Assessing sexual risk compensation following medical male circumcision in Zambia through a matched pseudo cohort analysis of nationally representative survey data

Medical male circumcision (MMC) is an established HIV prevention intervention, yet concerns persist that circumcised men may adopt higher-risk sexual behaviours following the procedure. Evidence from observational studies has been inconsistent, partly because many analyses do not adequately distinguish behaviours that occur before circumcision from those that occur afterwards. This study assessed the association between MMC and subsequent sexual behaviours while demonstrating how population-based cross-sectional survey data can be adapted to address this temporal challenge. We analysed nationally representative data from the Zambia Demographic and Health Survey (ZDHS) of 2024, including men aged 15–59 years who reported their circumcision status. Men who had undergone medical circumcision were compared with uncircumcised men using a matched pseudo-cohort framework that reconstructed temporal ordering based on age at circumcision. Propensity score overlap weighting was applied to improve comparability between circumcised and uncircumcised men, and odds ratios were estimated using logistic regression models incorporating overlap weights and accounting for the complex survey design. Sexual behaviour outcomes occurring after circumcision included condom non-use at last sexual intercourse, multiple sexual partners in the past 12 months, self-reported sexually transmitted infection (STI) symptoms and composite measures of sexual risk behaviour. The analysis included 9,609 men, of whom 33.3% were medically circumcised. MMC was associated with lower odds of condom non-use at last sexual intercourse (adjusted odds ratio [aOR] = 0.75, 95% confidence interval [CI]: 0.67–0.85, p < 0.001) and lower odds of reporting at least one component sexual risk indicator (aOR = 0.83, 95% CI 0.72–0.95, p = 0.008). MMC was not associated with having two or more sexual partners in the preceding 12 months, self-reported STI symptoms, or at least two component sexual risk indicators (all p > 0.050). In this population-based study, MMC was not associated with greater sexual risk under routine programme conditions within the overlap population defined by the weighting scheme. The findings show no evidence of behavioural risk compensation and illustrate the value of explicitly addressing temporality when analysing behavioural outcomes using cross-sectional survey data.