BACKGROUND Previous systematic reviews have consistently reported that coffee consumption has a preventive effect on the occurrence of type 2 diabetes mellitus(T2DM).However,further evaluations between coffee consumpt...BACKGROUND Previous systematic reviews have consistently reported that coffee consumption has a preventive effect on the occurrence of type 2 diabetes mellitus(T2DM).However,further evaluations between coffee consumption and the risk of T2DM in Asian populations are needed.AIM To conduct a meta-epidemiological study on systematic reviews evaluating the association between coffee consumption and the risk of T2DM in Asian people.METHODS The selection criterion was defined as a population-based prospective cohort study evaluating the association between coffee consumption and the risk of T2DM in Asian populations,reporting the adjusted relative risk(RR)and its 95%confidence interval(CI)for potential confounders.A fixed-effect model metaanalysis was applied to calculate the summary RR and its 95%CI in less than 50%of the I2 value indicating the level of heterogeneity.A two-stage fixed-effects doseresponse meta-analysis(DRMA)was performed to calculate the risk per unit dose(a cup per day).RESULTS A total of seven studies were selected in this meta-epidemiological study.The risk of T2DM in Asian populations was significantly reduced in the highest to the lowest dose group(summary RR=0.73,95%CI:0.66-0.82;I2 value=0.0%).The DRMA showed that drinking one cup of coffee per day reduced the risk of T2DM in Asian populations by 8%(RR=0.92,95%CI:0.90-0.95).CONCLUSION These findings support the conclusion that coffee consumption has a protective effect on the occurrence of T2DM in Asian men and women.展开更多
The International Agency for Research on Cancer and the World Health Organization have designated airborne particulates,including particulates of median aerodynamic diameter < 2.5um(PM_(2.5)),as Group 1 carcinogens...The International Agency for Research on Cancer and the World Health Organization have designated airborne particulates,including particulates of median aerodynamic diameter < 2.5um(PM_(2.5)),as Group 1 carcinogens.It has not been determined,however,whether exposure to ambient PM_(2.5) is associated with an increase in respiratory related diseases.This meta-analysis assessed the association between exposure to ambient fine particulate matter(PM_(2.5)) and the risk of respiratory tract diseases,using relevant articles extracted from PubMed,Web of Science,and Embase.In results,of the 1,126 articles originally identified,35(3.1%) were included in this meta-analysis.PM_(2.5)was found to be associated with respiratory tract diseases.After subdivision by age group,respiratory tract disease,and continent,PM_(2.5) was strongly associated with respiratory tract diseases in children,in persons with cough,lower respiratory illness,and wheezing,and in individuals from North America,Europe,and Asia.The risk of respiratory tract diseases was greater for exposure to traffic-related than non-traffic-related air pollution.In children,the pooled relative risk(RR) represented significant increases in wheezing(8.2%),cough(7.5%),and lower respiratory illness(15.3%).The pooled RRs in children were 1.091(95%CI:1.049,1.135) for exposure to<25 μg/m^3 PM_(2.5),and 1.126(95%CI:1.067,1.190) for exposure to > 25 μg/m^3 PM_(2.5).In conclusion,exposure to ambient PM_(2.5) was significantly associated with the development of respiratory tract diseases,especially in children exposed to high concentrations of PM_(2.5).展开更多
AIM: To quantify the association between diabetes and glaucoma using Meta-analysis.METHODS: Pub Med and Embase were searched using medical subject headings and key words related to diabetes and glaucoma. The inclusion...AIM: To quantify the association between diabetes and glaucoma using Meta-analysis.METHODS: Pub Med and Embase were searched using medical subject headings and key words related to diabetes and glaucoma. The inclusion criteria were: 1) the study design was a prospective cohort study; 2) the exposure of interest was diabetes; 3) the outcome of interest was primary open angle glaucoma(POAG); 4) risk ratios(RR) and the corresponding 95% confidence interval(CI). Data were pooled using fixed effects models to take into account heterogeneity between studies. Seven prospective studies were selected. Diabetes increased the incidence of glaucoma by 36%(OR=1.36, 95% CI=1.25-1.50). There was no evidence of statistical heterogeneity(I^2=0, P=0.53) or publication bias(the funnel plot did not identify obvious asymmetry).RESULTS: Seven prospective cohort studies were incorporated in this Meta-analysis. The pooled RR of the association between POAG and diabetes based on the risk estimates of the seven cohort studies was 1.36(95% CI=1.24-1.50), with no significant heterogeneity across studies(I^2=0; P=0.526). The sensitivity analysis yielded a range of RRs from 1.34(95% CI=1.22-1.48) to1.40(95% CI=1.18-1.67).CONCLUSION: Diabetes is associated with a significantly increased risk of glaucoma.展开更多
AIM: To evaluate the association between obesity and colorectal cancer risk. METHODS: We searched PubMed, EMBASE, and the Cochrane Library up to January 1, 2007. Cohort studies permitting the assessment of causal asso...AIM: To evaluate the association between obesity and colorectal cancer risk. METHODS: We searched PubMed, EMBASE, and the Cochrane Library up to January 1, 2007. Cohort studies permitting the assessment of causal association between obesity and colorectal cancer, with clear definition of obesity and well-defined outcome of colorectal cancer were eligible. Study design, sample size at baseline, mean follow-up time, co-activators and study results were extracted. Pooled standardized effect sizes were calculated. RESULTS: The pooled relative risk (RR) of colorectal cancer was 1.37 (95% CI: 1.21-1.56) for overweight and obese men, 1.07 (95% CI: 0.97-1.18) for women measured by body mass index (BMI). The pooled RR for the highest vs the lowest quantiles of BMI was 1.59 (95% CI: 1.35-1.86) for men and 1.22 (95% CI: 1.08-1.39) for women at risk of colon cancer, 1.16 (95% CI: 0.93-1.46) for men and 1.23 (95% CI: 0.98-1.54) for women at risk of rectal cancer. The pooled RR for the highest vs the lowest quantiles of waist circumference was 1.68 (95% CI: 1.36-2.08) for men and 1.48 (95% CI: 1.19-1.84) for women at risk of colon cancer, 1.26 (95% CI: 0.90-1.77) for men and 1.23 (95% CI: 0.81-1.86) for women at risk of rectal cancer. The pooled RR for the highest quantiles vs the lowest quantiles of waist-to-hip ratio was 1.91 (95% CI: 1.46-2.49) for men and 1.49 (95% CI 1.23-1.81) for women at risk of colon cancer, 1.93 (95% CI: 1.19-3.13) for men and 1.20 (95% CI: 0.81-1.78) for women at risk of rectal cancer. Compared with 'normal range', the pooled RR for proximal colon cancer was 1.14 (95% CI : 0.88-1.47) for the overweight and 1.41 (95% CI: 0.66-3.01) for the obese. The pooled RR for the highest quantiles vs the lowest quantiles was 2.05 (95% CI: 1.23-3.41) with waist circumference, 1.66 (95% CI: 0.69-3.99) with waist-to-hip ratio. Compared with'normal range', the pooled RR for distal colon cancer was 1.38 (95% CI: 1.02-1.87) for the overweight and 1.23 (95% CI: 0.80-1.90) for the obese. The pooled RR for the highest quantiles vs the lowest quantiles was 1.86 (95% CI: 1.05-3.30) with waist circumference, and 1.79 (95% CI: 0.82-3.90) with waist-to-hip ratio. CONCLUSION: Obesity is a statistically significant risk factor for colorectal cancer and the relationship is more signifi cant in men than in women among different cancer subsites. Indexes of abdominal obesity are more sensitive than those of overall obesity.展开更多
