Abstract：
BACKGROUND: Patients with traumatic brain injury associated with intracranial hemorrhage are commonly admitted to the intensive care unit (ICU); however, the need for ICU care for patients with isolated traumatic subarachnoid hemorrhage (tSAH) remains unclear. We aimed to investigate the association between the ICU admission practices and outcomes in patients with isolated tSAH.
METHODS: This observational study used a nationwide administrative database in Japan. We identified patients with isolated tSAH from the Japanese Diagnostic Procedure Combination inpatient database from July 1, 2010, to March 31, 2020. The primary outcome was in-hospital mortality, whereas the secondary outcomes were neurosurgical interventions, activities of daily living at discharge, and total hospitalization cost. We performed a risk-adjusted mixed-effect regression analysis to evaluate the association between hospital-level ICU admission rates and study outcomes. The ICU admission rates were categorized into quartiles: lowest, middle-low, middle-high, and highest. Moreover, we assessed the robustness of the results with a patient-level instrumental variable analysis.
RESULTS: Of the 61,883 patients with isolated tSAH treated at 962 hospitals, 16,898 (27.3%) patients were admitted to the ICU on the day of admission. Overall, 2465 (4.0%) patients died in the hospital, and 783 (1.3%) patients underwent neurosurgical interventions. There was no significant difference between the lowest and highest ICU admission quartile in terms of in-hospital mortality (3.7% vs. 4.3%; adjusted odds ratio 0.93; 95% confidence interval [CI] 0.78-1.10), neurosurgical interventions, and activities of daily living at discharge. However, the total hospitalization cost in the lowest ICU admission quartile was significantly lower than that in the highest quartile (US $3032 vs. $4095; adjusted difference US $560; 95% CI 33-1087). The patient-level instrumental variable analysis did not reveal a significant difference in in-hospital mortality between the patients who were admitted to the ICU and those who were not (risk difference 0.2%; 95% CI - 0.1 to 0.5).
CONCLUSIONS: There was no significant association between the ICU admission practices and outcomes in patients with isolated tSAH, whereas higher ICU admission rates were associated with significantly higher hospitalization costs. Our results provide an opportunity for improved health care allocation in the management of patients with isolated tSAH.
METHODS: This observational study used a nationwide administrative database in Japan. We identified patients with isolated tSAH from the Japanese Diagnostic Procedure Combination inpatient database from July 1, 2010, to March 31, 2020. The primary outcome was in-hospital mortality, whereas the secondary outcomes were neurosurgical interventions, activities of daily living at discharge, and total hospitalization cost. We performed a risk-adjusted mixed-effect regression analysis to evaluate the association between hospital-level ICU admission rates and study outcomes. The ICU admission rates were categorized into quartiles: lowest, middle-low, middle-high, and highest. Moreover, we assessed the robustness of the results with a patient-level instrumental variable analysis.
RESULTS: Of the 61,883 patients with isolated tSAH treated at 962 hospitals, 16,898 (27.3%) patients were admitted to the ICU on the day of admission. Overall, 2465 (4.0%) patients died in the hospital, and 783 (1.3%) patients underwent neurosurgical interventions. There was no significant difference between the lowest and highest ICU admission quartile in terms of in-hospital mortality (3.7% vs. 4.3%; adjusted odds ratio 0.93; 95% confidence interval [CI] 0.78-1.10), neurosurgical interventions, and activities of daily living at discharge. However, the total hospitalization cost in the lowest ICU admission quartile was significantly lower than that in the highest quartile (US $3032 vs. $4095; adjusted difference US $560; 95% CI 33-1087). The patient-level instrumental variable analysis did not reveal a significant difference in in-hospital mortality between the patients who were admitted to the ICU and those who were not (risk difference 0.2%; 95% CI - 0.1 to 0.5).
CONCLUSIONS: There was no significant association between the ICU admission practices and outcomes in patients with isolated tSAH, whereas higher ICU admission rates were associated with significantly higher hospitalization costs. Our results provide an opportunity for improved health care allocation in the management of patients with isolated tSAH.
摘要：
背景：合并颅内出血的创伤性脑损伤患者通常被送往重症监护病房（ICU）；然而，孤立性外伤性蛛网膜下腔出血(tSAH)患者是否需要ICU护理仍不清楚.我们旨在调查ICU入院实践与孤立性tSAH患者预后之间的关系。
方法：这项观察性研究使用了日本的全国性管理数据库。我们从2010年7月1日至2020年3月31日的日本诊断程序组合住院患者数据库中确定了孤立的tSAH患者。主要结果是住院死亡率，而次要结局是神经外科干预，出院时的日常生活活动，和住院总费用。我们进行了风险调整的混合效应回归分析，以评估医院级ICU入院率与研究结果之间的关系。ICU入院率分为四分位数：最低，中低,中高,和最高。此外，我们通过患者水平的工具变量分析评估了结果的稳健性.
结果：在962家医院接受治疗的61,883例孤立性tSAH患者中，入院当天有16,898名（27.3％）患者入院ICU。总的来说,2465名(4.0%)患者在医院死亡，783例(1.3%)患者接受了神经外科手术.就住院死亡率而言，最低和最高ICU入院四分位数之间没有显着差异（3.7％vs.4.3%；调整后赔率比0.93；95%置信区间[CI]0.78-1.10)，神经外科干预，出院时的日常生活活动。然而,最低ICU入院四分位数的总住院费用显着低于最高四分位数(3032美元vs.4095美元；调整后差额560美元；95%CI33-1087）。患者水平的工具变量分析未显示入住ICU的患者与未入住ICU的患者之间的住院死亡率差异显着（风险差异0.2％；95％CI-0.1至0.5）。
结论：在孤立性tSAH患者中，ICU入住实践与转归之间没有显著关联，而较高的ICU入院率与显著较高的住院费用相关.我们的结果为改善孤立性tSAH患者的医疗保健分配提供了机会。
方法：这项观察性研究使用了日本的全国性管理数据库。我们从2010年7月1日至2020年3月31日的日本诊断程序组合住院患者数据库中确定了孤立的tSAH患者。主要结果是住院死亡率，而次要结局是神经外科干预，出院时的日常生活活动，和住院总费用。我们进行了风险调整的混合效应回归分析，以评估医院级ICU入院率与研究结果之间的关系。ICU入院率分为四分位数：最低，中低,中高,和最高。此外，我们通过患者水平的工具变量分析评估了结果的稳健性.
结果：在962家医院接受治疗的61,883例孤立性tSAH患者中，入院当天有16,898名（27.3％）患者入院ICU。总的来说,2465名(4.0%)患者在医院死亡，783例(1.3%)患者接受了神经外科手术.就住院死亡率而言，最低和最高ICU入院四分位数之间没有显着差异（3.7％vs.4.3%；调整后赔率比0.93；95%置信区间[CI]0.78-1.10)，神经外科干预，出院时的日常生活活动。然而,最低ICU入院四分位数的总住院费用显着低于最高四分位数(3032美元vs.4095美元；调整后差额560美元；95%CI33-1087）。患者水平的工具变量分析未显示入住ICU的患者与未入住ICU的患者之间的住院死亡率差异显着（风险差异0.2％；95％CI-0.1至0.5）。
结论：在孤立性tSAH患者中，ICU入住实践与转归之间没有显著关联，而较高的ICU入院率与显著较高的住院费用相关.我们的结果为改善孤立性tSAH患者的医疗保健分配提供了机会。
