Equity, cost and disability adjusted life years (DALYs) of tuberculosis treatment supported by digital adherence technologies and differentiated care in Ethiopia: a trial-based distributional cost-effectiveness analysis.

Abstract

Background Evidence of the cost-effectiveness of digital adherence technologies (DATs) for supporting tuberculosis treatment has been inconclusive and primarily omitted patient incurred costs. We aimed to assess the societal costs, equity impact and cost-effectiveness of DATs and differentiated care compared to routine care in Ethiopia. Methods We conducted a distributional cost effectiveness analysis using data from the cluster randomised trial that evaluated the implementation of labels and pillbox followed by differentiated care to support tuberculosis treatment adherence in 78 health facilities in Ethiopia. We estimated the costs, cost per disability-adjusted life year (DALYs) averted and equity impact of the implementation of the DATs interventions. Costs and DALYs were estimated at a participant level based on patient events collected during the trial and the trial endpoints for intention to treat population. Uncertainty in cost-effectiveness estimates were assessed by plotting cost-effectiveness acceptability frontiers. The trial is registered at PACTR202008776694999 and has been completed. Findings The mean total societal treatment cost per trial participant was US$491 (95%CI: -127;1109) in the SOC, US$192 (95%CI: -121;479) in the labels and US$193 (95%CI: -178;564) in the pillbox study arms. We estimated that there was a 49-56% probability that the implementation of the DAT interventions, would improve the cost-effectiveness of tuberculosis treatment at a cost-effectiveness threshold of US$100. There was no difference in DALYs between socio-economic position groups (p=0.920), however, patient costs were less concentrated among those relatively poor in the intervention arms; labels (illness concentration index [ICI]=0.03 (95%CI: 0.01; 0.05)) and pillbox (ICI=0.01 (95%CI:-0.01; 0.02)); compared to the SOC (ICI=-0.05 (95%CI: -0.07; -0.02). Between group comparison (p<0.001). Interpretation DAT interventions were cost-saving and reduced the inequitable distribution of patient costs compared to the SOC. This highlights the potential value of interventions that reduce health service visits in improving the equitable distribution of health services.