AIM:To quantitatively assess the relationship between coffee consumption and incidence of pancreatic cancer in a meta-analysis of cohort studies. METHODS:We searched MEDLINE,EMBASE,Science Citation Index Expanded and ...AIM:To quantitatively assess the relationship between coffee consumption and incidence of pancreatic cancer in a meta-analysis of cohort studies. METHODS:We searched MEDLINE,EMBASE,Science Citation Index Expanded and bibliographies of retrieved articles.Studies were included if they reported relative risks(RRs)and corresponding 95%CIs of pancreatic cancer with respect to frequency of coffee intake.We performed random-effects meta-analyses and metaregressions of study-specific incremental estimates to determine the risk of pancreatic cancer associated with a 1 cup/d increment in coffee consumption. RESULTS:Fourteen studies met the inclusion criteria, which included 671 080 individuals(1496 cancer events) with an average follow-up of 14.9 years.Compared with individuals who did not drink or seldom drank coffee per day,the pooled RR of pancreatic cancer was 0.82 (95%CI:0.69-0.95)for regular coffee drinkers,0.86 (0.76-0.96)for low to moderate coffee drinkers,and 0.68(0.51-0.84)for high drinkers.In subgroup analyses,we noted that,coffee drinking was associated witha reduced risk of pancreatic cancer in men,while this association was not seen in women.These associations were also similar in studies from North America,Europe, and the Asia-Pacific region. CONCLUSION:Findings from this meta-analysis suggest that there is an inverse relationship between coffee drinking and risk of pancreatic cancer.展开更多
Objective To determine whether there was excessive risk of cancer among workers exposed to chrysotile fiber alone by applying a meta-analysis technique. Methods All data meeting the criteria of cohort studies on cance...Objective To determine whether there was excessive risk of cancer among workers exposed to chrysotile fiber alone by applying a meta-analysis technique. Methods All data meeting the criteria of cohort studies on cancer mortality among workers exposed only to chrysotile were incorporated into meta-analysis. Pooled standardized mortality ratios (SMRs) and their corresponding 95% confidence intervals (CIs) for main cancer sites were calculated using two approaches of unweighted ratio and random effect model. The heterogeneity and its sources of the results were examined with a Q-statistic and Z-score test. The dose-response effect as reflected in the percentage of all deaths due to mesothelioma served as a proxy measure of chrysotile exposure. Results A cohort of twenty six workers exposed to chrysotile alone was summarized. The significantly elevated meta-SMRs for all deaths (1.27), all cancers (1.28), cancers of respiratory organs (2.51), cancers of lung (2.35) and cancers of stomach (1.24) were observed. The significantly elevated meta-SMRs for lung cancer within occupational strata were observed among textile workers (3.55), asbestos product manufacturers (3.30), miners and millers (2.24), cement product workers (1.22), and for stomach cancer among asbestos product manufacturers (1.49). Meta-SMRs for cancers at other sites were not significant. Meta-SMR for lung cancer showed an increasing trend with an elevated percentage of all deaths from mesothelioma, but no such trend for stomach cancer. Conclusion There are excessive risks of lung cancer and mesothelioma among workers exposed to chrysotile fiber alone, and likely no convincing indication of an etiological association between chrysotile exposure and cancers at other sites.展开更多
Objective Studies of the association of hypertension with long-term exposure to particulate matter less than 2.5μm in diameter(PM2.5)have shown contradictory results and the magnitude of the association is still uncl...Objective Studies of the association of hypertension with long-term exposure to particulate matter less than 2.5μm in diameter(PM2.5)have shown contradictory results and the magnitude of the association is still unclear.Hence,we conducted a meta-analysis of cohort studies to assess the effect of long-term exposure to PM2.5 on incident hypertension.展开更多
Prevalent cohort studies involve screening a sample of individuals from a population for disease, recruiting affected individuals, and prospectively following the cohort of individuals to record the occurrence of dise...Prevalent cohort studies involve screening a sample of individuals from a population for disease, recruiting affected individuals, and prospectively following the cohort of individuals to record the occurrence of disease-related complications or death. This design features a response-biased sampling scheme since individuals living a long time with the disease are preferentially sampled, so naive analysis of the time from disease onset to death will over-estimate survival probabilities. Unconditional and conditional analyses of the resulting data can yield consistent estimates of the survival distribution subject to the validity of their respective model assumptions. The time of disease onset is retrospectively reported by sampled individuals, however, this is often associated with measurement error. In this article we present a framework for studying the effect of measurement error in disease onset times in prevalent cohort studies, report on empirical studies of the effect in each framework of analysis, and describe likelihood-based methods to address such a measurement error.展开更多
Studies of the associations between maternal exposure to particulate matter(PM) and risk of adverse effects on fetal growth are inconsistent and inconclusive. This question can be well answered by carefully designed b...Studies of the associations between maternal exposure to particulate matter(PM) and risk of adverse effects on fetal growth are inconsistent and inconclusive. This question can be well answered by carefully designed birth cohort studies; however, so far the evidence from such studies has not come to the same conclusion. We sought to evaluate the association between maternal exposures to PM and low birthweight(LBW) enrolling 14 studies from 11 centers,and to explore the influence of trimester and exposure assessment methods on between-center heterogeneity in this association. Data were derived from PubMed, Embase, Google Scholar, CNKI, and WanFang database, references from relevant articles, and results from published studies until March 2017. Using a random-effects meta-analysis, we combined the coefficient and odds ratios(OR) of individual studies conducted among 14 birth cohort studies.Random-effect meta-analysis results suggested that a 17% and 6% increase in risk of LBW was relevant to a 10 μg/m^3 rise in PM_(2.5) and PM_(10) exposure concentrations at the 3 rd trimester(pooled odds ratios(OR), 1.17 and 1.06; 95%confidence interval(CI), 0.94-1.46 and 0.97-1.15, respectively), but the null value was included in our 95% CI. Our results showed that exposure to PM_(2.5) and PM_(10) during pregnancy has a positive relevance to LBW based on birth cohort studies. However, neither reached formal statistical significance. Negative impacts on outcomes of birth is implied by maternal exposure to PM. Further mechanistic researches are needed to explain the connection between PM pollution and LBW.展开更多
