Seasonal variation in chronic heart failure hospitalizations and mortalityin France

Background-Circannual variation in blood pressure and in the incidence of a cute myocardial infarction is well known but has not been investigated in c hronic heart failure. This report describes and compares the seasonal varia tion of chronic heart failure hospitalizations and mortality in the French population. Methods and Results-All deaths that occurred among French adults over the p eriod 1992 to 1996 (n=138 602) and all discharges by adults in French publi c hospitals for chronic heart failure over the period 1995 to 1997 (n=324 0 13) were examined retrospectively. First, chronic heart failure deaths in F rance occurred with a striking annual periodicity and peaked in winter (Dec ember through January), both in the overall population and in subgroups def ined by age (>44 years old) and sex. The distribution of cumulative monthly deaths differed by nearly 35%, ranging from a peak of 20% above average in January to 15% below average in August (Roger's test: P<0.001). Second, ho spitalizations for chronic heart failure in French public hospitals followe d a similar seasonal pattern (P<0.001), with a winter-spring predominance ( +7% to +10% from December through April). Third, for persons greater than o r equal to 85 years old, excess hospitalizations occurred earlier in the ye ar, with marked synchronized peaks in January for both mortality and hospit alizations (P<0.001). Conclusions-Clear seasonal variations in adult chronic heart failure hospit alizations and deaths were identified. The considerable economic impact on health care services warrants further epidemiological investigations and a more comprehensive approach to disease management.