Objective: Critically ill patients require high-intensity care and may be at especially high risk of iatrogenic injury because they are severely ill. We sought to study the incidence and nature of adverse events and serious errors in the critical care setting.
Design: We conducted a prospective 1-year observational study. Incidents were collected with use of a multifaceted approach including direct continuous observation. Two physicians independently assessed incident type, severity, and preventability as well as systems-related and individual performance failures.
Setting: Academic, tertiary-care urban hospital.
Patients: Medical intensive care unit and coronary care unit patients.
Measurements and Main Results: The primary outcomes of interest were the incidence and rates of adverse events and serious errors per 1000 patient-days. A total of 391 patients with 420 unit admissions were studied during 1490 patient-days. We found 120 adverse events in 79 patients (20.2%), including 66 (55%) nonpreventable and 54 (45%) preventable adverse events as well as 223 serious errors. The rates per 1000 patient-days for all adverse events, preventable adverse events, and serious errors were 80.5, 36.2, and 149.7, respectively. Among adverse events, 13% (16/120) were life-threatening or fatal; and among serious errors, 11% (24/223) were potentially life-threatening. Most serious medical errors occurred during the ordering or execution of treatments, especially medications (61%; 170/277). Performance level failures were most commonly slips and lapses (53%; 148/277), rather than rule-based or knowledge-based mistakes.
Conclusions: Adverse events and serious errors involving critically ill patients were common and often potentially life-threatening. Although many types of errors were identified, failure to carry out intended treatment correctly was the leading category.
From the Divisions of General Internal Medicine (JMR, RK, EB, DWB), Sleep Medicine (CPL, JWC, SWL, CAC), Pulmonary and Critical Care Medicine (JWC, CML), Cardiology (PHS), and Infectious Disease (JTK), Department of Medicine, Brigham and Women's Hospital, Harvard Medical School; Division of General Pediatrics, Department of Medicine (CPL), Childrens Hospital, Harvard Medical School; and Division of Sleep Medicine (CPL, JWC, SWL, CAC), Harvard Medical School, Boston, MA.
This study was presented in part at the Annual Scientific Assembly of the Society of Critical Care Medicine, Orlando, FL, February 2004.
None of the authors have any financial interests that represent a potential conflict of interest.
This project was supported by the Agency for Healthcare Research and Quality (AHRQ; RO1 HS12032), affording data confidentiality protection by federal statute (Public Health Service Act; 42 U.S.C.), and the National Institute of Occupational Safety and Health (NIOSH) within the U.S. Centers for Disease Control (R01 OHO7567), which provided a Certificate of Confidentiality for data protection, and the Department of Medicine, Brigham and Women's Hospital; the Division of Sleep Medicine, Harvard Medical School; and the Brigham and Women's Hospital. Dr. Landrigan is the recipient of an AHRQ career development award (K08 HS13333); Dr. Cronin is the recipient of an AHRQ National Research Service Award (NRSA; F32 HS14130) and a National Heart, Lung, and Blood Institute fellowship in the program of training in Sleep, Circadian and Respiratory Neurobiology at Brigham and Women's Hospital (NHLBI; T32 HL079010); Dr. Lockley is the recipient of a traveling fellowship from the Wellcome Trust, UK (060018/B/99/Z); and Dr. Czeisler is the recipient of a Team Leadership Award from the National Space Biomedical Institute.