Predictors of Delirium in Corticosteroid-Treated Patients with Advanced Cancer: An Exploratory, Multicenter, Prospective, Observational Study

Background: Corticosteroids are often used to treat fatigue and anorexia, but occasionally produce delirium. Information on the predictors of delirium in corticosteroid-treated cancer patients remains limited. Objective: To identify potential factors predicting the development of delirium in corticosteroid-treated cancer patients. Design: An exploratory, multicenter, prospective, observational study. Setting/Subjects: Inclusion criteria for this study were patients who had metastatic or locally advanced cancer and a fatigue or anorexia intensity score of 4 or more on a 0-10 Numerical Rating Scale. Measurement: Univariate and multivariable analyses were performed to identify the predictors of delirium diagnosed by the Confusion Assessment Method (CAM) within three days of initiation of corticosteroids. Results: Among 207 patients administered corticosteroids, 35 (17%; 95% confidence interval [CI] 12%-23%) developed at least one episode of delirium diagnosed by the CAM. Factors predictive of the development of delirium were as follows: Palliative Performance Scale ≤20, Eastern Cooperative Oncology Group Performance Status (ECOG PS) = 4, the Support Team Assessment Schedule (STAS) score of drowsiness >1, concurrent opioid use, parenteral hydration volume ≤500 mL, and the absence of lung metastasis. A multivariable analysis identified the independent factors predicting responses as ECOG PS = 4 (odds ratio [OR] 4.0; 95% CI 1.7-9.3), STAS score of drowsiness >1 (OR 3.4; 95% CI 1.4-8.2), and concurrent opioid use (OR 3.7; 95% CI 1.0-13). Conclusion: Delirium in corticosteroid-treated advanced cancer patients may be predicted by PS, drowsiness, and concurrent opioid use. Larger prospective studies are needed to confirm these results.