Completion of Tuberculosis Preventive Therapy Among Household Contacts of Pulmonary Tuberculosis Patients in Lucknow, India: A Prospective Observational Study

Background: Tuberculosis preventive therapy (TPT) protects eligible household contacts from developing active tuberculosis, but only if they complete the course.This study assessed completion of a six-month TPT regimen among household contacts in Lucknow, India, and the factors associated with it.Methods: A community-based observational study was conducted from August 2023 to January 2024 among 407 household contacts identified through two randomly selected tuberculosis units of Lucknow district.Contacts of patients with pulmonary tuberculosis who had been started on TPT by the programme, after active tuberculosis was ruled out, were enrolled at home visits and followed up to the end of their course.Data were collected with a pretested, interviewer-administered questionnaire developed by the investigators.Completion of the prescribed TPT course was verified at the end of the course using TPT cards and an interview with a tablet count, and associations were tested using the chi-square test.Results: Of the 407 contacts, 345 (84.8%; 95% CI 81.0-87.9)completed TPT.At the initial assessment, 351 (86.2%) reported taking their medicines regularly.Completion was 94.9% (333/351) among regular users and 21.4% (12/56) among irregular users (p < 0.001).Completion also differed by caste (p = 0.012) and family type (p = 0.024).Among the 62 (15.2%) non-completers, the commonest reasons were non-adherence or other personal reasons, 22 (35.5%);adverse effects or advice to stop treatment, 14 (22.6%); and travel or migration, 8 (12.9%).Conclusion: Most contacts completed the six-month course.Contacts who reported irregular intake at the initial assessment were much less likely to complete treatment.Checking for missed doses early, assessing adverse symptoms, and making arrangements for contacts who migrate may help reduce non-completion.