Ruttimann U E, Patel K M, Pollack M M
Department of Pediatrics, George Washington University School of Medicine, Washington, DC, USA.
Pediatr Crit Care Med. 2000 Oct;1(2):133-9. doi: 10.1097/00130478-200010000-00008.
Investigation of associations of the diagnostic diversity and volumes with efficiency and quality of care.
Prospective observational study.
Thirty-two pediatric intensive care units (PICUs), 16 selected by random cluster sampling, and 16 volunteering.
Consecutive admissions of 11,165 patients.
The main outcome measures were length of PICU stay (LOS) and mortality rate, adjusted by generalized linear regression and multivariate logistic regression, respectively. Each diagnosis was categorized into 21 predefined, mutually exclusive categories. Diagnostic diversity of each PICU was characterized by an information-theoretical measure (entropy). For a patient-level analysis, the associations of this measure and PICU patient volume with outcomes were using regression models. For an institution-level analysis, the outcome measures of each PICU were adjusted using ratios of observed/predicted (by the regression models) values, and the associations of these ratios with diagnostic diversity and patient volume were investigated using linear bivariate regressions. Diagnostic diversity ranged in the PICUs from 0.823 to 0.928, when standardized to the uniform distribution with entropy of 1. Congenital heart diseases (12.6%) head traumas (11.5%), other central nervous system conditions (9.7%), and pneumonias (8.7%) constituted the largest diagnostic categories. Patient-level analysis indicated that longer adjusted LOS was associated with larger diagnostic diversity (p <.0001) and lower admission volumes (p <.0001). However, for a given increase in diagnostic diversity, a large LOS increase was associated with low-volume, but not high-volume units. Severity-adjusted mortality rates were inversely related (p =.036) only with admission volumes, but not diagnostic mix. Institution-level standardized LOS ratios correlated with diagnostic diversity (r2 = 0.145; p =.031). Institution-level standardized mortality ratios were inversely related (r2 = 0.123; p =.049) with admission volumes.
Patient volumes encountered in a PICU are important for maintaining quality and efficiency of care. In low-volume units, fewer diagnoses and higher volumes were both associated with higher efficiencies. In high volume units, diagnosis-specific volumes were generally large enough for achieving diagnosis-independent efficiency. Diagnostic mix was not associated with PICU mortality ratios, but higher PICU volumes were associated with lower mortality rates.
研究诊断多样性和病例数量与医疗效率及质量之间的关联。
前瞻性观察性研究。
32个儿科重症监护病房（PICU），其中16个通过随机整群抽样选取，16个为自愿参与。
连续收治的11165例患者。
主要结局指标分别为PICU住院时长（LOS）和死亡率，通过广义线性回归和多因素逻辑回归进行校正。每种诊断被归类为21个预先定义的、相互排斥的类别。每个PICU的诊断多样性通过信息论指标（熵）来表征。对于患者层面的分析，使用回归模型研究该指标及PICU患者数量与结局之间的关联。对于机构层面的分析，使用观察值/预测值（通过回归模型）的比率对每个PICU的结局指标进行校正，并使用线性双变量回归研究这些比率与诊断多样性和患者数量之间的关联。当标准化为熵为1的均匀分布时，各PICU的诊断多样性范围为0.823至0.928。先天性心脏病（12.6%）、头部外伤（11.5%）、其他中枢神经系统疾病（9.7%）和肺炎（8.7%）构成最大的诊断类别。患者层面的分析表明，校正后的LOS延长与更大的诊断多样性相关（p<0.0001），与较低的入院病例数量相关（p<0.0001）。然而，对于诊断多样性的给定增加，LOS的大幅增加与低病例数量的单位相关，但与高病例数量的单位无关。严重程度校正后的死亡率仅与入院病例数量呈负相关（p = 0.036），与诊断组合无关。机构层面的标准化LOS比率与诊断多样性相关（r2 = 0.145；p = 0.031）。机构层面的标准化死亡率比率与入院病例数量呈负相关（r2 = 0.123；p = 0.049）。
PICU中遇到的患者数量对于维持医疗质量和效率很重要。在低病例数量的单位中，较少的诊断和较高的病例数量均与更高的效率相关。在高病例数量的单位中，特定诊断的病例数量通常足以实现与诊断无关的效率。诊断组合与PICU死亡率比率无关，但较高的PICU病例数量与较低的死亡率相关。
