Incentives and accessibility: A pilot study to promote adherence to tb prophylaxis in a high-risk community

Setting. A community-based directly observed preventive therapy (DOPT) program for treatment of latent tuberculosis infection among injection drug users (IDUs) in an inner-city neighborhood. Objective. To test adherence to a 6-month course of DOPT using cash incentives and an easily accessible neighborhood location. Design. Street-recruited IDUs (N = 205) were screened for Mycobacterium tuberculosis (TB) infection using the Mantoux test and two controls. Subjects who had a purified protein derivative (PPD) reaction of ≥5 mm, were anergic, or had a history of a positive PPD received clinical evaluation at a community field site, provided in collaboration with the San Francisco Department of Public Health Tuberculosis Clinic. Twenty-eight subjects were considered appropriate candidates for prophylaxis with isoniazid, and 27 enrolled in the pilot study. Participants received twice- weekly DOPT at a community satellite office, with a $10 cash incentive at each visit. Results. The 6-month (26-week) regimen was completed by 24/27 (89%) participants. The median time to treatment completion was 27 weeks (range 26 to 34 weeks). The median proportion of dosing days attended in 6 months was 96%. Conclusion. Community-based DOPT using cash incentives resulted in high levels of adherence and treatment completion among drug users.