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Case Ascertainment

Where resuscitation is attempted there is significant variability between ambulance services in rates of successful initial resuscitation and survival to hospital discharge following an OHCA1,2. It has been postulated that when looking at the non-random and special variations when reporting health outcomes the biggest cause of variation is data3. Case ascertainment methods are one of the biggest causes of variation in reporting OHCA survival figures.

Case Ascertainment Pyramid

The aim of this research is to look at the ability of difference case ascertainment methods for OHCA to accurately identify cases of OHCA.

Four different methods of identifying OHCAs used by West Midlands Ambulance Service (WMAS) were examined to identify cases between October 2011 and June 2013. These were: manual search of paper records at WMAS station, electronic CPI (Clinical Performance Indicators) audit, interrogation of Computer Aided Dispatch 09 calls, and zero pulse/zero rate.

1 Perkins & Cooke (2012) Emerg Med J, 29(1), 3-5; 2 DH (2014); 3 Lilford et al (2004) Lancet, 363, 1147-54


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