The prognostic validity of delirium severity as measured by Delirium Observation Screening Scale (DOS scale) on adverse outcomes.

OBJECTIVE: To investigate whether an assessment of delirium severity at diagnosis using the Delirium Observation Screening Scale (DOS scale) predicts adverse outcomes in hospital and on discharge.

METHODS: A prospective cohort study was conducted on a convenience sample of patients admitted to an acute geriatric ward with delirium over an eight-month period. DOS scale was administered to the patients within 48 h of delirium diagnosis to measure delirium severity. Univariate logistic regression analysis was performed to evaluate the correlation between DOS scale and adverse outcomes.

RESULTS: Fifty-nine patients were included in the study. There was a moderate correlation between increasing DOS scores and duration of delirium (r = 0.46, p < 0.001), as well as increasing DOS scores and decline in mobility on discharge (r = 0.35, p = 0.007). There was a weak correlation between increasing DOS scores and functional decline as measured by change in Katz Index from admission to discharge (r = -0.27, p = 0.04). No statistically significant correlations were found between DOS scores and in-hospital mortality, inpatient complication rates or discharge to higher level of care.

CONCLUSION: Delirium severity as measured by DOS scale may be useful in predicting delirium duration and decline in mobility and function on discharge. Further research with larger sample sizes is needed to establish if this finding can be replicated and whether delirium severity predicts additional adverse outcomes. Measuring delirium severity at diagnosis may be useful for communicating prognostic information to family members and setting expectations and treatment goals.