Pulmonary function and Quality of Life in patients with treated smear positive pulmonary tuberculosis at three tuberculosis clinics in Nairobi, Kenya

Objective: The objective of the study was to evaluate the type of pulmonary impairment, factors associated with such impairment and the effect of pulmonary tuberculosis (PTB) on quality of life (QOL) of patients. Methods: This was a cross sectional study conducted at three health centres in Nairobi between May and June 2012. Patients above the age of 15 years with cured smear positive PTB two years prior to the study were assessed using the St Georges Respiratory questionnaire (SGRQ) and spirometry done using spiro lab III spirometer. Results: 183 patients (58% males) were enrolled. Out of these, 33% were HIV positive. The median age was 29.5years (IQR 25-38 years) and the median duration after starting TB treatment was 11.4 months. 22% of patients were current or former cigarette smokers. The median BMI was 21.1kg/m2 (Range 12.5 – 37). 53 patients (29%) had pulmonary impairment, the commonest being restrictive defects in 42 patients (23%, 95% CI, 16.8-29.1%), obstructive defects in 9 patients (5%, 95% CI, 1.76-8.08%) and combined defects in 2 patients (1%, 95% CI, -0.4-2.61%). Patients with abnormal lung function were younger {median age, 29 years (IQR, 22-36) vs 34 years (IQR, 27-39), p= 0.036} and more likely to be underweight (38% vs 9%, p= <0.005). Body mass index (BMI) was the only independent predictor of pulmonary function abnormality (p=0.001). The median QOL total score from the SGRQ was 3.16 (IQR, 0 – 8.9) signifying good QOL. Conclusions: The commonest lung function abnormality post PTB treatment was restrictive defect. Body mass index was the only independent predictor of abnormal pulmonary function.