Background:The degree of association between mortality and case volume/physician volume is well known for many surgical procedures and medical conditions. However, the link between physician volume and death rate in patients hospitalized for stroke remains unclear. This study analyzed the correlation between in-hospital stroke mortality and physician volume per hospital, considering board certification status.

Methods and Results:For this retrospective registry-based cohort study, data were obtained from the Japanese nationwide registry on patients hospitalized for ischemic stroke, intracerebral hemorrhage (ICH), and subarachnoid hemorrhage (SAH) between 2010 and 2016. The number of stroke care physicians and relevant board-certified physicians was also obtained. Odd ratios (ORs) of 30-day in-hospital mortality were estimated after adjusting for institutional and patient differences using generalized mixed logistic regression. From 295,150 (ischemic stroke), 98,657 (ICH), and 36,174 (SAH) patients, 30-day in-hospital mortality rates were 4.4%, 16.0%, and 26.6%, respectively. There was a correlation between case volume and physician volume. A higher number of stroke care physicians was associated with a reduction in 30-day mortality after adjusting for stroke case volume and comorbidities for all stroke types (all P for trend<0.05).

Conclusions:An increased number of stroke care physicians was associated with reduced in-hospital mortality for all types of stroke. The volume threshold of board-certified physicians depends on the specialty and stroke type.

背景：死亡率与病例数量/医生数量之间的关联程度在许多外科手术和医疗条件下是众所周知的。然而，医生数量与卒中住院患者死亡率之间的联系仍不清楚。本研究分析了院内卒中死亡率与每家医院的医生数量之间的相关性，并考虑了委员会认证状态。

方法和结果：对于这项基于登记的回顾性队列研究，数据来自日本全国登记处，关于 2010 年至 2016 年间因缺血性卒中、脑出血 (ICH) 和蛛网膜下腔出血 (SAH) 住院的患者。卒中护理医师和相关委员会的人数-还获得了认证的医生。在使用广义混合逻辑回归调整机构和患者差异后，估计了 30 天住院死亡率的优势比 (OR)。从 295,150 名（缺血性卒中）、98,657 名（ICH）和 36,174 名（SAH）患者中，30 天住院死亡率分别为 4.4%、16.0% 和 26.6%。病例数量和医生数量之间存在相关性。

结论：卒中护理医师数量的增加与所有类型卒中的住院死亡率降低相关。获得董事会认证的医生的数量阈值取决于专业和中风类型。