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.