Effect of reducing ambulance response times on deaths from out of hospital cardiac arrest: cohort study.
OBJECTIVE
To determine the association between ambulance response time and survival from out of hospital cardiopulmonary arrest and to estimate the effect of reducing response times.


METHODS
Cohort study.


METHODS
Scottish Ambulance Service.


METHODS
All out of hospital cardiopulmonary arrests due to cardiac disease attended by the Scottish Ambulance Service during May 1991 to March 1998.


METHODS
Survival rate to hospital discharge and potential improvement from reducing response times.


RESULTS
Of 13 822 arrests not witnessed by ambulance crews but attended by them within 15 minutes, complete data were available for 10 554 (76%). Of these patients, 653 (6%) survived to hospital discharge. After other significant covariates were adjusted for, shorter response time was significantly associated with increased probability of receiving defibrillation and survival to discharge among those defibrillated. Reducing the 90th centile for response time to 8 minutes increased the predicted survival to 8%, and reducing it to 5 minutes increased survival to 10-11% (depending on the model used).


CONCLUSIONS
Reducing ambulance response times to 5 minutes could almost double the survival rate for cardiac arrests not witnessed by ambulance crews.
Pell
J P
JP
Department of Medical Cardiology, University of Glasgow, Glasgow Royal Infirmary, Glasgow G31 2ER.
Sirel
J M
JM
Marsden
A K
AK
Ford
I
I
Cobbe
S M
SM
D000552:Ambulances / Q000592:standards*; D015331:Cohort Studies; D004554:Electric Countershock; D004638:Emergency Treatment / Q000401:mortality / Q000592:standards*; D006801:Humans; D016015:Logistic Models; D009203:Myocardial Infarction / Q000401:mortality* / Q000628:therapy*; D012606:Scotland / Q000453:epidemiology; D015996:Survival Rate; D013997:Time Factors