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The Multiple Sclerosis Performance Test (MSPT): An iPad-Based Disability Assessment Tool
Published on: June 30, 2014
The development of patient-reported outcome indices for multiple sclerosis (PRIMUS)
L C Doward1, S P McKenna, D M Meads
1Galen Research Ltd, Manchester, UK. ldoward@galen-research.com
Background:
Complex diseases such as multiple sclerosis (MS) present dilemmas over the choice of patient-reported outcome measures as no single scale can inform on all types of MS impact from the patient's perspective.
Objective:
To develop an outcome tool, the Patient-Reported Indices for Multiple Sclerosis (PRIMUS), to assess MS symptoms, activities, and quality of life.
Methods:
PRIMUS content was derived from qualitative interviews with UK MS patients and checked by clinical experts. Semi-structured cognitive debriefing interviews assessed scale face and content validity. PRIMUS scaling properties, reliability, and construct validity were assessed by a test-retest postal survey.
Results:
Cognitive debriefing interviews (n = 15) demonstrated scale clarity, relevance, and comprehensiveness. The postal survey was completed by 135 patients with MS. After removal of misfitting items and those exhibiting differential item functioning, all scales fitted the Rasch model, confirming unidimensionality. For all scales, test-retest reliability exceeded 0.80. Scale scores were related to perceived MS severity, general health, and symptoms of depression. Moderate correlations were observed between PRIMUS and Nottingham Health Profile scores.
Conclusions:
Clinicians and researchers can have confidence in scores obtained by respondents on the PRIMUS. The PRIMUS will aid the assessment of the impact of MS from the patient's perspective.
Insights
The Patient-Reported Indices for Multiple Sclerosis (PRIMUS) tool effectively assesses multiple sclerosis (MS) impact on symptoms, activities, and quality of life, providing reliable patient-reported outcomes.
Area of Science:
- Neurology
- Patient-Reported Outcomes
- Health Measurement
Background:
- Complex diseases like multiple sclerosis (MS) require comprehensive patient-reported outcome measures.
- Existing scales may not capture the full spectrum of MS impact from a patient's viewpoint.
Purpose of the Study:
- To develop the Patient-Reported Indices for Multiple Sclerosis (PRIMUS) outcome tool.
- PRIMUS aims to assess MS symptoms, daily activities, and overall quality of life.
Main Methods:
- Content derived from UK MS patient interviews and expert review.
- Cognitive debriefing assessed face and content validity.
- Test-retest postal surveys evaluated scaling properties, reliability, and construct validity.
Main Results:
- Cognitive debriefing confirmed scale clarity, relevance, and comprehensiveness.
- Rasch model analysis supported unidimensionality for all scales.
- High test-retest reliability (>0.80) and construct validity were demonstrated.
Conclusions:
- The PRIMUS tool provides reliable patient-reported outcomes for multiple sclerosis.
- PRIMUS can be confidently used by clinicians and researchers to assess MS impact.
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