Diastolic blood pressure and area of residence:: multilevel versus ecological analysis of social inequity
Diastolic blood pressure and area of residence:: multilevel versus ecological analysis of social inequity
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DOI：
10.1136/jech.55.11.791
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发表时间：
2001-11-01
影响因子：
6.3
通讯作者：
Berglund, G
中科院分区：
文献类型：
--
作者：
Merlo, J;Östergren, PO;Berglund, G
研究目的：在控制个体年龄和受教育程度后，研究舒张压的地理差异和社会环境（受教育程度低的人口普查百分比）对个体舒张压水平的影响。比较多层次分析和生态分析的结果。设计-采用多层线性回归模型进行横断面分析，妇女为一级，城市地区为二级，采用单层生态回归，以地区为分析单位。背景：瑞典马尔默（人口25万）。参与者：15 569名年龄在45岁至73岁之间的妇女，居住在17个城市地区，她们参加了马尔默饮食和癌症研究（1991-1996年）。主要结果：在“固定效应”多水平分析中，个体（beta =1.093， SE=0.167）和区域水平（beta =2.966， SE=1.250）的低教育成就与血压独立相关，尽管在“随机效应”多水平分析中，几乎没有人的血压总变异性可归因于区域（类内相关性=0.3%）。生态分析还发现地区教育变量与平均舒张压之间存在关联（beta =4.058， SE=1.345）。结论类内相关性很小，表明地理差异非常小，城市地区对个体血压几乎没有影响。然而，这些细微的差异足以检测出社会环境对血压的影响。生态研究高估了“固定”效应多水平分析中发现的关联，既没有将个体与区域水平区分开来，也没有提供类内相关性的信息。生态分析不足以评价健康方面的地理差异。
Study objectives-To study geographical differences in diastolic blood pressure and the influence of the social environment (census percentage of people with low educational achievement) on individual diastolic blood pressure level, after controlling for individual age and educational achievement. To compare the results of multilevel and ecological analyses.Design - Cross sectional analysis performed by multilevel linear regression modelling, with women at the first level and urban areas at the second level, and by single level ecological regression using areas as the unit of analysis.Setting - Malmo, Sweden (population 250000).Participants - 15 569 women aged 45 to 73, residing in 17 urban areas, who took part in the Malmo Diet and Cancer Study (1991-1996).Main results - In the "fixed effects" multilevel analysis, low educational achievement at both individual (beta =1.093, SE=0.167) and area levels (beta =2.966, SE=1.250) were independently associated with blood pressure, although in the "random effects" multilevel analysis almost none of the total variability in blood pressure across persons was attributable to areas (intraclass correlation=0.3%). The ecological analysis also found an association between the area educational variable and mean diastolic blood pressure (beta =4.058, SE=1.345).Conclusions-The small intraclass correlation found indicated very marginal geographical differences and almost no influence of the urban area on individual blood pressure. However, these slight differences were enough to detect an effect of the social environment on blood pressure. The ecological study overestimated the associations found in the "fixed" effects multilevel analysis, and neither distinguished individual from area levels nor provided information on the intraclass correlation. Ecological analyses are inadequate to evaluate geographical differences in health.