Meta-analysis is a method to obtain a weighted average of results from various studies. In addition to pooling effect sizes, meta-analysis can also be used to estimate disease frequencies, such as incidence and prevalence. In this article we present methods for the meta-analysis of prevalence. We discuss the logit and double arcsine transformations to stabilise the variance. We note the special situation of multiple category prevalence, and propose solutions to the problems that arise. We describe the implementation of these methods in the MetaXL software, and present a simulation study and the example of multiple sclerosis from the Global Burden of Disease 2010 project. We conclude that the double arcsine transformation is preferred over the logit, and that the MetaXL implementation of multiple category prevalence is an improvement in the methodology of the meta-analysis of prevalence.

Meta-analysis of prevalence

Sleep and immunity are bidirectionally linked. Immune system activation alters sleep, and sleep in turn affects the innate and adaptive arm of our body’s defense system. Stimulation of the immune s...

/pdf/the-sleep-immune-crosstalk-in-health-and-disease-27ylhsniq6.pdf

The Sleep-Immune Crosstalk in Health and Disease

Objective To establish a national body mass index (BMI) reference norm for the
purpose of screening and more active prevention and cure on overwight and obesity in Chinese children and
adolescente. Methods The 2000 Chinese National Survey on Students Constitution and Health was used as
reference population. In total there were more than 244.2 thousands of primary and secondary Han
nationality students aged 7 through 18 years old included in this study. The BMI distribution of various
Chinese children and adolescent groups were compared with the NCHS international norm, the percentage
values and with advanced ages, were calculated. In the beginning, three temporary norms were set up,
using the different combination of P85, P90 and P95 BMI percentages. Based on the intersect testing and
varifying of physiological, lipidemia biochemical and body composition measures, the best norm was then
selected. B-spline smoothing method was used to correct the curves, both for males and females, composed
by cut-off points at different ages. Results Using samples from the costal developed metropolis, the BMI
curves successfully overcame the shortcomings of low and depressive phenomenon of the total population, in
particular after the mid--adolescent period. The temporary Norm Ⅱ, composed by cut-off points of P85 for
overweight and P95 for obesity, was found to be the best among the three temporary norms, both shown by
its sensitivity and specificity. 24 and 28 were used as cut-off points for overweight and obesity in this norm,
both for males and females aged 18 years. These two cut-off points were consistent with those shown in the
Body Mass Index Reference Norm for Screening Overweight and Obesity in Chinese Adults. Three Samples
from Beijing, Henan and Sichuan, used as representatives of upper, middle and relative low levels of
physical growth of children and adolescents in China, were used for extra tests. The screening results
showed that among the male and female subjects aged 7 through 18 years, the prevalence rates were
17. 00% and 9. 46% for overweight, 9. 99% and 6. 47% for obesity in Beijing while 10. 86% and 6. 64%
for overweight, 4.27% and 3.07% for obesity in Henan, and 6.95% and 4.23% for overweight and
2. 84 % and 2. 09 % for obesity in Sichuan, respectively. Data clearly showed that the results were in
 accordance with the actural situation seen in the Chinese studens in 2000. Conclusion The newly
established reference norm seemed to be good for prospective studies as it considered the facts regarding the
rapid and strong tendency of secular growth changes seen in the Chinese children and adolesconts. It also
decreased the difference of growth levels between the Chinese children and adolescents and those of the
international norms. Ths norm was particularly developed for the Chinese which was also in consistent with
the Eastern Asia ethnic charcteristics so could be promoted in China.

Body mass index reference norm for screening overweight and obesity in Chinese children and adolescents

A large body of evidence has demonstrated that exposure to childhood maltreatment at any stage of development can have long-lasting consequences. It is associated with a marked increase in risk for psychiatric and medical disorders. This review summarizes the literature investigating the effects of childhood maltreatment on disease vulnerability for mood disorders, specifically summarizing cross-sectional and more recent longitudinal studies demonstrating that childhood maltreatment is more prevalent and is associated with increased risk for first mood episode, episode recurrence, greater comorbidities, and increased risk for suicidal ideation and attempts in individuals with mood disorders. It summarizes the persistent alterations associated with childhood maltreatment, including alterations in the hypothalamic-pituitary-adrenal axis and inflammatory cytokines, which may contribute to disease vulnerability and a more pernicious disease course. The authors discuss several candidate genes and environmental factors (for example, substance use) that may alter disease vulnerability and illness course and neurobiological associations that may mediate these relationships following childhood maltreatment. Studies provide insight into modifiable mechanisms and provide direction to improve both treatment and prevention strategies.

