"I don't like Mondays"---day of the week of coronary heart disease deaths in Scotland: study of routinely collected data

Abstract
Data linking all hospital discharges and deaths were obtained from the Scottish Morbidity Record and General Register Office (Scotland)respectively for all Scottish residents dying in 1986-95for whom coronary heart disease (ICD-9 (international classification of diseases, 9th revision) codes 410-414) was the principal cause of death. Information was obtained on whether death occurred in hospital and whether subjects had been admitted to hospital with coronary heart disease since 1981. People dying in Scotland from all other causes in 1986-95 formed a comparison group. The χ2 test was used to examine differences between the observed number of deaths per day and that expected in the absence of any weekly variation. Emergency admissions to hospital in Scotland for non-dependent alcohol abuse (ICD-9 code 305.0) were used as a proxy for excess alcohol consumption.