Comparison of patient‐reported outcome measures in multiple sclerosis

Background

Patient‐reported outcome measurements (PROMS) have been proposed sensitive outcome parameters in multiple sclerosis (MS). In this study, we assessed a German version of the Multiple Sclerosis Impact Scale (MSIS‐29) and a revised version of the Hamburg Quality of Life Questionnaire in Multiple Sclerosis (HAQUAMS) in comparison with rater‐ and physician‐based tools.

Methods

Consecutive MS patients (n = 117) of the MS outpatient unit were included. In addition to MSIS‐29 and HAQUAMS, the following parameters were obtained: Expanded Disability Status Scale (EDSS) and modified Multiple Sclerosis Functional Composite (MSFC) [9‐hole peg test (9HPT), 25‐foot walk test and symbol digit modalities test]. We investigated validity, internal consistency and test–retest reliability as well as correlation between these measures.

Results

Internal consistency (Cronbach's α ≤ 0.96) and test–retest coefficients (ICC ≤ 0.87) of both scales were high and satisfied psychometric standards. Convergent and discriminant validity was supported by direction, magnitude and pattern of correlation with other rater‐based measures depending on the functional subdomain. Both MSIS‐29 and HAQUAMS correlated with EDSS (ρ = 0.55 vs 0.62), but stronger correlation was found between MSIS‐29 and HAQUAMS total score (ρ = 0.90). Both scales distinguished between patient groups of varied disease severity and cognitive impairment.

Conclusion

Patient‐reported outcome measurements as MSIS‐29 and HAQUAMS seem to be valid instruments to detect different impairment levels in comparison with traditional rater‐based instruments like EDSS or MSFC.