Infectious disease during hospitalization is the major causative factor for prolonged hospitalization: multivariate analysis of diagnosis procedure combination (DPC) data of 20,876 cases in Japan.

This study aimed to evaluate causative factors for prolonged hospitalization based on hospitalization status, type of hospital ward, and comorbidities, specifically diabetes mellitus and infectious diseases, in 20,876 patients hospitalized in Saga University Hospital from April 1, 2012, to February 28, 2015. Prolonged hospitalization was defined as hospital days exceeding period 3 in the diagnosis procedure combination system. Among all factors, causative (risk) factors for prolonged hospitalization were evaluated by multiple logistic regression analysis. Multivariate analysis indicated causative factors for prolonged hospitalization were aging, comorbid diabetes mellitus, time spent in the intensive care unit, and infectious diseases contracted during hospitalization. The risk factors for contracting infectious diseases during hospitalization were aging, male sex, comorbid diabetes mellitus, and increased number of days spent in period 3 in the diagnosis procedure combination code. These data indicated that critical factors for discharge from hospital within an appropriate time frame were prevention of infectious diseases during hospitalization, and a fast and effective therapeutic approach to patients in the intensive care unit.