Impact of the hospitalist system on inpatient mortality and length of hospital stay in a teaching hospital in Japan: a retrospective observational study

Objective To examine the differences in the quality of care among inpatients before and after the introduction of the hospitalist system. Design A retrospective observational study. Setting A community teaching hospital in Japan. Participants The inpatients admitted between the preintervention (January-December 2018) and 1-year intervention (January-December 2019) periods. There were 8508 and 8788 inpatients in 2018 and 2019, respectively. Interventions The study compared the lengths of hospital stay and mortality among inpatients between the pre-and post-intervention (2018 and 2019) periods concerning the introduction of a hospital medicine department. Outcome measures The primary objective was to evaluate and compare the in-hospital mortality and the length of stay (LOS) between 2018 and 2019. The secondary objective was to identify the characteristics of hospitalists and non-hospitalists in the system. Results The LOS was significantly reduced after the introduction of the hospital medicine department (adjusted difference, -0.659 days; 95% CI -1.118 to -0.136, p=0.01). There were no differences in the adjusted mortalities between the two periods. Conclusions To the best of our knowledge, our study is the first involving a teaching hospital in Japan to reveal that the hospitalist system had a positive effect on the efficiency of inpatient care by shortening the LOS. Further studies are needed to clarify other benefits related to the introduction of the hospital medicine department in Japan.