Supplementary Material for: Healthcare Costs and Utilization among Patients Hospitalized for Malignant Pleural Effusion

Background: Malignant pleural effusion (MPE) poses a considerable healthcare burden, but little is known about trends in directly attributable hospital utilization. Objective: We aimed to study national trends in healthcare utilization and outcomes among hospitalized MPE patients. Methods: We analyzed adult hospitalizations attributable to MPE using the Healthcare Cost and Utilization Project – National Inpatient Sample (HCUP-NIS) databases from 2004, 2009, and 2014. Cases were included if MPE was coded as the principal admission diagnosis or if unspecified pleural effusion was coded as the principal admission diagnosis in the setting of metastatic cancer. Annual hospitalizations were estimated for the entire US hospital population using discharge weights. Length of stay (LOS), hospital charges, and hospital mortality were also estimated. Results: We analyzed 92,034 hospital discharges spanning a decade (2004–2014). Yearly hospitalizations steadily decreased from 38,865 to 23,965 during this time frame, the mean LOS decreased from 7.7 to 6.3 days, and the adjusted hospital mortality decreased from 7.9 to 4.5% (p = 0.00 for all trend analyses). The number of pleurodesis procedures also decreased over time (p = 0.00). The mean inflation-adjusted charge per hospitalization rose from USD 41,252 to USD 56,951, but fewer hospitalizations drove the total annual charges down from USD 1.51 billion to USD 1.37 billion (p = 0.00 for both analyses). Conclusions: The burden of hospital-based resource utilization associated with MPE has decreased over time, with a reduction in attributable hospitalizations by one third in the span of 1 decade. Correspondingly, the number of inpatient pleurodesis procedures has decreased during this time frame.背景：恶性胸腔积液（malignant pleural effusion, MPE）给美国医疗保健系统带来了沉重负担，但目前学界对其直接关联的住院医疗资源使用趋势的了解仍较为有限。 研究目的：本研究旨在探讨住院恶性胸腔积液患者的全国性医疗资源使用趋势与临床结局。 方法：本研究利用2004年、2009年及2014年的医疗成本与利用项目-全国住院患者样本（Healthcare Cost and Utilization Project – National Inpatient Sample, HCUP-NIS）数据库，分析与恶性胸腔积液直接相关的成人住院病例。纳入标准为：以恶性胸腔积液作为主要入院诊断，或在合并转移性癌症的情况下，以未特指性胸腔积液作为主要入院诊断。本研究通过出院权重估算全美所有住院人群的年度住院人次，并同时估算了住院时长（Length of Stay, LOS）、住院费用及住院死亡率。 结果：本研究共分析了2004至2014年十年间的92034例出院病例。在此研究时段内，年度住院人次从38865例稳步降至23965例；平均住院时长从7.7天缩短至6.3天；校正后的住院死亡率从7.9%降至4.5%（所有趋势分析的p值均为0.00）。胸膜固定术的实施例数也随时间呈下降趋势（p=0.00）。经通胀调整后的单次住院平均费用从41252美元升至56951美元，但由于住院总人次减少，年度总住院费用从15.1亿美元降至13.7亿美元（两项分析的p值均为0.00）。 结论：随着时间推移，与恶性胸腔积液相关的住院医疗资源使用负担有所降低，十年间直接相关的住院人次减少了三分之一。与此相对应，此研究时段内住院胸膜固定术的实施例数也有所减少。