Lavergne M Ruth, Kephart George
Department of Community Health and Epidemiology, Dalhousie University, Halifax, Nova Scotia, Canada.
Rural Remote Health. 2012;12:1848. Epub 2012 Feb 29.
Differences in health between urban and rural areas of Canada are well documented. Canadian rural communities are remarkably heterogeneous in terms of social, economic, and geographic characteristics. There is reason to believe that there is also considerable heterogeneity in health within rural Canada but existing literature has not given this adequate consideration. This article describes heterogeneity in health along the urban-rural continuum, both between and within categories of rural areas. Factors that may explain observed variations are then examined.
The study population included all adult (>18 years) respondents on the Canadian Community Health Survey Cycle 1.1, linked to census subdivision-level data from the corresponding Canadian Census. Study areas were classified according to Metropolitan Influenced Zones (MIZ), which group rural areas based on their degree of connectivity with nearby urban areas. Dichotomized Health Utilities Index (HUI) scores were the outcome variable. Random-intercept logistic regression models investigated the associations of HUI with individual and area characteristics. To describe between-area variation in health, the proportion of the total variation accounted for by the area random effect (the intra-class correlation coefficient [ICC]) was estimated. To aid interpretation of the magnitude of the effect of area relative to other variables in the models, the ICC was also expressed as a median odds ratio (MOR), or the median amount by which the probability of disability will change for an individual who moves from one area to another.
On a descriptive level, poorer health was observed in more remote rural areas, but the size of estimated effects for categories of rural areas was generally small compared with effects of other individual and area variables, and with the degree of heterogeneity between areas. The composition of rural areas is important in order to understand patterns in health. Individual income, education, and employment, and area characteristics such as Francophone or Aboriginal populations, and migration patterns help explain the gradient in health by MIZ, but considerable heterogeneity in health within categories of MIZ remains. In models stratified by MIZ, significant between-area heterogeneity was observed in all models, with MORs ranging from 1.18 to 1.53.
It was observed that heterogeneity in health among rural areas is substantial, and generally larger than the effect of rurality, itself, on health. More attention is needed to understand the characteristics of Canada's heterogeneous rural communities, and the different processes by which disparities in health emerge and persist. The findings suggest that a focus on rurality alone, emphasizing urban versus rural disparities, or even continuum-based approaches like MIZ, may be less informative than finding ways to classify and examine different types of rural areas according to factors relevant to health.
加拿大城乡地区的健康差异已有充分记录。加拿大农村社区在社会、经济和地理特征方面存在显著的异质性。有理由相信,加拿大农村地区内部在健康方面也存在相当大的异质性,但现有文献对此并未给予充分考虑。本文描述了城乡连续体中健康状况的异质性,包括农村地区类别之间以及内部的异质性。随后研究了可能解释观察到的差异的因素。
研究人群包括加拿大社区健康调查第1.1轮中的所有成年(>18岁)受访者,并与相应加拿大人口普查中的普查分区层面数据相链接。研究区域根据大都市影响区(MIZ)进行分类,MIZ根据农村地区与附近城市地区的连通程度对农村地区进行分组。二分健康效用指数(HUI)得分是结果变量。随机截距逻辑回归模型研究了HUI与个体及区域特征之间的关联。为描述区域间健康差异,估计了区域随机效应(组内相关系数[ICC])占总变异的比例。为便于解释模型中区域效应相对于其他变量的大小,ICC也表示为中位数优势比(MOR),即个体从一个区域迁移到另一个区域时残疾概率变化的中位数。
在描述层面上,在更偏远的农村地区观察到健康状况较差,但与其他个体和区域变量的效应以及区域间的异质性程度相比,农村地区类别估计效应的大小通常较小。农村地区的构成对于理解健康模式很重要。个体收入、教育和就业,以及诸如说法语或原住民人口等区域特征和移民模式有助于解释按MIZ划分的健康梯度,但MIZ类别内部在健康方面仍存在相当大的异质性。在按MIZ分层的模型中,所有模型均观察到显著的区域间异质性,MOR范围为1.18至1.53。
研究发现农村地区之间的健康异质性很大,并且通常大于农村地区本身对健康的影响。需要更多关注来了解加拿大异质性农村社区的特征,以及健康差距出现和持续存在的不同过程。研究结果表明,仅关注农村地区、强调城乡差距,甚至像MIZ这样基于连续体的方法,可能不如根据与健康相关的因素对不同类型的农村地区进行分类和研究那样提供更多信息。