Factors associated with bronchiectasis in Sri Lanka: evidence from a multicenter case-control study in the Colombo District.

Bronchiectasis is a complex disease with a rising prevalence globally. It is under-recognized in low and middle-income countries (LMICs), with limited research. Even though a wide range of risk factors are known, they lack the support of scientific evidence. Therefore, this study aimed to identify associated factors among patients in Sri Lanka. A multicenter unmatched case-control study (123 cases and 123 controls) was conducted in three government hospitals in Colombo District, Sri Lanka (May-June 2023). Cases were patients with newly diagnosed bronchiectasis confirmed using both clinical and radiological criteria, while controls were patients with other respiratory conditions and no evidence of bronchiectasis on clinical or radiological assessment. Data was collected using a validated interviewer-administered questionnaire, which was pretested and piloted. Administrative and ethical approval was obtained before data collection. Informed written consent was obtained from each participant before administering the tool. Multivariate logistic regression was performed. The response rate was 100%, with 246 participants. The mean age of patients with bronchiectasis was 64.0 years (SD = 11.7), compared with 60.7 years (SD = 14.0) among those without bronchiectasis. Females comprised 55.3%(n = 68) of cases, compared with 35.0% (n = 43) among controls. Bivariate analysis identified 12 independent variables. Multivariable logistic regression analysis identified the following factors independently associated with bronchiectasis after adjustment for confounders; female gender (aOR=2.27; 95%CI=1.25-4.13), age ≥60 years (aOR=2.35; 95%CI=1.13-4.87), having cardiovascular diseases (aOR=2.12; 95%CI=1.08-4.16), having rheumatoid arthritis (aOR=3.28; 95%CI=1.02-10.51), having other chronic respiratory diseases (aOR=3.19; 95%CI=1.76-5.80), history of pulmonary tuberculosis (aOR=3.47; 95%CI=1.66-7.73), exposure to indoor air pollution (aOR=2.39; 95%CI=1.30-4.39) and occupational exposure to chemicals (aOR=2.56; 95%CI=1.25-5.25). Recognition of these associated factors may facilitate earlier identification of bronchiectasis and prioritization of diagnostic evaluation in low- and middle-income settings.