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Background The epidemiological evidence of traumatic brain injury (TBI) and spinal cord injury (SCI) mortality in mainland China is lacking. We aimed to assess the trends of TBI and SCI mortality, and their association with sex, age, location and external causes of injury in south China. Methods Mortality data were derived from the Disease Surveillance Points (DSPs) system of Guangdong province between 2014 and 2018. We examined the trends in mortality with Cochran–Armitage trend test, and the association between the socio-demographic factors and the TBI and SCI mortality by using negative binomial models. Subgroup analysis was performed by stratifying the external causes of TBI and SCI. Results The age-standardized TBI mortality remained relatively stable (from 11.6 to 15.4 per 100,000), while the SCI mortality increased by 148.3% from 2014 to 2018. Compared with females and urban residents, the adjusted mortality rate ratios of males and rural residents were 2.3 and 2.0 for TBI, and 2.2 and 4.6 for SCI, respectively. TBI and SCI mortality increased substantially with age. Motor vehicle crashes and falls were the leading causes of TBI mortality in residents aged under 75 years and over 75 years, respectively. Falls were the most important external cause for SCI death of all ages. Conclusions Being male, rural and elderly residents are at higher risk of dying from TBI and SCI. The substantial burden of TBI and SCI caused by road traffic crashes and falls has called for the urgent need to improve injury prevention, pre-hospital aid, hospital treatment and recovery.

ObjectiveThis study aims to investigate the prevalence and risk factors of falls among the elderly in Guangdong, China.MethodsA cross-sectional study was conducted in six communities of Guangdong province. People over 60 years old were selected with multistage random-cluster sampling. Data on falls within the previous 12 months and fall-related risk factors were collected through a face-to-face interview.ResultsThe prevalence of falls among older adults was 11.9% (95% CI: 11.0% to 12.8%) among 5374 interviewees. The common injuries caused by falls were bruises/scrapes (40.0%) and fractures (15.5%), and most people fall while doing housework (35.0%). Univariate analysis showed that 14 factors were associated with falls among older adults, including gender, age, residence, occupation, education level, balance ability, situation of cognition, disease, depression, living arrangement, marital status, the behaviour of exercise, drinking and drug use (pConclusionsThe hazards caused by falls to the elderly in China cannot be ignored. A multidimensional customised fall prevention programme should be considered to reduce the risk of falls among the elderly based on the results above.

ObjectiveWe aimed to ascertain the trends of injury mortality during the COVID-19 period in southern China.MethodsWe conducted a population-based retrospective analysis to compare the mortality changes of all-cause injury and transport injuries, poisoning, falls, fire/heat/hot substances, drowning, self-harm and interpersonal violence, which were further stratified by sex and age. Comparisons were made between the COVID-19 period (between January 2020 and June 2020) and control period (between January 2019 and June 2019) in Guangdong province. We used the negative binomial models to explore the associations of deaths during the COVID-19 period, according to the different sex and age strata.ResultsThe all-cause injury mortality in Guangdong province decreased significantly from 28.65 per 100 000 population during the control period to 23.24 per 100 000 population during COVID-19 pandemic period. Similar results were found in specific injury categories. Mortality of self-harm increased by 139.26% in the 10–14 year group during the COVID-19 period as compared with the control period. Although mortality changes in some groups were not statistically significant, some increases were noteworthy during the COVID-19 period (ie, self-harm, transport injury and falls) in the 70–79 year group. The corresponding increase in mortality rate was 16.83%, 3.32% and 4.92%, respectively.ConclusionThe mortality of all-cause injury, transport injury and drowning during the COVID-19 pandemic was consistently decreased. However, the increase in mortality associated with falls, fire/heat/hot substance injury and self-harm in specific age populations warrant the targeted control and prevention measures for the population at risk.

