ESTABLISHING THRESHOLDS FOR ADVERSE PATIENT OUTCOMES

Objective: To establish thresholds for adverse patient outcomes in the absence of knowledge of patient illness severity indices. Outcomes: P ulmonary embolism, unplanned return to operating rooms, unplanned read missions, clean and contaminated wound infections, and hospital-acquir ed bacteraemia. Design: Analysis of results of surveys of hospitals in Australia by the Australian Council on Healthcare Standards following the introduction of clinical performance measures into the Accreditat ion process. Setting: Acute care hospitals in Australia undergoing Acc reditation surveys in 1993 and 1994. Methods: Stratification of hospit als into small (1-99 beds), medium (100-199 beds), and large (greater than or equal to 200 beds), calculation of mean rates for the above ou tcomes in each group, and establishment of thresholds based on two sta ndard errors from the mean. Results: The mean rate of occurrence of in cidents was higher for larger hospitals, Thresholds were generally low er for smaller and higher for larger hospitals. Conclusions: Bed-size is a useful index for ''flagging'' peer group variation, The methodolo gical issues in establishing thresholds and their implications in moni toring the quality of care in hospitals are discussed. Copyright (C) 1 996 Elsevier Science Ltd.