Participants, Study Size and Descriptive Data
During the study period of March to September 2004, 514 patients were seen at the rape center. Of these patients, 135 (26%) eligible participants were enrolled; 131 of those (97%) initiated PEP. Of the 514, 103 (20%) were seen after hours and did not provide consent to be contacted and 59 (14%) declined study participation. Eight (2%) did not have an eligible exposure, 60 (17%) were not contacted within 5 days of the initial exam, 28 (8%) were less than 14 years old, 15 (4%) between 14 and 18 years old did not obtain guardian consent, 13 (4%) were unable to follow up and 14 (4%) were unable to consent. Data were unavailable for the remaining 79 non-study patients. Characteristics of the 135 study participants are shown in Table .
Assaults often involved abduction and violence (Table ). Forty-six percent of perpetrators were known, commonly being neighbors, friends or ex-boyfriends. The perpetrator’s HIV status was usually unknown (97%). Anal or oral penetration was reported infrequently.
Characteristics of the assault and potential HIV exposure
PEP Initiation and Adherence
The median time to PEP initiation was 13 h [IQR 8, 22]. PEP was initiated within less than 24 h in 103 (79%) participants. The median days of PEP completed was 27 [IQR 27, 28]. However, 34% of participants had either stopped taking PEP, missed one or more doses on days 3–7, or were lost to follow-up prior to the week one study visit (Table ). Nineteen (15%) participants reported missing two or more doses in the prior week. Reasons commonly cited for missed doses included forgetting and being away from home. All participants reported good understanding of dosing instructions. In univariate analyses, there was a non-significant trend towards better adherence among those with more education and those who reported attending rape counseling (P = 0.090 and 0.129, respectively). These trends were stronger in the multivariate model (P = 0.057 and 0.069). No other variables were associated with adherence.
Symptoms and Laboratory Abnormalities
Symptoms were reported by 70% of participants, most commonly fatigue, nausea and headaches. The median time to study enrollment and initial symptom data collection was 3 days [IQR 2, 3] following PEP initiation. At the baseline study visit, significantly more participants who had not yet initiated PEP, or had initiated PEP within the previous 24 h, reported symptoms compared to participants who had initiated PEP more than 24 h prior (52% versus 17%; P = 0.003, Table ). In multivariate logistic regression models controlling for baseline symptoms, PEP was not associated with on-treatment symptoms (OR = 1.30, 95% CI = 0.66, 2.64). Symptoms at baseline were associated with subsequent symptoms in models including all participants who took PEP (OR = 2.68, 95% CI = 1.25, 5.74) and when restricting the analysis to just those 23 participants who had not yet initiated PEP or had initiated PEP within 24 h of the baseline visit (OR = 8.03, 95% CI = 1.8, 35.5). There were no laboratory abnormalities more severe than Grade 2 in any participants taking PEP. Four participants were pregnant at enrollment. A total of six incident pregnancies were detected by the 6 month visit.
Proportion of participants reporting ≥grade 2 symptoms stratified by PEP initiation within 24 h of interview
HIV Risk Behaviors
In the 6 months prior to the assault, 71 (58%) participants reported vaginal intercourse, which was unprotected in fifty participants. Among these, 32 (64%) did not know the HIV status of their partners. At week four, 44 participants (38%) reported having any intercourse since the prior visit, 61% of whom reported unprotected vaginal intercourse. Half of these cases did not know the HIV status of their partners. At months three and six, increasing proportions of participants reported intercourse. This was mostly unprotected and with partners of unknown HIV status (Table ). In the multivariate model, factors associated with unprotected sex in the 6 months following the assault included unprotected sex in the 6 months prior to the assault (OR = 6.46, 95% CI = 3.04, 13.74), time since the assault (per 30-day increments, OR = 1.33, 95% CI = 1.12, 1.57) and age (per 5-year increments OR = 1.30, 95% CI = 1.08, 1.57, Table ). Attending trauma counseling was protective (OR = 0.18, 95% CI = 0.05, 0.58).
Predictors of unprotected sexual intercourse in the 6 months following the assault
Baseline and Follow-up HIV Testing and Seroconversion
Two participants declined HIV testing at baseline but accepted it at their next visits. Testing was declined by three and 16 participants at months three and six, respectively. Those who declined cited not wanting to know their HIV status, an inability to cope with a positive result, or too short a time since the last test. In total, 81% of participants had an HIV test at months three or six. Four seroconversions were observed by 6 months (risk = 3.7%; 95% CI = 1.0, 9.1). Two occurred in participants who did not report other unprotected sex and thus were likely PEP failures. One of these occurred in the context of excellent reported adherence and the other with incomplete adherence to PEP. The other instances were likely to have resulted from ongoing exposures.
Service Delivery Issues
Sixty-one percent of follow-up visits occurred at the rape treatment center, twenty percent at home, and 19% at the research office in town. Missed visit tracing was required for 52 participants; 161 tracing attempts resulted in 45 participants returning for follow-up. Those participants missing visits cited being too busy, work-related issues, forgetting, family problems, having moved, transportation/money problems and school-related issues.
At least one rape counseling session was attended by 75 (56%) participants. At the baseline visit, staff referred 128 (95%) individuals for rape counseling; 61 (50%) of those who completed the week one visit attended counseling. At week one, week four and month three, 104 (90%), 79 (81%), 46 (98%) participants attending each visit had been referred, respectively; 67 (64%), 52 (64%), and 28 (61%) subsequently attended rape counseling.