Psychometric properties of the Turkish version of the freezing of gait questionnaire for patients with Parkinson's disease

Objective: Freezing of gait (FOG) is one of the disabling symptoms in Parkinson's disease (PD). The diagnosis and assessment of FOG may be difficult, but it is absolutely necessary. The aim of this study was to develop a Turkish version of the freezing of gait questionnaire (FOG-Q) and to assess the validity and reliability of the Turkish version of the FOG-Q in patients with PD. This study also investigated whether FOG-Q scores changed in subgroups based on severity of PD, fear of falling (FOF), and subtype of PD, and if the reliability of the FOG-Q was affected by these conditions. Methods: Following the translation process, 48 consecutive patients with PD were evaluated using the Turkish version of FOG-Q, the Unified Parkinson's Disease Rating Scale (UPDRS), modified Hoehn and Yahr (mHY), Berg Balance Scale (BBS), Falls Efficacy Scale (FES), Timed Up and Go Test (TUG), and Five Times Sit to Stand Test (FTSST). Results: The mean (SD) and median (q1-q3) FOG-Q scores were 4.44 (5.3) and 2 (0-15). FOG-Q demonstrated positive, strongest correlations with FES, TUG, UPDRS total score, and UPDRS part II-III (rs=0.693-0.603), and moderate correlations with FTSST, mHY, and UPDRS part I (rs=0.579-0.448). BBS negatively correlated with FOG-Q (rs=-0.643). Inter-rater and intra-rater reliability ranged from 0.849 and 0.914. The FOG-Q scores increased with disease progression and FOF (p<0.05). Conclusion: The Turkish version of the FOG-Q is a valid and reliable tool for the assessment of FOG in PD patients who are native Turkish speakers.