Abstract / Summary
Female sex workers (FSWs) remain disproportionately affected by HIV infection, yet HIV testing uptake continues to be constrained by stigma, limited access to healthcare services, and inadequate knowledge of HIV prevention and self-testing approaches.= Mobile phone-based education (MPBE) represents a promising strategy for delivering accessible, confidential, and context-specific HIV prevention information to underserved populations. This study evaluated the effect of a mobile phone-based educational intervention on HIV knowledge, HIV self-testing (HIVST) knowledge, and HIVST uptake among FSWs in Yenagoa, Bayelsa State, Nigeria. A two-arm quasi-experimental study was conducted among FSWs between November 2022 and March 2023. A total of 282 participants completed the study, comprising 137 participants in the intervention group and 145 in the control group. Baseline and endline assessments evaluated socio-demographic characteristics, HIV knowledge, HIVST knowledge, and HIVST uptake. The intervention group received structured HIV and HIVST education delivered through a WhatsApp-based mobile platform over five weeks, while the control group received routine HIV prevention services. Data were analysed using descriptive statistics, chi-square tests, Fisher’s exact tests, independent t-tests, and difference-in-differences (DID) analysis. Statistical significance was set at P < 0.05. Baseline characteristics were generally comparable between groups, although significant differences were observed in educational attainment, marital status, and engagement in other occupations. Following the intervention, the proportion of participants with good HIV knowledge increased substantially in the intervention group from 57.0% at baseline to 99.3% at endline, compared with minimal change in the control group (61.2% to 64.8%). The DID analysis demonstrated a 38.7 percentage-point greater improvement in HIV knowledge among intervention participants (95% CI: 0.25–0.53, P < 0.001). Similarly, good HIVST knowledge increased from 1.2% to 97.1% in the intervention group, with an additional DID effect of 84.9 percentage points compared with controls (95% CI: 0.79–0.91, P < 0.001). HIVST uptake increased from 2.4% to 74.5% in the intervention group compared with 1.2% to 22.1% in the control group, corresponding to a DID effect of 51.2 percentage points (95% CI: 0.41–0.61, P < 0.001). A structured mobile phone-based educational intervention was associated with substantial improvements in HIV knowledge, HIVST knowledge, and HIVST uptake among FSWs in Bayelsa State, Nigeria. Integrating culturally appropriate digital education with HIVST programmes may strengthen differentiated HIV testing approaches and improve access to prevention services among key populations. Future HIV prevention programmes should consider incorporating scalable mobile-based educational strategies alongside HIVST delivery while addressing digital access barriers. Longer-term evaluations are needed to determine sustainability, cost-effectiveness, and broader applicability across diverse key populations.