Smoking and housing status in Scottish MONICA: examples of a modified case-control analysis

Data from the Scottish MONICA Project in North Glasgow has been used to compare the characteristics of coronary heart disease cases with those of a sample of men and women drawn from the general population. A case-control methodology was used, with cases taken from the MONICA register of acute myocardial infarction events for 1985 and 1986, and controls from the MONICA population survey conducted in 1986. Information on smoking levels and on housing status is available for both cases and controls, and this information has been used to provide examples of possible analyses. Relative risks were estimated for smoking, and it was found that current smokers had 3.8 times the level of risk of never-smokers in men and 3.1 times in women. Some evidence for a dose-response relationship was found, with heavy smokers being at higher risk. A comparison of cases and controls by housing status revealed that both men and women in public housing are at higher risk than home owners, but that some of this increased risk is related to the higher smoking levels of council housing tenants. These analyses can be extended to other factors provided information is available on both coronary cases and survey subjects.