Evaluation of the introduction of a diagnosis procedure combination system for patient outcome and hospitalisation charges for patients with hip fracture or lung cancer in Japan

Abstract Objectives To evaluate the effects of introducing the Diagnosis Procedure Combination (DPC) system on outcomes, length of stay (LOS) and hospitalisation charges for patients with hip fractures or lung cancer. Patient outcome was evaluated by inpatient mortality, condition at discharge, and readmission within 42 days after discharge. Methods DPC data were collected from 92 Japanese Red Cross Medical Centres and community hospitals between April 2005 and December 2008. Pre- and post-DPC outcomes were compared by multivariate regression with difference-in-difference analysis. Results For hip fractures, the percentage of patients in worse condition at discharge was 150% higher when DPC was used [odds ratio (OR) = 2.556, P < 0.001]. For lung cancer, the percentage of patients in worse condition at discharge was about 30% lower when DPC was used (OR = 0.697, P = 0.001). The number of lung cancer diagnosis groups that did not require a long LOS increased. Inpatient mortality and readmission rates and hospitalisation charges did not change for either diagnosis, though the average LOS decreased. Conclusions Under the DPC system in Japan, some patients would be discharged ‘quicker’ and ‘sicker’, but other patients’ outcome at discharge improved. Although LOS decreased, hospitalisation charges did not decrease, and the readmission rate did not increase.