[The short-term effect of temperature on non-accidental mortality in Guangzhou, Changsha and Kunming].

OBJECTIVE: To explore the relationship between temperature and non-accidental mortality in Guangzhou, Changsha and Kunming;to evaluate the temperature-related risk of mortality; and thereby to provide scientific evidence for enacting the policy to tackle climate changes. METHOD: Daily meteorology data and mortality data were collected in 2006-2009 in Guangzhou, Changsha and Kunming. Distributed lag non-linear model (DLNM) was established and applied in a case-crossover design, which controlled the secular trend of time, to estimate the specified effects of temperature on non-accidental mortality at conditions of lag 0-2, lag 0-18 and lag 0-27 days, respectively. RESULT: An obvious seasonal periodicity was found in non-accidental mortality in Guangzhou, Changsha and Kunming during 2006-2009. The mortality number was comparatively high in the winters, and some high temperature days in summer; but was comparatively low in springs and autumn. An L-shaped relationship was found between temperature and mortality in Guangzhou and Kunming and a U-shaped relationship was found in Changsha. When daily mean temperature exceeded 28.2 °C, 24.5°C and 23.2°C, as average temperature increase 1°C, non-accidental mortality increased 4.56% (95%CI:2.74%-6.63%), 5.66% (95%CI:0.22%-12.65%) , -3.94% (95%CI:-32.77%-39.01%) , respectively; when daily mean temperature below 24.8°C, 20.0°C and 17.3°C, as average temperature decrease 1°C, the corresponding increase in non-accidental mortality were 3.28% (95%CI:2.41%-4.10%) (lag 0-18 days), 1.35% (95%CI:0.31%-1.77%) (lag 0-2 days) and 2.42% (95%CI:1.08%-3.27%) (lag 0-27 days) , respectively. The effects of hot weather were acute and short term; while the effects of cold weather had a several days delay, but a longer persistence. CONCLUSIONS: Extreme cold and hot temperature could increase the risk of non-accidental mortality in Guangzhou, Changsha and Kunming. The effects of cold weather had a several days delay, but a longer persistence.

Short-term effects of the 2008 cold spell on mortality in three subtropical cities in Guangdong Province, China.

BACKGROUND: Few studies have been conducted to investigate the impact of extreme cold events on mortality in subtropical regions. OBJECTIVE: In the present study we aimed to investigate the effects of the 2008 cold spell on mortality and the possibility of mortality displacement in three subtropical cities in China. METHODS: Daily mortality, air pollution, and weather data were collected from 2006 to 2009 in Guangzhou, Nanxiong (no air pollutants), and Taishan. We used a polynomial distributed lag model (DLM) to analyze the relationship between the 2008 cold spell and mortality. To observe the mortality displacement of the cold spell, we estimated the cumulative effects at lag0, lag0-6, lag0-13, lag0-20, and lag0-27 separately. RESULTS: During the 2008 cold spell, the cumulative risk of nonaccidental mortality increased significantly in Guangzhou [relative risk (RR) = 1.60; 95% CI: 1.19, 2.14] and Taishan (RR = 1.60; 95% CI: 1.06, 2.40) when lagged up to 4 weeks after the cold spell ended. Estimated effects at lag0-27 were more pronounced for males than for females, for respiratory mortality than for cardiovascular mortality, and for the elderly (≥ 75 years of age) than for those 0-64 years of age. Most of the cumulative RRs increased with longer lag times in Guangzhou and Taishan. However, in Nanxiong, the trend with cumulative RRs was less consistent, and we observed no statistically significant associations at lag0-27. CONCLUSION: We found associations between the 2008 cold spell and increased mortality in the three subtropical cities of China. The lag effect structure of the cold spell varied with location and the type of mortality, and evidence of short-term mortality displacement was inconsistent. These findings suggest that extreme cold is an important public health problem in subtropical regions.

[Investigation on the perception of risk level of heat wave and its related factors in Guangdong province].

OBJECTIVE: To investigate the risk perception of heat wave, and further explore its related factors in Guangdong province. METHODS: A total of 2183 adults were selected by a multi-stage sampling method in Guangdong province. Each subject was interviewed in their home with a structured questionnaire by a well trained investigator from September to November, 2010. The questionnaire contained socio-demographic characteristics, heat wave related knowledge, risk perception of heat wave, etc. Chi-square test and multivariate logistic regression were employed in this study. RESULTS: The average age of total 2183 participants was (39.31 ± 14.16) years, among which 53.37% (1165/2183) were males, and 48.74% (1064/2183) were selected from urban. About 38.11% (832/2183) of participants heard about heat wave, and 38.52% (841/2183) of subjects thought the heat wave had higher impact on their health (risk perception score of heat wave ≥ 5 points). About 81.91% (1788/2183) of all participants thought the weather in most recent years was hotter than several years ago. Among these people, 30.48% (545/1788) thought the main reason of weather becoming hotter was due to emission of carbon dioxide, and 26.51% (474/1788) thought it was due to air pollution. Results from the multivariate logistic regression showed that the risk perception score of heat wave were higher in subjects with higher education (OR = 2.16, 95%CI: 1.41 - 3.30), from urban(OR = 1.37, 95%CI: 1.10 - 1.72), with higher score of trust(OR = 1.08, 95%CI: 1.01 - 1.14) and participants with higher score of heat wave related knowledge (OR = 1.39, 95%CI: 1.27 - 1.52). Furthermore, compared to hierarchist, egalitarian (OR = 1.73, 95%CI: 1.30 - 2.29), individualist (OR = 1.93, 95%CI: 1.41 - 2.65) and fatalist (OR = 1.80, 95%CI: 1.41 - 2.29) also had higher risk perception score of heat wave. CONCLUSION: There is a lack of knowledge and risk perception to heat wave among the residents in Guangdong province. Risk perception of heat wave was higher in people who were from urban, had higher level of trust on government, experts and media, had higher health-related knowledge score, and non-hierarchists.

