Translation and evaluation of the HeartQoL in patients with coronary heart disease in Iceland

BACKGROUND: Health-related quality of life (HRQoL) reflects an individual's own perception of their symptom burden, functional limitations, prognosis, overall health and changes associated with treatment. The HeartQoL is a validated heart disease-specific questionnaire with a physical and an emotional subscale that is used internationally to assess HRQoL in patients with coronary heart disease (CHD). The aim of this study was to translate and evaluate the psychometric properties of the HeartQoL in patients with CHD in Iceland.

METHODS: Patients ≥ 18 years (n = 396; mean age 64.4 ± 8.8 years; 79.6% male) admitted with CHD were recruited from two hospitals in Iceland and completed the Icelandic versions of the HeartQoL, Short-Form 12v2 Health Survey (SF-12v2), and Hospital Anxiety and Depression Scale (HADS). A subsample of 47 patients completed the HeartQoL 14 days later. Confirmatory factor analysis for ordinal data was used to evaluate the measurement model with a physical and an emotional subscale. Convergent and divergent validity, internal consistency, and test-retest reliability were evaluated.

RESULTS: Overall, the hypothesized two-factor structure of the Icelandic version of the HeartQoL was supported. However, problems with cross-loadings and correlated error variances were identified. Convergent and divergent validity were supported in correlational analyses between HeartQoL, SF-12v2, and HADS. Internal consistency reliability, measured by ordinal alpha, was good for the physical (α = 0.96) and emotional (α = 0.90) subscale. According to intraclass correlations (ICC), acceptable test-retest reliability was demonstrated (ICC = 0.79-0.86).

CONCLUSION: With the two-factor structure confirmed, the Icelandic HeartQoL demonstrated satisfactory psychometric properties in the sample of patients with CHD. Users of the instrument can use the original scoring.