Stability and relative validity of the Multiple Sclerosis Impact Profile (MSIP)

To examine the stability and relative validity of the Multiple Sclerosis Impact Profile (MSIP) in criterion-related groups. The MSIP is a disease-targeted health impact measure based on a selection of International Classification of Functioning, Disability and Health (ICF) aspects selected by 98 patients and medical and non-medical health professionals.

Data were obtained from a postal survey of 377 individuals with Multiple Sclerosis (MS) attending the MS centre of the University Medical Center Groningen (UH) and 153 subjects from the MS patients' association. Stability was tested with t-tests for paired samples and intraclass correlation coefficients for repeated measures in a sample of 251 individuals from the UH sample. The Relative Validity (RV) was estimated using the Short Form Questionnaire (SF-36), the World Health Organization Quality of Life-BREF (WHOQOL-BREF), the Disability and Impact Profile (DIP), the Impact on Autonomy Questionnaire (IPAQ) and the Groningen Activity Restriction Scale (GARS).

These indicate that the MSIP is a stable measure in time. MSIP scales showed satisfactory and strong RV. In general, the domain-specific activities and participation measures (GARS and IPAQ) performed equally or slightly better than the comparable MSIP-scales, while the MSIP performed better than the multidimensional health impact measures (SF-36, DIP and WHOQOL-BREF).

The MSIP demonstrated good stability and RV compared to generic health impact and domain-specific measures.