Interpreting Errors in Temporal Orientation in Older Hospital Patients

Abstract

Normal variation in temporal orientation has been examined in community dwelling, healthy older subjects but not in elderly hospital patients. We examined the validity of errors in different aspects of temporal orientation as a guide to the presence or absence of cognitive impairment orientation in elderly hospital patients in 150 consecutive patients on the day after admission to an acute geriatric unit. Cognitive impairment (delirium or dementia or both) was diagnosed without reference to temporal orientation. Optimum cutoffs for error scores on the different aspects of temporal orientation (date/year/month/day of the week/time of day) were calculated to maximize the sum of sensitivity and specificity for detection of cognitive impairment. Of the 150 patients, 45 (30%) had cognitive impairment. The best cutoffs for detection of cognitive impairment were an error of more than 3 days in the date; any error in the year, month, or day of the week; and an error of more than 1 h in identifying the time of day. Error in identifying the year had the highest positive likelihood ratio (6.4 [95% confidence interval 4.0–10.3]) for detecting cognitive impairment and the lowest negative likelihood ratio (0.1 [0.04–0.3]) for the exclusion of cognitive impairment. Failure to identify the year correctly is the aspect of temporal orientation most closely related to cognitive impairment.