Chronic respiratory symptoms and lung abnormalities among people with a history of tuberculosis in Uganda: a national survey.

Background: People with pulmonary tuberculosis (TB) are at risk of developing chronic respiratory disorders due to residual lung damage. So far, the scope of the problem in high burden TB countries is relatively unknown. Methods: Chronic respiratory symptoms (cough and phlegm lasting >2 weeks) and radiological lung abnormalities were compared between adults with and without a history of TB among the general population of Uganda. Multivariable regression models were used to estimate odds ratios with adjustment for age, gender, smoking, education, setting and region. Random effects models accounted for village clustering effect. Results: Of 45,293 invited people from 70 villages, 41,154 (90.9%) participated in the survey. 798 had a history of TB and among them, 16% had respiratory symptoms and 41% x-ray abnormalities. Adjusted odds ratios showed strong evidence for individuals with a history of TB having increased risk of respiratory symptoms (OR=4·02, 95%CI: 3·25-4·96) and x-ray abnormalities (OR=17·52, 95%CI: 14·76-20·79); attributing 6% and 24% of the respective population risks. Conclusions: In Uganda, a history of TB was a strong predictor of respiratory symptoms and lung abnormalities, before older age and smoking. Eliminating TB disease could reduce the prevalence of chronic respiratory symptoms as much as eliminating smoking.