The methodological quality of cluster randomised controlled trials for managing tropical parasitic disease: a review of trials published from 1998 to 2007

The aim of this review was to assess the methodological quality of cluster randomised controlled trials (CRCT) for the management of tropical parasitic disease published between 1998 and 2007. A literature survey was conducted using Medline for CRCTs of interventions aimed at managing any one of the six major tropical parasitic diseases: malaria, leishmaniasis, lymphatic filariasis, onchocerciasis, schistosomiasis and trypanosomiasis (Chagas disease). Information was extracted from the published articles in order that, for each trial, categorical responses could be made to a pre-specified list of 12 questions concerning issues relating to the methodological quality of the trial, including choice of design, generalisability, baseline assessment, blinding, use or non-use of a matched design, and accounting for the intraclass correlation in both design and analysis. The literature survey found 38 CRCTs. Of the 35 CRCTs that reported at least one human outcome, 27 were for interventions in the management of malaria whilst the rest were for managing leishmaniasis (4 trials), lymphatic filariasis (2 trials) and schistosomiasis (2 trials). For every one of the pre-specified questions that concerned an issue associated with methodological quality, the responses were consistent with the practice of trialists in relation to the given issue being generally poor.