Individual longitudinal compliance to neglected tropical disease mass drug administration programmes, a systematic review

Repeated rounds of mass drug administration are the mainstay of transmission control for five of the 20 recognised neglected tropical diseases (NTDs); soil-transmitted helminths, schistosomiasis, lymphatic filariasis, onchocerciasis and trachoma. MDA programme efficiency is reliant upon participants swallowing treatment consistently at each treatment round, measured by the parameter compliance; the proportion of eligible participants swallowing treatment. Individually linked longitudinal compliance data is crucial for assessing MDA programmes, as such data will elucidate treatment behaviour patterns. Accurate monitoring of compliance across species will require the unanimous acceptance of epidemiological parameters across the research community. This review aims to update the review previously completed by Shuford et al (2016), which predominantly highlighted the interchange of parameters coverage (receiving treatment) and compliance (swallowing treatment). This review aims to find to collect the latest longitudinal compliance data reported by control programmes globally for the five MDA controllable species, searching PubMed and Web of Science in January 2022 for articles written since 2016 in English and Spanish. The review adhered to PRISMA guidelines and is registered with PROSPERO (registration number: CRD42022301991). Study title screening was aided by Rayyan, a machine learning software. Studies were considered for inclusion if primary compliance data for more than one time point, in a population larger than 100 participants were identified. All data analysis was conducted in R. A total of 89 studies were identified containing compliance data, 57 were longitudinal studies, 25 of which reported individually linked data which were analysed further. The association of increasing age with systematic treatment during was commonly reported. The review is limited by paucity of data. It is recommended for WHO to clearly define coverage, compliance, and longitudinal compliance in their treatment guides. Current definitions for species-specific guides contradict each other which may influence the incongruency seen definitions seen in this review.Author summaryNeglected tropical diseases (NTDs) affect 1.74 billion people globally, often those in low socio-economic communities in tropical and sub-tropical climates. Five NTDs can be effectively treated using repeated administration of drugs across endemic communities, described as mass-drug administration (MDA). Repeated treatment is necessary due to re-infection of treated people by untreated people in these endemic communities. As such, increasing the number of people treated at each round is clearly critical to increase the number of parasite-free individuals, which will then latterly reduce the amount of re-infection to the community and therefore increase the chance of reaching elimination of transmission. Currently, the measurement of MDA success is focused upon coverage, the acceptance of treatment. However, not everyone who accepts treatment swallows the treatment, which arguably is more important to measure as it records the reality of the MDA success. This review aims to capture all the papers providing compliance data for soil-transmitted helminths, schistosomiasis, lymphatic filariasis, onchocerciasis and trachoma.