What is the validity of diagnostic codes for hypertrophic cardiomyopathy in a Swedish regional cohort?
One-third of patients with diagnostic codes for hypertrophic cardiomyopathy in a Swedish regional cohort were misclassified, highlighting the need for caution when interpreting registry data.
PURPOSE: To validate diagnostic codes for hypertrophic cardiomyopathy (HCM), analyze misclassfications, and estimate the prevalence of HCM in an unselected Swedish regional cohort. PATIENTS AND METHODS: Using the hospitals' electronic medical records (used for the Swedish National Patient Register), we identified 136 patients from 2006 to 2016 with the HCM-related codes 142.1 and 142.2 (International Classification of Diseases). RESULTS: =0.118). CONCLUSION: One-third of patients diagnosed as HCM are misclassified, so registry data should be interpreted with caution. A correct diagnosis is important for decision-making and implementation of optimal HCM care; efforts should be made to increase awareness of HCM and diagnostic competence throughout the health care system.
Magnusson et al. (Tue,) studied this question.