Increasing Smear Positive Tuberculosis Case Detection Using a Clinical Score at Points of Primary Health Care – A Stepped Wedge Multicenter Trial from Africa

Abstract

Background: The Bandim TBscore is a clinical score that, based on signs and symptoms, predicts treatment outcome in Tuberculosis (TB) patients. A previous study revealed it useful as indicator of which health-seeking adults to refer for sputum smear microcopy. As clinical scores are rarely tested in randomized trials, we aimed to investigate whether the TBscore could be used to enhance the detection of smear positive TB. Methods: We carried out a stepped wedge cluster-randomized trial at three health centers (HCs) in Bissau, Guinea-Bissau, and Gondar, Ethiopia, to test the effect of the TBscore. The primary outcome was diagnostic yield for smear positive (SP) TB. Secondary outcomes were successful treatment and effect on overall 12 months mortality. Findings: From January 2017 until March 2018, we included 3571 adults. Overall, there was no effect of the intervention on SP TB detected (OR 1.39 (95%CI 0.75 – 2.56). In Bissau, only 69% of the sputum smears requested were done compared to 95% in Gondar. Analysis stratified by country, showed that the TBscore increased SP case detection in Gondar (OR 4.05 (95%CI 1.67 – 9.85)). There was no effect in Bissau (OR 0.47 (95%CI 0.22 – 1.05)). While the intervention had no effect on treatment success in either setting, mortality decreased during the intervention (HR 0.31 (95%CI 0.13-0.72)). Interpretation: Using the Bandim TBscore for triage before smear microscopy may improve case detection and decrease mortality. The effect relates to the health care centers laboratory capacity. Trial Registration: The study was registered at the Pan African Clinical Trials Registry (PACTR201611001838365). Funding Statement: The study was funded by grants from the Novo Nordisk Foundation, Scandinavian Society for Antimicrobial Chemotherapy Foundation, Gondar University and the Swedish research council. Declaration of Interests: The authors declare that they have no competing interests. Ethics Approval Statement: Approval was obtained from the Guinean Ministry of Health and the Ethics review board of the University of Gondar. Consultative approval was obtained from the Central Ethical Committee in Denmark. All patients provided written informed consent and were offered HIV-testing with preand post-test counseling. HIV-infected individuals were accompanied to nearby Anti-Retroviral Treatment centers.