Individual-level agreement between coverage surveys and treatment registers in mass drug administration: A secondary analysis of the multi-country DeWorm3 cluster randomized trial

@article{oborevwori2026individuallevel,
  title = {{Individual-level agreement between coverage surveys and treatment registers in mass drug administration: A secondary analysis of the multi-country DeWorm3 cluster randomized trial}},
  author = {Elohor Oborevwori and Kristjana Ásbjörnsdóttir and Sean Galagan and Katherine Sharrock and Kumudha Aruldas and Saravanakumar Puthupalayam Kaliapan and Rachael Pullan and Robin Bailey and Khumbo Kalua and James Simwanza and Stefan Witek-McManus and Moudachirou Ibikounlé and Adrian J. F. Luty and Sitara Swarna Rao Ajjampur and Arianna Means and Judd L. Walson},
  journal = {PLOS Neglected Tropical Diseases},
  year = {2026},
  month = sep,
  doi = {10.1371/journal.pntd.0014740},
  url = {https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0014740},
  note = {CC BY 4.0},
}

TY  - JOUR
TI  - Individual-level agreement between coverage surveys and treatment registers in mass drug administration: A secondary analysis of the multi-country DeWorm3 cluster randomized trial
AU  - Elohor Oborevwori
AU  - Kristjana Ásbjörnsdóttir
AU  - Sean Galagan
AU  - Katherine Sharrock
AU  - Kumudha Aruldas
AU  - Saravanakumar Puthupalayam Kaliapan
AU  - Rachael Pullan
AU  - Robin Bailey
AU  - Khumbo Kalua
AU  - James Simwanza
AU  - Stefan Witek-McManus
AU  - Moudachirou Ibikounlé
AU  - Adrian J. F. Luty
AU  - Sitara Swarna Rao Ajjampur
AU  - Arianna Means
AU  - Judd L. Walson
PY  - 2026
DA  - 2026/09/21
JO  - PLOS Neglected Tropical Diseases
DO  - 10.1371/journal.pntd.0014740
UR  - https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0014740
AB  - Background: Accurate measurement of treatment coverage is critical for the monitoring and evaluation of mass drug administration (MDA) programs, yet post-treatment coverage surveys are subject to multiple sources of bias and may not accurately reflect true individual-level treatment coverage. Using data from the DeWorm3 study, a multi-country randomized trial assessing the feasibility of interrupting soil-transmitted helminth (STH) transmission, we compared coverage estimates from treatment registers with post-treatment coverage surveys and identified factors associated with discordant treatment reporting. Methods: The DeWorm3 trial analyzed individual-level treatment data across six rounds of biannual MDA with albendazole for STH in Benin, India, and Malawi (2018–2020). Coverage surveys and treatment registers were linked using unique identifiers. This analytic sample included 12,162 individuals with matched survey and register records and non-missing treatment status from the final round of the intervention-arm. Concordance was summarized using percent discrepancy and Cohen’s kappa, and site-specific logistic regression models assessed factors associated with discrepancy. Results: While aggregate coverage was high (>95%) across all sites, individual-level discordance at round six occurred in 6.12% of individuals in Benin, 2.00% in India, and 4.39% in Malawi, driven predominantly by higher reporting in coverage surveys relative to register records. Kappa values were interpreted descriptively as treatment coverage was very high. Periurban/urban residence was associated with higher odds of discrepancy in Benin (OR: 3.65, 95% CI: 2.56–5.28) and Malawi (OR: 1.54, 95% CI: 1.11–2.12). In Malawi, male sex was also associated with higher discrepancy, while MDA awareness was associated with lower discrepancy. No covariates were significantly associated with discrepancy in India. Conclusions: Individual-level discordance between coverage surveys and treatment registers was present across all sites and rounds, with surveys consistently estimating higher levels of treatment. Predictors varied by site, suggesting measurement error is driven by site-level programmatic and contextual factors rather than individual demographic characteristics. Programs should implement systematic validation approaches as high aggregate coverage estimates may mask meaningful individual-level measurement error. Author summary: When large-scale medicine distribution programs treat entire communities for infectious diseases, knowing how many people actually received treatment is critical. Programs typically measure this by asking people whether they took their medication in a household survey conducted shortly after treatment. In this study, using data from the DeWorm3 trial, a large randomized trial conducted in Benin, India, and Malawi, we directly compared what people reported in surveys with what was recorded at the time of treatment for the same individuals. We found that while overall treatment rates appeared high in both data sources, a meaningful proportion of individuals gave responses in surveys that did not match their treatment records, with surveys generally reporting higher treatment than the records suggested. Importantly, the factors that predicted these mismatches differed substantially across the three countries, suggesting that measurement inaccuracies are shaped by local context rather than any universal characteristic of the individuals surveyed. These findings highlight that high overall treatment rates can mask important inaccuracies at the individual level, and that programs sole reliance on surveys to assess whether treatment goals are being met may be problematic, particularly when used to make critical programmatic decisions.
SN  - 1935-2735
ER  -