*Department of Research and Evaluation, Kaiser Permanente Southern California, Pasadena †Department of Medicine, University of California ‡Department of Medicine, Greater Los Angeles Veterans Affairs Healthcare System, Los Angeles, CA §Department of Emergency Medicine, Oregon Health and Science University, Portland, OR.
Med Care. 2014 Jul;52(7):602-11. doi: 10.1097/MLR.0000000000000141.
Emergency department (ED) crowding has been identified as a major threat to public health.
We assessed patient transit times and ED system crowding measures based on their associations with outcomes.
Retrospective cohort study.
We accessed electronic health record data on 136,740 adults with a visit to any of 13 health system EDs from January 2008 to December 2010.
Patient transit times (waiting, evaluation and treatment, boarding) and ED system crowding [nonindex patient length-of-stay (LOS) and boarding, bed occupancy] were determined. Outcomes included individual inpatient mortality and admission LOS. Covariates included demographic characteristics, past comorbidities, severity of illness, arrival time, and admission diagnoses.
No patient transit time or ED system crowding measure predicted increased mortality after control for patient characteristics. Index patient boarding time and lower bed occupancy were associated with admission LOS (based on nonoverlapping 95% CI vs. the median value). As boarding time increased from none to 14 hours, admission LOS increased an additional 6 hours. As mean occupancy decreased below the median (80% occupancy), admission LOS decreased as much as 9 hours.
Measures indicating crowded ED conditions were not predictive of mortality after case-mix adjustment. The first half-day of boarding added to admission LOS rather than substituted for it. Our findings support the use of boarding time as a measure of ED crowding based on robust prediction of admission LOS. Interpretation of measures based on other patient ED transit times may be limited to the timeliness of care.
急诊部（ED）拥堵已被确定为公共卫生的主要威胁。
我们评估了患者的转移时间和 ED 系统拥堵指标，以评估它们与结果的关联。
回顾性队列研究。
我们访问了 2008 年 1 月至 2010 年 12 月期间在 13 个卫生系统 ED 就诊的 136740 名成年人的电子健康记录数据。
确定了患者转移时间（等待、评估和治疗、住院）和 ED 系统拥堵（非索引患者住院时间和住院、床位占用）。结果包括患者个体住院死亡率和住院时间。协变量包括人口统计学特征、过去的合并症、疾病严重程度、到达时间和入院诊断。
在控制患者特征后，没有患者转移时间或 ED 系统拥堵指标预测死亡率增加。索引患者住院时间和较低的床位占用与住院时间有关（基于非重叠 95%CI 与中位数值相比）。随着住院时间从无到 14 小时增加，住院时间增加了额外的 6 小时。随着平均入住率低于中位数（80%入住率），住院时间减少了 9 小时。
在病例组合调整后，表明 ED 拥挤状况的指标不能预测死亡率。在住院时间的前半天增加而不是替代它。我们的研究结果支持使用住院时间作为 ED 拥挤的指标，因为它可以很好地预测住院时间。基于其他患者 ED 转移时间的指标的解释可能仅限于护理的及时性。
