The association between deaths from myocardial infarction and household size in England and Wales

Background Chronic infection with organisms such as Chlamydia pneumoniae is thought to cause coronary heart disease. We investigated whether myocardia l infarction deaths are associated with large household size and overcrowdi ng, as these are factors that may facilitate the transmission of infection. Design Ecological study of England and Wales. Methods Population data were obtained from the 1991 National Census and mor tality data were obtained from the Office of National Statistics. For vario us categories of household size and overcrowding, we calculated mortality r ates standardized for age, sex and deprivation. Results Standardized mortality rates for acute respiratory infections were associated with household size and overcrowding, while rates for myocardial infarction and gastric carcinoma, both putatively associated with chronic infection, were associated with household size. For combined deaths from ca uses other than myocardial infarction, there were small associations with h ousehold size and overcrowding. In the case of myocardial infarction, the a ssociation was generally strongest in the age group 45-54.9 years, for this age group, the standardized mortality rate ratio for the category of large st size household was 2.7 in the year 1991. Conclusions There is an association between household size and mortality fr om myocardial infarction, Chronic infection is a possible cause. (C) 2001 L ippincott Williams & Wilkins.