Objective:Psoriasis is an immune-mediated inflammatory,chronic,recurrent skin disease associated with a high risk of developing psychiatric disorders,especially depression and suicidal ideation,leading to functional d...Objective:Psoriasis is an immune-mediated inflammatory,chronic,recurrent skin disease associated with a high risk of developing psychiatric disorders,especially depression and suicidal ideation,leading to functional disability and poor quality of life.This study was conducted to comprehensively review and assess the epidemiologic association between psoriasis and the risk ratios(RRs)of depression or suicidal ideation.Methods:Five databases(PubMed,Wanfang Database,CNKI,The Cochrane Library,and EMBASE)were searched for prospective cohort studies on the prevalence of depression and/or suicidal ideation in patients with psoriasis updated to February 2,2023.Two independent reviewers evaluated and extracted the data,which were then pooled into a summary RR with corresponding 95%confidence interval(CI)using random-effects models.Results:Sixteen cohort studies comprising 1,166,840 patients with psoriasis and 3,294,205 controls were eligible for the final analysis.The pooled RR for depression was 1.43(95%CI=1.13-1.81)in patients with psoriasis and1.55(95%CI=1.40-1.71)in patients with psoriatic arthritis.In the subgroup analysis,Asian patients with psoriasis(RR=1.38,95%CI=1.17-1.63)had a lower pooled RR for depression than non-Asian patients(RR=1.45,95%CI=1.07-1.97),and patients with moderate-to-severe psoriasis(RR=1.69,95%CI=1.15-2.50)showed a higher RR for depression than patients with mild psoriasis(RR=1.60,95%CI=1.06-2.42).We also found no increase in the RR for suicidal ideation among people with psoriasis(RR=1.25,95%CI=0.95-1.65).Conclusion:Patients with psoriasis are at an increased risk of depression.Among patients with psoriasis,those with psoriatic arthritis,those who are non-Asian,and those with moderate-to-severe psoriasis are at higher risk for depression.However,the available evidence does not support an association between psoriasis and suicidal ideation.展开更多
Depression is a major health problem, especially for elderly people. According to the “homocysteine hypothesis of depression”, high homocysteine levels may cause depression of mood via cerebrovascular diseases. Whil...Depression is a major health problem, especially for elderly people. According to the “homocysteine hypothesis of depression”, high homocysteine levels may cause depression of mood via cerebrovascular diseases. Whilst biologically plausible, such hypothesis needs yet confirmation. We aimed at: 1) studying the relationships between homocysteinemia (HCY) and depression in a community-dwelling cohort of people aged 70 to 75 years at baseline;2) investigating plasma levels of HCY and 3) comparing these levels between males and females, in the same population. We exploited the data from four waves (2010, 2012, 2014 and 2018) of the longitudinal study “InveCeAb”, with specific regard towards mood assessment, by Geriatric Depression Scale (GDS) scoring, and diagnosis of clinically relevant or subthreshold depression. HCY plasma levels were measured in the waves 2012, 2014 and 2018. Sample attrition was due mainly to death or overall worsening. No statistically significant differences were found in plasma homocysteine levels in each wave, according to depressive symptoms. No correlations were found between plasma HCY levels in each wave with their corresponding GDS scores, even after adjustment for folate and cobalamin blood concentrations. Dichotomized levels of HCY (≤15 vs >15 μM/l) were not associated with dichotomized GDS scores (≤4 vs higher), clinically relevant and subthreshold depression diagnosis and any antidepressive use, in any wave. First (2012) HCY levels increased with participants’ increasing age, cross-sectionally. Listwise HCY concentrations decreased along the 3 waves. HCY levels were always higher in males than in females. Our results may challenge the “homocysteine hypothesis” of depression, whilst supporting the role of high homocysteinemia as a marker of overall bad health.展开更多
The intricacies of Alzheimer’s disease pathogenesis are being increasingly illuminated by the exploration of epigenetic mechanisms,particularly DNA methylation.This review comprehensively surveys recent human-centere...The intricacies of Alzheimer’s disease pathogenesis are being increasingly illuminated by the exploration of epigenetic mechanisms,particularly DNA methylation.This review comprehensively surveys recent human-centered studies that investigate whole genome DNA methylation in Alzheimer’s disease neuropathology.The examination of various brain regions reveals distinctive DNA methylation patterns that associate with the Braak stage and Alzheimer’s disease progression.The entorhinal cortex emerges as a focal point due to its early histological alterations and subsequent impact on downstream regions like the hippocampus.Notably,ANK1 hypermethylation,a protein implicated in neurofibrillary tangle formation,was recurrently identified in the entorhinal cortex.Further,the middle temporal gyrus and prefrontal cortex were shown to exhibit significant hypermethylation of genes like HOXA3,RHBDF2,and MCF2L,potentially influencing neuroinflammatory processes.The complex role of BIN1 in late-onset Alzheimer’s disease is underscored by its association with altered methylation patterns.Despite the disparities across studies,these findings highlight the intricate interplay between epigenetic modifications and Alzheimer’s disease pathology.Future research efforts should address methodological variations,incorporate diverse cohorts,and consider environmental factors to unravel the nuanced epigenetic landscape underlying Alzheimer’s disease progression.展开更多
Nowadays,doctors and nutritionists recommend individuals incorporate selenium-rich foods such as nuts,cereals,and mushrooms into their regular diet to maintain fitness and overall health.Selenium nanoparticles(SeNPs)e...Nowadays,doctors and nutritionists recommend individuals incorporate selenium-rich foods such as nuts,cereals,and mushrooms into their regular diet to maintain fitness and overall health.Selenium nanoparticles(SeNPs)exhibit strong chemopreventive capabilities.The anticipations for SeNPs with enhanced and tunable bioactive activities have led to a keen interest in phytofabrication.In this study,the aqueous extract of Clerodendron phlomidis plant leaves was utilized for the synthesis of SeNPs.In traditional Indian medicine,this plant extract is recognized as a significant anti-diabetic agent.The flavonoids tetrahydroxylflavone,7-hydroxyflavanone,and 6,4’-dimethyl-7-acetoxy-scutellarein present in this plant leaf extract demonstrate excellent anticancer activity.These secondary metabolites exhibit the ability to reduce sodium selenite into SeNPs.At a concentration of 13μg/mL,the synthesized SeNPs effectively inhibited the proliferation of the HepG2 cell line.The results suggest that the SeNPs possess promising anti-cancer potential against liver cancer and can be considered as a therapeutic agent for liver cancer treatment.Additionally,the cell cycle arrest induced by SeNPs was further confirmed by the fluorescence-activated cell sorting(FACS)method,indicating that SeNPs could efficiently differentiate cancer cells from normal cells.Notably,it showed a significant improvement in diethylnitrosamine(DEN)-induced Swiss Wistar rat groups.This scientific investigation highlights the high anti-cancer potential of SeNPs,positioning them as a promising therapeutic agent for liver cancer treatment.展开更多
