Psychometric properties of the Minnesota Living with Heart Failure Questionnaire (MLHF-Q)

Objective: To evaluate the psychometric properties of the Minnesota Living with Heart Failure Questionnaire (MLHF-Q) in patients with atrial fibrillat ion. Design: A prospective study of the patients who underwent DC electrical car dioversion. Setting: Clinics of cardiology and thoracic surgery of the University Hospi tal in Groningen, the Netherlands. Main outcome measures: The disease-specific MLHF-Q and generic measures of quality of life were administered. The sensitivity to change over time was tested with effect sizes (ES). Internal consistency of MLHF-Q scales was es timated with Cronbach's alpha. To evaluate the construct validity multitrai t-multimethod analysis was applied. The 'known group validity' was evaluate d by the comparison of mean scores and effect sizes between two groups of t he New York Heart Association (NYHA) classification (NYHA I versus II-III). Stability of MLHF-Q scales was estimated in a subgroup of patients who rem ained stable. Perfect congruence analysis and factor analysis were applied to confirm the a priori determined structure. Results: Cronbach's alpha was :0.80 of the MLHF-Q scales. Perfect congruenc e analysis (PCA) showed that the results resemble quite well the a priori a ssumed factor structure. Multitrait-multi method analysis showed convergent validity coefficients ranging from 0.59 to 0.73 (physical impairment dimen sion) and 0.39 to 0.69 (emotional dimension). The magnitude of change can b e interpreted as medium (ES = 0.50). The results of a 'test-retest' analysi s in a stable group can be valued as satisfactory for the MLHF-Q scales (Pe arson's r > 0.60). The physical dimension and the overall score of the MLHF -Q discriminated significantly between the NYHA I and II-III groups (p < 0. 001) with large effect sizes (ES > 1.0). Conclusions: The MLHF-Q has solid psychometric properties and the outcome o f the current study indicates that the MLHF-Q is an effective and efficient instrument.