The validity of a diagnosis of heart failure in a hospital discharge register

Background and aims: The accuracy of a diagnosis of heart failure (HF) in hospital discharge registers is largely unknown. We aimed to determine the validity of such a diagnosis in the Swedish hospital discharge register. Methods and results: In a population-based study of 2322 middle-aged men (the ULSAM study), 321 participants were diagnosed with HF according to the Swedish hospital discharge register, during a median follow-up time of 29 years. A review board examined the validity of the diagnosis according to the European Society of Cardiology definition of HF. Eighty-two percent of the possible cases were classified as having definite HF. An echocardiographic examination increased the validity to 88%. For patients treated at an internal medicine or cardiology clinic the validity was 86% and 91%, respectively. If HF was the primary diagnosis, the validity was 95%, irrespective of clinic type. Conclusion: The HF diagnosis in the Swedish hospital discharge register appears slightly less precise than for acute myocardial infarction and stroke. For population-based research, only those with a primary diagnosis of HF in the hospital discharge register should be regarded as definite HF cases, or alternatively the cases should be validated individually. (c) 2005 European Society of Cardiology. Published by Elsevier B.V. All rights reserved.