A Randomized, Controlled Trial of Interventions to Improve Adherence to Isoniazid Therapy to Prevent Tuberculosis in Injection Drug Users [Chaisson RE et al. Am J Med 2001; 110: 610]: The authors examined the relative merits of three methods to give INH to 300 participants in a trial with three strategies: 1) Supervised group which received DOT with 900 mg given twice weekly with observed swallowing; 2) Peer group that were given a monthly supply of 300 mg tabs for self-administration combined with counseling from a trained peer counselor plus support group meetings with a free lunch; and 3) Routine group that received a monthly supply of INH with instructions to take 300 mg/day. In addition, each of the three groups was further randomized to sub-groups that received $10 stipends each month for adherence. Groups 2 and 3 also had sub-groups that were monitored with MEMS containers. The results showed that about 80% in each group completed therapy, but there were substantial differences in the results according to MEMS monitoring. The 100% compliance in the Supervised Group was significantly better than the 57% of doses taken in the Peer Group, and the 49% in the Routine Group. The financial incentive had no impact on outcome. The authors concluded that adherence to INH preventive therapy in injection drug users was superior with supervised care and that a financial incentive had no impact on this outcome.
Comment: The results in this study are quite different than those reported by Tulsky et al. who examined the same issue of INH preventive therapy in homeless patients in San Francisco (Arch Intern Med 2000; 160: 697). This study showed lower over-all adherence rates and a substantial benefit only in the group that had financial incentive. It is not clear if these differences reflect fundamental differences between Baltimore and San Francisco, between homeless patients and injection drug users, or are related to the amount of the monetary award. Perhaps more important is the message from this study as applied to HIV care. The accompanying editorial by Bangsberg DR et al. (Am J 2001; 110: 664) acknowledges the relevance of this study of tuberculosis as applied to HIV: both represent public health problems in which resistance is a substantial risk due largely to non-adherence, and both require prolonged use of complicated regimens. Nevertheless, HIV seems to be distinctly different from TB due to the need for at least daily administration over a period of years and possibly a lifetime, which creates a very different logistical and financial challenges. The authors of the editorial conclude that there is a need to compare effectiveness of DOT and psychoeducational interventions before these decisions are made. However, they do acknowledge that patients who have a low motivational state combined with late stage HIV "are ideal candidates for DOT, which should be recommended regardless of socioeconomic status." Patients attending methadone clinics are another potentially attractive target group that is not mentioned.
posted 6/14/2001

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