Background Drowning is a leading cause of accidental death in children under 14 years of age in Guangdong, China. We developed a statistical model to classify the risk of drowning among children based on the risk factors. Methods A multiple-stage cluster random sampling was employed to select the students in Grades 3 to 9 in two townships in Qingyuan, Guangdong. Questionnaire was a self-reported measure consisting of general information, knowledge, attitudes and activities. A univariate logistic regression model was used to preliminarily select the independent variables at a P value of 0.1 for multivariable model. Three-quarters of the participants were randomly selected as a training sample to establish the model, and the remaining were treated as a testing sample to validate the model. Results A total of 8390 children were included in this study, about 12.18% (1013) experienced drowning during the past one year. In the univariate logistic regression model, introvert personality, unclear distributions of water areas on the way to school, and bad relationships with their classmates and families were positively associated with drowning. However, females, older age and lower swimming skills were negatively associated with drowning. After employing the prediction model with these factors to estimate drowning risk of the students in the testing samples, the results of Hosmer-Lemeshow tests showed non-significant differences between the predictive results and actual risk (χ2 = 5.97, P = 0.65). Conclusions Male, younger children, higher swimming skills, bad relationship with their classmates and families, introvert personality and unclear distributions of water areas on the way to school were important risk factors of non-fatal drowning among children. The prediction model based on these variables has an acceptable predictive ability.

Background As the fourth leading cause of death, injury is an important public health concern in Guangdong Province, China. The epidemiological characteristics of injury mortality is changing along with the social development. This study described the epidemiological characteristics of injury mortality in Guangdong Province by analyzing the death surveillance data in a few areas in Guangdong Province in 2015. Methods Using the mortality data from the Disease Surveillance Points (DSP) system, injury deaths were classified according to the International Classification of Disease-10th Revision (ICD-10). The data were stratified by areas (urban/rural), gender, age groups, injury types, and then overall and type-specific injury mortality rates were estimated for the whole Guangdong Province, China. Results We estimated that about 38,200 individuals died from injury in Guangdong Province in 2015, producing a mortality rate of 43.11/100,000. The overall age-standardized injury mortality in men was higher in rural areas compared with urban areas (41.29/100,000 versus 24.89/100,000). In terms of injury intent, unintentional injuries were the commonnest injury type, which accounted for 83.93% of the overall injury deaths, however, the deaths caused by suicide should not be ignored, which occupied 12.67% of the total injury deaths. In terms of injury cause type, falls, road-traffic accidents, suicide, drowning, and accidental poisoning were the top five leading types of injury deaths. Conclusions In Guangdong Province, injury is an important cause of death. Road-traffic accidents, falls, suicide, drowning, and accidental poisoning should be the priorities of intervention. Moreover, in rural areas, the men were the most targeted subpopulation of the prevention activities.

In this paper, we focus on the decentralized online learning problem where online data streams are separately collected and collaboratively processed by a network of decentralized agents. Comparing to centralized batch learning, such a framework is faithful to the decentralized and online natures of the data streams. We propose an online decentralized alternating direction method of multipliers that efficiently solves the online learning problem over a decentralized network. We prove its $$O(\sqrt{T})$$ regret bound when the instantaneous local cost functions are convex, and its $$O(\log T)$$ regret bound when the instantaneous local cost functions are strongly convex, where T is the number of iterations. Both regret bounds are in the same orders as those of centralized online learning. Numerical experiments on decentralized online least squares and classification problems demonstrate effectiveness of the proposed algorithm.

One-dimensional consolidation equation of unsaturated soils was derived in order to solve this special case of consolidation. The presented equation, not similar to Terzaghi’s equation, is a type of absolute nonlinear partial differential equation, and it was solved by finite difference method. An example was analyzed and the case of incompressible fluid consolidation was compared. Finally the experimental results from laboratory tests reported in the literature, was fitted by the presented equation, and the agreement was good. The results show that (1) the process of pore-air pressure dissipation is similar to that of pore-water pressure of saturated soils; (2) the compressibility of pore fluid is not an advantageous factor to quicken the consolidation; (3) the presented equation is effective to analyze the process of consolidation of unsaturated soils which consolidate mainly due to the dissipation of pore-air pressure.

In order to found an applicable equation of consolidation for gassy muddy clay, an effective stress formula of gas-charged nearly-saturated soils was introduced. And then, a consolidation equation was derived. Subsequently, supposing soils were under tangential loading, the expressions of pore water pressure were presented. The analytic solution of pore water pressure was attempted to be validated by the measured values in a real embankment. The parameters in the expressions of pore water pressure were gotten by the method of trial. The result shows that the consolidation model is rational and the analytic solution of pore water pressure is correct. The following conclusions can be made: 1) the influence of bubbles on the compressibility of pore fluid should be considered; 2) the effective stress would be influenced by bubbles, and the consolidation would depend on the compressibility of soil skeleton: the softer the soils are, the more distinct the influence of bubbles is; for normal clay, the influence of bubbles on the effective stress may be commonly neglected.

