Patient safety: What does it all mean?

1Queen Elizabeth II Health Sciences Centre and Dalhousie University, Halifax, Nova Scotia; 2Departments of Pathology and Laboratory Medicine, Medicine, and Microbiology and Infectious Diseases, University of Calgary, Calgary, Alberta Correspondence and reprints: Dr Lynn Johnston, Department of Medicine, Room 5014 ACC, Queen Elizabeth II Health Sciences Centre, 1278 Tower Road, Halifax, Nova Scotia B3H 2Y9. Telephone 902-473-5553, fax 902-473-7394, e-mail ljohnsto@dal.ca Received and accepted March 25, 2004 Anumber of articles have appeared in the medical literature over the past four years on the topic of patient safety, including a series in the New England Journal of Medicine in 2002 and 2003 (1). There has been considerable media interest, with a number of reports on medical errors and their associated consequences. The Royal College of Physicians and Surgeons of Canada sponsored a National Steering Committee on Patient Safety that published its report in 2002 (2). The committee made 19 recommendations intended to improve patient safety in Canadian health care (2). In 2003, the government of Canada committed $10 million/year for implementation of the recommendations, including support for the creation of a Canadian Patient Safety Institute (3). The Canadian Council on Health Services Accreditation has indicated its commitment to playing a major role in improving patient safety through accreditation (4). The Canadian Institutes for Health Information and Health Research have jointly funded the Canadian Adverse Events Study, examining the extent of adverse events in acute care hospitals with results expected to be published in 2004. This study includes 20 teaching, community and small hospitals in five provinces (British Columbia, Alberta, Ontario, Quebec and Nova Scotia). Clearly, patient safety has become a very relevant topic. From a historical perspective, Elihu Schimmel in 1964 (5) wrote that recent medical progress has brought dramatic advances in methods of diagnosis and treatment but, with each new advance, reports of adverse reactions have soon followed. As a chief resident, he undertook a prospective study of the type and frequency of complications (‘episodes’) occurring in response to medical care. Episodes occurring as a result of errors were excluded. There were 240 episodes in 198 of 1014 (19.5%) patients. The majority of episodes (49.6%) were reactions to therapeutic drugs, 9.6% were hospital acquired infections, 20% were life threatening or fatal, and 6.7% were fatal. Antimicrobials were associated with 29.4% of adverse reactions to medications. Six of the 16 deaths (37.5%) were in patients with hospital-acquired infections. Thirty-six years later, the Institute of Medicine (IOM) in the United States published To Err is Human: Building a Safer Health System (6). In it, they estimated that between 44,000 and 98,000 Americans die each year as a result of medical errors. These numbers were extrapolated from the results of three studies (7-9) examining the incidence of adverse events in hospitalized patients and have been vigorously debated. In the first two of these studies, investigators retrospectively estimated the incidence and nature of adverse events in patients hospitalized in 51 hospitals in New York State in 1984 (7,8). These studies were prompted by the need for better data on poor quality care and iatrogenic injury in the face of increasing numbers of malpractice claims and damages. The authors estimated the state-wide incidence of adverse events to have been 3.7%, of which 27.6% were due to negligence, defined as care that fell below the standard expected of physicians in their community (7). Elderly patients were at a higher risk of an adverse event. Certain specialties had higher rates of adverse events (but not negligence) in keeping with inherently higher risk procedures and patients. They further estimated that 13.6% of the adverse events caused death and extrapolated it to 13,451 deaths in New York State, due at least in part, to the result of adverse events. However, the authors acknowledged that many patients who died after an adverse event had very serious underlying disease and death could have been imminent in any event (7). One-half of the adverse eventrelated deaths were attributed to negligence. Nearly one-half of the adverse events resulted from operations, with wound infections (29% of surgical complications and 14% of all adverse events) being the most common surgical adverse event (8). Drug complications were the single most common type of adverse event (19%) and antimicrobials accounted for 16.3% of these (8). Using similar methodology, Thomas et al (9) performed a study of patients hospitalized in a random sample of 28 hospitals in Utah and Colorado in 1992. They determined that 2.9% of hospitalizations were associated with adverse events, with death following 6.6% of these events. Wound (11.4%) and nonwound (10%) infections accounted for 21.4% of surgery-related adverse events. Among adverse drug events, 24.9% were due to antibiotics. Notably, rates of adverse drug reactions varied among the different types of hospitals, suggesting that findings from one type of facility may not be generalizable with others. This study also found that inter-rater reliability was only moderate (kappa=0.4). These authors further estimated that health care costs for all adverse events totalled US$348,081,000 or 2.5% per capita of state health care expenditures (10). Postoperative complications and adverse drug events were the most expensive complications. There has been much debate over the accuracy of the estimates suggested in the IOM report and the way in which they were presented. MacDonald et al (11) pointed out that charts studied were identified by criteria (including death) intended to find patients with a high likelihood of experiencing an