BACKGROUND: Bystander cardiopulmonary resuscitation (CPR) has been proved to save lives; however, whether survival is affected by the training level of the bystander is not fully described.

AIM: To describe if the training level of laymen and medically educated bystanders affect 30-day survival in out-of-hospital cardiac arrests (OHCA).

METHODS: This observational study included all witnessed and treated cases of bystander CPR reported to the Swedish Registry of Cardiopulmonary Resuscitation between 2010 and 2014. Bystander CPR was divided into two categories: (a) lay-byCPR (non-medically educated) and (b) med-byCPR (off duty medically educated personnel).

RESULTS: During 2010-2014, 24,643 patients were reported to the OHCA registry, of which 6850 received lay-byCPR and 1444 med-byCPR; 16,349 crew-witnessed and non-witnessed cases and those with missing information were excluded from the analysis. The median interval from collapse to call for emergency medical services was 2min in both groups (p=0.97) and 2min from collapse to start of CPR for lay-byCPR versus 1min for med-byCPR (p<0.0001). There were no significant differences in CPR methods used; 64.3% (lay-byCPR) and 65.7% (med-byCPR) applied compressions and ventilation, respectively (p=0.33). The 30-day survival was 14.7% for lay-byCPR and 17.2% for the med-byCPR group (p=0.02). The odds ratio adjusted for potential confounders regarding survival (med-byCPR versus lay-byCPR) was 1.34 (95% confidence interval, 1.11-1.62; p=0.002).

CONCLUSIONS: In cases of OHCA, medically educated bystanders initiated CPR earlier and an increased 30-day survival was found compared with laymen bystanders. These results support the need to improve the education programme for laypeople.