Validation of the freezing of gait questionnaire in patients with Parkinson's disease

Mov Disord. 2009 Apr 15;24(5):655-61. doi: 10.1002/mds.21745.


To revalidate the Freezing of Gait Questionnaire (FOG-Q), patients with Parkinson's disease (PD) were randomly assigned to receive rasagiline (1 mg/day) (n = 150), entacapone (200 mg with each dose of levodopa) (n = 150), or placebo (n = 154). Patients were assessed at baseline and after 10 weeks using the FOG-Q, Unified Parkinson's Disease Rating Scale (UPDRS), Beck Depression Inventory (BDI), and Parkinson's Disease Questionnaire (PDQ-39). FOG-Q dimensionality, test-retest reliability, and internal reliability were examined. Convergent and divergent validities were assessed by correlating FOG-Q with UPDRS, BDI, and PDQ-39. Comparisons between FOG-Q item 3 and UPDRS item 14 were also made. Principal component analysis indicated that FOG-Q measures a single dimension. Test-retest reliability and internal reliability of FOG-Q score was high. FOG-Q was best correlated to items of the UPDRS relating to walking, general motor issues, and mobility. Correlations between baseline and endpoint suggested that FOG-Q item 3 is at least as reliable as UPDRS item 14. At baseline, 85.9% of patients were identified as "Freezers" using FOG-Q item 3 (> or =1) and 44.1% using UPDRS item 14 (> or =1) (P < 0.001). FOG-Q was a reliable tool for the assessment of treatment intervention. FOG-Q item 3 was effective as a screening question for the presence of FOG.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Aged
  • Analysis of Variance
  • Antiparkinson Agents / adverse effects
  • Antiparkinson Agents / therapeutic use
  • Catechols / therapeutic use
  • Double-Blind Method
  • Female
  • Freezing Reaction, Cataleptic / drug effects
  • Freezing Reaction, Cataleptic / physiology*
  • Gait Disorders, Neurologic / chemically induced
  • Gait Disorders, Neurologic / diagnosis*
  • Gait Disorders, Neurologic / drug therapy
  • Gait Disorders, Neurologic / physiopathology*
  • Humans
  • Indans / therapeutic use
  • Levodopa / adverse effects
  • Male
  • Middle Aged
  • Neuroprotective Agents / therapeutic use
  • Nitriles / therapeutic use
  • Parkinson Disease / drug therapy
  • Principal Component Analysis
  • Psychiatric Status Rating Scales
  • Reproducibility of Results
  • Severity of Illness Index
  • Statistics as Topic
  • Surveys and Questionnaires*


  • Antiparkinson Agents
  • Catechols
  • Indans
  • Neuroprotective Agents
  • Nitriles
  • rasagiline
  • Levodopa
  • entacapone