Usability and acceptability of self-testing for hepatitis C virus exposure in a high-prevalence urban informal settlement in Karachi, Pakistan.

BACKGROUND: Hepatitis C virus (HCV) antibody self-testing (HCVST) may help expand screening access and support HCV elimination efforts. Despite potential benefits, HCVST is not currently implemented in Pakistan. This study aimed to assess the usability and acceptability of HCVST in a high HCV prevalence informal settlement in Karachi, Pakistan. METHODS: We performed a cross-sectional study in a hepatitis C clinic from April through June 2023. Participants were invited to perform a saliva-based HCVST (OraSure Technologies, USA) while following pictorial instructions. A study member evaluated test performance using a standardized checklist and provided verbal support if a step could not be completed. Perceived usability and acceptability were assessed using a semi-structured questionnaire. The HCVST was considered successful if the participant was able to complete all steps and correctly interpret test results. Overall concordance and positive and negative agreement were estimated in comparison with the HCVST result read by the study member (inter-reader concordance and agreement) and result of a second rapid HCV test (Abbott Diagnostics Korea Inc, South Korea) performed by a trained user (inter-operator concordance and agreement). RESULTS: The study included 295 participants of which 97 (32%) were illiterate. In total, 280 (95%, 95% CI 92-97%) HCVSTs were successful. Overall, 38 (13%) people performed the HCVST without verbal assistance, 67 (23%) needed verbal assistance in one step, 190 (64%) in two or more. Assistance was most often needed in managing the test buffer and test reading times. The inter-reader concordance was 96% and inter-operator concordance 93%. Inter-reader and inter-operator positive percent agreement were 84 and 70%, respectively. All participants reported they would use HCVST again and would recommend it to friends and family. CONCLUSION: Saliva-based HCVST was very well accepted in this clinic-based setting. However, many people requested verbal support in several steps, highlighting the need for clear instructions for use and test devices that are simple to use, particularly in low literacy settings. Moderately low positive percent agreement with the results of a rapid test performed by a trained user highlights potential uncertainty in the accuracy of HCVST in the hands of lay users.

Cost-effectiveness of screening and treatment using direct-acting antivirals for chronic Hepatitis C virus in a primary care setting in Karachi, Pakistan.

Despite the availability of effective direct-acting antiviral (DAA) treatments for Hepatitis C virus (HCV) infection, many people remain undiagnosed and untreated. We assessed the cost-effectiveness of a Médecins Sans Frontières (MSF) HCV screening and treatment programme within a primary health clinic in Karachi, Pakistan. A health state transition Markov model was developed to estimate the cost-effectiveness of the MSF programme. Programme cost and outcome data were analysed retrospectively. The incremental cost-effectiveness ratio (ICER) was calculated in terms of incremental cost (2016 US$) per disability-adjusted life year (DALY) averted from the provider's perspective over a lifetime horizon. The robustness of the model was evaluated using deterministic and probabilistic sensitivity analyses (PSA). The ICER for implementing testing and treatment compared to no programme was US$450/DALY averted, with 100% of PSA runs falling below the per capita Gross Domestic Product threshold for cost-effective interventions for Pakistan (US$1,422). The ICER increased to US$532/DALY averted assuming national HCV seroprevalence (5.5% versus 33% observed in the intervention). If the cost of liver disease care was included (adapted from resource use data from Cambodia which has similar GDP to Pakistan), the ICER dropped to US$148/DALY, while it became cost-saving if a recently negotiated reduced drug cost of $75/treatment course was assumed (versus $282 in base-case) in addition to cost of liver disease care. In conclusion, screening and DAA treatment for HCV infection are expected to be highly cost-effective in Pakistan, supporting the expansion of similar screening and treatment programmes across Pakistan.