Assessment of adaptive functioning in huntington's disease

Abstract

The Huntington's Disease Activities of Daily Living (HD–ADL) scale is a 17‐item informant‐completed instrument for rating adaptive functioning in Huntington's disease (HD) patients. To assess the reliability and clinical correlates of the HD–ADL, it was administered along with the Mini‐Mental State Exam (MMSE) and Quantified Neurological Exam (QNE) to 93 HD patients. The HD‐ADL has high internal consistency (coefficient alpha = 0.91). Principal components factor analysis of the HD‐ADL revealed four factors (General Functioning, Domestic Activities, Home Upkeep, and Family Relationships) accounting for 72% of the total variance. MMSE score, motor impairment score, and duration of disease were the best predictors of HD‐ADL score. Similar results were obtained in an independent replication sample of patients. The HD‐ADL scores correlate with Shoulson and Fahn's total functional capacity (TFC) index (r = −0.89). The HD‐ADL scale is a reliable and valid instrument for assessing adaptive function in HD patients.