A study published in the New England Journal of Medicine (NEJM) found hospital acquisition by another hospital or hospital system was associated with modestly worse patient experiences and no significant changes in readmission or mortality rates. Effects on process measures of quality were inconclusive. Previous studies had shown that hospital mergers have led to higher prices for commercially insured patients, but research about effects on quality of care has been limited. Researchers used Medicare claims and Hospital Compare data from 2007 through 2016 on performance on four measures of quality of care (a composite of clinical-process measures, a composite of patient-experience measures, mortality, and the rate of readmission after discharge) and data on hospital mergers and acquisitions occurring from 2009 through 2013, to compare changes in the performance of acquired hospitals from the time before acquisition to the time after acquisition. The study sample included 246 acquired hospitals and 1986 control hospitals. Being acquired was associated with a modest differential decline in performance on the patient-experience measure and no significant differential change in 30-day readmission rates or in 30-day mortality. Acquired hospitals had a significant differential improvement in performance on the clinical-process measure, but this could not be attributed conclusively to a change in ownership because differential improvement occurred before acquisition.
- Changes in Quality of Care after Hospital Mergers and Acquisitions. The New England Journal of Medicine. January 2 2020.