NONADHERENCE IN TUBERCULOSIS TREATMENT - PREDICTORS AND CONSEQUENCES IN NEW-YORK-CITY

BACKGROUND: Poor adherence to antituberculosis treatment is the most i mportant obstacle to tuberculosis control. PURPOSE: TO identify and an alyze predictors and consequences of nonadherence to antituberculosis treatment. PATIENTS AND METHODS: Retrospective study of a citywide coh ort of 184 patients with tuberculosis in New York City, newly diagnose d by culture in April 1991--before the strengthening of its control pr ogram--and followed up through 1994. Follow-up information was collect ed through the New York City tuberculosis registry. Nonadherence was d efined as treatment default for at least 2 months. RESULTS: Eighty-eig ht of the 184 (48%) patients were nonadherent. Greater nonadherence wa s noted among blacks (unadjusted relative risk [RR] 3.0, 95% confidenc e interval [CI] 1.1 to 8.6, compared with whites), injection drug user s RR 1.5, 95% CI 1.1 to 2.0), homeless (RR 1.4, 95% CI 1.0 to 1.8), al coholics (RR 1.4, 95% CI 1.0 to 1.9), and HIV-infected patients (RR 1. 4, 95% CI 1.1 to 1.9); also, census-derived estimates of household inc ome were lower among nonadherent patients (P = 0.018). In multivariate analysis, only injection drug use and homelessness predicted nonadher ence, yet 46 (39%) of 117 patients who were neither homeless nor drug users were nonadherent. Nonadherent patients took longer to convert to negative culture (254 versus 64 days, P <0.001), were more likely to acquire drug resistance (RR 5.6, 95% CI 0.7 to 44.2), required longer treatment regimens (560 versus 324 days, P <0.0001), and were less lik ely to complete treatment (RR 0.5, 95% CI 0.4 to 0.7). There was no as sociation between treatment adherence and all-cause mortality. CONCLUS IONS: In the absence of public health intervention, half the patients defaulted treatment for 2 months or longer. Although common among the homeless and injection drug users, the problem occurred frequently and unpredictably in other patients. Nonadherence may contribute to the s pread of tuberculosis and the emergence of drug resistance, and may in crease the cost of treatment. These data lend support to directly obse rved therapy in tuberculosis. (C) 1997 by Excerpta Medica, Inc.