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 2004-6 the demographics of OHCAs 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 (68.8%): 18/128 (14.1%) reached before the EMS. The best combined FR/EMS mean (SD) CRI in 2005-6 (5 min 56 s (4)) was better than the EMS alone in 2004 (7 min (3); 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 2005-6 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 (SD) CRI in 2005-6 (9 min 22 s (6)) was better than the EMS alone in 2004 (11 min 2 s (6); 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%). TRIAL REGISTRATION NUMBER: ISRCTN07286796.

The obstacles to maximising the impact of public access defibrillation: an assessment of the dispatch mechanism for out-of-hospital cardiac arrest.

OBJECTIVES: To determine the diagnostic accuracy of advanced medical priority dispatch system (AMPDS) software used to dispatch public access defibrillation first responders to out-of-hospital cardiac arrests (OHCA). DESIGN: All true OHCA events in North and West Belfast in 2004 were prospectively collated. This was achieved by a comprehensive search of all manually completed Patient Report Forms compiled by paramedics, together with autopsy reports, death certificates and medical records. The dispatch coding of all emergency calls by AMPDS software was also obtained for the same time period and region, and a comparison was made between these two datasets. SETTING: A single urban ambulance control centre in Northern Ireland. POPULATION: All 238 individuals with a presumed or actual OHCA in the North and West Belfast Health and Social Services Trust population of 138 591 (2001 Census), as defined by the Utstein Criteria. MAIN OUTCOME MEASURES: The accurate dispatch of an emergency ambulance to a true OHCA. RESULTS: The sensitivity of the dispatch mechanism for detecting OHCA was 68.9% (115/167, 95% confidence interval (CI) 61.3% to 75.8%). However, the sensitivity for arrests with ventricular fibrillation (VF) was 44.4% (12/27) with sensitivity for witnessed VF of 47.1% (8/17). The positive predictive value was 63.5% (115/181, 95% CI 56.1% to 70.6%). CONCLUSIONS: The sensitivity of this dispatch process for cardiac arrest is moderate and will constrain the effectiveness of Public Access Defibrillation (PAD) schemes which utilise it. TRIAL REGISTRATION: controlled-trials.com ISRCTN07286796.

Repression and self-presentation: when audiences interfere with self-deceptive strategies.

To defend against threatening feedback, one may avoid and ignore it, or one may dwell on it and think of refutations. Repressors who received threatening feedback privately spent the least amount of time reading it, whereas repressors who received the same feedback publicly spent a long time reading it. Thus, the audience prevented repressors from ignoring threatening feedback; instead, they thought and worried about the partner's (bad) impression of them. Nonrepressors were unaffected by the favorability of the evaluation or the public nature of the situation. Repressors showed superior recall for the few bits of threatening information embedded in a generally favorable evaluation, suggesting that they are especially sensitive when their defenses are down.