Risk factors of treatment interruptions among drug-sensitive and drug-resistant pulmonary tuberculosis patients - A study from South Delhi, New Delhi, India.

Background: A variety of factors influence adherence to the lengthy duration of anti-tuberculosis treatment, making it a complicated and dynamic problem. The objective of this study was to investigate the treatment interruption patterns using pre-defined criteria among a cohort of pulmonary tuberculosis patients and to elicit the associated factors.

Methods: This prospective, observational study was conducted between October 2016 to May 2018. All smear and culture positive pulmonary tuberculosis patients (age ≥ 14 years) enrolled between October 1, 2016 to March 31, 2017 across 3 Designated Microscopy Centers (DMCs) were included and followed up till end of treatment for outcome in drug-sensitive, and till interim outcome at 6 months for drug-resistant TB patients. Patterns and reasons for interruptions were recorded as per the study protocol.

Results: 171 patients were enrolled in this study, of which 135 (78.94 %) were on Category-I and Category-II treatment (drug-sensitive tuberculosis), 23 (13 %) were multidrug-resistant (MDR) and 13 (8 %) were extensively drug resistant (XDR) tuberculosis patients. Among the drug-sensitive group, 65 (48 %) patients completed their treatment without any interruption while 70 (52 %) patients interrupted with at least one missed dose. Among the 36 MDR/XDR patients, 19 (53 %) patients did not interrupt treatment, but 17 (47 %) patients interrupted with at least one missing dose. The 87 patients in both sub-groups interrupted for 232 times/episodes of which 140 were short and 84 were long interruptions. The main reasons for interruption were found to be busy schedule in 63 (29 %) patients, adverse drug reactions in 40 (18.4 %) and comorbidities in 43 (19.8 %) patients. Feeling of early improvement/no improvement in 23 (10.5 %) patients, addictions in 27 (12.4 %) patients, lack of family support in 14 (6.4 %), unawareness of dosage and duration of treatment in 7 (3.20 %) patients were other common reasons.

Conclusion: The plurality of patients studied were found to be in the younger age group i.e., 14-25 years (n = 75), constituting nearly 44 % of all the patients included and male treatment interrupters (62 %) outnumbered the females (38 %), possibly owing to work schedule or addictions. The majority of interruptions were related to patient related factors (93.5 %), followed by DOTS provided factors (6.40 %) and system related factors (3.01 %). Further studies should be conducted to classify the factors of treatment interruptions in detail and also to study the impact of these interruptions' patterns on final outcomes.