Tuberculosis, Airway Obstruction and Mortality in a Finnish Population

There is little long-term follow-up data concerning the association between past pulmonary tuberculosis (TB), airway obstruction and mortality. We aimed to analyse a national health examination survey data from 6701 adult Finns undergoing spirometry between 1978 and 1980 (follow-up through 2013). We identified TB either through a disease history or by a TB-indicative scar on a chest x-ray. We specified obstruction using the lower limit of normal (LLN) and classified severity using the Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages 1-4. After adjusting for smoking and other confounders, past TB associated with obstruction. Compared to non-TB patients, the adjusted odds ratio (OR; 95% CI) of obstruction reached 2.21 (1.52-3.21) among patients with a scar recorded by one radiologist, 2.48 (1.63-3.78) when recorded by both radiologists and 4.59 (2.86-7.37) among patients with a disease history. Among those with neither past TB nor obstruction, with past TB only, with an obstruction only and with both, we found hazard ratios (HRs; 95% CIs) for subsequent mortality of 1.00 (reference), 1.11 (1.03-1.20), 1.62 (1.31-2.00) and 1.77 (1.45-2.16), adjusted for age, gender, smoking, body mass index (BMI), physical activity, education and general health. In conclusion, past TB strongly determines obstruction, although on its own quite weakly predicts premature death. TB and obstruction combined predict an additive mortality pattern.