February 4, 2016

expert reaction to new review on the impact of smoking bans on harms of passive smoking

Passive smoking has long been known to pose a health risk to non-smokers, and efforts to reduce levels of second-hand smoke have seen bans on indoor smoking in public and work places introduced in a number of countries, states, and regions. Publishing in the Cochrane Library a group of scientists have reported that national smoking legislation does reduce the harms of passive smoking and that populations benefit from reduced exposure to passive smoke. These comments accompanied a briefing.

Prof. Peter Weissberg, Medical Director, British Heart Foundation, said:

“This review strengthens previous evidence that banning smoking in public places leads to fewer deaths from heart disease and that this effect is greatest in the non-smoking population. So, in public health terms, this has been a successful piece of legislation. Smoking is bad for smokers and for those around them.”

“The point of a Cochrane review is to use data from multiple sources to form a conclusion. When looked at collectively, the message to be taken from these studies is clear and robust. Reduced exposure to smoke, leads to fewer fatal heart attacks. All of the studies reviewed are observational and all have their limitations, however, it would be difficult to study the effects of passive smoking in a more robust way, for example, it would be nearly impossible to conduct a randomised control trial.

“Without randomized intervention studies it is always difficult to be certain about causality. But it would be hard to come up with an alternative, plausible explanation. It is therefore entirely reasonable to conclude that it was cessation of exposure to smoke, rather than any other associated event, that led to the fall in heart attacks.”

‘Legislative smoking bans for reducing harms from secondhand smoke exposure, smoking prevalence and tobacco consumption (Review)’ by Frazer et al. published in The Cochrane Library on Thursday 4th February. 

Declared interests

Prof. Peter Weissberg: No conflicts of interest