Ong Michael K, Mangione Carol M, Romano Patrick S, Zhou Qiong, Auerbach Andrew D, Chun Alein, Davidson Bruce, Ganiats Theodore G, Greenfield Sheldon, Gropper Michael A, Malik Shaista, Rosenthal J Thomas, Escarce José J
Departments of Medicine and Health Services, University of California, Los Angeles, CA 90024, USA.
Circ Cardiovasc Qual Outcomes. 2009 Nov;2(6):548-57. doi: 10.1161/CIRCOUTCOMES.108.825612. Epub 2009 Oct 13.
Recent studies have found substantial variation in hospital resource use by expired Medicare beneficiaries with chronic illnesses. By analyzing only expired patients, these studies cannot identify differences across hospitals in health outcomes like mortality. This study examines the association between mortality and resource use at the hospital level, when all Medicare beneficiaries hospitalized for heart failure are examined.
A total of 3999 individuals hospitalized with a principal diagnosis of heart failure at 6 California teaching hospitals between January 1, 2001, and June 30, 2005, were analyzed with multivariate risk-adjustment models for total hospital days, total hospital direct costs, and mortality within 180-days after initial admission ("Looking Forward"). A subset of 1639 individuals who died during the study period were analyzed with multivariate risk-adjustment models for total hospital days and total hospital direct costs within 180-days before death ("Looking Back"). "Looking Forward" risk-adjusted hospital means ranged from 17.0% to 26.0% for mortality, 7.8 to 14.9 days for total hospital days, and 0.66 to 1.30 times the mean value for indexed total direct costs. Spearman rank correlation coefficients were -0.68 between mortality and hospital days, and -0.93 between mortality and indexed total direct costs. "Looking Back" risk-adjusted hospital means ranged from 9.1 to 21.7 days for total hospital days and 0.91 to 1.79 times the mean value for indexed total direct costs. Variation in resource use site ranks between expired and all individuals were attributable to insignificant differences.
California teaching hospitals that used more resources caring for patients hospitalized for heart failure had lower mortality rates. Focusing only on expired individuals may overlook mortality variation as well as associations between greater resource use and lower mortality. Reporting values without identifying significant differences may result in incorrect assumption of true differences.
近期研究发现，患有慢性病的老年医疗保险受益人在医院资源使用方面存在很大差异。通过仅分析死亡患者，这些研究无法确定不同医院在死亡率等健康结果方面的差异。本研究在对所有因心力衰竭住院的老年医疗保险受益人进行检查时，考察了医院层面死亡率与资源使用之间的关联。
对2001年1月1日至2005年6月30日期间在加利福尼亚州6家教学医院住院且主要诊断为心力衰竭的3999名患者，使用多变量风险调整模型分析其住院总天数、医院直接总成本以及首次入院后180天内的死亡率（“向前看”）。对研究期间死亡的1639名患者的子集，使用多变量风险调整模型分析死亡前180天内的住院总天数和医院直接总成本（“向后看”）。“向前看”风险调整后的医院死亡率均值在17.0%至26.0%之间，住院总天数为7.8至14.9天，指数化总直接成本为均值的0.66至1.30倍。死亡率与住院天数之间的斯皮尔曼等级相关系数为-0.68，死亡率与指数化总直接成本之间的相关系数为-0.93。“向后看”风险调整后的医院住院总天数均值在9.1至21.7天之间，指数化总直接成本为均值的0.91至1.79倍。死亡患者与所有患者在资源使用地点排名上的差异归因于不显著的差异。
在为因心力衰竭住院的患者提供护理时使用更多资源的加利福尼亚教学医院，死亡率较低。仅关注死亡患者可能会忽略死亡率差异以及更多资源使用与较低死亡率之间的关联。在未识别显著差异的情况下报告数值可能会导致对真实差异的错误假设。
