The Northern Ireland Public Access Defibrillation (NIPAD) study: effectiveness in urban and rural populations

Objective To assess the impact of mobile Automated External Defibrillators (AEDs) on Out-of-Hospital Cardiac Arrests (OHCAs) in urban and rural populations. Design Prospective before and after intervention, population study. Setting Urban and rural areas of 160,000 each. Patients, interventions and main outcome measures In 2004 to 2006 the demographics of OHCA were assessed. In 2005/6 AEDs were deployed (29 urban, 53 rural): 335 urban First Responders (FRs) and 493 rural FRs were trained in AED use and dispatched to OHCAs. Call-to-Response Interval (CRI), resuscitation and survival-to-discharge rates for OHCA were compared. Results In 2004 there were 163 urban OHCAs and the Emergency Medical Services (EMS) attended 158 (Ventricular Fibrillation (VF) 27/158(17.1%)). In 2005/6 there were 226 OHCAs, EMS attended 216 (VF 30/216(13.9%)). In 2005/6 FRs were paged to 128 OHCAs (56.6%), FRs attended 88/128(68.7%): 18/128(14%) reached before the EMS. The best combined FR/EMS mean CRI in 2005/6 (5min56s(SD4)) was better than the EMS-alone in 2004 (7min(SD3), (p=0.002). Survival rate was 5.1% in 2004, 1.4% in 2005/6 (p=NS). In 2004 there were 131 rural OHCAs, EMS attended 121 (VF 19/121(15.7%)). In 2005/2006 there were 122 OHCAs, EMS attended 114 (VF 19/114(16.7%)). In 2005/6 FRs were paged to 49 OHCAs, FRs attended 42/49(85.7%): 23/49(46.9%) reached before the EMS. The best combined FR/EMS mean CRI in 2005/6 (9min22s(SD6)) was better than the EMS-alone in 2004 (11min02s(SD6), (p=0.018). Survival rate was 2.5% in 2004, 3.5% in 2005/6 (p=NS). Conclusions Despite improvement in CRI there was no impact on survival (witnessed arrest 32.8%, VF 15.6%).