Background:Acupuncture for stroke has been endorsed by the World Health Organization,and the Chinese Guidelines for the Diagnosis and Treatment of Acute Ischemic Stroke 2018 lists acupuncture for stroke as a Level II ...Background:Acupuncture for stroke has been endorsed by the World Health Organization,and the Chinese Guidelines for the Diagnosis and Treatment of Acute Ischemic Stroke 2018 lists acupuncture for stroke as a Level II recommendation with Level B evidence.The efficacy of acupuncture in the treatment of acute ischaemic stroke needs to be approved by more high-quality studies.However,there are currently no real-world studies of acupuncture for stroke.Methods:Stroke patients who meet the study criteria and are hospitalized from February 2021 to March 2022 in 23 medical institutions across China,including the First Teaching Hospital of Tianjin University of Chinese Medicine.The number of patients planned to be recruited is 3,000.Due to the impact of COVID-19,we have applied to the competent authorities for an extension(recruit patients until December 2022).Basic patient information and treatment information will be registered at admission,at discharge,and on the following dates after the onset of the disease:90±7 days,180±7 days,and 360±7 days after the onset of the disease.Establish a database for statistical analysis.Discussion:This study proposes to conduct a prospective cohort study of acupuncture intervention for stroke in a real-world medical setting.Analysis of the effect pattern of acupuncture intervention on the recovery of neurological function system and swallowing disorder in stroke patients.Evaluate the long-term effects of acupuncture intervention for stroke and recurrence of cardiovascular and cerebrovascular events.展开更多
BACKGROUND Autoimmune pancreatitis(AIP)has been linked with elevated immunoglobulin(Ig)G4 levels.The characteristics and outcomes of AIP based on serum markers have not been fully evaluated.AIM To compare clinical fea...BACKGROUND Autoimmune pancreatitis(AIP)has been linked with elevated immunoglobulin(Ig)G4 levels.The characteristics and outcomes of AIP based on serum markers have not been fully evaluated.AIM To compare clinical features,treatment efficacy,and outcome of AIP based on serum IgG4 levels and analyze predictors of relapse.METHODS A total of 213 patients with AIP were consecutively reviewed in our hospital from 2006 to 2021.According to the serum IgG4 level,all patients were divided into two groups,the abnormal group(n=148)with a high level of IgG4[>2×upper limit of normal(ULN)]and the normal group(n=65).The t-test or Mann-Whitney U test was used to compare continuous variables.Categorical parameters were compared by theχ^(2) test or Fisher’s exact test.Kaplan-Meier curves Zhou GZ et al.Clinical characteristics and outcome of AIP WJG https://www.wjgnet.com 5126 September 21,2023 Volume 29 Issue 35 and log-rank tests were established to assess the cumulative relapse rates.Univariate and multivariate analyses were used to investigate potential risk factors of AIP relapse.RESULTS Compared with the normal group,the abnormal group had a higher average male age(60.3±10.4 vs 56.5±12.9 years,P=0.047);higher level of serum total protein(72.5±7.9 g/L vs 67.2±7.5 g/L,P<0.001),IgG4(1420.5±1110.9 mg/dL vs 252.7±106.6 mg/dL,P<0.001),and IgE(635.6±958.1 IU/mL vs 231.7±352.5 IU/mL,P=0.002);and a lower level of serum complement C3(100.6±36.2 mg/dL vs 119.0±45.7 mg/dL,P=0.050).In addition,a lower number of cases with abnormal pancreatic duct and pancreatic atrophy(23.6%vs 37.9%,P=0.045;1.6%vs 8.6%,P=0.020,respectively)and a higher rate of relapse(17.6%vs 6.2%,P=0.030)were seen in the abnormal group.Multivariate analyses revealed that serum IgG4[(>2×ULN),hazard ratio(HR):3.583;95%confidence interval(CI):1.218–10.545;P=0.020]and IgA(>1×ULN;HR:5.908;95%CI:1.199–29.120;P=0.029)and age>55 years(HR:2.383;95%CI:1.056–5.378;P=0.036)were independent risk factors of relapse.CONCLUSION AIP patients with high IgG4 levels have clinical features including a more active immune system and higher relapse rate.Several factors,such as IgG4 and IgA,are associated with relapse.展开更多
Case-cohort sampling is a commonly used and efficient method for studying large cohorts.In many situations,some covariates are easily measured on all cohort subjects,and surrogate measurements of the expensive covaria...Case-cohort sampling is a commonly used and efficient method for studying large cohorts.In many situations,some covariates are easily measured on all cohort subjects,and surrogate measurements of the expensive covariates also may be observed.In this paper,to make full use of the covariate data collected outside the case-cohort sample,we propose a class of weighted estimators with general time-varying weights for the additive hazards model,and the estimators are shown to be consistent and asymptotically normal.We also identify the estimator within this class that maximizes efficiency,and simulation studies show that the efficiency gains of the proposed estimator over the existing ones can be substantial in practical situations.A real example is provided.展开更多
Case-cohort design is an efficient and economical design to study risk factors for diseases with expensive measurements,especially when the disease rate is low.When several diseases are of interest,multiple case-cohor...Case-cohort design is an efficient and economical design to study risk factors for diseases with expensive measurements,especially when the disease rate is low.When several diseases are of interest,multiple case-cohort design studies may be conducted using the same subcohort.To study the association between risk factors and each disease occurrence or death,we consider a general additive-multiplicative hazards model for case-cohort designs with multiple disease outcomes.We present an estimation procedure for the regression parameters of the additive-multiplicative hazards model,and show that the proposed estimator is consistent and asymptotically normal.Large sample approximation works well in finite sample studies in simulation.Finally,we apply the proposed method to a real data example for illustration.展开更多
Case-cohort study designs are widely used to reduce the cost of large cohort studies. When several diseases are of interest, we can use the same subcohort. In this paper, we will study the casecohort design of margina...Case-cohort study designs are widely used to reduce the cost of large cohort studies. When several diseases are of interest, we can use the same subcohort. In this paper, we will study the casecohort design of marginal additive hazards model for multiple outcomes by a more efficient version.Instead of analyzing each disease separately, ignoring the additional exposure measurements collected on subjects with other diseases, we propose a new weighted estimating equation approach to improve the efficiency by utilizing as much information collected as possible. The consistency and asymptotic normality of the resulting estimator are established. Simulation studies are conducted to examine the finite sample performance of the proposed estimator, which confirm the efficiency gains.展开更多
