Background Delirium, a neuropsychiatric syndrome that occurs throughout medical illness trajectories, is frequently misdiagnosed. The Memorial Delirium Assessment Scale (MDAS) is a commonly used tool in palliative care (PC) settings. Our objective was to establish and validate the Memorial Delirium Assessment Scale‐Thai version (MDAS‐T) in PC patients. Materials and Methods The MDAS was translated into Thai. Content validity, inter‐rater reliability, and internal consistency were explored. The construct validity of the MDAS‐T was analyzed using exploratory factor analysis. Instrument testing of the MDAS‐T, the Thai version of the Confusion Assessment Method for the Intensive Care Unit (CAM‐ICU‐T), and the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition as the gold standard was performed. The receiver operating characteristic (ROC) curve was used to determine the optimal cutoff score. The duration of each assessment was recorded. Results The study enrolled 194 patients. The content validity index was 0.97. The intraclass correlation coefficient and Cronbach's α coefficient were 0.98 and 0.96, respectively. A principal component analysis indicated a homogeneous, one‐factor structure. The area under the ROC curve was 0.96 (95% confidence interval [CI], 0.93–0.99). The best combination of sensitivity and specificity (95% CI) of the MDAS‐T were 0.92 (0.85–0.96) and 0.90 (0.82–0.94), respectively, with a cutoff score of 9, whereas the CAM‐ICU‐T yielded 0.58 (0.48–0.67) and 0.98 (0.93–0.99), respectively. The median MDAS‐T assessment time was 5 minutes. Conclusion This study established and validated the MDAS‐T as a good and feasible tool for delirium screening and severity rating in PC settings. Implications for Practice Delirium is prevalent in palliative care (PC) settings and causes distress to patients and families, thereby making delirium screening necessary. This study found that the MDAS‐T is a highly objective and feasible test for delirium screening and severity monitoring in PC settings and can greatly improve the quality of care for this population.

Purpose The aim of this study is to establish the prevalence, associated factors, and clinical impact of delirium in newly referred palliative care patients and the percentage of delirium diagnoses missed by primary medical teams. Methods Newly referred palliative care patients were evaluated and were reviewed for possible associated factors of delirium. Univariable and multivariable analysis were used to identify associated factors. Median overall survival and survival curves were analyzed. The percentage of missed diagnosis in IPD patients was identified. Results We included 350 palliative care patients. Nearly all patients had cancer diagnosis (96.6%). The overall prevalence of delirium was 44.0%. The independent associated factors of delirium were age ≥ 63 years (adjusted odds ratio [aOR], 7.0; 95% CI, 2.2–22.9), palliative performance scale ≤ 20% (aOR, 54.5; 95% CI, 13.1–228.0), brain metastasis (aOR, 15.6; 95% CI, 3.7–66.7), urinary tract infection (aOR, 18.8; 95% CI, 4.7–75.5), sepsis (aOR, 59.0; 95% CI, 4.4–797.8), hyponatremia (aOR, 8.8; 95% CI, 2.6–29.8), and hypercalcemia (not applicable). Interestingly, opioids and benzodiazepines were not associated with delirium. Delirious patients had significantly shorter survival (median survival 11 days). Delirium diagnoses were missed for 76.1%. Conclusion Nearly half of the palliative care patients had delirium, which was associated with noticeably short survivals. We identified the independent factors associated with the delirium. Despite having a remarkably high prevalence rate and being a well-known poor prognostic factor, there was still a very high rate of missed delirium diagnoses. Effective, routine, delirium screening of palliative care patients needs to be emphasized.