不同研究设计的相对危险度估计

根据不同的研究设计，在队列研究中可分别估计累积发病率比（ＣＩＲ）、发病密度比（ＩＤＲ）和发病比值（ＩＯＲ）。当疾病罕见时，这３个比之值很接近。在病例对照研究中，是否可用暴露比值比（ＥＯＲ）作为ＣＩＲ或ＩＤＲ的无偏估计，取决于抽样方法和疾病率高低。本文还讨论了在不同抽样设计下ＥＯＲ与ＣＩＲ或ＩＤＲ之间的关系。     

病例队列研究设计中相对危险度的估计及其应用

目的:系统介绍病例队列研究设计的基本原理,以及风险比（ HR）的常用估计方法及其应用。 方法:首先,介绍病例队列研究设计的基本原理;其次,对Prentice法、Self-Prentice法和Barlow法加权Cox比例风险回归模型进行描述和说明;最后,以上海市女性健康队列研究为例,分析全队列数据与...     

病例—对照研究的相对危险度估计

相对危险度(RR)和比值比(OR)是在流行病学病例-对照研究的关系衡量中常使用的两个参数。已经证明,当所研究的疾病的发病率很低时,OR 可以看做是相对危险度 RR 的近似值。然而在从选择病例组和对照组开始的病例—对照研究中,如果疾病的发病率不是很低的,那么用 OR 近似地代替 RR将会产生很大的不精确性。本文探讨了两种类型的病例—对照研究中 OR 和 RR 的特性,以及这两个参数之间的关系,分析了作为相对危险度近似值的 OR 对真正 RR 值偏离的程度,并介绍了四个推导公式,提供在不考虑疾病发病率的大小和 RR 的大小的情况下,借助于一些辅助信息对 OR 进行校正,以获得精确的 RR 的方法。     

病例对照研究中相对危险度的估计方法及其应用

本文介绍了在没有发病率很低之假设的条件下,病例对照研究中相对危险度的估计方法,包括已知总体中某些参数条件下的估计以及利用 Bayes 定理和多变量模型推算暴露别发病率条件下的估计。利用两个例子说明了这些方法的应用。     

胃癌危险因素的广义相对危险度分析

应用ＧＬＩＭ软件对胃癌高发区福建省长乐市胃癌分子流行病学资料进行广义相对危险度分析,探讨代谢酶基因多态、吸烟与胃癌危险性的联系。结果表明：细胞色素Ｐ４５０２Ｅ１（ＣＹＰ２Ｅ１）、谷胱甘肽转硫酶Ｍ１（ＧＳＴＭ１）基因型和吸烟对胃癌的联合作用是一超相乘形式,偏向于相乘结构。正确识别暴露因素间交互作用的模式,对肿瘤的一级预防具有重要意义     

空间相对危险度估计方法在传染病风险评估中的应用

介绍可变带宽核密度算法、疾病空间相对危险度估计方法以及空间危险度统计学检验等在疾病风险评估中应用原理, 利用2013年云南省鲁甸及周边县区感染性腹泻病网络直报数据中其他感染性腹泻病的空间相对危险度进行估计并绘制疾病图。结果显示其他感染性腹泻病高风险热点区域主要集中于研究地区的东南部大片区域内, 表明基于可变带宽的核密度疾病空间风险度估计方法结合疾病制图技术, 可为确定重点防控人群和区域提供直观可视化的工具。     

