Responsiveness and minimal clinically important difference of the Minnesota living with heart failure questionnaire

The Minnesota Living with Heart Failure Questionnaire (MLHFQ) is one of the most widely used health-related quality of life questionnaires for patients with heart failure (HF). The objective of the present study was to explore the responsiveness of the MLHFQ by estimating the minimal detectable change (MDC) and the minimal clinically important difference (MCID) in Spain.

Patients hospitalized for HF in the participating hospitals completed the MLHFQ at baseline and 6 months, plus anchor questions at 6 months. To study responsiveness, patients were classified as having "improved", remained "the same" or "worsened", using anchor questions. We used the standardized effect size (SES), and standardized response mean (SRM) to measure the magnitude of the changes scores and calculate the MDC and MCID.

Overall, 1211 patients completed the baseline and follow-up questionnaires 6 months after discharge. The mean changes in all MLHFQ domains followed a trend (P < 0.0001) with larger gains in quality of life among patients classified as "improved", smaller gains among those classified as "the same", and losses among those classified as "worsened". The SES and SRM responsiveness parameters in the "improved" group were ≥ 0.80 on nearly all scales. Among patients classified as "worsened", effect sizes were < 0.40, while among patients classified as "the same", the values ranged from 0.24 to 0.52. The MDC ranged from 7.27 to 16.96. The MCID based on patients whose response to the anchor question was "somewhat better", ranged from 3.59 to 19.14 points.

All of these results suggest that all domains of the MLHFQ have a good sensitivity to change in the population studied.