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The Devastating Clinical Consequences of Child Abuse and Neglect: Increased Disease Vulnerability and Poor Treatment Response in Mood Disorders

The epidemiology of benzodiazepine misuse: A systematic review.

Self-reported sleep disturbances in HIV-infected people: a meta-analysis of prevalence and moderators.

Association between sleep duration, suicidal ideation, and suicidal attempts among Chinese adolescents: The moderating role of depressive symptoms

Bullying, Depression, and Suicidal Ideation Among Adolescents in the Fujian Province of China: A Cross-sectional Study.

Objectives Given the differences between general high school (GHS) and vocational high school (VHS) students, this study aimed to investigate the lifetime prevalence of non-medical use of prescription pain relievers (NMUPPR) among high school students as well as the associations between NMUPPR and individual-level factors and school category. Methods A cross-sectional study was conducted in GHS and VHS students in 2012 in Chongqing, and 11 906 students’ questionnaires were completed and qualified for the survey. Self-reported NMUPPR and information regarding individual-level determinants and school category were collected. A multilevel multivariate logistic regression model was fitted to explore independent predictors of NMUPPR. Results The total lifetime prevalence of NMUPPR was 11.3%, and NMUPPR was more prevalent among VHS students (15.8%) compared with GHS students (9.8%). Overall, the results indicated that VHS students were more likely to be involved in NMUPPR (adjusted OR (AOR)=1.64, 95% CI 1.42 to 1.89). Regarding the individual-level predictors of NMUPPR, below-average family economic status was negatively correlated with NMUPPR (AOR=0.77, 95% CI 0.60 to 0.98), and students with more pocket money were more likely to be engaged in NMUPPR. Students who had difficult family relationships, had poor relationships with teachers, had parents or friends who engaged in non-medical prescription drug use, and considered or attempted suicide were more likely to be engaged in NMUPPR. Conclusions NMUPPR among high school students is a multidetermined phenomenon. The current findings indicate that VHS students are an important subgroup of adolescents and highlight the need for additional research as well as targeted prevention and intervention programmes for NMUPPR.

https://bmjopen.bmj.com/content/bmjopen/5/7/e007569.full.pdf

Non-medical use of prescription pain relievers among high school students in China: a multilevel analysis

Objectives Recent studies have suggested that sexual minorities are more likely to have poor sleep quality. This study aims to explore sleep quality among sexual minority adolescents and examines the association between sexual minority status and sleep quality. Design Cross-sectional survey. Setting A total of 506 high schools in seven Chinese provinces. Participants A total of 150 822 students in grades 7–12 completed the questionnaires, and 123 459 students who reported being aware of their sexual orientation were included in analyses. Main outcome measures The Pittsburgh Sleep Quality Index, sexual attraction and school bullying victimisation. Results Of the 123 459 students who were analysed, 5.00% self-reported as sexual minorities. Only 26.67% of sexual minority students slept 8 or more hours/day, which is less than their heterosexual peers (35.70%; χ2=130.04, P Conclusions Our study suggested that poor sleep quality was common in sexual minority adolescents, and more attention should be paid to sleep problems in this population. Conducting interventions to reduce school bullying behaviours is an important step to improving sleep quality in sexual minority adolescents. Further, studies are warranted that focus on the risk factors and mechanisms of and interventions for sleep problems in sexual minority adolescents.

https://bmjopen.bmj.com/content/bmjopen/7/12/e017067.full.pdf

Pengsheng Li

Papers

Self-reported sleep disturbances in HIV-infected people: a meta-analysis of prevalence and moderators.

Association between sleep duration, suicidal ideation, and suicidal attempts among Chinese adolescents: The moderating role of depressive symptoms

Bullying, Depression, and Suicidal Ideation Among Adolescents in the Fujian Province of China: A Cross-sectional Study.

Non-medical use of prescription pain relievers among high school students in China: a multilevel analysis

Is sexual minority status associated with poor sleep quality among adolescents? Analysis of a national cross-sectional survey in Chinese adolescents.