文摘BACKGROUND Previous systematic reviews have consistently reported that coffee consumption has a preventive effect on the occurrence of type 2 diabetes mellitus(T2DM).However,further evaluations between coffee consumption and the risk of T2DM in Asian populations are needed.AIM To conduct a meta-epidemiological study on systematic reviews evaluating the association between coffee consumption and the risk of T2DM in Asian people.METHODS The selection criterion was defined as a population-based prospective cohort study evaluating the association between coffee consumption and the risk of T2DM in Asian populations,reporting the adjusted relative risk(RR)and its 95%confidence interval(CI)for potential confounders.A fixed-effect model metaanalysis was applied to calculate the summary RR and its 95%CI in less than 50%of the I2 value indicating the level of heterogeneity.A two-stage fixed-effects doseresponse meta-analysis(DRMA)was performed to calculate the risk per unit dose(a cup per day).RESULTS A total of seven studies were selected in this meta-epidemiological study.The risk of T2DM in Asian populations was significantly reduced in the highest to the lowest dose group(summary RR=0.73,95%CI:0.66-0.82;I2 value=0.0%).The DRMA showed that drinking one cup of coffee per day reduced the risk of T2DM in Asian populations by 8%(RR=0.92,95%CI:0.90-0.95).CONCLUSION These findings support the conclusion that coffee consumption has a protective effect on the occurrence of T2DM in Asian men and women.
基金supported by the National Natural Science Foundation of China(Grant No.81473013 and No.81673210)Jiangsu Province Blue Project of UniversityInnovation of Graduate Student Training Project in Jiangsu Province(KYLX15_0976)
文摘The International Agency for Research on Cancer and the World Health Organization have designated airborne particulates,including particulates of median aerodynamic diameter < 2.5um(PM_(2.5)),as Group 1 carcinogens.It has not been determined,however,whether exposure to ambient PM_(2.5) is associated with an increase in respiratory related diseases.This meta-analysis assessed the association between exposure to ambient fine particulate matter(PM_(2.5)) and the risk of respiratory tract diseases,using relevant articles extracted from PubMed,Web of Science,and Embase.In results,of the 1,126 articles originally identified,35(3.1%) were included in this meta-analysis.PM_(2.5)was found to be associated with respiratory tract diseases.After subdivision by age group,respiratory tract disease,and continent,PM_(2.5) was strongly associated with respiratory tract diseases in children,in persons with cough,lower respiratory illness,and wheezing,and in individuals from North America,Europe,and Asia.The risk of respiratory tract diseases was greater for exposure to traffic-related than non-traffic-related air pollution.In children,the pooled relative risk(RR) represented significant increases in wheezing(8.2%),cough(7.5%),and lower respiratory illness(15.3%).The pooled RRs in children were 1.091(95%CI:1.049,1.135) for exposure to<25 μg/m^3 PM_(2.5),and 1.126(95%CI:1.067,1.190) for exposure to > 25 μg/m^3 PM_(2.5).In conclusion,exposure to ambient PM_(2.5) was significantly associated with the development of respiratory tract diseases,especially in children exposed to high concentrations of PM_(2.5).
基金Supported by the Plan of Wenzhou Science and Technology(No.Y20160439)
文摘AIM: To quantify the association between diabetes and glaucoma using Meta-analysis.METHODS: Pub Med and Embase were searched using medical subject headings and key words related to diabetes and glaucoma. The inclusion criteria were: 1) the study design was a prospective cohort study; 2) the exposure of interest was diabetes; 3) the outcome of interest was primary open angle glaucoma(POAG); 4) risk ratios(RR) and the corresponding 95% confidence interval(CI). Data were pooled using fixed effects models to take into account heterogeneity between studies. Seven prospective studies were selected. Diabetes increased the incidence of glaucoma by 36%(OR=1.36, 95% CI=1.25-1.50). There was no evidence of statistical heterogeneity(I^2=0, P=0.53) or publication bias(the funnel plot did not identify obvious asymmetry).RESULTS: Seven prospective cohort studies were incorporated in this Meta-analysis. The pooled RR of the association between POAG and diabetes based on the risk estimates of the seven cohort studies was 1.36(95% CI=1.24-1.50), with no significant heterogeneity across studies(I^2=0; P=0.526). The sensitivity analysis yielded a range of RRs from 1.34(95% CI=1.22-1.48) to1.40(95% CI=1.18-1.67).CONCLUSION: Diabetes is associated with a significantly increased risk of glaucoma.
文摘AIM: To evaluate the association between obesity and colorectal cancer risk. METHODS: We searched PubMed, EMBASE, and the Cochrane Library up to January 1, 2007. Cohort studies permitting the assessment of causal association between obesity and colorectal cancer, with clear definition of obesity and well-defined outcome of colorectal cancer were eligible. Study design, sample size at baseline, mean follow-up time, co-activators and study results were extracted. Pooled standardized effect sizes were calculated. RESULTS: The pooled relative risk (RR) of colorectal cancer was 1.37 (95% CI: 1.21-1.56) for overweight and obese men, 1.07 (95% CI: 0.97-1.18) for women measured by body mass index (BMI). The pooled RR for the highest vs the lowest quantiles of BMI was 1.59 (95% CI: 1.35-1.86) for men and 1.22 (95% CI: 1.08-1.39) for women at risk of colon cancer, 1.16 (95% CI: 0.93-1.46) for men and 1.23 (95% CI: 0.98-1.54) for women at risk of rectal cancer. The pooled RR for the highest vs the lowest quantiles of waist circumference was 1.68 (95% CI: 1.36-2.08) for men and 1.48 (95% CI: 1.19-1.84) for women at risk of colon cancer, 1.26 (95% CI: 0.90-1.77) for men and 1.23 (95% CI: 0.81-1.86) for women at risk of rectal cancer. The pooled RR for the highest quantiles vs the lowest quantiles of waist-to-hip ratio was 1.91 (95% CI: 1.46-2.49) for men and 1.49 (95% CI 1.23-1.81) for women at risk of colon cancer, 1.93 (95% CI: 1.19-3.13) for men and 1.20 (95% CI: 0.81-1.78) for women at risk of rectal cancer. Compared with 'normal range', the pooled RR for proximal colon cancer was 1.14 (95% CI : 0.88-1.47) for the overweight and 1.41 (95% CI: 0.66-3.01) for the obese. The pooled RR for the highest quantiles vs the lowest quantiles was 2.05 (95% CI: 1.23-3.41) with waist circumference, 1.66 (95% CI: 0.69-3.99) with waist-to-hip ratio. Compared with'normal range', the pooled RR for distal colon cancer was 1.38 (95% CI: 1.02-1.87) for the overweight and 1.23 (95% CI: 0.80-1.90) for the obese. The pooled RR for the highest quantiles vs the lowest quantiles was 1.86 (95% CI: 1.05-3.30) with waist circumference, and 1.79 (95% CI: 0.82-3.90) with waist-to-hip ratio. CONCLUSION: Obesity is a statistically significant risk factor for colorectal cancer and the relationship is more signifi cant in men than in women among different cancer subsites. Indexes of abdominal obesity are more sensitive than those of overall obesity.
