Quick MSA-QoL: A validated, abbreviated health-related quality of life questionnaire for use in Multiple System Atrophy.

BACKGROUND

Health-related quality of life is an important patient-reported outcome, which can be assessed using instruments such as the Multiple System Atrophy (MSA) Quality of Life (MSA-QoL) scale. However, at 40-items its length can prove burdensome, particularly to patients with a disease such as MSA. This can contribute to respondent burden and poor-quality response data.

OBJECTIVE

The objective of this study was to develop an abbreviated MSA-QoL scale for use in clinical practise and trials (Quick MSA-QoL).

METHODS

A single-factor 15-item scale was developed with data from 310 patients with MSA, using exploratory factor analysis (EFA). A separate dataset (n = 279) was used for analysis of psychometric properties and for confirmatory factor analysis.

RESULTS

Missing data was minimal, with even distribution of scores and negligible floor/ceiling effects (0/0.4%). Reliability was high (Cronbach alpha 0.870, test-retest reliability 0.950). Good item-total scale correlations were observed (r = 0.402-0.618), and the overall scale correlated well with other validated questionnaires including the original MSA-QoL (r = 0.862). Confirmatory factor analysis demonstrated acceptable model fit indices. Responsiveness data from re-administration of the Quick MSA-QoL 10 months from baseline testing found the overall scale to be sensitive to change.

CONCLUSIONS

These data suggest that the Quick MSA-QoL is a suitable and efficient scale for use in clinical trials, minimising respondent burden and maintaining data quality.