OBJECTIVES: The Prosthesis evaluation questionnaire (PEQ) is used to assess patient-reported prosthesis-related quality of life. PEQ mobility section consists of 12 items. This study assessed the properties of the original mobility section of the Finnish version of the PEQ instrument on a visual analog scale (VAS) and its modified version with five response categories.

METHODS: Patients having undergone major lower extremity amputation for various reasons were recruited for this cross-sectional study and completed the PEQ instrument (scale, 0-100 points) and its modified mobility section, the Locomotor Capabilities Index (LCI-5) (scale, 0-48 points), the Houghton scale, the 15D health-related quality of life instrument, and answered general health and pain questions on a VAS. Participants who completed the mobility sections twice (n= 117) in a 2-week interval were included. The two versions of the PEQ mobility section were compared with each other and with the other instruments.

RESULTS: Mean (SD) scores of the original and the modified mobility section were 58 (25) and 31 (13) and coefficients of variation 0.42 and 0.43, respectively. Reproducibility (intraclass correlation coefficient) was consistent between the measures (0.87 and 0.85, respectively). Even though Spearman's correlation coefficient was high (r= 0.83) and Kendal coefficient of concordance excellent (0.91), considerable differences were noted between the two measures. Significant correlation (p<0.001) was found for both measures with the PEQ scales of Utility, Well-being, and Social burden. The original section had significant correlation with the scales of Frustration and Perceived Responses (p<0.01 and <0.001, respectively). There were differences in correlations with all other patient-reported instruments.

CONCLUSIONS: The original and the modified mobility section of the PEQ have moderate measurement differences. Thus their results are not directly comparable. Nonetheless, both measures are reliable and valid, but the modified version with five response categories is easier to complete and analyze in clinical work.