Validity and reliability of the Finnish version of the Multiple Sclerosis Impact Scale-29.

Anna Wiksten,Eija Rosti‐Otajärvi,Juhani Ruutiainen,Päivi Hämäläinen,Tanja Hakkarainen

doi:10.1002/brb3.725

Abstract

BackgroundThe Multiple Sclerosis Impact Scale‐29 (MSIS‐29) has been increasingly used to evaluate the self‐perceived impact of multiple sclerosis (MS) on a patient.ObjectivesThe aim of this study was to evaluate the psychometric properties of the Finnish version of MSIS‐29 in patients with MS.MethodsA total of 553 patients with MS completed the MSIS‐29 and self‐administered questionnaires capturing information on demographics, disease characteristics and severity, perceived quality of life (EuroQol 5D‐3L instrument), and fatigue (Fatigue Severity Scale).ResultsThe data quality for MSIS‐29 was excellent, with 99.5% computable scores for the MSIS‐29 physical scale and 99.3% for the MSIS‐29 psychological scale. Floor and ceiling effects were minimal. Excellent Cronbach's alpha values of 0.97 and 0.90 were seen for MSIS‐29 physical and psychological subscales, respectively. The physical subscale showed highest correlations with measures of physical functioning, such as disease severity and the mobility domain of the quality of life. Similarly, the psychological subscale showed highest correlations with self‐reported fatigue and the anxiety/depression domains of the quality of life. MSIS‐29 physical scores related strongly to disease severity, whereas the MSIS‐29 psychological scores increased in mild disease but declined in more severe disease forms.ConclusionThe Finnish version of MSIS‐29 has satisfactory psychometric properties. Consistent with the previous recommendations, the use of two MSIS‐29 subscale scores instead of a total score was supported.

Highlights

Multiple sclerosis (MS) is an incurable progressive neurological disease, with a wide spectrum of symptoms covering fatigue, visual disturbances, limb weaknesses, deficits in coordination and balance, bladder and bowel disturbance, pain, reduced heat tolerance, dysarthria, cognitive dysfunction, and depression (McDonald & Ron, 1999)
For the evaluation of convergent and divergent validity of MSIS-29, Spearman correlation coefficients were used to examine the relationship between the MSIS-29 physical and psychological scores with the disease severity (Patient Assessment of Expanded Disability Status Scale (EDSS) Levels), quality of life (EQ-5D/utility, mobility, anxiety/depression, and VAS), and fatigue (FSS)
The aim of this study was to evaluate the psychometric properties of the Finnish version of MSIS-29 using standard techniques evaluating data quality, scaling assumptions, acceptability, reliability, and validity

Summary

Introduction

Multiple sclerosis (MS) is an incurable progressive neurological disease, with a wide spectrum of symptoms covering fatigue, visual disturbances, limb weaknesses, deficits in coordination and balance, bladder and bowel disturbance, pain, reduced heat tolerance, dysarthria, cognitive dysfunction, and depression (McDonald & Ron, 1999). Robust methods to evaluate physical and psychological disease burden of MS are needed in population-based and rehabilitation studies as well as for the continuous evaluation of individual patients. Several measurement scales, both disease specific and generic, have been used to evaluate functioning and quality of life of patients with MS. Methods: A total of 553 patients with MS completed the MSIS-29 and self- administered questionnaires capturing information on demographics, disease characteristics and severity, perceived quality of life (EuroQol 5D-3L instrument), and fatigue (Fatigue Severity Scale). Consistent with the previous recommendations, the use of two MSIS-29 subscale scores instead of a total score was supported

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