Shiyi Cao

Shift work and diabetes mellitus: a meta-analysis of observational studies

Background Observational studies suggest that shift work may be associated with diabetes mellitus (DM). However, the results are inconsistent. No systematic reviews have applied quantitative techniques to compute summary risk estimates. Objectives To conduct a meta-analysis of observational studies assessing the association between shift work and the risk of DM. Methods Relevant studies were identified by a search of PubMed, Embase, Web of Science and ProQuest Dissertation and Theses databases to April 2014. We also reviewed reference lists from retrieved articles. We included observational studies that reported OR with 95% CIs for the association between shift work and the risk of DM. Two authors independently extracted data and assessed the study quality. Results Twelve studies with 28 independent reports involving 226 652 participants and 14 595 patients with DM were included. A pooled adjusted OR for the association between ever exposure to shift work and DM risk was 1.09 (95% CI 1.05 to 1.12; p=0.014; I2=40.9%). Subgroup analyses suggested a stronger association between shift work and DM for men (OR=1.37, 95% CI 1.20 to 1.56) than for women (OR=1.09, 95% CI 1.04 to 1.14) (p for interaction=0.01). All shift work schedules with the exception of mixed shifts and evening shifts were associated with a statistically higher risk of DM than normal daytime schedules, and the difference among those shift work schedules was significant (p for interaction=0.04). Conclusions Shift work is associated with an increased risk of DM. The increase was significantly higher among men and the rotating shift group, which warrants further studies.

A systematic review of antibiotic utilization in China

OBJECTIVES Reliable data about antibiotic utilization in the large pharmaceutical market of the worlds most populous country, the Peoples Republic of China, are in short supply. Although many primary studies have investigated the use of antibiotics in China, most of the relevant studies were published in the Chinese language. This systematic review aims to summarize reported percentages of outpatient encounters resulting in the prescription of antibiotics in China. METHODS We systematically searched and reviewed studies of antibiotic prescribing patterns in China, published in Chinese or English between 2000 and August 2012. The study quality was assessed and the overall percentage of outpatient encounters resulting in the prescription of antibiotics was calculated using random-effects meta-analysis. Subgroup analyses were conducted to investigate heterogeneity across studies. RESULTS We included 57 eligible studies (with a total of 556 ,435 outpatient encounters). The overall percentage of outpatients prescribed antibiotics was 50.3% (95% CI: 47.4%-53.1%). Of the outpatients prescribed antibiotics, 74.0% (95% CI: 71.3%-76.6%) were prescribed one antibiotic, 23.3% (95% CI: 21.1%-25.7%) were prescribed two antibiotics and 2.0% (95% CI: 1.3%-2.8%) were prescribed three or more antibiotics. The proportion of antibiotic utilization differed greatly across hospital levels and geographical regions and fluctuated over time. CONCLUSIONS The percentage use of antibiotics is high in China. The excessive use of antibiotics is particularly more problematic in lower-level hospitals and in less developed western China. The implementation and impact of the national efforts to control the excessive use of antibiotics should be appropriately evaluated.

Consumption of fruit and vegetable and risk of coronary heart disease: A meta-analysis of prospective cohort studies

BACKGROUND Observational studies suggest that an association between fruit and vegetable consumption and coronary heart disease (CHD). However, the results are inconsistent. We conducted a meta-analysis to evaluate the relationship of fruit and vegetable consumption with CHD risk and quality the dose-response relationship between them. METHODS Relevant prospective studies were identified by a search of PubMed, Embase and Web of Science databases to July 2014. A random-effects model was used to calculate the pooled relative risk (RR) and 95% confidence intervals (CI). RESULTS Twenty-three studies involving 937,665 participants and 18,047 patients with CHD were included. Compared with the lowest consumption levels of total fruit and vegetable, fruit and vegetable, the RR of CHD was 0.84 (95% CI, 0.79-0.90), 0.86 (95% CI, 0.82-0.91), 0.87 (95% CI, 0.81-0.93), respectively. The dose-response analysis indicated that, the RR of CHD was 0.88 (95% CI: 0.85-0.91) per 477 g/day of total fruit and vegetable consumption, 0.84 (95% CI: 0.75-0.93) per 300 g/day of fruit intake and 0.82 (95% CI: 0.73-0.92) per 400 g/day of vegetable consumption. A nonlinear association of CHD risk with fruit or vegetable consumption separately was found (P for nonlinearity <0.001). In the subgroup analysis of location, a significant inverse association was observed in Western populations, but not in Asian populations. CONCLUSIONS This meta-analysis indicates that total fruit and vegetable, fruit and vegetable consumption, are significantly associated with a lower risk of CHD. The significant inverse association was found in Western populations, but not in Asian populations, which warrants further research.

Smoking and risk of erectile dysfunction: systematic review of observational studies with meta-analysis.

