Fig. 1

The results of sensitivity analysis. X-axis: Initial pH value before implementation of the extracorporeal cardio-pulmonary resuscitation (ECPR). Y-axis: The adjusted odds ratio and 95% confidence interval (CI) for favorable neurological outcome referred to median value in the pH ≥ 7.03 group (pH 7.13) were adjusted by sex (men, women), age (< 65, 65–74 and ≥ 75 years), witnessed by bystander, CPR by bystander, pre-hospital initial cardiac rhythm (shockable, non-shockable), cardiac rhythm on hospital arrival (shockable, non-shockable and ROSC) and the time from call to blood test. The method in detail was described in additional file 1