职业接尘及吸烟致呼吸系统疾病死亡危险度比较的队列研究

目的 比较接尘、吸烟对呼吸系统疾病死亡的影响.方法 在1989年至1992年广州建立职业健康监护档案的基础上对30岁以上、职业接触粉尘和无粉尘接触的80 987名工人进行前瞻性队列研究.结果 （1）队列平均年龄43.5岁,职业性粉尘接触率16.3%,吸烟率43.7%,饮酒率33.5%.（2）队列平均随访8年,35人失访,失访率0.04%,总死亡1 593人中,219人死于肺癌,90人死于非恶性肿瘤性呼吸系统疾病.（3）调整相关因素后,相对于不吸烟者,吸烟者肺癌死亡相对危险度（RR）为3.32,是粉尘接触者相对于无粉尘接触者肺癌死亡RR（1.53）的2.2倍.粉尘接触者非恶性肿瘤性呼吸系统疾病死亡RR为2.41,是吸烟者（1.89）的1.28倍.尤其是矽尘接触者,其非恶性肿瘤性呼吸系统疾病死亡RR为5.72,是吸烟者的3.03倍.既接触粉尘又吸烟,呼吸系统疾病死亡RR增加更明显.（4）男性吸烟者呼吸系统疾病死亡危险分别随日吸烟量、烟龄的增加而增加.结论 职业接触粉尘和吸烟均可引致超额的呼吸系统疾病死亡,两者存在协同作用.吸烟致肺癌死亡RR高于接尘,而致非恶性肿瘤性呼吸系统疾病死亡RR则低于接尘.吸烟与呼吸系统疾病死亡危险存在明显的剂量-效应关系.     

瑞典斯德哥尔摩市社区人群老年痴呆和阿尔茨海默病的危险因素队列研究

目的探讨老年痴呆和阿尔茨海默病（AD）的危险因素。方法在6年问（1991-1996年）对斯德哥尔摩市一个社区非痴呆老年人群（n=1301,年龄≥75岁）进行两次随访检查,并按照美国老年精神病协会制订的DSM—Ⅲ—R标准诊断随访期间痴呆和AD新发病例。研究对象在基线调查时对有关因素暴露情况系经问卷调查、临床检查和查阅住院病例登记资料库等方法确定。采用Cox比例风险模型对资料进行统计分析。结果随访期间共有350例被诊断为痴呆,包括260例AD患者。多因素分析结果显示,痴呆和AD发病的危险因素有年龄大、文化程度低、认知功能损害、体力活动障碍、低舒张压、糖尿病、缺血性心脏病和携带APOEa4基因。脑卒中和心房纤维颤动亦能增加痴呆的危险性,而服用抗高血压药物则可降低痴呆和AD发病的危险性。结论某些人口统计学因素、认知和体力功能障碍、血管性疾病及遗传易感性是老年痴呆和AD的重要危险因素;使用抗高血压药物及控制高血压相关的血管性疾病可能会降低痴呆发病的危险性。     

队列研究资料发病率的贝叶斯估计

目的 以某一模拟队列资料的宫颈上皮内瘤变Ⅱ级(cervical intraepithelial neoplasia,CINⅡ°)及以上(CIN Ⅲ°、宫颈癌)的发病率估计为例,探讨Bayse法在队列研究资料发病率估计中的应用.方法 假设某地区进行官颈癌基线筛查8万人,对其中5万基线筛查阴性者进行隔年随访,总计随访10万人年.其中1 000人细胞学阳性,需要做病理学检查,最终收到900份病理报告,检出CINⅡ°及以上者120例,通过Bayse法估计该地区CINⅡ°及以上的发病情况.结果 通过Bayse法考虑病理检查随访人群中的失访病例以及细胞学检查阴性人群中的漏诊病例,估计该队列CINⅡ°及以上的发病率为180.23/10万,95％ CI为(146.59/10万～226.06/10万).结论 基于Bayse法,考虑了病理检查随访人群中的失访病例以及细胞学检查阴性人群中的漏诊病例,估计得到的该地区CINⅡ°及以上的发病率更合理、更准确.     

随访资料中总的相对危险度的Poisson回归模型估计

病例随访研究或队列研究中,当暴露因素和混杂因素间存在交互作用时,用传统的方法估计暴露组的总的相对危险度是无意义的。由于肿瘤学、放射学等随访资料常服从 Poisson 分布,因而可用 Poisson 回归模型拟合并检验混杂因素与交互作用是否存在。当交互作用不存在时,可通过模型参数估计总的相对危险度。本文通过对肺癌不同病程分期资料和不同的随访时间分层进行Poisson 回归模型拟合,其结果表明这种估计是有效的。     

A comparison of maximum likelihood and Jewell's estimators of the odds ratio and relative risk in single 2 x 2 tables

This paper compares the maximum likelihood estimators of the odds ratio and relative risk in 2 x 2 tables with less biased estimators recently proposed by Jewell for small samples. In addition to bias, location in the confidence interval, and relative likelihood are calculated for ranges of sample sizes, probabilities (of exposure or disease) and true values of the odds ratio and relative risk. Jewell's estimators perform poorly from the perspectives of confidence intervals and likelihood. Given these and other problems, continued use of the maximum likelihood estimators is recommended.     