Background There are many recent observational studies on smoking and risk of erectile dysfunction (ED) and whether smoking increases the risk of ED is still inconclusive. The objective of this meta-analysis was to synthesize evidence from studies that evaluated the association between smoking and the risk of ED. Methods We searched PubMed, Embase, Web of Science, and Scopus in January 2013 to identify cohort and case-control studies that evaluated the association between smoking and ED. Study quality of included studies was assessed by the Newcastle-Ottawa scale. Random-effects meta-analyses were used to combine the results of included studies. Results Four prospective cohort studies and four case-control studies involving 28, 586 participants were included. Because of significant heterogeneity after including case-control studies in meta-analysis, the consistent results of prospective cohort studies were considered more accurate, Because of significant heterogeneity after including case-control studies in meta-analysis, the consistent results of prospective cohort studies were considered more accurate, Compared with non-smokers, the overall odd ratio of ED in prospective cohort studies was 1.51(95% CI: 1.34 to 1.71) for current smokers, and it was 1.29 (95% CI: 1.07 to 1.47) for former smokers. Evidence of publication bias was not found. Conclusion Evidence from epidemiological studies suggests that smoking, especially current smoking, may significantly increase the risk of ED

Coffee consumption and risk of prostate cancer: a meta-analysis of prospective cohort studies

Observational studies and animal evidence suggest an association between coffee consumption and the risk of prostate cancer. However, the results are inconsistent. We evaluated the association by conducting a meta-analysis of prospective cohort studies. PubMed and Embase were searched through June 2013 to identify studies that met predetermined inclusion criterion. A random-effects model was used to calculate the pooled risk estimates. Ten prospective cohort studies involving 8973 patients with prostate cancer and 206 096 participants were included in this systematic review. Compared with individuals who seldom or never drink coffee, the pooled relative risk of prostate cancer was 0.88 (95% confidence interval: 0.82-0.95) for regular coffee drinkers. Exclusion of any single study did not materially alter the combined risk estimate. Visual inspection of a funnel plot and Beggs and Eggers tests did not indicate evidence of publication bias. In summary, integrated evidence from prospective cohort studies supports the hypothesis that coffee consumption may decrease the risk of prostate cancer.

Effectiveness of interventions for hypertension care in the community - a meta-analysis of controlled studies in China

BackgroundHypertension is a serious public health problem in China and in other developing countries. Our aim is to conduct a systematic review of studies on the effectiveness of community interventions for hypertension management in China.MethodsChina National Knowledge Infrastructure, PubMed, and references of retrieved articles were searched to identify randomised or quasi-randomised controlled studies that evaluated community hypertension care in mainland China. One reviewer extracted and a second reviewer checked data from the included studies.ResultsWe included 94 studies, 93 of which were in Chinese language, that evaluated the following interventions: health education, improved monitoring, family-support, self-management, healthcare management changes and training of providers. The study quality was generally poor, with high risk of biased outcome reporting and significant heterogeneity between studies. When reported, the vast majority of the included studies reported statistically significantly improved outcomes in the intervention group. By assuming zero treatment effects for missing outcomes, the weighted reduction in the intervention group was 6∙9 (95% CI: 4∙9 to 8∙9) mm Hg for systolic BP, and 3∙8 (95% CI: 2∙6 to 5∙0) mm Hg for diastolic BP. Exploratory subgroup analyses found no significant differences between different interventions.ConclusionsAfter taking account of possible reporting biases, a wide range of community interventions for hypertension care remain effective. The findings have implications for China and other low and middle income countries facing similar challenges. Because of significant heterogeneity and high risk of bias in the available studies, further well designed studies should be conducted in China to provide high quality evidence to inform policy decisions on hypertension control.

Hepatitis B virus status and the risk of pancreatic cancer: a meta-analysis.

Objective Whether hepatitis B virus (HBV) infection increases the risk of pancreatic cancer (PaC) is controversial. We carried out a meta-analysis to evaluate the association between HBV status and the risk of PaC. Methods PubMed, Embase, and the China National Knowledge Infrastructure were searched from their inception through April 2012 for case–control and cohort studies that have reported an association between HBV status and the risk of PaC. The reference lists of pertinent publications were also reviewed for potential studies. Methodological quality was assessed using the Newcastle–Ottawa Quality Assessment Scale. A random-effects model was used to summarize odd ratios (ORs) and 95% confidence intervals (CIs). Results We included seven case–control studies and three cohort studies, involving 5883 PaC cases. The summary OR of developing PaC was 1.22 (95% CI: 0.90–1.67) for individuals who were HBV surface antigen (HBsAg)-positive. Compared with the individuals who were never exposed to HBV infection, the summary OR of the risk of PaC was 1.60 (95% CI: 1.26–2.05) for chronic or inactive HBsAg carriers (HBsAg-positive) and 1.76 (95% CI: 1.05–2.93) for anti-HBc-positive but anti-HBs-negative individuals. Conclusion Inactive HBsAg carrier status and possible occult HBV infection may increase the risk of PaC. Large population-based multicenter prospective studies are required to further confirm this finding.