In empirical finance, it is well-known that the volatility of asset returns is highly persistent. The persistence of the volatility process may be checked by testing for a unit root on stochastic volatility models. In this paper, a Bayesian test statistic based on decision theory is developed for testing a unit root on multivariate stochastic volatility models. At last, the developed approach is applied to investigate the persistent effect of financial crisis on the two main stock markets in China.

BISHOP’s effective stress or two state stress variables are unsatisfactory for unsaturated soils where one of fluid phases is discontinuous, so new expressions of effective stress should be founded. The approach for derivation was according to the principle of equilibrium of forces (i.e., the stress-sharing principle), and it was firstly validated by demonstrating TERZAGHI’s principle of effective stress. And then, the derivations were subdivided into four parts according to different pore air states: 1) air bubbles were spherical and suspended in pore water; 2) air bubbles were bound on soil skeleton; 3) air bubbles held almost the single section of pore; 4) air phase was continuous. The different formulae of effective stress were presented. Conclusions are drawn as follows: 1) For nearly-saturated soils, the “real” effective stress would be a little smaller than TERZAGHI’s effective stress; 2) For soils in which air phase is discontinuous in the form of bubbles, a new concept of pore air elastic pressure is put forward, and the total stress can be constituted by effective stress, pore water pressure and pore air elastic pressure; 3) For soils in which air phase is continuous, effective stress is equal to the value of the total stress plus suction; 4) Suction can be divided into two parts: one is the effect caused by additional pressure, and the other is the contract action by the “skin”.

It is a complicated problem for consolidation analysis of unsaturated soils. Nowadays’ theories are very theoretical, and the parameters in them are so many that it is difficult to solve the equations, i.e., they are not excellently fit for application in engineering. So it is significant to get a simplified theory for consolidation analysis of unsaturated soils. In this paper, according to the phenomena observed in consolidation’s experiments for unsaturated soils, it is assumed that pore-air pressure undergoes an instantaneous dissipation and the consolidation of unsaturated soils can be described as the process of dissipation of excess pore-water pressure. Then a simplified consolidation model is put forward. And based on the principle of the whole soil mass conversation, the continuity equation is founded. Subsequently one- dimensional consolidation equation is derived, which is similar to Terzaghi’s equation for consolidation of saturated soils. Finally, the numerical results from the derived equation are compared with the experimental results from laboratory tests reported in the literature, and the agreement is good. It can be concluded that the hypothesis is rational and the simplified computation is practical in engineering.

This study is to examine the contribution of socioeconomic status (SES) to the risk of nonfatal pedestrian injury among children. The sample was obtained from two urban cities of China using multi-staged randomized sampling. Information was collected by respondents' reporting using self-administrative way in the classroom under the guidance of interviewers. A logistic regression analysis was applied to examine the associations between SES and nonfatal children pedestrian injury. The results showed that boys and children aged 10 had significantly increased odds of suffering nonfatal pedestrian injury. Migrant children were at higher risk of being injured. Students whose mothers' educational levels were either less than secondary school or postgraduate were more likely to sustain injury. Children who were from wealthier families or poorer families easily suffered from injury compared to children from middle families. Children living with grandparents, or siblings, or a single father, or a single mother were all at increased risk of injury. The possible causes or pathways of these SESs' impacts on pedestrian injury were explored in discussion. This study suggests that SESs are important determinants of nonfatal pedestrian injury among children in China.

Objective To examine relationships between weight status and different forms of bullying victimization among adolescents aged 11-18 years. Methods The relationships between weight status and bullying victimization (physical, verbal, and relational) were examined utilizing data from the Guangdong Provincial Youth Health Behavior Survey. Data on height, weight, and victimization behaviors were collected by self-reporting from 12 439 subjects. (χ 2 test and logistic regression were used to analyze relationships between weight and bullying victimization. Results The incidence of victimization for adolescents aged 11-18 years was 8.6%, with higher rates for boys (12.4%) than for girls (4.7%). For children with normal, overweight and obese body mass index (BMI), the incidence rates of victimization were 8.2%, 17.3%, and 11.5%, respectively. Compared to normal weight, overweight was a risk factor for bullying victimization (OR=1.60, 95% CI:1.18-2.17), and it also increased children's risk of being teased in a hurtful way (OR=2.13, 95% CI: 1.41-3.24) and being made fun of due to physical appearance (OR=3.58, 95% CI: 2.27-5.67). Obesity only increased the risk for children of being made fun of due to physical appearance (OR=2.45, 95% CI: 1.44-4.15). Conclusions The victimization for children at school is common in Guangdong province, China. Overweight and obese children are more likely to be victims of bullying behaviors, especially verbal victimization.

