Coyte P, Wang P P, Hawker G, Wright J G
Department of Health Administration and Institute for Policy Analysis, University of Toronto, Ontario, Canada.
J Rheumatol. 1997 Dec;24(12):2403-12.
To determine the relationship between regional variations in knee replacement (KR) utilization rates in Ontario, Canada, and the reported prevalence of arthritis and rheumatism as a chronic health problem.
Utilization data were acquired from the Canadian Institute for Health Information for KR procedures performed in Ontario between fiscal years 1984 and 1990. Census information was obtained from Statistics Canada. Disease prevalence data were derived from the 1990 Ontario Health Survey (OHS). Public Health Units (PHU) were used as the unit of analysis, with utilization rates defined as the number of KR performed on all PHU residents (irrespective of where these procedures were performed) divided by the population. Direct methods were used to standardize utilization for age, sex, and disease prevalence. The extremal quotient, the weighted coefficient of variation, and the systematic component of variation were used as measures of variation. The relationship between the number of KR performed in each age-sex-year strata and various demographic (age and sex), disease prevalence, and regional dummy variables was estimated using a Poisson regression model.
Regional variation in the standardized utilization of KR surgery was wide, but declined over the study period; the extremal quotient fell from 8.0 to 3.3, the weighted coefficient of variation fell from 0.49 to 0.30, and the systematic component of variation fell from 0.20 to 0.17. Variation in the provision of KR surgery remained even after controlling for the demographic composition of the population and disease prevalence. Moreover, while demographic, regional, and temporal covariates were significant (p < 0.0001) in accounting for over 90% of the variation in utilization, disease prevalence was not significant (p > 0.05).
This study merged population based reports of disease prevalence with administrative data to account for regional variations in utilization. While regional variations in KR surgery have fallen over time, variations remain even after adjusting for patient reported disease prevalence. The finding that demographic variables and the reported prevalence of disease were poorly correlated suggests that current area variation studies may not be adjusting fully for disease prevalence or severity.
确定加拿大安大略省膝关节置换（KR）使用率的地区差异与所报告的关节炎和风湿病作为慢性健康问题的患病率之间的关系。
利用数据取自加拿大卫生信息研究所，涵盖1984年至1990财政年度在安大略省进行的KR手术。人口普查信息来自加拿大统计局。疾病患病率数据源自1990年安大略省健康调查（OHS）。公共卫生单位（PHU）用作分析单位，使用率定义为在所有PHU居民中进行的KR手术数量（无论这些手术在何处进行）除以人口数。采用直接法对年龄、性别和疾病患病率进行使用率标准化。极值商、加权变异系数和变异的系统成分用作变异度量。使用泊松回归模型估计每个年龄 - 性别 - 年份分层中进行的KR手术数量与各种人口统计学（年龄和性别）、疾病患病率和地区虚拟变量之间的关系。
KR手术标准化使用率的地区差异很大，但在研究期间有所下降；极值商从8.0降至3.3，加权变异系数从0.49降至0.30，变异的系统成分从0.20降至0.17。即使在控制了人口的人口统计学组成和疾病患病率之后，KR手术提供的差异仍然存在。此外，虽然人口统计学、地区和时间协变量在解释超过90%的使用率变异方面具有显著性（p < 0.0001），但疾病患病率并不显著（p > 0.05）。
本研究将基于人群的疾病患病率报告与行政数据相结合，以解释使用率的地区差异。虽然KR手术的地区差异随着时间推移有所下降，但即使在调整患者报告的疾病患病率之后差异仍然存在。人口统计学变量与所报告的疾病患病率相关性较差这一发现表明，当前的地区差异研究可能没有充分调整疾病患病率或严重程度。
