Gaps in TB preventive therapy for persons initiating antiretroviral therapy in Uganda: an explanatory sequential cascade analysis.

The WHO recommends TB symptom screening and TB preventive therapy (TPT) for latent TB infection (LTBI) in persons living with HIV (PLWH). However, TPT uptake remains limited. We aimed to characterize and contextualize gaps in the TPT care cascade among persons enrolling for antiretroviral therapy (ART). Four PEPFAR-supported facilities in Uganda. We studied a proportionate stratified random sample of persons registering for ART when TPT was available. Patient-level data on eligibility, initiation, and completion were obtained from registers to determine proportion of eligible patients completing each cascade step. We interviewed providers and administrators and used content analysis to identify barriers to guideline-concordant TPT practices. Of 399 study persons, 309 (77%) were women. Median age was 29 (IQR 25-34), CD4 count 405 cells/µL (IQR 222-573), and body mass 23 kg/m² (IQR 21-25). Of 390 (98%) screened, 372 (93%) were TPT-eligible. Only 62 (17%) eligible PLWH initiated and 36 (58%) of 62 completed TPT. Providers reported hesitating to prescribe TPT because they lacked confidence excluding TB by symptom screening alone and feared promoting drug resistance. Although isoniazid was available, past experience of irregular supply discouraged TPT initiation. Providers pointed to insufficient TB-dedicated staff, speculated that patients discounted TB risk, and worried TPT pill burden and side effects depressed ART adherence. While screening was nearly universal, most eligible PLWH did not initiate TPT. Only about half of those who initiated completed treatment. Providers feared promoting drug resistance, harbored uncertainty about continued availability, and worried TPT could antagonize ART adherence. Our findings suggest urgent need for stakeholder engagement in TPT provision.