Factors associated with failure to complete isoniazid treatment for latent tuberculosis infection in Rhode Island.
BACKGROUND
The treatment of latent tuberculosis infection (LTBI) is essential for tuberculosis elimination in the United States, but the major limitation is poor adherence to therapy. To aid the design of targeted adherence interventions, we investigated the factors associated with noncompletion of isoniazid (INH) therapy for LTBI.


METHODS
A retrospective analysis of patients with who failed to complete vs those who completed 9 months of INH therapy at the RISE TB Clinic (Miriam Hospital; Providence, RI) in 2003 was performed. Factors associated with treatment noncompletion were examined using univariate and multiple logistic regression analysis.


RESULTS
Of 845 patients with LTBI, 690 patients (81.6%) initiated INH therapy, of whom 426 patients (61.7%) completed therapy, and 246 patients (35.6%) were lost to follow-up. Treatment was discontinued in 18 patients (2.6%). Patients who failed to complete therapy were younger (mean age, 30.6 vs 33.8 years, respectively; p = 0.006), and were more likely to be uninsured (42.9% vs 29.8%, respectively; p = 0.0004), to be postpartum (66.7% vs 37.3%, respectively; p = 0.043), and to report treatment side effects (54.8% vs 30.1%, respectively; p < 0.0001). Reported treatment side effects (odds ratio [OR], 3.6; 95% confidence interval [CI], 2.2 to 6.2) and lack of medical insurance (OR, 1.7; 95% CI, 1.1 to 2.7) were each associated with treatment noncompletion in a model including both. Also, pregnant women were more likely than nonpregnant women to fail to initiate INH treatment (52.1% vs 14.7%, respectively; p < 0.0001).


CONCLUSIONS
LTBI patients who are young, pregnant or postpartum, uninsured, and/or report treatment side effects may require additional case management to improve INH treatment completion rates.
Kwara
Awewura
A
Department of Medicine, Miriam Hospital, RISE Building, Providence, RI 02906, USA. akwara@lifespan.org
Herold
Jacqueline S
JS
Machan
Jason T
JT
Carter
E Jane
EJ
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000995:Antitubercular Agents / Q000009:adverse effects / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007538:Isoniazid / Q000009:adverse effects / Q000627:therapeutic use*; D016015:Logistic Models; D008297:Male; D017057:Medically Uninsured; D008875:Middle Aged; D010349:Patient Compliance; D049590:Postpartum Period; D012189:Retrospective Studies; D012237:Rhode Island; D012307:Risk Factors; D016896:Treatment Outcome; D014376:Tuberculosis / Q000188:drug therapy* / Q000209:etiology
D000995:Antitubercular Agents; D007538:Isoniazid