Objective: Acute cardiovascular events show seasonal and circadian patterns in occurrence. The aim of this retrospective study, based on the database of hospital admissions of the Emilia-Romagna region, Italy, was to confirm the existence of a seasonal or weekly pattern of hospital admission of acute myocardial infarction (AMI), and to verify possible differences between nonfatal or fatal cases. Methods: The study included all cases of AMI hospitalized between 1998 and 2006. Day of admission was categorized, respectively, into four 3-month intervals, into twelve 1-month intervals, and into seven 1-day intervals for statistical analysis, performed by test goodness of fit and partial Fourier series on the total number of cases, males and females, and nonfatal or fatal cases. Results: The database included 64191 patients with AMI (62.9% males, 12.3% fatal). AMI was most frequent in winter and least in summer (p<0.0001). The highest number of cases was recorded in January and the lowest in July (p<0.0001). Chronobiologic analysis showed winter peaks for total cases (January, p=0.035), females (December, p=0.009), and fatal cases (January, p<0.001). AMI was most frequent on Monday and least on Sunday (p<0.0001). Comparing observed versus expected events, there was a significantly higher frequency of cases on weekdays and reduced on weekends, for total (p<0.0001), nonfatal (p<0.0001), and fatal cases (p=0.0001). Conclusions: This study confirms a significantly higher frequency of AMI admissions in Winter and on Monday. No difference in the frequency rate of nonfatal versus fatal events, depending of patients’ admissions on weekdays or weekends, was found.
Seasonal and weekly patterns of hospital admissions for nonfatal and fatal myocardial infarction
MANFREDINI, Roberto;MANFREDINI, Fabio;BOARI, Benedetta;
2009
Abstract
Objective: Acute cardiovascular events show seasonal and circadian patterns in occurrence. The aim of this retrospective study, based on the database of hospital admissions of the Emilia-Romagna region, Italy, was to confirm the existence of a seasonal or weekly pattern of hospital admission of acute myocardial infarction (AMI), and to verify possible differences between nonfatal or fatal cases. Methods: The study included all cases of AMI hospitalized between 1998 and 2006. Day of admission was categorized, respectively, into four 3-month intervals, into twelve 1-month intervals, and into seven 1-day intervals for statistical analysis, performed by test goodness of fit and partial Fourier series on the total number of cases, males and females, and nonfatal or fatal cases. Results: The database included 64191 patients with AMI (62.9% males, 12.3% fatal). AMI was most frequent in winter and least in summer (p<0.0001). The highest number of cases was recorded in January and the lowest in July (p<0.0001). Chronobiologic analysis showed winter peaks for total cases (January, p=0.035), females (December, p=0.009), and fatal cases (January, p<0.001). AMI was most frequent on Monday and least on Sunday (p<0.0001). Comparing observed versus expected events, there was a significantly higher frequency of cases on weekdays and reduced on weekends, for total (p<0.0001), nonfatal (p<0.0001), and fatal cases (p=0.0001). Conclusions: This study confirms a significantly higher frequency of AMI admissions in Winter and on Monday. No difference in the frequency rate of nonfatal versus fatal events, depending of patients’ admissions on weekdays or weekends, was found.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
