Adequacy of hospital discharge status as a measure of outcome among injured patients

Context.-Crude mortality rates at the time of hospital discharge are commonly used to assess the quality of care provided to patients hospitalized following trauma. Objectives.-To evaluate the adequacy of hospital death rates as an outcome measure following trauma and to determine the influence of noninjury illness as a cause of hospital death and the frequency of postdischarge death. Design.-Retrospective cohort analyses using hospital discharge data for injured patients cross-linked to death certificate data that provided 1 year of followup for all patients discharged alive. Patients.-A total of 90 048 injured patients admitted to all acute care hospitals in the state of Washington from 1991 through 1993 and discharged with at least 1 diagnosis coded in the International Classification of Diseases, Ninth Revision, Clinical Modification to indicate trauma. Main Outcome Measures.-Death in the hospital and death within 30 days of hospital discharge. Results.-Among 1912 injured patients with in-hospital deaths, 825 death certificates (43%) listed a noninjury cause of death, The overall mortality rate at hospital discharge was 21.2 per 100 000 hospitalized injured patients, and was 12.1 per 100 000 for trauma deaths and 9.1 per 100 000 for those designated as nontrauma deaths. Patients with trauma-related death designations were younger (mean age, 51.5 years vs 77.9 years), had shorter lengths of stay (median stay, 2 days vs 5 days), and sustained more severe injures (P<.001). Including the 1273 deaths that occurred within 30 days of hospital discharge increased rates for trauma-designated deaths to 14.1 per 100 000 and increased rates for nontrauma-designated deaths to 21.3 per 100 000. Conclusions.-Hospital discharge death rates are incomplete measures of death frequency for injured patients. Designation of the cause of death, especially among older, hospitalized, injured patients often reflects preexisting medical conditions. Adequate assessment of mortality following trauma requires measurement of the frequency of death following hospital discharge.