北京市怀柔区4～6岁学龄前儿童视力调查

目的了解北京市怀柔区4~6岁学龄前儿童的视力状况。方法 2009年对怀柔区25个幼儿园的4~6岁儿童共3 829例应用国际标准视力表检查视力。结果视力低常患病率11.33%。视力低常与年龄相关,5岁最高。结论学龄前儿童视力低常率随年龄增加而降低,表明视功能发育逐渐成熟。

北京市女性乳腺癌危险因素与乳腺癌相关性的探讨

目的:探讨北京女性年龄、危险因素及内源性类固醇性激素与乳腺癌的关系,以及性激素与乳腺密度的关系。方法:随机选取493例北京市女性,年龄25～76岁,中位年龄44岁。分为≤40岁组(165名)、>40岁组(242名)和绝经后组(86名)。对全体受检者进行问卷调查及危险因素统计,行数字化乳腺X射线检查,并用半定量方法计算乳腺密度百分比,检测血浆雌二醇和孕酮水平。结果:乳腺癌及良性病变的检出率分别是1.2%和7.3%。除去乳腺癌患者,共有危险因素者146名。绝经后组有危险因素组的乳腺密度显著高于无危险因素组,P<0.05。绝经后组乳腺密度与雌二醇及孕酮之间存在轻度正相关(r=0.315,P=0.003;r=0.256,P=0.017)。多远逻辑回归分析显示,乳腺癌检出率随着年龄及危险因素呈递增趋势(χ2=5.7,P=0.017;χ2=4.7,P=0.03)。乳腺癌检出率在高年龄组是低年龄组的4.2倍,有危险因素组是无危险因素组的4.9倍。结论:乳腺癌检出率随年龄增长上升,有危险因素者检出率高于无危险因素者。绝经后组有危险因素女性的乳腺密度显著高于同龄的无危险因素者。乳腺密度应作为乳腺癌普查的观察指标。

Spatial-temporal characteristics of epidemic spread in-out flow——Using SARS epidemic in Beijing as a case study

For better detecting the spatial-temporal change mode of individual susceptible-infected-symptomatic-treated-recovered epidemic progress and the characteristics of information/material flow in the epidemic spread network between regions,the epidemic spread mechanism of virus input and output was explored based on individuals and spatial regions.Three typical spatial information parameters including working unit/address,onset location and reporting unit were selected and SARS epidemic spread in-out flow in Beijing was defined based on the SARS epidemiological investigation data in China from 2002 to 2003 while its epidemiological characteristics were discussed.Furthermore,by the methods of spatial-temporal statistical analysis and network characteristic analysis,spatial-temporal high-risk hotspots and network structure characteristics of Beijing outer in-out flow were explored,and spatial autocorrelation/heterogeneity,spatial-temporal evolutive rules and structure characteristics of the spread network of Beijing inner in-out flow were comprehensively analyzed.The results show that(1)The outer input flow of SARS epidemic in Beijing concentrated on Shanxi and Guangdong provinces,but the outer output flow was disperse and mainly includes several north provinces such as Guangdong and Shandong.And the control measurement should focus on the early and interim progress of SARS breakout.(2)The inner output cases had significant positive autocorrelative characteristics in the whole studied region,and the high-risk population was young and middle-aged people with ages from 20 to 60 and occupations of medicine and civilian labourer.(3)The downtown districts were main high-risk hotspots of SARS epidemic in Beijing,the northwest suburban districts/counties were secondary high-risk hotspots,and northeast suburban areas were relatively safe.(4)The district/county nodes in inner spread network showed small-world characteristics and information/material flow had notable heterogeneity.The suburban Tongzhou and Changping districts were the underlying high-risk regions,and several suburban districts such as Shunyi and Huairou were the relatively low-risk safe regions as they carried out minority information/material flow.The exploration and analysis based on epidemic spread in-out flow help better detect and discover the potential spatial-temporal evolutive rules and characteristics of SARS epidemic,and provide a more effective theoretical basis for emergency/control measurements and decision-making.