Regional Variations in In-hospital Mortality, Care Processes, and Spending in Acute Ischemic Stroke Patients in Japan

Background: Little is known about the regional variations in ischemic stroke care in Japan. This study investigates the regional variations and associations among outcomes, care processes, spending, and physician workforce availability in acute ischemic stroke care. Methods: Using administrative claims data from National Claims Database, we identified National Health Insurance beneficiaries aged 65 years and older and Long Life Medical Care System beneficiaries from 9 prefectures who had been hospitalized for acute ischemic stroke between April 2010 and March 2012. Patients were grouped according to their subprefectural regions of residence known as secondary medical areas (SMAs). Performances in 8 outcome and process of care measures were analyzed in each SMA. Multilevel regression models with 2 levels (patient and regional) were used to analyze age-and sex-adjusted inhospital mortality, hospitalization spending, and tissue plasminogen activator (tPA) utilization rate. The associations between regional supply of physicians for stroke care and the various quality measures were investigated. Results: We analyzed 49,440 acute ischemic stroke patients. The regional variations among SMAs in in-hospital mortality, spending, and tPA utilization were 3.2-, 1.7-, and 5.9-fold, respectively. Higher physician supply was significantly associated with lower in-hospital mortality and higher spending. Additionally, spending had a significantly negative correlation with regional continuity of care planning rate but a significantly positive correlation with rehabilitation rate. Conclusions: The study revealed substantial regional variations in Japanese ischemic stroke care. Improving the allocative efficiency of physicians and establishing continuity of care networks may be useful in mitigating regional disparities and reconstructing the stroke care system.