Evaluation of Tuberculosis Recurrence and Its Determinants in the Southeast of Iran: A Nested Case-Control Study Based on Data From 2012 to 2018

Background and Objectives: In addition to effective treatment, tuberculosis recurrence is a very important challenge regarding the treatment of this infection. This study was conducted to evaluate the risk factors associated with tuberculosis recurrence.   Methods: In this nested case-control study, 202 tuberculosis patients with recurrence and 202 matched controls in terms of age, sex and place of residence were studied. The cases and controls were selected from a cohort of tuberculosis patients in Sistan and Baluchestan province between 2011 and 2018. The data were collected using interviews and patients’ records. The independent t-test, chi-square and multiple conditional logistic regression were used to analyze the data.   Results: The drug abuse history (OR=6.1), 3+ smear positive (OR=3.03), chest X-ray suggestive of tuberculosis (OR=4.9), drug resistance (OR=7.3), low socioeconomic status (OR=3.9), weight loss (OR=3.1), chest pain (OR=3.2), history of digestive disease (OR=22.1), smoking (OR=6.1), and imprisonment (OR=3.7) significantly increased the chance of recurrence among tuberculosis patients (p<0.05). On the other hand, the chance of recurrence was significantly lower in patients with coughs (OR=0.29) and a small family size (OR=0.28).   Conclusion: According to the results, tobacco use, drug use, low socio-economic status, life conditions, and disease conditions are the most important determinants of tuberculosis recurrence. In general, epidemiologic factors related to tuberculosis recurrence are not similar in different regions; therefore, educational programs for patients and their families and prevention methods should be considered based on related factors in different regions.