Background
Poor adherence to tuberculosis (TB) treatment is associated with disease recurrence and death. Little research has been conducted in India to understand TB medication non-adherence.
Methods
We enrolled adult drug-susceptible TB patients, about half of whom were people living with HIV (PLHIV), in Chennai, Vellore, and Mumbai. We conducted a single unannounced home visit to administer a survey assessing reasons for non-adherence and collect a urine sample that was tested for isoniazid content. We described patient-reported reasons for non-adherence and identified factors associated with non-adherence (i.e., negative urine test) using multivariable logistic regression. We also assessed the association between non-adherence and treatment outcomes.
Results
Of 650 participants in the cohort, 77 (11.8%) had a negative urine test. Non-adherence was independently associated with daily wage labor (aOR 2.7, CI: 1.1—6.5, p=0.03), the late continuation treatment phase (aOR 2.0, CI:1.1—3.9, p=0.03), smear-positive pulmonary disease (aOR 2.1, CI: 1.1—3.9, p=0.03), alcohol use (aOR 2.5, CI: 1.2—5.2, p=0.01), and spending >=30 minutes collecting medication refills (aOR 6.6, CI: 1.5—29.5, p=0.01). PLHIV reported greater barriers to collecting medications than non-PLHIV. Among 167 patients reporting missing doses, reported reasons included traveling from home, forgetting, feeling depressed, and running out of pills. The odds of unfavorable treatment outcomes were 4.0 (CI: 2.1—7.6) times higher among patients with non-adherence (p<0.0001).
Conclusion
Addressing structural and psychosocial barriers will be critical to improve TB treatment adherence in India. Urine isoniazid testing may help identify non-adherent patients to facilitate early intervention during treatment.