Three studies were included (n=1,583): two RCTs (n=704) and one non-randomised trial with a crossover design (n=879). All included studies were of generally good quality (one scored 4 on the Jadad scale and the others scored 3). Blinding was not possible in any of the studies.
CPR plus AED was associated with significantly greater chances of survival to hospital admission compared to CPR alone (RR 1.22, 95%CI: 1.04, 1.43, p=0.014). The NNT with CPR plus AED to gain one survival to hospital admission was 17 (NNT 17). CPR plus AED was also associated with significantly greater survival to hospital discharge compared to CPR alone (RR 1.39, 95% CI: 1.06, 1.83 p=0.019). The NNT with CPR plus AED to gain one survival to hospital discharge was 24 (NNT 24). When the non-randomised trial was excluded in a sensitivity analysis, CPR plus AED continued to show significant benefits in survival to hospital admission (RR 1.34, 95%CI: 1.09, 1.64) and survival to hospital discharge (RR 1.38, 95% CI: 0.99, 1.92).
There was no evidence of statistical heterogeneity for either of the outcomes. From examination of the funnels plots, the reviewers report that publication bias may exist.