Measuring Daytime Drowsiness in Nursing Home Residents: The MSLT-NH

A standardized method of assessing daytime drowsiness in frail nursing home residents has not been previously available. We present here the development and test characteristics of an instrument to measure daytime drowsiness in nursing home residents with cognitive and functional impairment, the Multiple Sleep Latency Test-Nursing Home (MSLT-NH). In a standardized manner, the resident is tested three times in one day (at 9 a.m., 11 a.m., and 1 p.m.) to measure the amount of time until the subject falls asleep. The average sleep latency (minutes to fall asleep) is the measure of interest. We tested the MSLT-NH in 95 residents from six community nursing homes in the Los Angeles area (82% of subjects were female; 81% were white, mean age was 86.6 years and mean score on the Mini-Mental State Examination [MMSE] was 9.4). Interrater reliability of the MSLT-NH was quite good (correlations between raters ranged from 0.98 to 0.99; all p values were <.0001). Validity was assessed by comparing MSLT-NH results to simultaneous wrist activity estimation of sleep, and by comparing MSLT-NH findings to results from nighttime sleep estimation by wrist actigraphy the night prior to MSLT-NH. The percent agreement between MSLT-NH and wrist actigraph ranged from 77% to 79% MSLT-NH results were significantly associated with peak duration of nighttime sleep episodes the night prior to testing. The MSLT-NH was also quite acceptable for use in the NH setting. In conclusion, we have developed a promising measure of daytime drowsiness in NH residents. Further testing will help establish whether this test is a clinically useful measure of daytime drowsiness from medications or other conditions in the NH setting.