Impact of telephonic psycho-social support on adherence to post-exposure prophylaxis (PEP) after rape

South Africa has one of the highest rates of both rape and HIV infections. Of great concern is the possibility of HIV transmission during the assault, but adherence to post-exposure prophylaxis (PEP) has been varied and low. We developed a telephonic psycho-social support, leaflet and adherence diary intervention for rape victims and tested its impact on adherence to PEP. A randomised control trial was conducted in the Western and Eastern Cape and 279 rape survivors were enrolled in two arms. The intervention involved the providing of an information leaflet including an adherence diary and follow-up support through telephone calls by a counsellor during the 28 days of taking the PEP. The controls received the leaflet. Follow-up interviews and tablet checks were done with 253 participants to assess adherence. The primary outcome was completion of 28 days of PEP with no more than three missed doses (94% adherence). There was more adherence in the intervention arm (38.2% vs. 31.9%), but the estimated intervention effect of 6.5% (95% CI: -4.6 to 17.6%) was not statistically significant, p=0.13. The intervention was associated with the reading of the pamphlet (p=0.07) and an increased use of the diary (p=0.01), but did not reduce depressive psychopathology. Overall adherence was greater amongst those who read the leaflet and used the medication diary. The study showed that the intervention was not effective in significantly improving adherence and adherence levels were low in both study arms. Further research to understand reasons for non-adherence is needed before further interventions are developed.