The effect of bystander cardiopulmonary resuscitation on the survival of out-of-hospital cardiac arrests: a systematic review and meta-analysis

Abstract Background For many years, bystander cardiopulmonary resuscitation (BCPR) has been considered as a favorable factor to improve survival of out-of-hospital cardiac arrests (OHCAs). To examine the effect of BCPR on the survival of OHCAs and whether BCPR might also improve survival when the initial rhythm of OHCAs is limited, we performed a meta-analysis on published observational studies. Methods We did a systematic review to identify all studies published up to March, 2018, in any language, that reported the relation between BCPR and the survival of OHCAs. Using standard forms, two authors independently identified studies for inclusion and extracted information. The outcome was survival. Meta-regression was done to ascertain weighted factors for the outcomes. Results Data were extracted from 19 studies involving 232,703 patients. Firstly, pooled odds ratio (OR) from 16 cohort studies showed that BCPR was associated with improved chance of survival of OHCAs compared with NO-BCPR (OR 1.95, 95% confidence interval [CI]: 1.66–2.30). Secondly, from 8 cohort studies of OHCAs whose initial rhythm is limited, the pooled OR was 2.10 (95% CI, 1.68–2.63) of 6 articles for shockable rhythm and 1.07 (95% CI, 0.37–3.13) of 2 articles for non-shockable rhythm. Meta-regression showed a relation between the survival of OHCAs and BCPR was influenced by area (p