background The aim of this study was to investigate trends in the distribution, prevalence, awareness, treatment, and control of hypertension in a Chinese population that has had the fastest growing gross domestic product in the world over the past 3 decades. methods Four standardized cross-sectional health surveys were conducted between 2002 and 2010 in a population consisting of 85 million residents in Guangdong Province. Multistage cluster sampling was adopted to recruit representative samples. The data were obtained through on-site health examinations and face-to-face interviews. results The aging trend in this population was not significant (P = 0.17) during the survey period, whereas body mass index/waist circumference increased significantly (P = 0.047 for body mass index and P

To explore the prevalence of weight misperception and related influencing factors among adult residents in Guangdong province so as to provide information for prevention and control on weight misperception.A multi-stage stratified random sampling method was used to select the sample. Forty-two streets/villages were selected from 21 counties/districts through randomly sampling. Four communities were then chosen from every selected town or district, followed by 40 families chosen from every village or community. Questionnaire was used to collect data on weight perception and its related risk factors. SPSS 16.0 was used for data analysis.There were 6625 respondents participating in the study. Out of them, 50.2% participants misperceived their weight status, among which 35.9% of them underestimated while 14.3% overestimated their weights. Females aged 15 - 24 were more likely to overestimate weights than males in the same age group (38.6% vs. 18.5%), while males were more likely to underestimate weights than females (25.8% vs. 8.5%). The prevalence of underestimation on weights increased with the increase of age in both males and females but the prevalence of overestimation on weights decreased. Data from multivariate results from logistic analysis showed that rural residents, males, being elderly, residents with low education level, manual occupations (agriculture, forestry, animal husbandry and fishery), low family income and with anxiety were the major risk factors on underestimation of weight. However, factors as being urban residents, females, adolescents, minority and never having received weight measurement etc. were the major risk factors of overestimated on weight.Misperceptions of weight status in Guangdong province exhibited a high prevalence with complicated influencing factors, calling for more psychological research to be carried out to prevent and reduce the misperceptions on weight status.

BackgroundThe American Diabetes Association and World Health Organization have recently adopted the HbA1c measurement as one method of diagnostic criteria for diabetes. The change in diagnostic criteria has important implications for diabetes treatment and prevention. We therefore investigate diabetes using HbA1c and glucose criteria together, and assess the prevalent trend in a developing southern Chinese population with 85 million residents.MethodsA stratified multistage random sampling method was applied and a representative sample of 3590 residents 18 years of age or above was obtained in 2010. Each participant received a full medical check-up, including measurement of fasting plasma glucose, 2-hour post-load plasma glucose, and HbA1c. Information on history of diagnosis and treatment of diabetes was collected. The prevalence of diabetes obtained from the present survey was compared with the data from the survey in 2002.ResultsThe prevalence of diabetes based on both glucose and HbA1c measurements was 21.7% (95% CI: 17.4%-26.1%) in 2010, which suggests that more than 1 in 5 adult residents were suffering from diabetes in this developing population. Only 12.9% (95% CI: 8.3%-17.6%) of diabetic residents were aware of their condition. The prevalence of pre-diabetes was 66.3% (95% CI: 62.7%-69.8%). The prevalence of diabetes and pre-diabetes which met all the three diagnostic thresholds (fast plasma glucose, 2 hour post-load plasma glucose, and HbA1c) was 3.1% and 5.2%, respectively. Diabetes and pre-diabetes as determined by HbA1c measurement had higher vascular risk than those determined by glucose levels. The prevalence of diabetes increased from 2.9% (95% CI: 2.0%-3.7%) in 2002 to 13.8% (95% CI: 10.2%-17.3%) in 2010 based on the same glucose criteria.ConclusionsOur results show that the diabetes epidemic is accelerating in China. The awareness of diabetes is extremely low. The glucose test and HbA1c measurement should be used together to increase detection of diabetes and pre-diabetes.

