Supplementary Material for: Variability in Palliative Care Use after Intracerebral Hemorrhage at US Hospitals: A Multilevel Analysis

Background: Palliative care (PC) is an essential component of comprehensive care of patients with intracerebral hemorrhage (ICH). In the present study, we sought to characterize the variability of PC use after ICH among US hospitals. Methods: ICH admissions from hospitals with at least 12 annual ICH cases were identified in the Nationwide Inpatient Sample between 2008 and 2011. We used multilevel logistic regression modeling to estimate between-hospital variance in PC use. We calculated the intraclass correlation coefficient (ICC), proportional variance change, and median OR after accounting for individual-level and hospital-level covariates. Results: Among 26,791 ICH admissions, 12.5% received PC (95% CI 11.5–13.5). Among the 629 included hospitals, the median rate of PC use was 9.1 (interquartile range 1.5–19.3) per 100 ICH admissions, and 150 (23.9%) hospitals had no recorded PC use. The ICC of the random intercept (null) model was 0.274, suggesting that 27.4% of the overall variability in PC use was due to between-hospital variability. Adding hospital-level covariates to the model accounted for 25.8% of the between-hospital variance observed in the null model, with 74.2% of between-hospital variance remaining unexplained. The median OR of the fully adjusted model was 2.62 (95% CI 2.41–2.89), indicating that a patient moving from 1 hospital to another with a higher intrinsic propensity of PC use had a 2.63-fold median increase in the odds of receiving PC, independent of patient and hospital factors. Conclusions: Substantial variation in PC use after ICH exists among US hospitals. A substantial proportion of this between-hospital variability remains unexplained even after accounting for patient and hospital characteristics.

背景：姑息治疗（Palliative Care, PC）是脑出血（Intracerebral Hemorrhage, ICH）患者综合诊疗体系中的核心组成部分。本研究旨在明确美国医院中ICH患者接受姑息治疗的使用差异情况。
方法：本研究从2008至2011年的全国住院患者样本（Nationwide Inpatient Sample）中，筛选出年ICH收治量至少12例的医院的ICH住院病例。采用多水平logistic回归模型估算不同医院间姑息治疗使用率的差异方差。同时计算组内相关系数（Intraclass Correlation Coefficient, ICC）、方差变化比例及调整个体与医院层面协变量后的中位数优势比（Odds Ratio, OR）。
结果：在26791例ICH住院病例中，12.5%的患者接受了姑息治疗（95%置信区间：11.5%~13.5%）。纳入研究的629家医院中，每100例ICH住院患者的姑息治疗使用率中位数为9.1（四分位距：1.5~19.3），其中150家医院（占比23.9%）未记录有姑息治疗使用情况。随机截距（空）模型的组内相关系数为0.274，表明姑息治疗使用率的整体变异中有27.4%来源于医院间差异。在模型中加入医院层面协变量后，可解释空模型中25.8%的医院间方差，剩余74.2%的医院间变异仍未得到解释。完全校正模型的中位数优势比为2.62（95%置信区间：2.41~2.89），提示在不考虑患者与医院自身因素的前提下，患者从姑息治疗内在使用倾向更低的医院转至更高的医院时，其接受姑息治疗的优势比中位数将提升至原来的2.63倍。
结论：美国各医院对ICH患者的姑息治疗使用率存在显著差异。即便校正了患者与医院的相关特征，仍有相当比例的医院间变异未得到合理解释。