Interpretability of the European Heart Failure Self-care Behaviour scale

Abstract

Objective: The European Heart Failure Self-care Behaviour scale (EHFScBs) is a valid patient-reported questionnaire to measure self-care behavior of heart failure (HF) patients. We assessed the interpretability of the EHFScBs.

Methods: We used data of 1,023 HF patients. Interpretability refers to the clinical meaning of the score and its changes over time. We operationalized interpretability by evaluating distributions of EHFScBs scores across relevant HF subgroups by eyeballing, by testing the risk on hospitalizations and mortality of a plausible threshold, and by determining a clinically relevant minimal important change (MIC). The scale score ranged from 0 to 100, with a higher score meaning better self-care. A threshold of ≥70 was defined as adequate and <70 as inadequate self-care.

Results: The EHFScBs scores were similarly normally distributed among the subgroups with a mean between 57.8 (SD 19.4) and 72.0 (SD 18.0). The 464 HF patients with adequate self-care had significantly less all-cause hospitalizations than the 559 patients with inadequate self-care.

Conclusion: The degree of self-care showed to be independent of relevant HF subgroups. A single threshold of 70 accurately discriminated between patients with adequate and inadequate self-care.

Practice implications: The threshold of 70 can be used in designing studies and informing health policy makers.

Keywords: heart failure; interpretability; patient-reported outcome; self-care; threshold and minimal important change.

Figure 1

Distribution of the EHFScBs scores at 12 months in relevant subgroups of HF (y-axis, number of patients; x-axis, EHFScBs score [0–100]). Abbreviations: EHFScBs, European Heart Failure Self-care Behaviour scale; HF, heart failure; NYHA, New York Heart Association functional classification; LVEF, left ventricular ejection fraction; CES-D, Centre for Epidemiologic Studies Depression scale.

Figure 1

Distribution of the EHFScBs scores at 12 months in relevant subgroups of HF (y-axis, number of patients; x-axis, EHFScBs score [0–100]). Abbreviations: EHFScBs, European Heart Failure Self-care Behaviour scale; HF, heart failure; NYHA, New York Heart Association functional classification; LVEF, left ventricular ejection fraction; CES-D, Centre for Epidemiologic Studies Depression scale.

Figure 2

Correlations of change in the EHFScBs score during 12 months on the x-axis and the anchors on the y-axis. Abbreviations: EHFScBs, European Heart Failure Self-care Behaviour scale; MLHFQ, Minnesota Living with Heart Failure Questionnaire; HF, heart failure; BNP, B-type natriuretic peptide.