The combined effects of healthy lifestyle behaviors on all cause mortality: A systematic review and meta-analysis

Objective

Lifestyle factors are related to mortality. Although much is known about the impact of single factors, the current evidence about the combined effects of lifestyle behaviors on mortality has not yet been systematically compiled.

Method

We searched Medline, Embase, Global Health, and Somed up to February 2012. Prospective studies were selected if they reported the combined effects of at least three of five lifestyle factors (obesity, alcohol consumption, smoking, diet, and physical activity). The mean effect sizes that certain numbers of combined lifestyle factors have on mortality were compared to the group with the least number of healthy lifestyle factors by meta-analysis. Sensitivity analyses were conducted to explore the robustness of the results.

Results

21 studies (18 cohorts) met the inclusion criteria of which 15 were included in the meta-analysis that comprised 531,804 people with a mean follow-up of 13.24 years. The relative risks decreased proportionate to a higher number of healthy lifestyle factors for all cause mortality. A combination of at least four healthy lifestyle factors is associated with a reduction of the all cause mortality risk by 66% (95% confidence interval 58%-73%).

Conclusion

Adherence to a healthy lifestyle is associated with a lower risk of mortality.     

Impact of Individual and Combined Health Behaviors on All Causes of Premature Mortality Among Middle Aged Men in Korea: The Seoul Male Cohort Study

Objectives

The aim of this study was to evaluate and quantify the risk of both individual and combined health behaviors on premature mortality in middle aged men in Korea.

Methods

In total, 14 533 male subjects 40 to 59 years of age were recruited. At enrollment, subjects completed a baseline questionnaire, which included information about socio-demographic factors, past medical history, and life style. During the follow-up period from 1993 to 2008, we identified 990 all-cause premature deaths using national death certificates. A Cox proportional hazard regression model was used to estimate the hazard ratio (HR) of each health risk behavior, which included smoking, drinking, physical inactivity, and lack of sleep hours. Using the Cox model, each health behavior was assigned a risk score proportional to its regression coefficient value. Health risk scores were calculated for each patient and the HR of all-cause premature mortality was calculated according to risk score.

Results

Current smoking and drinking, high body mass index, less sleep hours, and less education were significantly associated with all-cause premature mortality, while regular exercise was associated with a reduced risk. When combined by health risk score, there was a strong trend for increased mortality risk with increased score (p-trend < 0.01). When compared with the 1-9 score group, HRs of the 10-19 and 20-28 score groups were 2.58 (95% confidence intervals [CIs], 2.19 to 3.03) and 7.09 (95% CIs, 5.21 to 9.66), respectively.

Conclusions

Modifiable risk factors, such as smoking, drinking, and regular exercise, have considerable impact on premature mortality and should be assessed in combination.     

Low digit ratio predicts early age at menarche in colombian schoolgirls

Background: The ratio between the lengths of the second and fourth fingers (digit ratio: 2D : 4D), a purported negative correlate of prenatal androgen exposure, has been inversely related to age at menarche. However, a recent study found high digit ratios in carriers of a single variant in the LIN28B gene, which has been linked to delayed menarche. Methods: We investigated the association of digit ratio and age at menarche in 299 pre‐menarcheal girls aged 5–12 years who participated in a longitudinal cohort study in Bogotá, Colombia. Finger lengths were measured at baseline and the occurrence of menarche was periodically ascertained over a median 32 months of follow‐up. We used time‐to‐event analysis to estimate median ages at menarche as well as hazard ratios for menarche according to tertiles of the digit ratio for each hand. Results: Estimated median age at menarche was lower for girls in the lowest digit ratio tertile of the right hand compared with those in the highest (12.0 vs. 12.3 years; P‐value = 0.04). After adjustment for baseline age, height‐ and body mass index‐for‐age z‐scores, the hazard of menarche was 86% higher in girls of the lowest digit ratio tertile (hazard ratio 1.9 [95% confidence interval 1.2, 2.9]) compared with those in the highest digit ratio tertile of the right hand. No significant associations were found with the left hand. Conclusions: Digit ratio was positively associated with age at menarche in this longitudinal investigation, consistent with results from a recent gene‐linkage study.     

