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

BMJ 2000; 320 doi: https://doi.org/10.1136/bmj.320.7229.218 (Published 22 January 2000) Cite this as: BMJ 2000;320:218

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Day of week and myocardial infarction: "We don't like Monday too"

Editor - In their interesting paper, Christine Evans and coll. (1)
reported an excess of death from coronary heart disease outside hospital
on Monday in Scotland. They hypothesized that it may be partly
attributable to increased drinking at the weekend, although other
mechanisms, e.g., work related stress, may also play a role.
Available data on weekly distribution of myocardial infarction are not
unequivocal, although several studies found a Monday preference (2-3).

Several years ago, a collaborative study from our group (4) conducted in
the cities of Ferrara and Padua (Northern Italy) on 817 consecutive
patients admitted to the Emergency Department for myocardial infarction
did not show a statistically significant difference in weekday
distribution for population as a whole and subgroups by gender and age.

However, a higher Monday preference (p <0.01) was found when analyzing
active workers (n = 264) compared with retired subjects (n = 553). Other
studies, conducted in Germany (5-6) reported a 20.5% and 20% increase in
the occurrence of myocardial infarction on Monday, respectively. In the
study by Spielberg et al (6), when data on working or retired patients
were separated, the occurrence on Monday was increased by 24% in working
patients and 19% for retired patients, although this difference was not
statistically significant).

It has to be stressed that several factors may be taken into account when
discussing these data, e.g., differences in socioepidemiological features
of sample populations and lifestyle habits. In Italy, for example, we do
not have the “weekend excess” in drinking usually observed in Northern
European countries, in the German studies drinking habits are not
mentioned, and working activity is not analysed in the Scottish study.

Thus, it seems reasonable to assume that a constellation of factors, e.g.,
stress, starting of working activity, drinking habits, and other possible
underlying factors may contribute to a Monday preference of myocardial
infarction. Though final conclusions can not be drawn yet, Dr Evans et al
add a further reason to appreciate the weekend more (Thank God It’s
Saturday!).

1) Evans C, Chalmers J, Capewell S, Redpath A, Finlayson A, Boyd J,
et al. “I don’t like Mondays” - day of week of coronary heart disease
deaths in Scotland: study of routinely collected data. BMJ 2000;320:218-9.

2) Thompson DR, Pohl JEF, Sutton TW. Acute myocardial infarction and day
of the week. Am J Cardiol 1992;69:266-7.

3) Gnecchi-Ruscone T, Piccaluga E, Guzzetti S, Contini M, Montano N,
Nicolis E. Morning and Monday: critical periods for the onset of acute
myocardial infarction-the GISSI 2 study experience. Eur Heart J
1994;15:882-7.

4) Bilora F, Vigna GB, Manfredini R, Gallerani M, Chiesa M, San Lorenzo I.
Acute myocardial infarction incidence during the week: a chronobiological
evaluation. Minerva Cardioangiol 1993;43:559-62.

5) Willich SN, Löwel H, Lewis M, Hörmann A, Arntz HR, Keil U. Weekly
variation of acute myocardial infarction: increased Monday risk in the
working population. Circulation 1994;90:87-93.

6) Spielberg C, Falkenhahn D, Willich SN, Wegscheider K, Völler H.
Circadian, day-of-week, and seasonal variability in myocardial infarction:
comparison between working and retired patients. Am Heart J 1996;132:579-
85.

Roberto Manfredini, MD, First Internal Medicine

Massimo Gallerani, MD, Second Internal Medicine

Dept. of Clinical and Experimental Medicine, University of Ferrara
Medical School,
I-44100 Ferrara, Italy

Competing interests: No competing interests

22 January 2000
Roberto Manfredini
Professor of Emergency Medicine
University of Ferrara Medical School