Validation of the slovene version of the Kansas City Cardiomyopathy Questionnaire

Introduction

Heart failure (HF) is a chronic condition that affects patients’ quality of life (QoL). Disease-specific patient-reported outcome measures, such as the Kansas City Cardiomyopathy Questionnaire (KCCQ), are increasingly used to capture the impact of HF. This study aimed to evaluate the psychometric properties of the Slovene version of the KCCQ, including internal consistency, construct validity, and test-retest reliability.

Methods

A prospective cohort study was conducted in Slovene-speaking HF patients recruited from outpatient clinics. Participants completed the KCCQ, EuroQol-5D-5L, and a demographic questionnaire. Clinical data, including ejection fraction, New York Heart Association (NYHA) class, Charlson Comorbidity Index, and medication use, were collected. Internal consistency was assessed using Cronbach’s alpha. Test-retest reliability was evaluated in a subset of randomly selected patients who completed the KCCQ twice within two weeks. Construct validity was examined through convergent correlations with the EQ-5D-5L and known-groups comparisons.

A total of 230 participants, who were recruited from cardiology outpatient clinics or general practitioners, were included. 35 completed the KCCQ twice.

Results

Internal consistency was strong (α=0.741–0.916), and test–retest reliability was excellent (ICC=0.938). The KCCQ correlated significantly with EQ-5D-5L (r=0.604, p<0.001). The instrument differentiated clearly by NYHA class, age, living status, and comorbidity burden. Worse QoL was associated with EF≤40%, older age, and living alone, while no significant sex differences were observed.

Conclusion

The Slovene version of the KCCQ demonstrated strong psychometric properties, including excellent test–retest reliability, and is a valid tool for assessing QoL in patients with HF.Correlation between NYHA class and KCCQFor image description, please refer to the figure legend and surrounding text.Correlation between EQ-5D VAS score andFor image description, please refer to the figure legend and surrounding text.