Development of a Bilingual MS-Specific Health Classification System: The Preference-Based Multiple Sclerosis Index

Area of Science:

• Neurology
• Health Outcomes Research
• Patient-Reported Outcomes

Background:

• The Preference-Based Multiple Sclerosis Index (PBMSI) is under development to measure health outcomes in multiple sclerosis (MS).
• Qualitative review of PBMSI items is crucial for ensuring content validity and usability.
• Expert and patient perspectives are essential for refining health measurement tools.

Purpose of the Study:

• To qualitatively review and refine items for the Preference-Based Multiple Sclerosis Index (PBMSI).
• To gather expert and patient feedback on item clarity, meaning, response options, and recall periods.
• To enhance the accuracy and reduce measurement error of the PBMSI.

Main Methods:

• Cognitive interviews using the verbal probing method were conducted with 22 patients with multiple sclerosis (MS).
• Interviews explored participant difficulties, response rationales, item clarity, meaning, response appropriateness, and recall periods.
• Interviews were conducted in English and French, digitally recorded, and transcribed.

Main Results:

• The study sample comprised 22 respondents with a mean age of 52 years; 82% were women and diagnosed with MS for a mean of 12 years.
• The highest level of education completed was university or college for 86% of the sample.
• Modifications were implemented for each PBMSI item, including adjustments to recall period, instructions, and phrasing.

Conclusions:

• Patient and expert feedback facilitated item clarification and language simplification.
• Uniformity in item instructions and response options was enhanced.
• This qualitative review is expected to improve the accuracy of reporting and reduce measurement error for the PBMSI.