on the safe, easy and effective use of pre-exposure prophylaxis: 2020. South Afr J HIV Med. 2020;21(1):1–8. 
  4. Mathews C, Lombard C, Puren A, Cheyip M, Ayalew K, Jonas KN. Evaluation of a South African combination HIV prevention programme for adolescent girls and young women: HERStory Study. South African Med Res Counc. 2020; 
  5. UNAIDS. Global AIDS Update: Confronting Inequalities – Lessons for pandemic responses from 40 years of AIDS [Internet]. 2021. Available from:
  6. Govender K, Masebo WGB, Nyamaruze P, Cowden RG, Schunter BT, Bains A. HIV prevention in adolescents and young people in the Eastern and Southern African region: A review of key challenges impeding actions for an effective response. Open AIDS J. 2018;12:53. 
  7. Delany-Moretlwe S, Scorgie F, Harvey S. The EMPOWER study: an evaluation of a combination HIV prevention intervention including oral PrEP for adolescent girls and young women in South Africa and Tanzania. London London Sch Hyg Trop Med. 2018; 
  8. Croucamp Y, Malone S, Prasad R, Noble-Campbell P, Mulhausen J, Gomez A, et al. Understanding HIV prevention in high-risk adolescent girls and young women in two South African provinces. South African Heal Rev. 2019;2019(1):167–71. 
  9. Rousseau E, Katz AWK, O’Rourke S, Bekker L-G, Delany-Moretlwe S, Bukusi E, et al. Adolescent girls and young women’s PrEP-user journey during an implementation science study in South Africa and Kenya. PLoS One. 2021;16(10):e0258542. 
  10. White JS, Dow WH. Intertemporal choices for health. Behav Econ public Heal. 2015;27:62. 
  11. Galárraga O, Genberg BL, Martin RA, Laws MB, Wilson IB. Conditional economic incentives to improve HIV treatment adherence: literature review and theoretical considerations. AIDS Behav. 2013;17(7):2283–92. 
  12. Stoner MCD, Kilburn K, Godfrey-Faussett P, Ghys P, Pettifor AE. Cash transfers for HIV prevention: A systematic review. PLoS Med. 2021;18(11):e1003866. 
  13. UNAIDS. HIV Prevention Among Adolescent Girls and Young Women [Internet]. 2016. Available from:
  14. Björkman Nyqvist M, Corno L, De Walque D, Svensson J. Incentivizing safer sexual behavior: evidence from a lottery experiment on HIV prevention. Am Econ J Appl Econ. 2018;10(3):287–314. 
  15. Galárraga O, Harries J, Maughan-Brown B, Cooper D, Short SE, Lurie MN, et al. The Empower Nudge lottery to increase dual protection use: a proof-of-concept randomised pilot trial in South Africa. Reprod Health Matters. 2018;26(52):67–80. 
  16. Thirumurthy H, Masters SH, Rao S, Murray K, Prasad R, Zivin JG, et al. The effects of providing fixed compensation and lottery-based rewards on uptake of medical male circumcision in Kenya: a randomized trial. J Acquir Immune Defic Syndr. 2016;72(Suppl 4):S309. 
  17. Barnabas R V, van Heerden A, McConnell M, Szpiro AA, Krows ML, Schaafsma TT, et al. Lottery incentives have short‐term impact on ART initiation among men: results from a randomized pilot study. J Int AIDS Soc. 2020;23:e25519. 
  18. Celum CL, Gill K, Morton JF, Stein G, Myers L, Thomas KK, et al. Incentives conditioned on tenofovir levels to support PrEP adherence among young South African women: a randomized trial. J Int AIDS Soc. 2020;23(11):e25636. 
  19. London AJ, Borasky Jr DA, Bhan A, Network EWG of the HIVPT. Improving ethical review of research involving incentives for health promotion. PLoS Med. 2012;9(3):e1001193. 
  20. Velloza J, Kapogiannis B, Bekker L-G, Celum C, Hosek S, Delany-Moretlwe S, et al. Interventions to improve daily medication use among adolescents and young adults: what can we learn for youth pre-exposure prophylaxis services? AIDS. 2021;35(3):463. 
  21. 21. Wong CA, Hakimi S, Santanam TS, Madanay F, Fridman I, Ford C, et al. Applying behavioral economics to improve adolescent and young adult health: a developmentally-sensitive approach. J Adolesc Heal. 2021;69(1):17–25.
  22. Moscibrodzki P, Dobelle M, Stone J, Kalumuna , Chiu YM and Hennig N. 2018.Free versus purchased mosquito net ownership and use in Budondo sub-county, Uganda. Malaria Journal, 17, 363
  23. Comfort A.B and Krezanoski P.J. 2017. The effect of price on demand for and use of bednets: evidence from a randomized experiment in Madagascar. Health Policy and Planning, 32: 178–193
  24. The Decision Lab, Why do we take mental shortcuts? Accessed online at
  25. Kahneman D, Knetsch J.L and Thaler R.H. 1991. Anomalies: The Endowment Effect, Loss Aversion, and Status Quo Bias. The Journal of Economic Perspectives, 5(1): 193-206

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