Psychometric evaluation of the Finnish version of the impact on participation and autonomy questionnaire in persons with multiple sclerosis

Abstract

Objective: The objective of this study was to evaluate the psychometric properties of the impact on participation and autonomy (IPA) questionnaire. The Finnish version of IPA (IPAFin) was translated into Finnish using the protocol for linguistic validation for patient-reported outcomes instruments.

Methods: A total of 194 persons with multiple sclerosis (MS) (mean age 50 years SD 9, 72% female) with moderate to severe disability participated in this study. A confirmatory factor analysis (CFA) was used to confirm the four factor structure of the IPAFin. The work and educational opportunities domain was excluded from analysis, because it was only applicable to 51 persons. Internal consistency was investigated by calculating Cronbach’s alpha.

Results: CFA confirmed the construct validity of the IPA (standardized root mean square residual (SRMR) = 0.06, comparative fit index (CFI) = 0.93, Tucker–Lewis index =0.93, root mean square error of approximation (RMSEA) = 0.06), indicating a good fit to the model. There was no difference in the models for females and males. Cronbach’s alpha for the domains ranged between 0.80 and 0.91, indicating good homogeneity.

Conclusions: The construct validity and reliability of the IPAFin is acceptable. IPAFin is a suitable measure of participation in persons with MS.