文摘AIM:To quantitatively assess the relationship between coffee consumption and incidence of pancreatic cancer in a meta-analysis of cohort studies. METHODS:We searched MEDLINE,EMBASE,Science Citation Index Expanded and bibliographies of retrieved articles.Studies were included if they reported relative risks(RRs)and corresponding 95%CIs of pancreatic cancer with respect to frequency of coffee intake.We performed random-effects meta-analyses and metaregressions of study-specific incremental estimates to determine the risk of pancreatic cancer associated with a 1 cup/d increment in coffee consumption. RESULTS:Fourteen studies met the inclusion criteria, which included 671 080 individuals(1496 cancer events) with an average follow-up of 14.9 years.Compared with individuals who did not drink or seldom drank coffee per day,the pooled RR of pancreatic cancer was 0.82 (95%CI:0.69-0.95)for regular coffee drinkers,0.86 (0.76-0.96)for low to moderate coffee drinkers,and 0.68(0.51-0.84)for high drinkers.In subgroup analyses,we noted that,coffee drinking was associated witha reduced risk of pancreatic cancer in men,while this association was not seen in women.These associations were also similar in studies from North America,Europe, and the Asia-Pacific region. CONCLUSION:Findings from this meta-analysis suggest that there is an inverse relationship between coffee drinking and risk of pancreatic cancer.
基金This study was partially supported by a grant from the Research Foundation in the year of 1997 of the Japan-China Medical Association (No. 001).
文摘Objective To determine whether there was excessive risk of cancer among workers exposed to chrysotile fiber alone by applying a meta-analysis technique. Methods All data meeting the criteria of cohort studies on cancer mortality among workers exposed only to chrysotile were incorporated into meta-analysis. Pooled standardized mortality ratios (SMRs) and their corresponding 95% confidence intervals (CIs) for main cancer sites were calculated using two approaches of unweighted ratio and random effect model. The heterogeneity and its sources of the results were examined with a Q-statistic and Z-score test. The dose-response effect as reflected in the percentage of all deaths due to mesothelioma served as a proxy measure of chrysotile exposure. Results A cohort of twenty six workers exposed to chrysotile alone was summarized. The significantly elevated meta-SMRs for all deaths (1.27), all cancers (1.28), cancers of respiratory organs (2.51), cancers of lung (2.35) and cancers of stomach (1.24) were observed. The significantly elevated meta-SMRs for lung cancer within occupational strata were observed among textile workers (3.55), asbestos product manufacturers (3.30), miners and millers (2.24), cement product workers (1.22), and for stomach cancer among asbestos product manufacturers (1.49). Meta-SMRs for cancers at other sites were not significant. Meta-SMR for lung cancer showed an increasing trend with an elevated percentage of all deaths from mesothelioma, but no such trend for stomach cancer. Conclusion There are excessive risks of lung cancer and mesothelioma among workers exposed to chrysotile fiber alone, and likely no convincing indication of an etiological association between chrysotile exposure and cancers at other sites.
文摘Objective Studies of the association of hypertension with long-term exposure to particulate matter less than 2.5μm in diameter(PM2.5)have shown contradictory results and the magnitude of the association is still unclear.Hence,we conducted a meta-analysis of cohort studies to assess the effect of long-term exposure to PM2.5 on incident hypertension.
文摘Prevalent cohort studies involve screening a sample of individuals from a population for disease, recruiting affected individuals, and prospectively following the cohort of individuals to record the occurrence of disease-related complications or death. This design features a response-biased sampling scheme since individuals living a long time with the disease are preferentially sampled, so naive analysis of the time from disease onset to death will over-estimate survival probabilities. Unconditional and conditional analyses of the resulting data can yield consistent estimates of the survival distribution subject to the validity of their respective model assumptions. The time of disease onset is retrospectively reported by sampled individuals, however, this is often associated with measurement error. In this article we present a framework for studying the effect of measurement error in disease onset times in prevalent cohort studies, report on empirical studies of the effect in each framework of analysis, and describe likelihood-based methods to address such a measurement error.
文摘Studies of the associations between maternal exposure to particulate matter(PM) and risk of adverse effects on fetal growth are inconsistent and inconclusive. This question can be well answered by carefully designed birth cohort studies; however, so far the evidence from such studies has not come to the same conclusion. We sought to evaluate the association between maternal exposures to PM and low birthweight(LBW) enrolling 14 studies from 11 centers,and to explore the influence of trimester and exposure assessment methods on between-center heterogeneity in this association. Data were derived from PubMed, Embase, Google Scholar, CNKI, and WanFang database, references from relevant articles, and results from published studies until March 2017. Using a random-effects meta-analysis, we combined the coefficient and odds ratios(OR) of individual studies conducted among 14 birth cohort studies.Random-effect meta-analysis results suggested that a 17% and 6% increase in risk of LBW was relevant to a 10 μg/m^3 rise in PM_(2.5) and PM_(10) exposure concentrations at the 3 rd trimester(pooled odds ratios(OR), 1.17 and 1.06; 95%confidence interval(CI), 0.94-1.46 and 0.97-1.15, respectively), but the null value was included in our 95% CI. Our results showed that exposure to PM_(2.5) and PM_(10) during pregnancy has a positive relevance to LBW based on birth cohort studies. However, neither reached formal statistical significance. Negative impacts on outcomes of birth is implied by maternal exposure to PM. Further mechanistic researches are needed to explain the connection between PM pollution and LBW.
