ABSTRACT
Objective To investigate the epidemic character of injuries among rural left-behind children, so as to provide evidence for strategies and processes on preventing injuries. Methods Using stratified cluster sampling, a town was randomly selected from each of the two layers with different economic development levels in Qingxin district, Qingyuan city, Guangdong Province. The local left-behind children of 3-9 grades from 3 elementary schools and 3 middle schools were randomly selected from the local area. The student self-administered questionnaire was used to investigate the occurrence of injuries, personal circumstances, family environment and school situation in the past year. Data of injury situation, personal situation, family situation and school situation during last year were analysed by Chi-square and multiple logistic analysis. Results Injuries were reported to occur in 440 left-behind children, with an injury rate of 17.5%. Significant difference of injury rate was observed between groups divided by grades, being only-child in family, health conditions, anxiety, getting along with other students, teacher’s attitude to students, emphasizing security by teachers, knowledge level about injury, and injury-relative behaviors (all P<0.05). Multivariate logistic regression model results suggested that middle school, physical health, behavioral level, and relationship with classmates are protective factors, anxiety is a risk factor (OR=1.262,95%CI:1.009~1.577,P=0.041). Conclusions We have to take some comprehensive methods to prevent injuries that are influenced by all kinds of factors. While constructing an advantage circumstance to left-behind children, their awareness of security should also be improved to reduce the occurrence of injuries.
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This paper aims to achieve Bootstraping in hierarchical data and to provide a method for the estimation on confidence interval (CI) of intraclass correlation coefficient (ICC).First,we utilize the mixed-effects model to estimate data from ICC of repeated measurement and from the two-stage sampling.Then,we use Bootstrap method to estimate CI from related ICCs.Finally,the influences of different Bootstraping strategies to ICC' s CIs are compared.The repeated measurement instance show that the CI of cluster Bootsraping containing the true ICC value.However,when ignoring the hierarchy characteristics of data,the random Bootsraping method shows that it has the invalid CI.Result from the two-stage instance shows that bias obsered between cluster Bootstraping's ICC means while the ICC of the original sample is the smallest,but with wide CI.It is necessary to consider the structure of data as important,when hierarchical data is being resampled.Bootstrapping seems to be better on the higher than that on lower levels.
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To explore the improvement of clinical symptoms after treatment on patients with depression under the latent growth curve modeling.514 patients were studied with Hamilton Depression Rating Scale for depression and nonlinear conditional.Latent growth curve modeling was constructed to assess the features of outcome growth trajectory and possible related influencing factors.Results indicated that the outcome measure showing nonlinear growth trajectory and rapid drop during the first follow-up period and then declining or leveling off for the rest of the observation period on symptoms of anxiety,cognitive disturbance,retardation,sleeping disorder and HAMD scores.The variances of both latent intercept and the slope growth factor were statistically significant,indicating they varied across individuals.Gender did not show significant effect on both the intercept and the slope growth factor for the six outcomes,while age had a significant positive effect on initial weight loss,sleep disorder and HAMD scores at the baseline (0.015,0.048 and 0.068,P＜0.05) survey.Marriage showed significant positive effect on intercept factor of anxiety symptoms (0.563,P＜0.05) but negative effect on slope growth factor (-0.244,P＜0.05) while family history had significant positive effect on intercept factor regarding retardation (0.471,P＜0.05).The level of received education had a significant negative effect on intercept factor of anxiety symptoms and HAMD scores (-0.424 and-0.914,P＜0.05).Latent growth curve models allowed the researchers to study the overall growth trajectory as well as the captured individual differences on these trajectories over time,that also provided a powerful tool for the analysis on longitudinal data.
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Objective To explore the attitudes towards the Smoking Ban policy and the bias in different levels of related society sanctions so as to provide evidence for implementing anti-smoking measures in the public places.Methods A multi-univariate-multilevel logistic model was developed to find the relation between penalty attitudes and the covariates' effects.Results 74.6％ (3647/4892) and 61.2％ (2994/4892) of the residents agreed to punish either the managers of public places or to the smokers.The two kinds of attitude were associated (x2 =1253.45,P＜0.0001 ).Residents being female,aged between thirty and fifty-nine years old,having had higher than college education,being non-current smokers,with high scores on knowledge of tobacco control,tended to have the attitude of punishing the public place managers and smokers.However,those persons exposed to everyday secondhand smoke or being non-current smokers,tended to punish the smokers in the generalized Wald test.Conclusion There was strong evidence noticed that most of the residents in Guangzhou had supported the ‘tobacco control penalty'.Factors as age,sex,level of education received,knowledge on hazards of smoking,being current smokers and under secondhand smoke exposure were the influencing factors.Non-current smokers and those who exposed to secondhand smoke everyday,would prefer to take different penalties policies.
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Objective To analyze the awareness on health among high school students and its influencing factors in Guangdong. Methods Multi-stage sampling and questionnairs "2009 health awareness survey of the Chinese citizens" developed by our Department of Health, were used. Data were analyzed by multivariate multilevel model under MLwinN 2.19 software. Results The mean scores on knowledge and ideas, behaviors and related skills among 1606 high school students of Guangdong province, were 69.08 ± 14.81,60.05 ± 16.85 and 74.99 ± 21.17 respectively. Three items on health showed that they all related to each other and relations between grades (0.972,0.715 and 0.855) were greater than the individuals (0.565,0.426 and 0.438). Conclusion Factors as students from outside the Pearl River Delta region or from the rural areas, being male, at general secondary schools, at grade one, with poor academic performance and more pocket money etc., had lower levels on those related information of health.