Racial disparities in the frequency of patient safety events: results from the National Medicare Patient Safety Monitoring System

Med Care. 2011 May;49(5):504-10. doi: 10.1097/MLR.0b013e31820fc218.


Background: Although there is extensive evidence of racial disparities in processes and outcomes of medical care, there has been limited investigation of disparities in patient safety.

Objective: To determine whether there are racial disparities in the frequency of adverse events studied in the Medicare Patient Safety Monitoring System.

Design and subjects: Abstraction of 102,623 randomly selected charts from hospital discharges of non-Hispanic white and black Medicare patients between January 1, 2004 and December 31, 2007 to assess frequency of patient safety events in 4 domains: general (pressure ulcers and falls), selected nosocomial infections, selected procedure-related adverse events, and adverse drug events due to anticoagulants and hypoglycemic agents.

Measures: Racial disparities in risk of patient safety events, and differences in adverse event rates among hospital groups stratified by percentage of black patients.

Results: Blacks had higher adjusted risk than whites of suffering one of the measured nosocomial infections (1.34; 95% confidence interval, 1.17-1.55; P < 0.001) and one of the measured adverse drug events (1.29; 95% confidence interval, 1.19-1.40; P < 0.001). After adjustment for patient and hospital factors, patients in hospitals with the highest percentages of black patients were at increased risk of experiencing one of the measured nosocomial infections (1.9% vs. 1.5%; P < 0.001) and adverse drug events (8.7% vs. 7.8%; P < 0.01).

Conclusions: Hospitalized blacks are at higher risk than whites of experiencing certain patient safety events. In addition, hospitals serving high percentages of black patients have higher risk-adjusted rates of selected patient safety events.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Accidental Falls / statistics & numerical data
  • Aged
  • Aged, 80 and over
  • Anticoagulants / adverse effects
  • Black People / statistics & numerical data
  • Chi-Square Distribution
  • Cross Infection / epidemiology
  • Female
  • Healthcare Disparities / statistics & numerical data*
  • Hospitalization / statistics & numerical data
  • Humans
  • Hypoglycemic Agents / adverse effects
  • Male
  • Medicare / standards
  • Medicare / statistics & numerical data
  • Middle Aged
  • Pressure Ulcer / epidemiology
  • Quality Indicators, Health Care / statistics & numerical data
  • Quality of Health Care / standards
  • Quality of Health Care / statistics & numerical data
  • Racial Groups / statistics & numerical data*
  • Safety / statistics & numerical data
  • United States / epidemiology
  • White People / statistics & numerical data


  • Anticoagulants
  • Hypoglycemic Agents