Identification and estimation of the number of patients with mild disease visiting during after-hours at large hospitals

Abstract

Patients with mild disease visiting outpatients services at night, on holidays or in the after-hours （so-called convenient visits） present various problems to the emergency medical system.　In this study, we describe models that we developed to identify patients with mild disease from the data on health insurance claims for outpatient services and a medical record survey to estimate the number of these patients.　A survey of the medical records of outpatients who presented to any one of the 2 medical institutions belonging to the National Hospital Organization at night, on holidays or in the after-hours, excluding those hospitalized on the same day, identified patients with mild disease, and logistic regression analysis using health insurance claim data led to the construction of 3 patient identification models.　Of these, （1） the medical examination category model and （2） medical examination content-medical cost model, which can estimate the number of patients from the data on health insurance claims for outpatient services alone, were used to estimate the number of outpatients with mild disease who presented to any of the 84 hospitals with 200 or more beds belonging to the National Hospital Organization at night, on holidays or in the after-hours, excluding those hospitalized on the same day.　The analyses using models （1） and （2） revealed that the proportion of such patients was 43.8% and 42.8%, respectively, with significant differences, according to estimation by both models, in the proportions of patients with mild disease between institutions with 200-299 beds and those with more than 500 beds （Dunnett’s t　p=0.01, p<0.01）.　The results suggest that guidance should be provided to patients attempting to visit hospitals during after-hours to improve the efficiency of the emergency medical system.