The populations studied were adults. However, for the effect of passive smoking, studies focussing on in utero, infants, children and adolescents were also included.
The effects of both active smoking and passive smoking were investigated.
Active smoking includes anyone who is a current smoker (smokes at the present time), ever smoker, ex- or former smoker (someone who has previously smoked). It includes the smoking of cigarettes, cigars, pipes and rolled tobacco only. It excludes the smoking of shisha, electronic cigarettes and smokeless tobacco products.
Passive smoking is when someone is in contact with second-hand smoke or environmental tobacco smoke from any source, both in the home or workplace. It doesn’t include passive smoke exposure relating to cooking fuels. It occurs when tobacco smoke is in any environment, causing people within that environment to breathe it in.
When looking at active smoking, data were compared between current smokers and never smokers where possible.
When looking at passive smoking, data were compared between those exposed to passive smoke (adults, children and utero) and to those never exposed to any form of passive smoke.
The health outcomes for active and passive smoke exposure in adults included:
The health outcomes relating to passive smoke exposure in children included:
Click here to see a flow diagram (PDF)