Off‐Hour Admission and Mortality Risk for 28 Specific Diseases: A Systematic Review and Meta‐Analysis of 251 Cohorts

Background A considerable amount of studies have examined the relationship between off‐hours (weekends and nights) admission and mortality risk for various diseases, but the results remain equivocal. Methods and Results Through a search of EMBASE, PUBMED, Web of Science, and Cochrane Database of Systematic Reviews, we identified cohort studies that evaluated the association between off‐hour admission and mortality risk for disease. In a random effects meta‐analysis of 140 identified articles (251 cohorts), off‐hour admission was strongly associated with increased mortality for aortic aneurysm (odds ratio, 1.52; 95% CI, 1.30–1.77), breast cancer (1.50, 1.21–1.86), leukemia (1.45, 1.17–1.79), respiratory neoplasm (1.32, 1.20–1.26), pancreatic cancer (1.32, 1.12–1.56), malignant neoplasm of genitourinary organs (1.27, 1.08–1.49), colorectal cancer (1.26, 1.07–1.49), pulmonary embolism (1.20, 1.13–1.28), arrhythmia and cardiac arrest (1.19, 1.09–1.29), and lymphoma (1.19, 1.06–1.34). Weaker (odds ratio <1.19) but statistically significant association was noted for renal failure, traumatic brain injury, heart failure, intracerebral hemorrhage, subarachnoid hemorrhage, stroke, gastrointestinal bleeding, myocardial infarction, chronic obstructive pulmonary disease, and bloodstream infections. No association was found for hip fracture, pneumonia, intestinal obstruction, aspiration pneumonia, peptic ulcer, trauma, diverticulitis, and neonatal mortality. Overall, off‐hour admission was associated with increased mortality for 28 diseases combined (odds ratio, 1.11; 95% CI, 1.10–1.13). Conclusions Off‐hour admission is associated with increased mortality risk, and the associations varied substantially for different diseases. Specialists, nurses, as well as hospital administrators and health policymakers can take these findings into consideration to improve the quality and continuity of medical services.

Sleep duration and risk of stroke events and stroke mortality: A systematic review and meta-analysis of prospective cohort studies

BACKGROUND Numerous studies have suggested the relationship between sleep duration and risks of stroke mortality and morbidity, however, the effect estimates varied substantially across studies and it remains unknown how many hours of habitual sleep are associated with the lowest risk of stroke outcomes. Therefore, we performed a dose-response meta-analysis of prospective cohort studies to evaluate the relation of sleep duration with risk of total mortality and stroke events. METHODS PubMed and Embase databases were searched through January 2016, and multivariate-adjusted relative risks were pooled by using fixed-effects models. Semiparametric and dose-response methods were used to assess the relationship of sleep duration and risk of stroke and stroke mortality. RESULTS Eleven articles with 16 independent reports were included in our meta-analysis. An approximate J-shaped relationship was detected between sleep duration and risk of stroke and stroke mortality. No evidence of a curve linear relationship was seen between sleep duration and risk of stroke or stroke mortality. Compared with 7-h sleep duration per day, the pooled relative risks for stroke events were 1.07 (95% CI 1.02-1.12) for each 1-h shorter sleep duration among individuals who slept <7h per day and 1.17 (1.14-1.20) for each 1-h increase of sleep duration among individuals with longer sleep duration and the pooled RR for stroke mortality was 1.17 (95% CI 1.13-1.20) per 1-h increase of sleep duration. CONCLUSIONS Both short and long duration of sleep are predictors of stroke outcomes, and long sleep duration is significant marker of stroke mortality.

Consumption of hot beverages and foods and the risk of esophageal cancer: a meta-analysis of observational studies

BackgroundPrevious studies have mostly focused on the effects of specific constituents of beverages and foods on the risk of esophageal cancer (EC). An increasing number of studies are now emerging examining the health consequences of the high temperature of beverages and foods. We conducted a meta-analysis to summarize the evidence and clarify the association between hot beverages and foods consumption and EC risk.MethodsWe searched the PubMed, Embase, and Web of Science databases for relevant studies, published before May 1, 2014, with the aim to estimate the association between hot beverage and food consumption and EC risk. A random-effect model was used to pool the results from the included studies. Publication bias was assessed by using the Begg test, the Egger test, and funnel plot.ResultsThirty-nine studies satisfied the inclusion criteria, giving a total of 42,475 non-overlapping participants and 13,811 EC cases. Hot beverage and food consumption was significantly associated with EC risk, with an odds ratio (OR) of 1.82 (95% confidence interval [CI], 1.53–2.17). The risk was higher for esophageal squamous cell carcinoma, with a pooled OR of 1.60 (95% CI, 1.29–2.00), and was insignificant for esophageal adenocarcinoma (OR: 0.79; 95% CI: 0.53–1.16). Subgroup analyses suggests that the association between hot beverage and food consumption and EC risk were significant in Asian population (OR: 2.06; 95% CI: 1.62-2.61) and South American population (OR: 1.52; 95% CI: 1.25-1.85), but not significant in European population (OR: 0.95; 95% CI: 0.68-1.34).ConclusionsHot beverage and food consumption is associated with a significantly increased risk of EC, especially in Asian and South American populations, indicating the importance in changing people’s dietary habits to prevent EC.