The TV advert for the first-aid charity, an expanded version of which was also available on YouTube, featured a man being treated for cancer, recovering, then choking at a barbecue. The on-screen text at the end of the advert said: "First aid could help prevent up to 140,000 deaths every year. The same number of people that die from cancer."
The advert received 144 complaints, making it the 10th most complained about advert in 2012.
Full Fact, an independent fact-checking organisation, wrote to the ASA, arguing the claim that first aid could prevent 140,000 deaths was misleading and could not be substantiated.
But St John Ambulance told the ASA that it had obtained cancer mortality figures for 2010 from Cancer Research UK that showed a total of 137,999 deaths in England and Wales alone for that year.
The charity also took mortality data from the Office for National Statistics in 2010 and reviewed it for cases in which first-aid knowledge could have affected a person’s chance of survival or prevented their death. It arrived at a figure of 139,907 such deaths in 2010.
The ASA decided the advert did not breach its rules on misleading advertising and did not uphold the complaint from Full Fact.
St John Ambulance welcomed the ruling, saying that 20,000 people had requested its first-aid guide in the wake of the campaign. Scott Jacobson, director of brand at St John Ambulance, said: "The ASA’s decision to reject the complaint was the right one. Since the advert first appeared, the response has been overwhelmingly positive."
But Full Fact maintained that the charity’s evidence was not strong enough. Will Moy, director of Full Fact, said: "It's no longer possible to expect blind faith from the public. To earn trust, charities must be prepared to back what they say with evidence. We believe the standard of proof for such a striking claim must be higher than this."