Reduction in acute myocardial infarction mortality in the United States: risk-standardized mortality rates from 1995-2006.
BACKGROUND
During the last 2 decades, health care professional, consumer, and payer organizations have sought to improve outcomes for patients hospitalized with acute myocardial infarction (AMI). However, little has been reported about improvements in hospital short-term mortality rates or reductions in between-hospital variation in short-term mortality rates.


OBJECTIVE
To estimate hospital-level 30-day risk-standardized mortality rates (RSMRs) for patients discharged with AMI.


METHODS
Observational study using administrative data and a validated risk model to evaluate 3,195,672 discharges in 2,755,370 patients discharged from nonfederal acute care hospitals in the United States between January 1, 1995, and December 31, 2006. Patients were 65 years or older (mean, 78 years) and had at least a 12-month history of fee-for-service enrollment prior to the index hospitalization. Patients discharged alive within 1 day of an admission not against medical advice were excluded, because it is unlikely that these patients had sustained an AMI.


METHODS
Hospital-specific 30-day all-cause RSMR.


RESULTS
At the patient level, the odds of dying within 30 days of admission if treated at a hospital 1 SD above the national average relative to that if treated at a hospital 1 SD below the national average were 1.63 (95% CI, 1.60-1.65) in 1995 and 1.56 (95% CI, 1.53-1.60) in 2006. In terms of hospital-specific RSMRs, a decrease from 18.8% in 1995 to 15.8% in 2006 was observed (odds ratio, 0.76; 95% CI, 0.75-0.77). A reduction in between-hospital heterogeneity in the RSMRs was also observed: the coefficient of variation decreased from 11.2% in 1995 to 10.8%, the interquartile range from 2.8% to 2.1%, and the between-hospital variance from 4.4% to 2.9%.


CONCLUSIONS
Between 1995 and 2006, the risk-standardized hospital mortality rate for Medicare patients discharged with AMI showed a significant decrease, as did between-hospital variation.
Krumholz
Harlan M
HM
Section of Cardiovascular Medicine, Yale University School of Medicine, 1 Church St, Ste 200, New Haven, CT 06510, USA. harlan.krumholz@yale.edu
Wang
Yun
Y
Chen
Jersey
J
Drye
Elizabeth E
EE
Spertus
John A
JA
Ross
Joseph S
JS
Curtis
Jeptha P
JP
Nallamothu
Brahmajee K
BK
Lichtman
Judith H
JH
Havranek
Edward P
EP
Masoudi
Frederick A
FA
Radford
Martha J
MJ
Han
Lein F
LF
Rapp
Michael T
MT
Straube
Barry M
BM
Normand
Sharon-Lise T
SL
D000368:Aged; D000369:Aged, 80 and over; D014487:Centers for Medicare and Medicaid Services, U.S.; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D007902:Length of Stay; D008297:Male; D009203:Myocardial Infarction / Q000401:mortality*; D012306:Risk; D014481:United States / Q000453:epidemiology
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