National trends in patient safety for four common conditions, 2005-2011.
BACKGROUND
Changes in adverse-event rates among Medicare patients with common medical conditions and conditions requiring surgery remain largely unknown.


METHODS
We used Medicare Patient Safety Monitoring System data abstracted from medical records on 21 adverse events in patients hospitalized in the United States between 2005 and 2011 for acute myocardial infarction, congestive heart failure, pneumonia, or conditions requiring surgery. We estimated trends in the rate of occurrence of adverse events for which patients were at risk, the proportion of patients with one or more adverse events, and the number of adverse events per 1000 hospitalizations.


RESULTS
The study included 61,523 patients hospitalized for acute myocardial infarction (19%), congestive heart failure (25%), pneumonia (30%), and conditions requiring surgery (27%). From 2005 through 2011, among patients with acute myocardial infarction, the rate of occurrence of adverse events declined from 5.0% to 3.7% (difference, 1.3 percentage points; 95% confidence interval [CI], 0.7 to 1.9), the proportion of patients with one or more adverse events declined from 26.0% to 19.4% (difference, 6.6 percentage points; 95% CI, 3.3 to 10.2), and the number of adverse events per 1000 hospitalizations declined from 401.9 to 262.2 (difference, 139.7; 95% CI, 90.6 to 189.0). Among patients with congestive heart failure, the rate of occurrence of adverse events declined from 3.7% to 2.7% (difference, 1.0 percentage points; 95% CI, 0.5 to 1.4), the proportion of patients with one or more adverse events declined from 17.5% to 14.2% (difference, 3.3 percentage points; 95% CI, 1.0 to 5.5), and the number of adverse events per 1000 hospitalizations declined from 235.2 to 166.9 (difference, 68.3; 95% CI, 39.9 to 96.7). Patients with pneumonia and those with conditions requiring surgery had no significant declines in adverse-event rates.


CONCLUSIONS
From 2005 through 2011, adverse-event rates declined substantially among patients hospitalized for acute myocardial infarction or congestive heart failure but not among those hospitalized for pneumonia or conditions requiring surgery. (Funded by the Agency for Healthcare Research and Quality and others.).
From Qualidigm, Wethersfield (Y.W., M.L.M., N.R.V., T.P.M., M.M.P., J.M.F., S.-Y.H., D.G.), the Division of Pulmonary and Critical Care Medicine, University of Connecticut School of Medicine, Farmington (M.L.M.), and the Center for Outcomes Research and Evaluation, Yale-New Haven Hospital (Y.W., H.M.K.), the Department of Health Policy and Management, Yale School of Public Health (H.M.K.), and the Section of Cardiovascular Medicine and the Robert Wood Johnson Clinical Scholars Program (H.M.K.) and the Section of General Internal Medicine (T.P.M., D.G., H.M.K.), Department of Internal Medicine, Yale University School of Medicine, New Haven - all in Connecticut; the Department of Biostatistics, Harvard School of Public Health (Y.W.), and the Department of Medicine, Brigham and Women's Hospital and Harvard Medical School (J.M.F.) - all in Boston; and the Agency for Healthcare Research and Quality, Department of Health and Human Services, Rockville (N.E., J.B.), and the Centers for Medicare and Medicaid Services, Department of Health and Human Services, Baltimore (R.E.K., N.S.) - both in Maryland.
Yun
Y
Wang
Noel
N
Eldridge
Mark L
ML
Metersky
Nancy R
NR
Verzier
Thomas P
TP
Meehan
Michelle M
MM
Pandolfi
JoAnne M
JM
Foody
Shih-Yieh
SY
Ho
Deron
D
Galusha
Rebecca E
RE
Kliman
Nancy
N
Sonnenfeld
Harlan M
HM
Krumholz
James
J
Battles
D000465:Algorithms; D003428:Cross Infection / Q000453:epidemiology*; D064420:Drug-Related Side Effects and Adverse Reactions / Q000453:epidemiology*; D005260:Female; D006333:Heart Failure / Q000150:complications*; D017052:Hospital Mortality; D006760:Hospitalization; D006801:Humans; D008297:Male; D006278:Medicare; D009203:Myocardial Infarction / Q000150:complications*; D061214:Patient Safety / Q000706:statistics & numerical data*; D011014:Pneumonia / Q000150:complications*; D016012:Poisson Distribution; D011183:Postoperative Complications / Q000453:epidemiology*; D013514:Surgical Procedures, Operative; D014481:United States