Purpose: To determine whether the terrorist attacks on September 11, 2001, affected the health of persons far from the attacks, we studied rates of urgent and emergency medical evaluations among the 3 million persons enrolled in a managed care plan in Northern California.
Methods: Using a computerized database of all urgent care and emergency department evaluations, we monitored physician diagnoses made during the 6 weeks before and after September 11, 2001, at 16 hospitals in the Kaiser Permanente Medical Care Program. Actual rates of evaluations and diagnoses were compared with expected rates based on similar periods in 1998, 1999, and 2000.
Results: There were 4260 fewer urgent and emergent medical evaluations than expected during the 6 weeks beginning September 11, 2001 (-4%; 95% confidence interval [CI]: -3% to -5%; P <0.0001; N = 95,603). Emergency department visits occurred at the expected rate (-1%; 95% CI: -2% to 1%; P = 0.34), but urgent care visits were reduced (-9%; 95% CI: -8% to -11%; P <0.0001). Evaluations were particularly less frequent during the week beginning September 11 (-7%; 95% CI: -4% to -9%; P <0.0001), but a decrease persisted afterwards. Compared with expected rates, injuries (P <0.0001) and ill-defined/symptom-related diagnoses (P <0.0001) were less frequent, while gastrointestinal diagnoses (P = 0.01) were more frequent, during the 6 weeks after the attacks. Total urgent and emergent evaluations were mostly unchanged on September 11; only diagnoses associated with cardiac ischemia were more frequent (+70%; 95% CI: 10% to 163%; P = 0.02).
Conclusion: Total urgent and emergent medical evaluations in a California managed care plan were reduced during the 6 weeks after the September 11th attacks. These results may help in allocation of resources during national disasters.