Validating the HeartQoL questionnaire in patients with atrial fibrillation

BACKGROUND: Atrial fibrillation (AF) is associated with impaired health-related quality-of-life (HRQL). When assessing HRQL, disease-specific and generic instruments are used, which may hinder outcome comparisons across studies. A newly developed core ischaemic heart disease-specific HRQL questionnaire, the HeartQoL, offers a single measurement instrument which may allow outcome comparisons across cardiac diseases. The aim of the study was to evaluate the psychometric properties of HeartQoL in an AF population treated with ablation by assessing its factor structure, construct validity, internal consistency, and test-retest reliability. DESIGN AND METHODS: Data were collected in two phases: (a) a cross-sectional study including 462 patients with AF/atrial flutter who completed the HeartQoL and the Short-Form 36 (SF-36), allowing for the evaluation of internal consistency, factor structure and construct validity; and (b) a longitudinal study including 55 patients completing HeartQoL twice to evaluate test-retest reliability. RESULTS: The two-factor structure of HeartQoL was largely confirmed in patients with AF. Internal consistency was high (Cronbach's alpha (α) ≥ 0.90) and test-retest reliability good (intra-class correlation ≥ 0.90). The construct validity was supported, as subscales of HeartQoL correlated strongly with similar (r ≥ 0.78) and weakly (r ≤ 0.47) with dissimilar subscales of SF-36. The HeartQoL demonstrated ability to distinguish between different clinical subgroups of patients, indicating sensitivity. CONCLUSION: The HeartQoL showed overall satisfactory psychometric properties, demonstrating it to be a valid instrument in the evaluation of HRQL in patients with AF treated with ablation. This suggests that HeartQoL may be a valuable instrument for making HRQL comparisons across the spectrum of cardiac diseases.