Annual rates of admission and seasonal variations in hospitalizations for heart failure

Abstract

Aims: To investigate the annual hospitalization rate and seasonal variation in confirmed heart failure (HF) admissions.

Methods and results: Records from all admissions to one hospital during 1 year with a HF diagnostic code were reviewed. From 1953 admissions, 595 were excluded because they did not fulfill the diagnostic criteria. A total of 1069 patients had 1358 admissions with confirmed HF. Mean age was 74.8 +/- 11.5 years, 42% were males. The admission data were matched with data from the municipal census with 537,666 people aged > or = 15 years. There were 2.5 admissions per 1000 for the adult population and 26.5/1000 in those aged > or = 80 years. There were 444 males and 625 females, giving a higher rate of admission for female patients 2.2/1000 vs. 1.7/1000 (P < 0.0001), although age adjusted rates in females were higher only for > or = 80 years. Echocardiogram was performed in 706 patients (66%), 325 (46%) had a normal ejection fraction. This proportion increased in females--64% vs. 29% males--and in older patients--55% in > or = 75 vs. 39% in < 75 years. Mortality during the first admission of 1996 was 8.3%. There was a seasonal variation in HF hospitalizations (P < 0.0001) peaking at 25% above average in January and dipping to 33% below average in August.

Conclusion: The rate of HF admissions was 2.5/1000 with an elderly preponderance and a higher rate of admission in males < 80 years and in females > or = 80 years. A seasonal variation ranging from 25% above average in January to 33% below average in August was observed.