Australian modified Lawton's Instrumental Activities of Daily Living Scale contributes to diagnosing older adults with cognitive impairment

Objective To assess the ability of the Australian Modified Lawton's Instrumental Activities of Daily Living (IADL) Scale (Modified Lawton's Scale) to screen for cognitive impairment in patients without physical or sensory deficits. Methods Prospective single-blind study of diagnostic accuracy. Results Data were available for 249 patients. At <= 25 points on the Modified Lawton's Scale, the area under the receiver operating characteristic curve (AUC) for patients with dementia was 0.90 (95% CI 0.83, 0.96), with sensitivity of 95% and specificity of 84%. The scale had decreased ability to identify patients with mild cognitive impairment (MCI) with the AUC highest at 0.76 (95% CI 0.67, 0.84), with a sensitivity of 77% and specificity of 74% at <= 26 points. The Modified Lawton's Scale had a significant strong correlation with the Mini-Mental State Examination (0.73) (P <= 0.001). Conclusion A score of <= 25 on the Modified Lawton's Scale may indicate cognitive impairment impacting on IADL.