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 persons 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 British Columbia between 1992 and 1994 were evaluated. Therapy completion rates and 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 and 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 (36.6%) 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-cooperation in both groups. There were three deaths in the SAD group, one of which was due to suicide by self-ingestion of INH.

CONCLUSIONS

These data demonstrate that in aboriginal people compliance with preventive therapy can be improved by DOPT. Non random allocation to treatment groups might have influenced our findings, and further prospective randomized trials and cost-effectiveness analyses are required.