Prior studies have reported increased out-of-hospital cardiac arrests (OHCA) incidence and lower survival during the COVID-19 pandemic. We evaluated how the COVID-19 pandemic affected OHCA incidence, bystander CPR rate and patients' outcomes, accounting for regional COVID-19 incidence and OHCA characteristics.individual patient data meta-analysis of studies which provided a comparison of OHCA incidence during the first pandemic wave (COVID-period) with a reference period of the previous year(s) (pre-COVID period). We computed COVID-19 incidence per 100,000 inhabitants in each of 97 regions per each week and divided it into its quartiles.we considered a total of 49,882 patients in 10 studies. OHCA incidence increased significantly compared to previous years in regions where weekly COVID-19 incidence was in the fourth quartile (>136/100,000/week), and patients in these regions had a lower odds of bystander CPR (OR 0.49, 95%CI 0.29-0.81,p=0.005). Overall, the COVID-period was associated with an increase in medical etiology (89.2% vs 87.5%,p<0.001) and OHCAs at home (74.7% vs 67.4%,p<0.001), and a decrease in shockable initial rhythm (16.5% vs 20.3%,p<0.001). The COVID-period was independently associated with pre-hospital death (OR 1.73, 95%CI 1.55-1.93,p<0.001) and negatively associated with survival to hospital admission (OR 0.68, 95%CI 0.64-0.72,p<0.001) and survival to discharge (OR 0.50, 95%CI 0.46-0.54,p<0.001).During the first COVID-19 pandemic wave, there was higher OHCA incidence and lower bystander CPR rate in regions with a high-burden of COVID-19. COVID-19 was also associated with a change in patient characteristics and lower survival independently of COVID-19 incidence in the region where OHCA occurred.