Development of the St. George Hospital Memory Disorders Clinic Occupational Therapy Assessment Scale

The St. George Hospital Memory Disorders Clinic Occupational Therapy Assessment Scale (OTAS) is a performance-based assessment of activities of daily living (ADL) administered in the home environment to monitor function among patients with early cognitive decline. Of the 30 items investigated, 19 items that measured "higher" functional domains were found to be useful in discriminating between subjects. Psychometrically, these 19 items had high internal consistency (coefficient alpha = .89) and high interrater reliability (kappa coefficient range: .71-1.0), and correlated well with other measures of higher function (Lawton's instrumental activities of daily living scale: r = .75; Nottingham extended ADL scale: r = .67). However, unlike these latter measures, the OTAS also correlated well with the Mini-Mental State Examination (r = .73), indicating that OTAS is a valid instrument that should be sensitive to functional problems among patients in the early stages of cognitive impairment.