Background The metabolic syndrome has been shown to increase the incidence of cardiovascular disease. Little information exists on the prevalence of the metabolic syndrome for southern Chinese. We therefore investigate the prevalence of the metabolic syndrome in a southern Chinese population with 85 million residents. Methods The Guangdong Nutrition and Health Survey 2002 is a cross-sectional survey designed to assess the health and nutritional status of 85 million residents in Guangdong province located in southern China. Stratified multistage random sampling method was applied in this survey and a provincial representative sample of 6,468 residents aged 20 years or above was obtained in the present study. The participants received a full medical check-up including measurement of blood pressure, obesity indices, fasting lipids and glucose levels. Data describing socioeconomic and lifestyle factors was also collected through interview. Metabolic syndrome was defined in accordance with the International Diabetes Federation criteria. Results The prevalence of metabolic syndrome was 7.30%, translating into a total of 4.0 million residents aged 20 years or above having the condition in this southern Chinese population. The urban population had higher prevalence of the syndrome than the rural population (10.57% vs 4.30%). Females had a higher prevalence of metabolic syndrome than males (8.99% vs 5.27%). More than 60% of the adults had at least one component of the metabolic syndrome. Conclusions Our results indicate that a large proportion of southern Chinese adults have the metabolic syndrome and associated risk factors. The metabolic syndrome has become an important public health problem in China. These findings emphasize the urgent need to develop population level strategies for the prevention, detection, and treatment of cardiovascular risk in China.

To explore the relationship between distorted weight perception and suicide ideation among normal weight adolescents in Guangdong province.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.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).The prevalence of distorted weight perception was high and it significantly associated with suicide ideation.

In engineering, the pore pressure parameter is a useful factor. However, the expression of the compressibility coefficient of pore fluid, which is needed in calculating the parameter, is still not acceptable. Based on the pore water pressure, the definition of compressibility coefficient is proposed. The difference between pore air pressure and pore water pressure is considered according to the effect of surface tension. In order to simply the expression, introduced are two parameters: parameter T R which deals with the influence of surface tension; parameter Φ which is used to reflect the status of pore air. The expression of compressibility coefficient derived can be extended to the application on unsaturated soils with lower degree of saturation. Then, the pore pressure parameters for K 0 loading and isotropic loading are presented. Finally, the formula is validated with the experimental results from field and laboratory tests reported in the literatures, and the agreement is good. The pore pressure parameter is not constant during loading, as should be indicated.

To compare the magnitude of inequities in health-related behaviors among males in Guangdong province, and to investigate the extent of the disparities.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 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.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.

The term of quasi-saturated soil is not currently used in the literatures. However this type of soils is distributed extensively, such as the soils formulated by air sparging as a remediation technology for treatment of contaminated aquifers. In engineering, quasi-saturated soils are usually considered as saturated soils. Nevertheless the characteristic of quasi-saturated soils is very different from that of saturated soils. The differences are concluded as following: a) air bubbles block the pores so that the hydraulic conductivity decreases very much; b) the experiment model shows that the un-drained shear strength of quasi-saturated soils is higher than saturated soils; c) due to the compressibility of pore mixture fluid, the instant deformation occurs when the quasi-saturated soils are loaded; d) more time is needed to complete the consolidation of quasi-saturated soils when compared with saturated soil; e) the property of wave propagation in quasi-saturated soils differs from saturated soils and so on. In this paper, authors table some key questions about quasi-saturated soils firstly. Then according to the questions, the results or progress of research in quasi-saturated soils are introduced and summarized. Conclusions and recommendations for future research are addressed in the end: the research of quasi-saturated soils develops mainly around the effect of air bubbles.

To understand the prevalence of suicide attempts and its related risk factors in Guangdong province to provide scientific basis information for suicide intervention.Multi-stage stratified random sampling method was used to select the sample. 42 streets or towns were selected from 21 counties or districts through randomly sampling. 4 communities were then chosen from every selected town or district, followed by 40 families chosen from every village or community. Questionnaire was used to collect data on suicide attempts and its related risk factors. SPSS 16.0 was used for data analysis.6625 peoples were participated in the study. The 12-month incidence of suicidal attempts was 0.8%. It was higher for females (1.1%) than that for males (0.5%), and the 25 - 35 years (1.6%) age group was among the highest. There was no significant difference between the prevalence rates in urban or rural residents.from multivariate analysis showed that factors as: being female (OR = 2.1), experienced negative events of life (OR = 15.5), in poor sleeping condition (OR = 1.6), feeling lonely (OR = 1.5) and anxiety (OR = 1.8) were high risk for suicide attempts.Suicide attempts in Guangdong province exhibited a high prevalence with complicated influencing factors. Comprehensive countermeasures are needed to prevent and reduce suicidal behaviors.