铁矿工人尘肺发病及影响因素分析

目的 分析铁矿接尘工人尘肺的发病规律及影响因素,为铁矿工人尘肺防制提供依据.方法 以某铁矿1960年至1974年在册且工作1年以上的所有接尘工人建立队列,随访至2003年底.尘肺诊断由职业病诊断小组确定.采用Cox比例风险模型分析危险因素.结果 队列接尘工人3647名,累积接尘132 574.4人年.诊断尘肺316例,人年发病率为0.24％.1960年前开始接尘者中发现尘肺274例(86.7％),人年发病率为0.40％,明显高于1960年后开始接尘工人尘肺人年发病率(43例,0.07‰).尘肺发病平均潜伏期是(26.0±7.3)年.尘肺晋级年限分别为0+晋Ⅰ期(5.3士3.2)年,Ⅰ晋Ⅱ期为(6.6±5.2)年,Ⅱ晋Ⅲ期为(1 1.3±5.0)年,随诊断年代的推后,各期晋级年限均有延长趋势.164例尘肺为脱尘后诊断,平均脱尘8.3年.铁矿工尘肺发病危险度随累积接尘量增加而上升,呈明显的接触剂量-反应关系.尘肺患者年平均累积接尘量为(173.7±91.6)mg/m3,远高于非尘肺接尘工人(112.1±64.8)mg/m3.除累积接尘量外,影响尘肺发病风险因素包括肺结核(HR=5.9,P＜0.01)、吸烟(HR=1.7,P＜0.01).结论 累积接尘量与尘肺发病之间存在明显的剂量-反应关系,并发结核、吸烟是影响尘肺发病的危险因素.     

Duration of cigarette smoking is a risk factor for oropharyngeal cancer mortality among Japanese men and women: the Ibaraki Prefectural Health Study (IPHS)

PurposeThe relationship between duration of cigarette smoking and the risk of oropharyngeal cancer has not been studied in the general Japanese population. Thus, the aim of the present study was to examine the relationship between the duration of cigarette smoking and the risk of oropharyngeal cancer mortality in the Japanese population.MethodsIn this large cohort study, 32,989 men and 63,894 women, ages 40–79 years, who completed health check-ups in Ibaraki Prefecture, Japan, in 1993 were followed through 2008. Oropharyngeal cancer mortality was identified by death certificates. Smoking habits were divided into five categories, and years of cigarette smoking and pack-year classifications were divided into four categories. Hazard ratios and 95% confidence intervals for oropharyngeal cancer mortality were calculated by use of the Cox proportional hazards regression models.ResultsDuring the follow-up period, deaths from oropharyngeal cancer occurred in 38 of 32,989 men and 31 of 63,894 women. The multivariate hazard ratios for oropharyngeal cancer mortality were significantly greater for those subjects currently smoking for 40 years or longer (hazard ratio: 4.22, 95% confidence interval: 1.23–14.51), and they were greater with longer years of cigarette smoking among men (P for trend = .027).ConclusionsSmoking duration can be a risk factor for oropharyngeal cancer mortality in the Japanese population.     

