• Vol. 38 No. 12, 1081–1084
  • 15 December 2009

The Effect of Temperature on Illness Severity in Emergency Department Congestive Heart Failure Patients

ABSTRACT

Introduction: Previous studies revealed fewer visits for congestive heart failure (CHF) to emergency departments (EDs) in New Jersey, USA and fewer admissions for CHF to a Southern Indian and an Israeli hospital during warmer months. Using hospital admission rate for CHF as a marker for illness severity, we hypothesized that CHF would also be less severe in warmer months. Materials and Methods: This is a retrospective cohort study which included all ED visits from 1 January 2004 to 31 January 2006. We analysed the monthly CHF hospital admission rates. We a priori chose to compare the admission rates for the 4 warmest to the 4 coldest months. Results: Of a total of 136,347 ED visits, 1083 (0.8%) were accounted for CHF. Hospital admission rate was 55.8%. Although there was a statistically significant increase in ED visits for CHF during the colder months, the 4 warmer months from June to September had 1.15 times higher hospital admission rate than the 4 coldest months from November to February. Conclusions: Contrary to our hypothesis, we found a statistically significant increase in the percentage of CHF visits admitted to the hospital during the warmer months. This suggests that although there are less ED CHF visits in the warmer months, a greater percentage tend to be severe.


Congestive heart failure (CHF) is one of the leading causes of morbidity and mortality around the world. It is estimated that more than 5 million people in the United States (USA) have CHF.1,2 The annual number of deaths and hospitalisations resulting from CHF has increased steadily to reach almost 900,000 hospital admissions and 300,000 deaths per year in the USA.3,4 The estimated prevalence of CHF in adults over the age of 75 years old is 10%, with a lifetime risk of almost 20%.5

This article is available only as a PDF. Please click on “Download PDF” to view the full article.