To evaluate the outcome of health education program on drowning prevention among primary and secondary school children in rural areas.A township was selected and all the students from grade 3 to 5, grade 7 to 8, and grade 10 to 11 were selected to take part in the program. Twelve intervention measures on natural water safety and drowning prevention were carried out for one year. Information was collected using the same questionnaire before and after the intervention program.One year after the intervention was carried out, children's knowledge on drowning prevention improved significantly (13.21, 95%CI: 12.51 - 13.90), and a positive effect was also noticed among boys (12.77, 95%CI: 11.77 - 13.77), girls (13.80, 95%CI: 12.82 - 14.78), and among primary school children(15.51, 95%CI: 14.30 - 16.72), senior high school children (10.78, 95%CI: 9.50 - 12.05) and junior high school children (12.77, 95%CI: 11.84 - 13.71). Overall rates on risk behaviors dropped from 41.4% to 32.2% (by 22.2%) including 15.6% for boys, 35.2% for girls and 13.8%, 29.3%, 26.3% for primary school children, senior high school children, junior high school children, respectively. The incidence rates for non-fatal drowning decreased by 58.9% (from 5.6% to 2.3%). The person-times for treatment on sight, in emergency settings, in outpatient clinic or in the hospitals had a reduction from 399, 78, 36 to 175, 32, 14, respectively.Health education program could improve children's perception on water safety, and reduce their risk behaviors as well as on the incidence of non-fatal drowning in the rural areas.

To understand the incidence and characteristics of nonfatal drowning among primary and middle school students in rural area and to provide basic information for intervention.A rural town was selected and all students from 3th-8th grades, 10th grade and 11th grade were studied. All data were collected, using a self-administrated questionnaires which was guided by investigator.The overall incidence rate of nonfatal drowning was 5.65% (549/9732) and were 7.69%, 5.80%, 2.39% for primary, secondary and high school students, respectively. Male students had a higher rate (7.14%) than that of females (4.03%). The incidence rates of non-treated, treated in emergency and under hospitalization were 4.52%, 0.77% and 0.35%. The major reasons of drowning were swimming (46.88%), falling into waters (15.67%), diving (13.79%) and rescuing others (6.24%). The proportion of drowning occurred in the afternoon, evening, at noon or in the morning were 59.94%, 15.64%, 14.77% and 9.65% respectively. The common sites of drowning were river/lake (42.48%), swimming pool (19.56%), reservoir (11.39%) and pond (4.38%). 66.76% of the drowning cases were witnessed by other person, and 17.86% were conscious when being removed from waters.The incidence of nonfatal drowning among students in rural areas was high, and the natural body of waters was the most common site causing drowning while swimming was the major reason of drowning. Intervention targeting on primary and middle school students in rural should be carried out to reduce the incidence.

To describe the characteristics of child pedestrian traffic injuries among aged 0-14 years old in Guangzhou city and to provide information on road, vehicle and human injuries in pedestrian.A database of all motor vehicle crashes involving child pedestrian traffic injury cases over a five-year period (2000-2004), was from the police department.The annual pedestrian traffic injury rates on incidence, mortality and case fatality were 17.63/ 1,100,000, 1.78/ 100,000 and 10.07% respectively. Both incidence rate and mortality peaked in the 5-9 age group were 26.80/ 100,000 and 2.57/ 100,000, with case fatality peaked in the 0-4 age group (13.29%). For males, the incidence (20.98/ 100,000) and mortality (2.00/ 100,000) were higher than that in females (13.83/ 100,000, and 1.52/ 100,000). The main injured parts of body would include multi-areas (40.34%), head (26.75%) and lower limbs (21.53%). 10.07% of the cases died and 66.18% and 23.75% of them having had severe and slight injures. The major causes were due to drivers (57.50%) and pedestrians (33.47%) faults with top three responsible vehicles were cars (40.14%), two-wheeled motorcycles (34.38%) and vans (22.15%).Data from pediatric pedestrian injury poses a threat to children and adolescents, data suggesting that it is important to change behaviors of both drivers and pedestrians.

