Implementation Fidelity of Diabetes Mellitus Screening Among Tuberculosis Patients in Primary Healthcare in Karanganyar District, Indonesia: A Mixed-Method Study

Background Indonesia faces a dual burden of high tuberculosis (TB) burden and rising diabetes mellitus (DM) prevalence. Given that DM is a significant risk factor for TB, screening people with TB for DM comorbidity is important for early management to mitigate adverse outcomes. Objectives This study aimed to measure the degree of implementation fidelity, moderating factors, and barriers to implementing DM screening among TB patients in Indonesia's Primary Healthcare setting. Methods A sequential explanatory mixed method was used. A cross-sectional survey was conducted with 42 Directly Observed Treatment, Short-course providers to assess adherence to DM screening guidelines. Screening coverage was evaluated through the TB information system. In-depth interviews with providers, managers, and patients identified key barriers and enablers. Results Screening coverage ranges from 36.3% to 97.6% between 2020 and 2024. High fidelity was reported among providers, with 95% screening for DM at the time of TB diagnosis. Facilitators included TB-DM policy availability, screening affordability, provision of equipment, and patients' responsiveness. However, delays in data reporting and insufficient cross-sector collaboration posed challenges to the implementation. Conclusion Despite positive progress in integrating TB-DM care, addressing barriers is essential to optimize the programme's impact. Strengthening reporting mechanisms and fostering collaboration could enhance programme outcomes.