A cluster randomised trial to evaluate the effect of optimising TB/HIV integration on patient level outcomes: the "merge" trial protocol.

INTRODUCTION: We describe the design of the MERGE trial, a cluster randomised trial, to evaluate the effect of an intervention to optimise TB/HIV service integration on mortality, morbidity and retention in care among newly-diagnosed HIV-positive patients and newly-diagnosed TB patients. DESIGN: Eighteen primary care clinics were randomised to either intervention or standard of care arms. The intervention comprised activities designed to optimise TB and HIV service integration and supported by two new staff cadres-a TB/HIV integration officer and a TB screening officer-for 24 months. A process evaluation to understand how the intervention was perceived and implemented at the clinics was conducted as part of the trial. Newly-diagnosed HIV-positive patients and newly-diagnosed TB patients were enrolled into the study and followed up through telephonic interviews and case note abstractions at six monthly intervals for up to 18 months in order to measure outcomes. The primary outcomes were incidence of hospitalisations or death among newly diagnosed TB patients, incidence of hospitalisation or death among newly diagnosed HIV-positive patients and retention in care among HIV-positive TB patients. Secondary outcomes of the study included measures of cost-effectiveness. DISCUSSION: Methodological challenges of the trial such as implementation of a complex multi-faceted health systems intervention, the measurement of integration at baseline and at the end of the study and an evolving standard of care with respect to TB and HIV are discussed. The trial will contribute to understanding whether TB/HIV service integration affects patient outcomes