Mass casualty terrorist bombings: A comparison of outcomes by bombing type

Study objective We compared the epidemiologic outcomes of terrorist bombings that produced 30 or more casualties and resulted in immediate structural collapse, occurred within a confined space, or occurred in open air. Methods We identified eligible studies of bombings through a MEDLINE search of articles published between 1966 and August 2002 and a manual search of published references. Pooled and median rates of mortality, immediately injured survival, emergency department use, hospitalization, and injury were determined for each bombing type. Results We found 35 eligible articles describing 29 terrorist bombings, collectively producing 8,364 casualties, 903 immediate deaths, and 7,461 immediately surviving injured. Pooled immediate mortality rates were structural collapse 25% (95% confidence interval [CI] 6% to 44%), confined space 8% (95% CI 1% to 14%), and open air 4% (95% CI 0% to 9%). Biphasic distributions of mortality were identified in all bombing types. Pooled hospitalization rates were structural collapse 25% (95% CI 6% to 44%), confined space 36% (95% CI 27% to 46%), and open air 15% (95% CI 5% to 26%). Unique patterns of injury rates were found in all bombing types. Conclusion Patterns of injury and health care system use vary with the type of terrorist bombing.