Comparison of hospital risk-standardized mortality rates calculated by using in-hospital and 30-day models: an observational study with implications for hospital profiling.
BACKGROUND
In-hospital mortality measures, which are widely used to assess hospital quality, are not based on a standardized follow-up period and may systematically favor hospitals with shorter lengths of stay (LOSs).


OBJECTIVE
To assess the agreement between performance measures of U.S. hospitals by using risk-standardized in-hospital and 30-day mortality rates.


METHODS
Observational study.


METHODS
Nonfederal acute care hospitals in the United States with at least 30 admissions for acute myocardial infarction (AMI), heart failure (HF), and pneumonia from 2004 to 2006.


METHODS
Medicare fee-for-service patients admitted for AMI, HF, or pneumonia from 2004 to 2006.


METHODS
The primary outcomes were in-hospital and 30-day risk-standardized mortality rates (RSMRs).


RESULTS
Included patients comprised 718,508 admissions to 3135 hospitals for AMI, 1,315,845 admissions to 4209 hospitals for HF, and 1,415,237 admissions to 4498 hospitals for pneumonia. The hospital-level mean patient LOS varied across hospitals for each condition, ranging from 2.3 to 13.7 days for AMI, 3.5 to 11.9 days for HF, and 3.8 to 14.8 days for pneumonia. The mean RSMR differences (30-day RSMR minus in-hospital RSMR) were 5.3% (SD, 1.3) for AMI, 6.0% (SD, 1.3) for HF, and 5.7% (SD, 1.4) for pneumonia; distributions varied widely across hospitals. Performance classifications differed between the in-hospital and 30-day models for 257 hospitals (8.2%) for AMI, 456 (10.8%) for HF, and 662 (14.7%) for pneumonia. Hospital mean LOS was positively correlated with in-hospital RSMRs for all 3 conditions.


CONCLUSIONS
Medicare claims data were used for risk adjustment.


CONCLUSIONS
In-hospital mortality measures provide a different assessment of hospital performance than 30-day mortality and are biased in favor of hospitals with shorter LOSs.


BACKGROUND
The Centers for Medicare & Medicaid Services and National Heart, Lung, and Blood Institute.
Yale University School of Medicine, Yale-New Haven Hospital Center for Outcomes Research and Evaluation, New Haven, Connecticut 06510, USA. Elizabeth.Drye@yale.edu
Elizabeth E
EE
Drye
Sharon-Lise T
SL
Normand
Yun
Y
Wang
Joseph S
JS
Ross
Geoffrey C
GC
Schreiner
Lein
L
Han
Michael
M
Rapp
Harlan M
HM
Krumholz
D000368:Aged; D006333:Heart Failure / Q000401:mortality; D017052:Hospital Mortality; D006761:Hospitals / Q000592:standards*; D006801:Humans; D007902:Length of Stay; D006278:Medicare; D009203:Myocardial Infarction / Q000401:mortality; D010360:Patient Transfer / Q000706:statistics & numerical data; D011014:Pneumonia / Q000401:mortality; D011787:Quality of Health Care; D014481:United States