Newspaper and television stories of catastrophic injuries occurring at the hands of clinicians spotlight the problem of medical error but provide little insight into its nature or magnitude.1 Clinicians, patients, and policymakers may underestimate the magnitude of risk and the extent of harm. We review the epidemiology of medical error, concentrating primarily on the prevalence and consequences of error, which types are most common, which clinicians make errors, and the risk factors that increase the likelihood of injury from error.
- The Harvard and Australian studies into medical error remain the only studies that provide population level data on the rates of injuries to patients in hospitals and they identified a substantial amount of medical error
- In the United States medical error results in 44000-98000 unnecessary deaths each year and 1000000 excess injuries
- Errors often occur when clinicians are inexperienced and new procedures are introduced
- Extremes of age, complex care, urgent care, and a prolonged hospital stay are associated with more errors