Testing patient-reported outcome measurement equivalence in multinational clinical trials: An exemplar using the 12-item Multiple Sclerosis Walking Scale

Abstract

BackgroundAlthough multinational clinical trials frequently use patient-reported outcomes to measure efficacy, measurement equivalence across cultures and languages, a scientific requirement, is rarely tested. Clinically accessible accounts are rare; exemplars are needed.ObjectiveTo develop and test a Turkish version of the Multiple Sclerosis Walking Scale (MSWS-12v2) as a clinical exemplar for examining measurement equivalence.MethodsThe MSWS-12v2 Turkish (MSWS-12v2T) was developed using recognised methods for linguistic equivalence. Rasch measurement theory was used to examine measurement performance (multiple tests of targeting, scale performance, and person measurement) and measurement equivalence (differential item functioning). UK data (n = 3310) were used for comparisons and differential item functioning testing.ResultsOne hundred and twenty-four people from two Turkish centres completed the MSWS-12v2T. Rasch measurement theory evidence supported MSWS-12v2T as reliable (person separation = 0.96) and valid (thresholds ordered; no concerning item misfit, bias, or person misfit). However, four items demonstrated significantly different performance between UK and Turkish samples. These item differences significantly affected scores (person measurements) at the group-level (p < 0.001). Individual person differences were less pronounced.ConclusionsLinguistic equivalence does not guarantee measurement equivalence; independent testing is required. Rasch measurement theory enables sophisticated and unique examinations of cross-cultural measurement equivalence and we recommend this be tested routinely in pivotal multiple sclerosis clinical trials.

Physical, cognitive and psychosocial effects of telerehabilitation-based motor imagery training in people with multiple sclerosis: A randomized controlled pilot trial

“…[21][22][23] Perceived walking ability was assessed by the Turkish version of 12-Item MS Walking Scale (MSWS-12), which has been shown to be valid and reliable. 24 Balance and balance confidence were assessed with commonly used outcome measures in MS including TUG, 18 the Turkish version of the Activities-specific Balance Confidence (ABC) Scale, 25,26 Cognitive functions were assessed by the Symbol Digit Modalities Test (SDMT), 27 Selective Reminding Test (SRT), 28 and 10/36 Spatial Recall Test (10/ 36SRT). 29 Psychosocial domains including fatigue, anxiety, depression, and quality of life were evaluated using valid and reliable measures for pwMS.…”

Exploring regional variations in the cross‐cultural, international implementation of the Patient Reported Outcomes Burdens and Experience (PROBE) study

“…A few examples of cross‐language and cross‐cultural validation have been published. Dib et al developed a Turkish language version of assessment tools for patients with multiple sclerosis . The investigators compared the results when using the Turkish version with those obtained using the UK version.…”

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“…Timed-25 Foot Walking (T25FW) was used to assess gait speed on 7.62 m pathway (14). The perceived walking performance was evaluated using the 12-item MS Walking Scale (MSWS-12) (15).…”