Measuring disability in nursing home residents: Validity and reliability of a newly developed instrument

A 24-item multidimensional nurse-administered Nursing Home Disabilities Instrument (NHDI) was developed to measure disabilities in nursing home residents. We present the psychometric features and value of this instrument, with the following domains assessed: Mobility, Activities of Daily Living (ADLs), Alertness, Resistance to Nursing Assistance, Incontinence, Cognition, and Perception. Test-retest and interrater reliability was assessed using the Spearman correlation coefficient. Internal consistency was examined by Cronbach's alpha. Criterion validity tests were performed by comparing the scales with scales of the Elderly Residents Rating Scale (BOP). Test-retest reliability correlation coefficients ranged from 0.63 to 0.94. Interrater reliability was high for the scales Cognition, Mobility, ADL, and Incontinence (0.79 to 0.93), moderate for Resistance (0.51), and low for Perception (0.33). Cronbach's alpha of the scales was high, ranging from 0.78 (Alertness) to 0.93 (Mobility); only Perception showed a low alpha: 0.54, Criterion validity was high for Cognition, ADL, and Mobility (0.75 to 0.78), and moderate for Alertness (0.59). The NHDI appears to be a valid and efficient multidimensional instrument for measuring disabilities in nursing home residents. These findings imply that the NHDI is a useful instrument for nursing homes to achieve a reliable assessment of cognitively impaired elders.