To investigate the serum levels of cholesterol, triglyceride and high density lipoprotein cholesterol in children aged 3-14 years and its influencing factors.The cross-sectional survey study population was a representative sample from Guangdong province obtained by multi-stage randomized cluster sampling. Serum lipids in 6188 children agedor = 3 years were assayed using automatic biochemical instrument. The data of social and demographic status were collected by face-to-face interview, and height and weight were obtained by physical examination.The age-standardized and region-weighted means of serum total cholesterol (TC), triglyceride (TG), and high density lipoprotein cholesterol (HDL-C) were 0.80 mmol/L, 3.50 mmol/L and 1.28 mmol/L, respectively. For the mean of TG, there was no difference between metropolitan and middle city, nor between rich county and poor county. For TC, it was the highest in metropolitan, and there was no difference between rich and poor county. For HDL-C, the difference existed between every two regions. The age-standardized and region-weighted prevalence of high TG, high TC and low HDL-C were 2.2%, 2.1% and 8.0%, respectively. Metropolitan, rich county, low weight and age between 7.0-9.9 years are protecting factors for high TG, and the number of family between 3-4, age between 7.0-9.9, metropolitan, middle city and poor county are risk factors for high TC. Male, family income per year between 800-9999 RMB, middle city, rich county are protecting factors for low HDL-C.The prevalence of abnormal serum lipid was still low compared with other regions in China. The region, number of family member, age and sex may be the important factors influencing on serum lipid levels.

To describe the epidemiological characteristics of overweight and obesity among people aged 18 and over in Guangdong province in 2002, and to identify the populations and regions under high risk.Cross-sectional survey was used through sampling on multi-stage randomized clusters. Data of socialeconomic status were collected by face-to-face interview. Data on weight and height was obtained through physical check-ups.A sample size of 15 130 people and the mean body mass index (BMI) was 22.03 +/- 3.38 with no significant difference between males and females. However the significant difference was seen between cities and rural areas. The crude prevalence rate of overweight and obesity were 16.8% and 1.8%, and the age-adjusted rate were 15.0% and 1.7%, respectively. The crude rate of overweight in cities (24.8%) and males (17.5%) were higher than that in rural areas (9.4%) and females (16.2%). The crude rate of obesity in cities was seen higher than that in the rural areas, but not significantly different between females and males. The results of logistic regression analysis showed that the major risk factors influencing overweight would include household income, age, gender, smoking habits, physical exercises and location of residence.About one sixth of the citizens in Guangdong province were considered to be overweighted and obesive had become an important public health problem. Integrated measures must be taken for prevention and control.

Background Drowning is a major cause of morbidity and mortality for children, yet non-fatal drowning remains poorly understood. The aim of this study was to explore potential modifiable risk factors of non-fatal drowning among children in rural areas of China. Methods A cross-sectional survey was first conducted to obtain non-fatal drowning cases, and 7432 students in grades three to eight from 17 schools participated in the cross sectional survey. Of these, 805 students reported that they experienced non-fatal drowning in the previous year. Then 368 cases were selected randomly to participate in a 1:1 matched case-control study. Each drowning case was matched by one control with the same sex and similar age (the gap less than 2 years) who was selected randomly from the same class. Results Boys were more likely to be involved in non-fatal drowning. Non-fatal drowning most often happened in the afternoon (65.1%) and natural bodies of water were the most common sites of drowning (71.1%). Swimming, diving and playing in natural waters were the leading activities that preceded non-fatal drowning. The significant risk factors for non-fatal drowning were swimming in natural waters without adult supervision (OR = 3.40, 95% CI: 1.92-6.03), playing in or beside natural waters (OR = 2.08, 95% CI: 1.17-3.70) and poor swimming skills (OR = 2.74, 95% CI: 1.14-6.62). However, the following variables were protective factors: supervisor aged 30 years or over (OR = 0.20, 95% CI: 0.09-0.49) and no water activities (OR = 0.36, 95% CI: 0.18-0.70). Conclusions The reduction in dangerous water activities, swimming training and enhancement in supervision among children might decrease the risk of non-fatal drowning.