Impaired lung function and mortality in Eastern Europe: results from multi-centre cohort study.

ABSTRACT

BACKGROUND: The association between impaired lung function and mortality has been well documented in the general population of Western European countries. We assessed the risk of death associated with reduced spirometry indices among people from four Central and Eastern European countries. METHODS: This prospective population-based cohort includes men and women aged 45-69 years, residents in urban settlements in Czech Republic, Poland, Russia and Lithuania, randomly selected from population registers. The baseline survey in 2002-2005 included 36,106 persons of whom 24,993 met the inclusion criteria. Cox proportional hazards models were used to estimate the hazard ratios of mortality over 11-16 years of follow-up for mild, moderate, moderate-severe and very severe lung function impairment categories. RESULTS: After adjusting for covariates, mild (hazard ratio (HR) 1.25; 95% CI 1.15‒1.37) to severe (HR 3.35; 95% CI 2.62‒4.27) reduction in FEV1 was associated with an increased risk of death according to degree of lung impairment, compared to people with normal lung function. The association was only slightly attenuated but remained significant after exclusion of smokers and participants with previous history of respiratory diseases. The HRs varied between countries but not statistically significant; the highest excess risk among persons with more severe impairment was seen in Poland (HR 4.28, 95% CI 2.14‒8.56) and Lithuania (HR 4.07, 95% CI 2.21‒7.50). CONCLUSIONS: Reduced FEV1 is an independent predictor of all-cause mortality, with risk increasing with the degree of lung function impairment and some country-specific variation between the cohorts.