[Association between distorted weight perception and suicide ideation among normal weight adolescents].

OBJECTIVE: To explore the relationship between distorted weight perception and suicide ideation among normal weight adolescents in Guangdong province. METHODS: This study used the data of Guangdong Provincial Youth Health Risk Behavior Survey in 2004 and 2007. To identify the association between distorted weight perception and suicide ideation, a logistic regression analysis was performed. The effects of age, economic status, mother's education, mental health, and depression were also adjusted. RESULTS: A total of 12 729 people participated in this study, 6096 males and 6633 females. The prevalence of suicide ideation among normal weight adolescents was 13.58% (1729/12 729) in the past 12 months, with higher prevalence in girls (16.15%, 1071/6633) than that in boys (10.79%, 658/6096) (χ(2) = 77.71, P = 0.00). It was common that the adolescents misperceived their weight. Only 44.93% (5719/12 729) of normal weight students correctly perceived their body weight while 43.52% (5540/12 729) of them overestimated their weight and 11.43% (1455/12 729) underestimated their weight. The distorted weight perception in girls (65.58%, 4350/6633) was higher than that in boys (43.39%, 2645/6096) (χ(2) = 993.91, P = 0.00). Distorted weight perception was significantly associated with suicide ideation after controlling for factors age, economic status, mother's education, mental health, and depression. The students who overestimate their body weight were more likely to have suicide ideation than that who correctly perceived their weight (OR = 1.43, 95%CI: 1.27 - 1.61). CONCLUSION: The prevalence of distorted weight perception was high and it significantly associated with suicide ideation.

Nonfatal child pedestrian injury in two urban cities of Guangdong Province, China: results from a cross-sectional survey.

OBJECTIVE: To describe the epidemiological characteristics of nonfatal child pedestrian injuries and provide information to help understand an important public-health problem. METHODS: This was a school-based, cross-sectional questionnaire survey. The sample (42 750 children) was obtained from two urban cities of Guangdong Province, China, using multi-stage randomized sampling. Information was collected by the respondents self-reporting in the classroom. RESULTS: The incidence rate of nonfatal child pedestrian injuries in the cities was 2.0%. Boys had a higher incidence rate (2.6%) than girls (1.4%). Compared to other children, those aged 10 years are at the highest risk. The primary places of occurrence were sidewalks, residential roads, and crosswalks. High-risk behavior of the children immediately prior to injury included mid-block crossings, playing on roads, and crossing on red lights. The major vehicles that caused pedestrian injuries were bicycles, car or vans, and motorcycles. Bruises, fractures, and injuries to the internal organs were the top three types of injuries. Almost 40% of victims were hospitalized, and nearly 30% of the victims suffered long-term disabilities. CONCLUSION: This study shows that nonfatal child pedestrian injuries are a very serious public-health problem in the urban cities of Guangdong. Based on the epidemiological characteristics, prevention strategies and further research should be carried out to reduce the occurrence of injuries.

[Study on health-related behaviors among males in rural and urban residents from Guangdong province].

OBJECTIVE: To compare the magnitude of inequities in health-related behaviors among males in Guangdong province, and to investigate the extent of the disparities. METHODS: Data sets available from the Guangdong Chronic Diseases and Risk Factors Survey 2007 are used. Concentration index (C) and concentration curve are employed to measure the differential of males' health-related behaviors across urban and rural areas in Guangdong. Odds ratios of 6 health-related behaviors among different areas are derived from 4 logistic models, after adjusting for age, married state, educational status, occupation and income. RESULTS: Results from Cs reveal that the inequality gradients disadvantageous to men in rural areas are:smoking (C = -0.075, P = 0.000), alcohol intake (C = -0.023, P = 0.002), blood pressure (C = 0.106, P = 0.000), blood sugar (C = 0.114, P = 0.000) and weight (C = 0.107, P = 0.000), while lack of physical activity (C = 0.044, P = 0.000)concentrates in the more affluent areas. The magnitudes of these inequalities appear to be higher on health-seeking behaviors than on health-risk behaviors. After adjusting for age and marital status, there is still strong evidence showing the rural-urban differences in the health related behaviors among males in Guangdong province. When educational status, occupation and income are added to the logistic model as control factors, the results have led to a loss of statistical significance on such rural-urban inequalities, indicating that socioeconomic factors play an important role on these health-related behaviors which leads to the inequalities among males in Guangdong province. CONCLUSION: To reduce the gaps in health-related behaviors seen in the rural and urban areas, effective policies should be developed to change the social determinants of rural-urban differences in health and to strengthen the implementation of health-related programs on those vulnerable groups.