基金supported by the Guangzhou Basic Research Plan Jointly Funded by the City,School(Hospital),and/or Enterprise(No.SL2022A03J00202)the Science and Technology Program of Guangzhou(Grant No.202102080095)+1 种基金the Characteristic Clinic Project of Guangzhou Health Commission(No.2019TS68)the Medical Science and Technology Research Foundation of Guangdong Province(No.A2022052).
文摘Objective:Psoriasis is an immune-mediated inflammatory,chronic,recurrent skin disease associated with a high risk of developing psychiatric disorders,especially depression and suicidal ideation,leading to functional disability and poor quality of life.This study was conducted to comprehensively review and assess the epidemiologic association between psoriasis and the risk ratios(RRs)of depression or suicidal ideation.Methods:Five databases(PubMed,Wanfang Database,CNKI,The Cochrane Library,and EMBASE)were searched for prospective cohort studies on the prevalence of depression and/or suicidal ideation in patients with psoriasis updated to February 2,2023.Two independent reviewers evaluated and extracted the data,which were then pooled into a summary RR with corresponding 95%confidence interval(CI)using random-effects models.Results:Sixteen cohort studies comprising 1,166,840 patients with psoriasis and 3,294,205 controls were eligible for the final analysis.The pooled RR for depression was 1.43(95%CI=1.13-1.81)in patients with psoriasis and1.55(95%CI=1.40-1.71)in patients with psoriatic arthritis.In the subgroup analysis,Asian patients with psoriasis(RR=1.38,95%CI=1.17-1.63)had a lower pooled RR for depression than non-Asian patients(RR=1.45,95%CI=1.07-1.97),and patients with moderate-to-severe psoriasis(RR=1.69,95%CI=1.15-2.50)showed a higher RR for depression than patients with mild psoriasis(RR=1.60,95%CI=1.06-2.42).We also found no increase in the RR for suicidal ideation among people with psoriasis(RR=1.25,95%CI=0.95-1.65).Conclusion:Patients with psoriasis are at an increased risk of depression.Among patients with psoriasis,those with psoriatic arthritis,those who are non-Asian,and those with moderate-to-severe psoriasis are at higher risk for depression.However,the available evidence does not support an association between psoriasis and suicidal ideation.
文摘Depression is a major health problem, especially for elderly people. According to the “homocysteine hypothesis of depression”, high homocysteine levels may cause depression of mood via cerebrovascular diseases. Whilst biologically plausible, such hypothesis needs yet confirmation. We aimed at: 1) studying the relationships between homocysteinemia (HCY) and depression in a community-dwelling cohort of people aged 70 to 75 years at baseline;2) investigating plasma levels of HCY and 3) comparing these levels between males and females, in the same population. We exploited the data from four waves (2010, 2012, 2014 and 2018) of the longitudinal study “InveCeAb”, with specific regard towards mood assessment, by Geriatric Depression Scale (GDS) scoring, and diagnosis of clinically relevant or subthreshold depression. HCY plasma levels were measured in the waves 2012, 2014 and 2018. Sample attrition was due mainly to death or overall worsening. No statistically significant differences were found in plasma homocysteine levels in each wave, according to depressive symptoms. No correlations were found between plasma HCY levels in each wave with their corresponding GDS scores, even after adjustment for folate and cobalamin blood concentrations. Dichotomized levels of HCY (≤15 vs >15 μM/l) were not associated with dichotomized GDS scores (≤4 vs higher), clinically relevant and subthreshold depression diagnosis and any antidepressive use, in any wave. First (2012) HCY levels increased with participants’ increasing age, cross-sectionally. Listwise HCY concentrations decreased along the 3 waves. HCY levels were always higher in males than in females. Our results may challenge the “homocysteine hypothesis” of depression, whilst supporting the role of high homocysteinemia as a marker of overall bad health.
文摘The intricacies of Alzheimer’s disease pathogenesis are being increasingly illuminated by the exploration of epigenetic mechanisms,particularly DNA methylation.This review comprehensively surveys recent human-centered studies that investigate whole genome DNA methylation in Alzheimer’s disease neuropathology.The examination of various brain regions reveals distinctive DNA methylation patterns that associate with the Braak stage and Alzheimer’s disease progression.The entorhinal cortex emerges as a focal point due to its early histological alterations and subsequent impact on downstream regions like the hippocampus.Notably,ANK1 hypermethylation,a protein implicated in neurofibrillary tangle formation,was recurrently identified in the entorhinal cortex.Further,the middle temporal gyrus and prefrontal cortex were shown to exhibit significant hypermethylation of genes like HOXA3,RHBDF2,and MCF2L,potentially influencing neuroinflammatory processes.The complex role of BIN1 in late-onset Alzheimer’s disease is underscored by its association with altered methylation patterns.Despite the disparities across studies,these findings highlight the intricate interplay between epigenetic modifications and Alzheimer’s disease pathology.Future research efforts should address methodological variations,incorporate diverse cohorts,and consider environmental factors to unravel the nuanced epigenetic landscape underlying Alzheimer’s disease progression.
文摘Nowadays,doctors and nutritionists recommend individuals incorporate selenium-rich foods such as nuts,cereals,and mushrooms into their regular diet to maintain fitness and overall health.Selenium nanoparticles(SeNPs)exhibit strong chemopreventive capabilities.The anticipations for SeNPs with enhanced and tunable bioactive activities have led to a keen interest in phytofabrication.In this study,the aqueous extract of Clerodendron phlomidis plant leaves was utilized for the synthesis of SeNPs.In traditional Indian medicine,this plant extract is recognized as a significant anti-diabetic agent.The flavonoids tetrahydroxylflavone,7-hydroxyflavanone,and 6,4’-dimethyl-7-acetoxy-scutellarein present in this plant leaf extract demonstrate excellent anticancer activity.These secondary metabolites exhibit the ability to reduce sodium selenite into SeNPs.At a concentration of 13μg/mL,the synthesized SeNPs effectively inhibited the proliferation of the HepG2 cell line.The results suggest that the SeNPs possess promising anti-cancer potential against liver cancer and can be considered as a therapeutic agent for liver cancer treatment.Additionally,the cell cycle arrest induced by SeNPs was further confirmed by the fluorescence-activated cell sorting(FACS)method,indicating that SeNPs could efficiently differentiate cancer cells from normal cells.Notably,it showed a significant improvement in diethylnitrosamine(DEN)-induced Swiss Wistar rat groups.This scientific investigation highlights the high anti-cancer potential of SeNPs,positioning them as a promising therapeutic agent for liver cancer treatment.
