Background: Isoniazid is the standard medication used to treat latent tuberculosis infection (LTBI). The lengthy treatment with isoniazid, its perceived hepatotoxicity, and the increasing influx of foreign-born persons from countries with a higher prevalence of isoniazid resistance have compromised this regimen. In 2000, the Centers for Disease Control and Prevention guidelines recommended 4 months of rifampin (4R) as an acceptable alternative regimen to 9 months of isoniazid (9H). In a county chest clinic in northern New Jersey, a self-administered 9H regimen for patients with LTBI was generally prescribed until the year 2002. After recognizing poor completion rates, LTBI treatment was shifted predominantly to the alternative 4R regimen.
Methods: Medical records of patients placed on LTBI treatment during 2000 (predominantly a 9H regimen) and 2003 (predominantly a 4R regimen) were reviewed. A total of 474 patients were included in the study. chi(2), Fishers exact, two-sample t, and Wilcoxon rank-sum tests and logistic regression were used to analyze the data. The main outcome variable was treatment completion.
Results: A total of 80.5% of patients receiving 4R and 53.1% receiving 9H completed treatment (p < 0.0001); 34.7% of patients receiving 9H were unavailable for follow-up, compared to 12.6% receiving 4R (p = <0.0001). Fewer drug reactions were observed in the group receiving 4R compared to the group receiving 9H (3.1% vs 5.8%), although this was not statistically significant. Logistic regression analysis identified treatment regimen as a significant predictor for treatment completion (odds ratio [OR], 5.1; 95% confidence interval [CI], 3.3 to 8.1). Employment was negatively associated with treatment completion in the same model (OR, 0.54; 95% CI, 0.34 to 0.94).
Conclusions: Patients receiving 4R were significantly more likely to complete therapy than those receiving 9H.