Identification of risk factors for radiological sequelae in patients treated for pulmonary tuberculosis: Prospective observational cohort study

Objective of study This study is designed to assess risk factors & magnitude of residual radiological lesion in patients treated for pulmonary tuberculosis. Methods This is a retrospective observational cohort study which included patients who were newly diagnosed as pulmonary tuberculosis and have completed 6 months of treatment. Statistical analysis Categorical data were expressed as proportion and continuous data were expressed as mean ± SD. The obtained data were analysed by means of frequency distribution table and descriptive statistics using SPSS version 20 for Windows (SPSS Inc., Chicago, Ill, USA) and Chi-square test and student t test were used for statistical analysis. We assessed association between risk factors and development of radiological sequelae, using univariate statistical analysis and odds ratio. P-values less than 0.05 were considered statistically significant. Results Data from 128 patients was used for analysis. The average age in this cohort was 32.84 ± 17.47 years and 68.75% patients were male. Residual x-ray lesions were observed in 92 (71.87%) cases out of 128 study patients. 72.82% of residual lesions appeared as parenchymal fibrosis, 13.04% as bronchiectasis, 2.17% as cavity & 3.26% appeared as calcification. Patients with advanced lesions (34.78% vs 16.66%), bilateral lesions (29.34% vs 11.11%) or cavity (18.47% vs 2.77%) in chest x-ray or Sputum smear positivity for AFB were found to have significant radiological sequelae. Among the variables associated with the risk of having pulmonary tuberculosis sequelae were cavity (OR: 7.03), sputum smear positive for AFB (OR: 4.03), Advanced lesions (OR: 3.38) & bilateral lesions (OR: 2.90) in chest x-ray. Conclusion This study concluded that a large number of patients remain with residual radiological sequelae despite good clinical response. Patients with extensive lesions, presence of cavity or bilateral involvement in chest x-ray and sputum smear positive for acid fast bacilli were often associated with residual radiological opacity.