Chen E, Naylor C D
Clinical Epidemiology Unit, Sunnybrook Health Science Centre, University of Toronto, Ontario, Canada.
Med Care. 1994 May;32(5):420-35. doi: 10.1097/00005650-199405000-00002.
Unexplained variation in length of stay (LOS) following acute myocardial infarction (AMI) has been observed among American hospitals. We explored this phenomenon in the universal hospital care system of Ontario, Canada's largest province, analyzing general hospital discharge abstracts for all patients with a primary diagnosis of AMI. Case homogeneity was increased by excluding inter-hospital transfers, in-hospital deaths, patients with revascularization during the index admission and patients with severe comorbid conditions. This left 11,411 records of patients in 187 hospitals from April 1, 1990 to March 31, 1991. The mean length of stay was 9.9 days with standard deviation of 3.8. Available patient and hospital characteristics explained only 12% of the individual variation in LOS. Interinstitutional variation remained highly significant after controlling for patients' characteristics within the 87 hospitals admitting more than 50 cases per annum; these hospitals accounted for 84% of the eligible provincial admissions. The grand mean length of stay for 87 hospitals was 10 days, ranging from 6.6 to 12.9 days. Stepwise multiple linear regression analyses showed that lower caseload was associated with an increased length of hospitalization. Thus, despite Ontario's uniform system of hospital funding and medical insurance, a large amount of unexplained variation in length of stay exists for patients hospitalized with AMI, affecting thousands of bed-days per annum.
美国医院中已观察到急性心肌梗死（AMI）后住院时长（LOS）存在无法解释的差异。我们在加拿大最大省份安大略省的全民医院护理系统中探究了这一现象，分析了所有以AMI为主要诊断的患者的综合医院出院摘要。通过排除医院间转诊、院内死亡、首次住院期间接受血运重建的患者以及患有严重合并症的患者，病例同质性得到了提高。这留下了1990年4月1日至1991年3月31日期间187家医院中11411例患者的记录。平均住院时长为9.9天，标准差为3.8天。现有的患者和医院特征仅解释了住院时长个体差异的12%。在对每年收治超过50例患者的87家医院内的患者特征进行控制后，机构间差异仍然非常显著；这些医院占该省符合条件入院患者的84%。87家医院的总体平均住院时长为10天，范围从6.6天至12.9天。逐步多元线性回归分析表明，较低的病例数与住院时间延长相关。因此，尽管安大略省有统一的医院资金和医疗保险系统，但AMI住院患者的住院时长仍存在大量无法解释的差异，每年影响数千个住院日。
