[Validation of selected aspects of psychometry of the Polish version of the Multiple Sclerosis Impact Scale 29 (MSIS-29)].

BACKGROUND AND PURPOSE

Because of the small number of self-reported measures of disease impact on the quality of patients' life used in Poland and specific for multiple sclerosis (MS), the aim of the study was to validate selected aspects of psychometry of the Polish adaptation of the Multiple Sclerosis Impact Scale 29, MSIS-29.

MATERIAL AND METHODS

MSIS-29 was first published by Hobart and Thompson in 2001, and consists of 29 questions, the first 20 of which address the physical impact component and 9 assess the psychological impact. The higher the score, the worse is the impact of the disease on quality of patient's life. Validation analysis consisted of translation of the original English version into Polish according to all necessary translation principles and of assessment of convergent validity and internal reliability of the Polish version of MSIS-29. 104 randomly selected patients with definite MS (according to McDonald criteria) were examined: 77 women and 27 men; mean age was 36.9+/-9.4 years, and the mean disease duration was 9.05+/-6.68 years. The disability of the patients was assessed according to the Expanded Disability Status Scale (EDSS). Apart from the examined measure (MSIS-29) subjects were also asked to complete the Functional Assessment of Multiple Sclerosis (FAMS), Beck's Depression Inventory (BDI-II) and the Fatigue Severity Scale (FSS).

RESULTS

MSIS-29 correlated with EDSS, FAMS, BDI-II and FSS. Internal consistency of MSIS-29 was satisfactory.

CONCLUSIONS

Psychometric-statistical analysis showed that the Polish version of MSIS-29 is a valuable measure to examine the impact of disease on patients' life. The studies should be continued taking into account other aspects of psychometry.