Is the readmission rate a valid quality indicator? A review of the evidence.
BACKGROUND
Hospital readmission rates are increasingly used for both quality improvement and cost control. However, the validity of readmission rates as a measure of quality of hospital care is not evident. We aimed to give an overview of the different methodological aspects in the definition and measurement of readmission rates that need to be considered when interpreting readmission rates as a reflection of quality of care.


METHODS
We conducted a systematic literature review, using the bibliographic databases Embase, Medline OvidSP, Web-of-Science, Cochrane central and PubMed for the period of January 2001 to May 2013.


RESULTS
The search resulted in 102 included papers. We found that definition of the context in which readmissions are used as a quality indicator is crucial. This context includes the patient group and the specific aspects of care of which the quality is aimed to be assessed. Methodological flaws like unreliable data and insufficient case-mix correction may confound the comparison of readmission rates between hospitals. Another problem occurs when the basic distinction between planned and unplanned readmissions cannot be made. Finally, the multi-faceted nature of quality of care and the correlation between readmissions and other outcomes limit the indicator's validity.


CONCLUSIONS
Although readmission rates are a promising quality indicator, several methodological concerns identified in this study need to be addressed, especially when the indicator is intended for accountability or pay for performance. We recommend investing resources in accurate data registration, improved indicator description, and bundling outcome measures to provide a more complete picture of hospital care.
Department of Public Health, Centre for Medical Decision Making, Erasmus MC, Rotterdam, the Netherlands.
Claudia
C
Fischer
Department of Public Health, Centre for Medical Decision Making, Erasmus MC, Rotterdam, the Netherlands.
Hester F
HF
Lingsma
Department of Medical Decision Making, Leiden University Medical Centre, Leiden, the Netherlands.
Perla J
PJ
Marang-van de Mheen
Department of Public Health, Amsterdam Medical Centre, Amsterdam, the Netherlands.
Dionne S
DS
Kringos
Department of Public Health, Amsterdam Medical Centre, Amsterdam, the Netherlands.
Niek S
NS
Klazinga
Department of Public Health, Centre for Medical Decision Making, Erasmus MC, Rotterdam, the Netherlands.
Ewout W
EW
Steyerberg
D006761:Hospitals; D006801:Humans; D007902:Length of Stay; D010359:Patient Readmission; D011786:Quality Control