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BackgroundMany studies have investigated heat wave related mortality, but less attention has been given to the health effects of cold spells in the context of global warming. The 2008 cold spell in China provided a unique opportunity to estimate the effects of the 2008 cold spell on mortality in subtropical regions, spatial heterogeneity of the effects, stratification effect and added effects caused by sustained cold days.MethodsThirty-six study communities were selected from 15 provinces in subtropical China. Daily mortality and meteorological data were collected for each community from 2006 to 2010. A distributed lag linear non-linear model (DLNM) with a lag structure of up to 27 days was used to analyze the association between the 2008 cold spell and mortality. Multivariate meta-analyses were used to combine the cold effects across each community.ResultsThe 2008 cold spell increased mortality by 43.8% (95% CI: 34.8% ~ 53.4%) compared to non-cold spell days with the highest effects in southern and central China. The effects were more pronounced for respiratory mortality (RESP) than for cardiovascular (CVD) or cerebrovascular mortality (CBD), for females more than for males, and for the elderly aged ≥75 years old more than for younger people. Overall, 148,279 excess deaths were attributable to the 2008 cold spell. The cold effect was mainly from extreme low temperatures rather than sustained cold days during this 2008 cold spell.ConclusionsThe 2008 cold spell increased mortality in subtropical China, which was mainly attributable to the low temperature rather than the sustained duration of the cold spell. The cold effects were spatially heterogeneous and modified by individual-specific characteristics such as gender and age.

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BackgroundIn the 12th Five-Year Plan, the Chinese government set the goal of increasing life expectancy by one year. The purpose of this study is to examine the impact of major causes of death on the life expectancy of the Chinese people between 1950 and 2010 and predict changing trends to identify major issues requiring future attention.MethodsA continuous database organised by population and death data on diseases by age group between 1950 and 2010 were created from A Province in Eastern China. The diseases were classified into four categories by the International Classification of Diseases-10 (ICD-10): infectious and parasitic diseases, chronic diseases, accidental injuries, and maternal diseases. Potential gains in life expectancy (PGLEs) were applied to reflect the impact on life expectancy caused by deaths from various diseases, by using the cause-eliminated life table.ResultsThe PGLEs of infectious and parasitic diseases decreased from 15.59 years in 1950, to 0.07 year in 2010, and have remained low since 2000. However, the PGLEs of chronic diseases increased from 8.70 years in 1950, to 13.36 years in 2010, and indicated an increasing future trend. The two opposite trends exhibited a ‘scissors-like difference’. The proportion of accidental injuries and maternal diseases in the death spectrum was low. The PGLEs of accidental injuries decreased from 2.95 years in 1950, to 0.86 year in 2010, maintaining a low level, while the PGLEs of maternal diseases dropped from 0.56 to 0.002 year during the same period, approaching zero.ConclusionsThe findings of this study provide useful information, which could contribute to a more effective allocation of public health programmes. In recent years, chronic diseases and accidental injuries have emerged as major factors influencing life expectancy. Primary and secondary prevention actions, such as public education, modification of behaviours, and introduction of safety measures should be emphasised in efforts to promote life expectancy. The morbidity and mortality rates of infectious, parasitic, and maternal diseases should be maintained at low levels.

IntroductionAssociation has been reported between ambient fine particulate matter (PM) and adverse outcomes of cerebrovascular events. However, it remains unclear that whether short-term exposure to PM relates to stroke and the lag of health effects. This triggers us to examine the relationship between PM and population stroke morbidity in Chengdu.MethodsThe daily average concentration of atmospheric pollutants and meteorological factors and daily morbidity of stroke in Chengdu (2013–2015) were collected. Based on time series analysis-generalized additive models (GAM), single-pollutant, two-pollutant and multi-pollutant model were established. The effects of atmospheric PM2.5 (defined as PM less than 2.5μm in aerodynamic diameter), PMc(defined as PM less than 10μm and more than 2.5μm in aerodynamic diameter) and PM10 (defined as PM less than 10μm in aerodynamic diameter) concentration on the daily mortality of stroke were analyzed, respectively.ResultsThe three-year mean concentrations of PM2.5, PMc and PM10 for air pollutants were 75.9, 43.9 and 119.7 μg/m3, respectively. PM2.5 on the current day (lag0) and with a moving average of 0–1 days were significantly associated with the increasing risk of stroke morbidity, and PM2.5 with a lag of 0–1 days had greater association, whereas for PMc and PM10 there were no significant association observed. In our study, every 10μg/m3 increase of PM2.5 was associated with 0.69% percent change in stroke morbidity (95%CI: 0.01~1.38). For females, every 10μg/m3 increase of PM2.5 contributes to 0.80% percent change of onset. And for the group of age less than 65, we observed 0.78% higher risk every 10μg/m3 increase of PM2.5.ConclusionsThese findings suggest that short-term exposure to PM2.5 within 1 day is associated with the onset of stroke, and the younger people (age<65) and females are more sensitive than older people and males.