Completion of isoniazid preventive therapy among HIV-infected patients in Tanzania.

Setting: Isoniazid preventive therapy (IPT) has not been widely implemented due to questions about acceptance, adherence and side effects.
Objective: To examine factors related to completion of IPT among human immunodeficiency virus (HIV) infected subjects in Tanzania.
Design: HIV-infected subjects in the DarDar TB vaccine trial with CD4 cell counts >or=200 cells/mm(3) and a positive tuberculin skin test (TST) were counseled, offered IPT for 6 months and seen monthly.
Results: Among 1932 subjects, TST results were positive in 631 (33%): 568 (90%) were offered IPT, 565 (99%) accepted and three (<1%) refused. Of the 565 subjects who accepted IPT, 493 (87%) completed treatment and 72 (13%) did not. Non-completion was physician-initiated in 24 (33%, due to active TB or side effects), patient-initiated in 42 (58%, due to self-cessation or loss to follow-up) and due to death in 6 (8%, unrelated to IPT). Interviews were conducted among 109 completers and 20 non-completers (12 physician- and 8 patient-initiated). Completers were motivated by fear of TB (44%), understanding the importance of IPT (32%) and counseling (22%). Patient-initiated non-completers were dissuaded by stigma (58%), side effects (14%) and travel distance (1%).
Conclusions: HIV-infected subjects provided with counseling, monthly follow-up and travel reimbursement have high rates of IPT completion with minimal side effects.