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UKCRC Health Research Classification System

Smoking and tobacco

Advice on health categories

The coding for studies on smoking and tobacco will depend on the nature of the research.

Use Mental Health for studies of tobacco and nicotine addiction and associated behavioural problems.

Only use the following standardised breakdown of health categories and percentages for general studies on smoking and tobacco where there is no other indication of disease area:

Health Category Percentage
Cancer and neoplasms 25
Cardiovascular 25
Respiratory 25
Stroke 25


Advice on research activities

Smoking is considered a risk factor for other diseases. Therefore, interventions to reduce smoking should be coded as 3 Prevention, even if the person already smokes. Use 5 Treatment Development or 6 Treatment Evaluation for studies focussed on treatment of an existing smoking-related disease and in cases of secondary prevention.

Additional guidance on differentiating secondary and primary prevention and distinguishing between preventative and treatment interventions are also available.