Acceptance and safety of directly observed versus self-administered isoniazid preventive therapy in aboriginal peoples in British Columbia

OBJECTIVE: To document experience with directly observed chemoprophylaxis ( DOPT) compared to self-administered isoniazid (INH) among aboriginal person s in British Columbia. DESIGN: DOPT was compared to self-administered delivery (SAD) over a 3-year period. All aboriginal persons who received INH chemoprophylaxis in Britis h Columbia between 1992 and 1994 were evaluated. Therapy completion rates a nd adverse outcomes associated with SAD were compared with DOPT. Treatment allocation was by patient choice. RESULTS: Of 608 people who received INH prophylaxis, 443 received SAD (mean age 31.6 years) and 165 received DOPT (mean age 23.9 years). Two hundred a nd seventy (60.9%) SAD compared to 124 (75.2%) in the DOPT group completed 6 months of INH (P = 0.0011). The 12-month completion rates were 162/443 (3 6.6%) for the SAD group and 84/165 (50.9%) for the DOPT group (P = 0.0014). Adverse reactions requiring discontinuation of medication occurred in 13.5 % of the patients on SAD and 9.7% of those receiving DOPT (P = 0.202). The most common reason cited for failure to complete therapy was non-cooperatio n in both groups. There were three deaths in the SAD group, one of which wa s due to suicide by self-ingestion of INH. CONCLUSIONS: These data demonstrate that in aboriginal people compliance wi th preventive therapy can be improved by DOPT. Non random allocation to tre atment groups might have influenced our findings, and further prospective r andomized trials and cost-effectiveness analyses are required.