Predictors of tuberculosis disease in smokers: a case-control study in northeastern Malaysia

Objective. Tuberculosis (TB) is a leading infectious disease. However, many TB cases remain undetected and only present symptoms at a late stage of the infection. Therefore, targeted TB screening in high-risk populations, including smokers, is crucial. This study aimed to determine the predictors of TB disease among the smoker population in northeast Malaysia from 2019 to 2020. Methods. A case-control study was conducted involving smokers aged 18 years and older from health clinics in Bachok Kelantan, Malaysia. Data were collected via face-to-face interviews or telephone calls from 159 participants, randomly selected from outpatient TB records. Simple and multiple logistic regression, using R software, were used to identify the determinants of TB. Results. Most participants were male (59.1%) and had a secondary education (56.0%). Active smokers constituted 35.2% of the group, and the mean (SD) duration of exposure to smoking was 23.9 (16.47) and 18.4 (12.84) years for the case and control groups, respectively. Being an ex-smoker (adjusted odds ratio (AOR) 6.17; 95% CI [1.55- 28.32]; p = 0.013), weight loss (AOR 13.45; 95% CI [4.58-44.46]; p < 0.005), night sweats (AOR 63.84; 95% CI [8.99-1392.75]; p < 0.005) and duration of symptoms (AOR 1.02; 95% CI [1.01-1.04]; p = 0.022) were shown to be significant predictors for TB disease. Conclusion. Four predictors of TB disease in the population of smokers were recognised in this study and should be prioritised for early TB screening and diagnosis. This may help increase TB detection, initiate prompt treatment and reduce complications among the group at risk for TB.