Variation in the rates of adverse events between hospitals and hospital departments MARIEKE ZEGERS 1 , MARTINE C. DE BRUIJNE 2 , PETER SPREEUWENBERG 1 , CORDULA WAGNER 1,2 , GERRIT VAN DERWAL 2,3 AND PETER P . GROENEWEGEN 1,4,5 1 NIVEL, Netherlands Institute for Health Services Research, Utrecht, The Netherlands, 2 VU University Medical Centre (VUmc), Department of Public and Occupational Health, EMGO Institute for Health and Care Research, Amsterdam, The Netherlands, 3 Netherlands Health Care Inspectorate, Utrecht, The Netherlands, 4 Department of Sociology, Utrecht University, Utrecht, The Netherlands, and 5 Department of Human Geography, Utrecht University, Utrecht, The Netherlands Address reprint requests to: Marieke Zegers, NIVEL, Netherlands Institute for Health Services Research, PO Box 1568, 3500 BN Utrecht, The Netherlands. Tel: þ31-302729834; Fax: þ31-302729729; E-mail: m.zegers@iq.umcn.nl Accepted for publication 12 December 2010 Abstract Objective. The objective of this study wasto analyze the variation in the rates of adverse events (AEs), and preventable AEs, between hospitals and hospital departments in order to investigate the room for improvement in reducing AEs at both levels. In addition, we explored the extent to which patient, department and hospital characteristics explain differences in the rates of AEs. Design. Structured retrospective patient record review of hospital admissions. Setting. Twenty-one Dutch hospitals. Population. A representative random sample of 7113 hospital admissions in 2004. Main outcome measures. Variation in AEs, and preventable AEs, between hospitals and hospital departments and the expla- natory factors of the variation. Results. The rates of AEs varied between hospitals (P ¼ 0.05) and hospital departments (P , 0.05). The rates of preventable AEs only varied significantly between hospital departments. The clustering of preventable AEs in hospital departments was more than twice that found in hospitals (ICC 9.5 versus 3.5%). The type of hospital explained 35% of the inter-hospital var- iance in AEs. Patient and department characteristics explained 23% of the inter-department variance in preventable AEs. Conclusions. In addition to interventions to improve the overall patient safety within a hospital, interventions tailored for specific departments are necessary to reduce their patient safety risks. Monitoring and comparing the performance of hospi- tals should not be limited to the hospital level, but should be extended to the individual department since there can be signifi- cant differences in the rates of preventable AEs between different departments within the same hospital. Keywords: adverse events, hospital, safety, record review,risk management Introduction Patient record review studies have shown that a substantial number of patients in acute care hospitals experience adverse events (AEs) and that part of the AEs contributed to the patient’s death. Approximately half of the AEs were judged to be preventable [1 – 12]. Based on these findings, patient safety programs have been initiated to reduce the amount of AEs. There is a growing interest in measuring the variation in the quality of health care between healthcare institutions. Comparative measures of mortality and morbidity are used by healthcare professionals to improve care, by patients to select their caregiver, by insurers to contract doctors and hos- pitals and by hospital managers and policy makers to monitor the quality of care [13]. Hospital care is organized at different levels and it is argued that the incidence rates of AEs differ more between hospital departments than between hospitals. Hospital departments are specialist units, such as cardiology, intensive care and neurology, and vary widely in the services they offer. Moreover, the study of Smits et al. [14] showed that the patient safety culture among hospital employees varies more between hospital departments than International Journal for Quality in Health Care # The Author 2011. Published by Oxford University Press in association with the International Society for Quality in Health Care; all rights reserved Page 1 of 8 International Journal for Quality in Health Care 2011; pp. 1–8 10.1093/intqhc/mzq086 International Journal for Quality in Health Care Advance Access published January 11, 2011 by guest on July 27, 2016 Downloaded from