Spatiotemporal variations in Chronic Obstructive Pulmonary Disease mortality in China: multilevel evidence from 2006 to 2012
Mortality of Chronic Obstructive Pulmonary Disease (COPD) is on the decline in China. It is not known if this trend occurs across all areas or whether spatiotemporal variations manifest. We used data from the nationally representative China Mortality Surveillance System to calculate annual COPD mortality counts (2006-2012) stratified by 5-year age groups (aged > 20), gender and time for 161 counties and districts (Disease Surveillance Points, or DSP). These counts were linked to annually adjusted denominator populations. Multilevel negative binomial regression with random intercepts and slopes were used to investigate spatiotemporal variation in COPD mortality adjusting for age, gender and area-level risk factors. COPD mortality rate decreased markedly from 105.1 to 73.7 per 100,000 during 2006 to 2012 and varied over two-fold between DSPs across China. Mortality rates were higher in the west compared with the east (Rate ratio (RR) 2.15, 95% confidence intervals (CI) 1.73, 2.68) and in rural compared with the urban (RR 1.87, 95% CI 1.55, 2.25). Adjustment for age, gender, urban/rural, region, smoking prevalence, indoor air pollution, mean body mass index and socioeconomic circumstances accounted for 67% of the geographical variation. Urban/rural differences in COPD mortality narrowed over time, but the magnitude of the east-west inequality persisted without change. Immediate action via large-scale interventions to enhance the prevention and management of COPD are needed specifically within China's western region in order to tackle this crucial health inequality and leading preventable cause of death.