Communities of Practice for lay health worker-delivered contact investigation for TB: Mechanisms and context - Project Summary/Abstract Tuberculosis (TB) remains among the top 10 causes of death worldwide, disproportionately impacting low- income countries. Contact investigation for TB is recommended by the WHO to find and prevent additional cases. Contact investigation is often carried out by lay health workers who receive on-the-job training; however, lack of relevant in-service training is a major barrier to their delivery of high-quality health services. One approach to facilitating lay health worker training is to implement Communities of Practice (CoPs). CoPs are groups of professionals who meet regularly to support each other and share knowledge to advance their practice toward a common goal. CoPs have been used in the health field to improve the delivery of high-quality care by physicians and nurses in middle- and high-income countries. However, additional studies are needed that identify how CoPs can be used to facilitate the performance of lay health workers in low-income countries. My training proposal addresses the gaps in understanding how CoPs function in low-income countries through two scientific aims and four training aims that leverage Dr. Luke Davis’ (Sponsor) implementation trial of CoPs (5R01 AI104824-08, 2021-2023). Dr. Davis’ trial aims to address gaps in the implementation of TB contact investigation in Uganda; our research team found that only 20% of high-risk contacts completed TB evaluation in full, far below the WHO target of ≥90%. Separate from the funded trial, I will test my conceptual model of how and in what contexts CoPs can improve delivery of contact investigation. In Aim 1, I will test my hypothesis that lay health worker self-efficacy, or their confidence delivering high-quality health services, mediates the effects of CoPs on contact investigation. I will seek training and mentorship in survey methods and psychometrics to validate a widely used self-efficacy measure for use in Uganda. I will also receive training and guided mentorship in mediation analysis to assess if lay health worker self-efficacy mediates the effects of CoPs on contact investigation. In Aim 2, I will seek training and mentorship in advanced qualitative methods to identify contextual factors that impact the effectiveness of CoPs. By evaluating mechanisms of action and contextual factors pertinent to CoPs, our findings can explain why the parent trial improved, or failed to improve, outcomes. Our findings will also yield insights on how to design and implement lay health worker CoPs to improve delivery of high-quality health services, which can be applied to other low-income settings. My training plan and the collaborative environments at Yale and the Uganda TB Implementation Research Consortium will allow me to develop research, clinical, and professional skills needed for a research career as a physician-epidemiologist who uses implementation science to mitigate health disparities in low-income countries. My training plan outlines coursework, mentored research, and clinical experiences to enhance my skills in implementation trials, advanced biostatistics, qualitative methods, and infectious diseases medicine.