Role of the Functional Gait Assessment in Validating Item Difficulty Hierarchy and Fall Risk for Idiopathic Normal...

Area of Science:

• Neurology
• Geriatrics
• Rehabilitation Medicine

Background:

• Falls and gait-balance disturbances are significant clinical manifestations of idiopathic normal pressure hydrocephalus (iNPH).
• Accurate assessment of fall risk is crucial for managing iNPH patients and preventing injuries.

Purpose of the Study:

• To validate the Functional Gait Assessment (FGA) item-difficulty hierarchy in iNPH.
• To determine the optimal cutoff score of the FGA for predicting falls.
• To identify specific FGA items most indicative of fall risk in iNPH.

Main Methods:

• One hundred eighty-eight iNPH patients were assessed using the FGA, Timed Up-and-Go (TUG), and 10-Meter Gait Speed (10MGS) tests.
• Rasch analysis was employed to confirm the FGA item hierarchy and score-logit relationships.
• Logistic regression identified the optimal FGA fall cutoff and key fall-related items.

Main Results:

• The FGA item hierarchy was validated, with item 7 ('gait with narrow base of support') being the most difficult.
• An FGA cutoff score of ≤15 demonstrated high accuracy (AUC: 0.901) in predicting falls, outperforming TUG and 10MGS.
• Key fall-related FGA items included 'change in gait speed,' 'gait with narrow base of support,' and 'stair steps.'

Conclusions:

• The FGA is a valid and effective tool for assessing fall risk in iNPH patients.
• Leveraging FGA's item difficulty and characteristics can facilitate early diagnosis and personalized interventions.
• Findings support the use of FGA for tailored rehabilitation and fall prevention strategies in iNPH.