Comparing performance on the months of the year backwards test in hospitalised patients with delirium, dementia and no cognitive impairment: an exploratory study

Purpose: To investigate performance of the Months of the Year Backwards (MOTYB) test in older hospitalised patients with delirium, dementia, and no cognitive impairment. Methods: Secondary analysis of data from a case-control study of 149 hospitalised patients aged ≥65 years with delirium [with or without dementia (N=50)], dementia [without delirium (N=46)] and no cognitive impairment (N=53). Verbatim transcripts of MOTYB audio recordings were analysed to determine group differences in response patterns. Results: In the total sample [median age 85y (IQR 80-88), 82% female], patients with delirium were more often unable to recite months backward to November (36/50 = 72%) than patients with dementia (21/46 = 46%; p<0.01) and both differed significantly from patients without cognitive impairment (2/53 = 4%; p’s<0.001). 121/149 (81%) of patients were able to engage with the test. Patients with delirium were more often unable to engage with MOTYB (23/50 = 46%; e.g. due to reduced arousal) than patients with dementia (5/46 =11%; p<0.001); both groups differed significantly (p’s<0.001) from patients without cognitive impairment (0/53=0%). There was no statistically significant difference between patients with delirium (2/27 = 7%) and patients with dementia (8/41 = 20%) in completing MOTYB to January, but performance in both groups differed (p<0.001 and p<0.02, respectively) from patients without cognitive impairment (35/53 = 66%). Conclusion: Delirium was associated with inability to engage with MOTYB and low rates of completion. In patients able to engage with the test, error-free completion rates were low in delirium and dementia. Recording of engagement and patterns of errors may add useful information to MOTYB scoring. Keywords: Attention, Cognitive Dysfunction, Delirium, Dementia, Case-Control Studies