Abstract 12314: Sex Differences in Symptoms Reported to Emergency Medical Dispatch in Acute Myocardial Infarction - Impact on Prehospital Delay
Background The management of acute myocardial infarction (AMI) is time critical. Improved patient outcomes are associated with reduced time from symptom onset to definitive care. Previous studies have identified that women have longer pre-hospital delays and this is associated with less likelihood of presentation with chest pain. We sought to measure the effect of sex (adjusted for age) on symptoms reported to the ambulance dispatch by AMI patients and the effect on pre-hospital time intervals.
Methods The Perth (Western Australia) Emergency Department (ED) dataset (population 1.7 million) was used to identify confirmed AMI patients who arrived by ambulance between Jan 1 2008 to Oct 31 2009. The emergency telephone call to the ambulance service was transcribed to identify demographic characteristics of the caller, the patient, and presenting symptoms. The ambulance operations data was used to examine ambulance time intervals. Differences between men and women were analyzed using univariate and age-adjusted multivariable techniques.
Results A total of 3329 AMI patients presented to one of the Perth EDs: 2100 arrived by ambulance. After pre-defined exclusions, 1681 calls were analyzed, of which 1060 (63.1%) were men. Women were older than men (mean 77.6 vs 69.1 years, p< 0.001) and were less likely to report chest pain (54% vs 69%; OR = 0.54; 95% CI 0.44 - 0.67), even after adjustment for age. The call to scene time interval did not differ by sex, irrespective of presenting symptoms. However, ‘on-scene’ ambulance time was longer for women than men, (median 17.4 vs 18.6 mins; p<0.001). Women were also less likely than men to be allocated a priority 1 (lights and sirens) ambulance (p<0.001), even for patients with chest pain. Self-reported time from onset of symptoms to emergency call was analyzed for a sub-set of patients (n=861): women delayed longer than men in calling for help (median 60 vs 104 min; p=0.006).
Conclusion Women with AMI are more likely to delay calling an ambulance and less likely to report chest pain as their presenting symptom. The reason for longer on-scene times for women and less likelihood of being allocated a priority 1 ambulance (even when experiencing chest pain) needs further examination.
- © 2011 by American Heart Association, Inc.