基金supported by the Tianjin Municipal Science and Technology Bureau.Grant number(No.20ZYJDSY00020).
文摘Background:Acupuncture for stroke has been endorsed by the World Health Organization,and the Chinese Guidelines for the Diagnosis and Treatment of Acute Ischemic Stroke 2018 lists acupuncture for stroke as a Level II recommendation with Level B evidence.The efficacy of acupuncture in the treatment of acute ischaemic stroke needs to be approved by more high-quality studies.However,there are currently no real-world studies of acupuncture for stroke.Methods:Stroke patients who meet the study criteria and are hospitalized from February 2021 to March 2022 in 23 medical institutions across China,including the First Teaching Hospital of Tianjin University of Chinese Medicine.The number of patients planned to be recruited is 3,000.Due to the impact of COVID-19,we have applied to the competent authorities for an extension(recruit patients until December 2022).Basic patient information and treatment information will be registered at admission,at discharge,and on the following dates after the onset of the disease:90±7 days,180±7 days,and 360±7 days after the onset of the disease.Establish a database for statistical analysis.Discussion:This study proposes to conduct a prospective cohort study of acupuncture intervention for stroke in a real-world medical setting.Analysis of the effect pattern of acupuncture intervention on the recovery of neurological function system and swallowing disorder in stroke patients.Evaluate the long-term effects of acupuncture intervention for stroke and recurrence of cardiovascular and cerebrovascular events.
基金Young Scholar Independent Innovation Science Fund of Chinese PLA General Hospital,No.22QNCZ020National Key Research and Development Program,No.2022YFC2504003.
文摘BACKGROUND Autoimmune pancreatitis(AIP)has been linked with elevated immunoglobulin(Ig)G4 levels.The characteristics and outcomes of AIP based on serum markers have not been fully evaluated.AIM To compare clinical features,treatment efficacy,and outcome of AIP based on serum IgG4 levels and analyze predictors of relapse.METHODS A total of 213 patients with AIP were consecutively reviewed in our hospital from 2006 to 2021.According to the serum IgG4 level,all patients were divided into two groups,the abnormal group(n=148)with a high level of IgG4[>2×upper limit of normal(ULN)]and the normal group(n=65).The t-test or Mann-Whitney U test was used to compare continuous variables.Categorical parameters were compared by theχ^(2) test or Fisher’s exact test.Kaplan-Meier curves Zhou GZ et al.Clinical characteristics and outcome of AIP WJG https://www.wjgnet.com 5126 September 21,2023 Volume 29 Issue 35 and log-rank tests were established to assess the cumulative relapse rates.Univariate and multivariate analyses were used to investigate potential risk factors of AIP relapse.RESULTS Compared with the normal group,the abnormal group had a higher average male age(60.3±10.4 vs 56.5±12.9 years,P=0.047);higher level of serum total protein(72.5±7.9 g/L vs 67.2±7.5 g/L,P<0.001),IgG4(1420.5±1110.9 mg/dL vs 252.7±106.6 mg/dL,P<0.001),and IgE(635.6±958.1 IU/mL vs 231.7±352.5 IU/mL,P=0.002);and a lower level of serum complement C3(100.6±36.2 mg/dL vs 119.0±45.7 mg/dL,P=0.050).In addition,a lower number of cases with abnormal pancreatic duct and pancreatic atrophy(23.6%vs 37.9%,P=0.045;1.6%vs 8.6%,P=0.020,respectively)and a higher rate of relapse(17.6%vs 6.2%,P=0.030)were seen in the abnormal group.Multivariate analyses revealed that serum IgG4[(>2×ULN),hazard ratio(HR):3.583;95%confidence interval(CI):1.218–10.545;P=0.020]and IgA(>1×ULN;HR:5.908;95%CI:1.199–29.120;P=0.029)and age>55 years(HR:2.383;95%CI:1.056–5.378;P=0.036)were independent risk factors of relapse.CONCLUSION AIP patients with high IgG4 levels have clinical features including a more active immune system and higher relapse rate.Several factors,such as IgG4 and IgA,are associated with relapse.
基金partly supported by the National Natural Science Foundation of China Grants(No.11231010,11171330 and 11101314)Key Laboratory of RCSDS,CAS(No.2008DP173182)and BCMIIS
文摘Case-cohort sampling is a commonly used and efficient method for studying large cohorts.In many situations,some covariates are easily measured on all cohort subjects,and surrogate measurements of the expensive covariates also may be observed.In this paper,to make full use of the covariate data collected outside the case-cohort sample,we propose a class of weighted estimators with general time-varying weights for the additive hazards model,and the estimators are shown to be consistent and asymptotically normal.We also identify the estimator within this class that maximizes efficiency,and simulation studies show that the efficiency gains of the proposed estimator over the existing ones can be substantial in practical situations.A real example is provided.
基金partly supported by the Natural Science Research Project of Universities of Anhui Province(No.KJ2016B026)partly supported by the National Natural Science Foundation of China Grants(No.11301355)the Technology Foundation for Selected Overseas Chinese Scholar,Ministry of Personnel of Beijing,China
文摘Case-cohort design is an efficient and economical design to study risk factors for diseases with expensive measurements,especially when the disease rate is low.When several diseases are of interest,multiple case-cohort design studies may be conducted using the same subcohort.To study the association between risk factors and each disease occurrence or death,we consider a general additive-multiplicative hazards model for case-cohort designs with multiple disease outcomes.We present an estimation procedure for the regression parameters of the additive-multiplicative hazards model,and show that the proposed estimator is consistent and asymptotically normal.Large sample approximation works well in finite sample studies in simulation.Finally,we apply the proposed method to a real data example for illustration.
基金supported by Graduate Innovation Foundation of Shanghai University of Finance and Economics,China(Grant No.CXJJ2014-453)the second author is supported by National Natural Science Foundation of China(Grant No.11301355)+1 种基金the Technology Foundation for Selected Overseas Chinese Scholar,Ministry of Personnel of BeijingChina
文摘Case-cohort study designs are widely used to reduce the cost of large cohort studies. When several diseases are of interest, we can use the same subcohort. In this paper, we will study the casecohort design of marginal additive hazards model for multiple outcomes by a more efficient version.Instead of analyzing each disease separately, ignoring the additional exposure measurements collected on subjects with other diseases, we propose a new weighted estimating equation approach to improve the efficiency by utilizing as much information collected as possible. The consistency and asymptotic normality of the resulting estimator are established. Simulation studies are conducted to examine the finite sample performance of the proposed estimator, which confirm the efficiency gains.
