The validation of a Japanese version of the New Freezing of Gait Questionnaire (NFOG-Q).

Abstract

This study aimed to develop a Japanese version of the New Freezing of Gait Questionnaire (NFOG-Q) and investigate its validity and reliability. After translating the NFOG-Q according to a standardised protocol, 56 patients with Parkinson's disease (PD) were administered it. Additionally, the MDS-UPDRS parts II and III, Hoehn and Yahr (H&Y) stage, and number of falls over 1month were evaluated. Spearman's correlation coefficients (rho) were used to determine construct validity, and Cronbach's alpha (α) was used to examine reliability. The interquartile range of the NFOG-Q scores was 10.0-25.3 (range 0-29).The NFOG-Q scores were strongly correlated with the MDS-UPDRS part II, items 2.12 (walking and balance), 2.13 (freezing), 3.11 (freezing of gait), and 3.12 (postural stability) and the postural instability and gait difficulty score (rho = 0.515-0.669), but only moderately related to the MDS-UPDRS item 3.10 (gait), number of falls, disease duration, H&Y stage, and time of the Timed Up-and-Go test (rho = 0.319-0.434). No significant correlations were observed between age and the time of the 10-m walk test. The internal consistency was excellent (α = 0.96). The Japanese version of the NFOG-Q is a valid and reliable tool for assessing the severity of freezing in patients with PD.