Purpose of the Study:
Bystander CPR (BCPR) more than doubles the chances of survival from out-of-hospital cardiac arrest (OHCA). In UK BCPR rates are variable and lower than those of other countries. This study investigates the trends in BCPR rates in England.
Materials and Methods:
The OHCAO registry collected details of 76,456 OHCAs from English ambulance services between 2013 and 2015, where resuscitation was commenced or continued by EMS personal; in accordance with Utstein guidelines. We assessed temporal variation and time trends in incidence for OHCA and BCPR.
Results:
The odds of having an OHCA varied significantly by time of day and day of week, and there were monthly and seasonal variations. 
BCPR rate in bystander-witnessed events increased during the morning to about lunchtime, plateaued until about 19:00h then declined. The odds of receiving BCPR was significantly higher during the day compared to the night (OR=1.14; 95%CI=1.08-1.19). BCPR rates were greater at the weekend than mid-week (OR=1.04; 95%CI=0.99-1.10), and during the autumn/winter compared to spring/summer (OR=1.07; 95%CI=1.02-1.12).
BCPR rates have increased significantly from 51% in April 2013 to 66% in December 2015 (p<0.05); the increase being observed for both men and women, and most age groups. Regression analysis showed there was significant variation during this time; an increase in February 2014, dips in May 2014 and March 2015, and an increase around June 2015.
Conclusions:
We have shown for the first time in England significant temporal variability in OHCA and BCPR incidence. The trend of increasing BCPR is encouraging and likely to be associated with national and local initiatives to improve BCPR rates. However, there is still room for improvement in specific areas of the country, and a need for continued awareness programmes.

Temporal Changes in Bystander Cardiopulmonary Resuscitation Rates in England