Implementation science to improve the quality of tuberculosis diagnostic services in Uganda

Nucleic acid amplification tests such as Xpert MTB/RIF (Xpert) have the potential to revolutionize tuberculosis (TB) diagnostics and improve case finding in resource-poor settings. However, since its introduction over a decade ago in Uganda, there remain significant gaps along the cascade of care for patients undergoing TB diagnostic evaluation at peripheral health centers. We utilized a systematic, implementation science-based approach to identify key reasons at multiple levels for attrition along the TB diagnostic evaluation cascade of care. Provider- and health system-level barriers fit into four key thematic areas: human resources, material resources, service implementation, and service coordination. Patient-level barriers included the considerable costs and time required to complete health center visits. We developed a theory-informed strategy using the PRECEDE framework to target key barriers by streamlining TB diagnostic evaluation and facilitating continuous quality improvement. The resulting SIMPLE TB strategy involve four key components: 1) Single-sample LED fluorescence microscopy; 2) Daily sputum transport to Xpert testing sites; 3) Text message communication of Xpert results to health centers and patients; and 4) Performance feedback to health centers using a quality improvement framework. This combination of interventions was feasible to implement and significantly improved the provision of high-quality care for patients undergoing TB diagnostic evaluation. We conclude that achieving high coverage of Xpert testing services is not enough. Xpert scale-up should be accompanied by health system co-interventions to facilitate effective implementation and ensure that high quality care is delivered to patients.