Turkish adaptation, validity and reliability of freezing of gait questionnaire

Purpose: Freezing of gait is defined as; sudden, brief, episodic absence of stepping despite willingly intention to walk and characterized with sudden lockdown of motor system. 50% of Parkinson's Disease patients experience freezing of gait at least once. Freezing of gait is one of most common risk factors of falls in Parkinson's Disease patients. Purpose of this study is; to make Turkish adaptation (in both lingual and cultural aspects) of Freezing of Gait Questionnaire, to determinate its psychometric properties, and to make it possible to be used by clinicians to evaluate freezing of gait. Method: 69 patients were included in this study. Construct validity was determined evaluating convergent and divergent validity. Convergent validity was indicated when Freezing of Gait Questionnaire scores correlated moderate to high with UPDRS-Part2, UPDRS-Part3, UPDRS-Question14 and UPDRS-Question15. Divergent validity was indicated when Freezing of Gait Questionnaire scores correlated lower then the ones investigated for convergent validity with Mini Mental Test and UPDRS-Part1. Test-retest reliability was determined by applying Freezing of Gait Questionnaire again 7-14 days after first evaluation. Results: Kendall's Tau correlation coefficients investigated for convergent validity are found respectively; 0.509, 0.350, 0.531, 0.367 (p<0.05). Kendall's Tau correlation coefficients investigated for divergent validity are found respectively; -0.062 (p>0.05), 0.322 (p<0.05). Internal consistency Cronbach's Alpha coefficient is determined as 0.860. Test-retest Intraclass Correlation coefficient is calculated as 0.978. Conclusion: According to statistical analysis Freezing of Gait Questionnaire is a valid and reliable tool for evaluating freezing of gait in Turkish population. Keywords: Validity, Reliability, Freezing of Gait, Parkinson's Disease, Turkish Freezing of Gait Questionnaire, Motor Freeze