中国孕前队列研究现状

孕前队列对于分析和探讨人类生殖健康、生命孕育前与早期阶段各种因素对妊娠结局和子代健康的影响具有重要价值。本文就中国已建立的孕前队列基本情况与特点进行综述。     

队列人群脑血管病危险因素干预效果评价

目的：分析队列人群脑血管病危险因素干预前后变化及对脑卒中发病的影响，评价干预效果。方法：1987年在长沙市区选取1个干预社区和1个对照社区，选择具有可比性的两组人群，对35岁以上居民的脑血管病危险因素进行调查，作为基线指标，并将其作为随访对象（已确诊的脑血管病患者除外）。对干预组进行14年的脑血管病危险因素综合干预，同时监测脑卒中发病情况，2000年进行复查。结果：14年后，干预组高血压、糖尿病患病率和平均收缩压、舒张压、体重均增加，其变化分别为33.8％-35.7％，30/万-129/万，128.41-134.49mmHg(1mmHg=0.133kPa)，77.78-78.54mmHg，54.80-57.78kg，对照组上述值的变化分别是从35.9％-56.8％，30/万-228/万，127.70-141.80mmHg，78.27-82.89mmHg，54.92-59.69kg，除干预组的高血压患病人数和舒张压增加未达到统计学意义外，其余各指标增加差异均具有显著性，但均以对照组增加明显；两组人群的饮酒率均有显著性下降，吸烟虽有下降但差异无统计学意义，两组人群进行比较，无论吸烟率还是饮酒率变化差异均无显著性；干预组累积脑卒中发病率（3.4％）明显低于对照组（4.7％）。结论：高血压、糖尿病等脑血管病的危险因素随着年龄的增长也逐渐递增，但进行积极干预可明显控制危险因素的增长，进而降低脑卒中的发病率。     

Study of the epidemiology of COVID-19 in Ontario elementary and secondary school education workers: an interim analysis following the first school year

ObjectiveTo estimate the incidence of SARS-CoV-2 in education workers and the factors associated with infection between March 2020 and July 2021.MethodsA prospective cohort study of education workers working ≥8 h per week in Ontario, Canada. Participants self-reported results of tests for SARS-CoV-2 and completed online surveys about demographic information, exposures, and vaccinations against SARS-CoV-2. Participants submitted self-collected dried blood spots. Antibodies to SARS-CoV-2 spike, the receptor binding domain of spike, and nucleocapsid were assessed. Multivariable regression was used to assess risk factors for infection.ResultsOf 2834 participants, 85% were female, 81% were teaching staff, and 86% had received at least one dose of SARS-CoV-2 vaccine. Of the 1983 who had been tested via a respiratory specimen, 4.9% reported a positive test. Five additional participants had serologic testing suggestive of a previous infection (3.6% overall incidence). In multivariable regression analysis, risk factors for infection included exposure to a SARS-CoV-2 infected adult (adjusted incidence rate ratio (aIRR) 13.6; 95% confidence interval 8.6, 21.3) or child (aIRR 2.3; 1.3, 4.2) in the household, or school student (aIRR 1.9; 1.2, 3.2), or travel outside the province within 14 days of testing (aIRR 6.0; 1.5, 23.6).ConclusionIn the first 18 months of the pandemic, education workers had a similar risk of infection with SARS-CoV-2 as other Ontario residents. Practicing protective measures whenever any household member has been exposed to a possible case and at all times when exposed to anyone from outside the home would help reduce the risk of infection.     

南京市男男性行为人群随访中队列保持研究

目的 了解南京市男男性行为人群(men who have sex with men,MSM)随访中HIV新发感染率、队列保持情况及其影响因素.方法 采用前瞻性队列研究,于2008年4月始对符合纳入标准的361名MSM招募者进行间隔6个月和12个月的随访,检测HIV抗体,估算HIV抗体阳转率,并分析MSM的社会人口学和高危行为特征与12个月时队列保持率的关系.结果 南京MSM队列12个月的HIV抗体阳转率为5.09/100人年,随访12个月时队列保持率为61.5%.多因素Logistic回归分析显示,与队列保持率有统计学意义的变量为户籍所在地为南京(OR=2.430,95% CI=1.409～4.190)、6个月能随访到(OR=11.664,95% CI=6.509～20.901)、寻找性伴场所为互联网(OR=2.222,95% CI=1.228～4.022)、近1年参加同伴教育活动(OR=2.080,95% CI=1.095～3.950)和年龄大于30岁(OR=3.296,95% CI=1.737～6.253).结论 该地区MSM人群中有较高的HIV新发感染率和高危性行为暴露率,户籍为当地、年龄较大、近1年接受过同伴教育以及通过互联网寻找性伴的MSM较容易保持在随访队列中.