Critically ill patients with cancer who develop delirium have a higher risk of dying in the hospital or intensive care unit (ICU), according to a study published in JCO Oncology Practice.

Researchers found that cancer patients with delirium had a more than 5-fold greater risk of in-hospital mortality and a more than 10-fold greater risk of dying in the ICU, when compared with cancer patients who did not develop delirium.

The study included 915 critically ill cancer patients who were admitted to a cancer center between January and December 2018. The median age of the patients was 64.9 years, 43.8% were women, 78.0% had metastatic disease, and 6.0% had central nervous system (CNS) involvement. The most common cancer types were hematologic (25.7%), gastrointestinal (20.9%), thoracic (13.8%), and genitourinary (9.6%) cancers.

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Delirium screening was performed twice daily using the Confusion Assessment Method for the ICU, which is designed to assess acute fluctuations in mental status, inattention, disorganized thinking, and altered levels of consciousness. 

A total of 371 patients (40.5%) had delirium. In a multivariate analysis, there were several factors associated with a higher risk of delirium, including:

  • Older age (odds ratio [OR], 1.01; 95% CI, 1.00-1.02; P =.038)
  • Longer pre-ICU hospital length of stay (OR, 1.04; 95% CI, 1.02-1.06; P <.001)
  • Not being resuscitated on admission (OR, 2.18; 95% CI, 1.07-4.44; P =.032)
  • Higher Mortality Probability Model II score (OR, 1.02; 95% CI, 1.01-1.02; P <.001)
  • Neurologic diagnosis (OR, 2.84; 95% CI, 1.69-4.79; P <.001)
  • Mechanical ventilation (OR, 2.67; 95% CI, 1.84-3.87; P <.001)
  • CNS involvement (OR, 2.25; 95% CI, 1.20-4.20; P =.011).

The median length of ICU stay was significantly longer for patients with delirium than for those without it — 6.0 days and 3.0 days, respectively (P <.001). The median length of hospital stay was significantly longer as well — 20.0 days and 12.0 days, respectively (P <.001).

The rate of ICU mortality was significantly higher for patients with delirium than for those without it — 24.0% and 2.6%, respectively (P <.001). In a multivariate analysis, delirium was independently associated with an increased risk of death in the ICU (OR, 10.75; 95% CI, 5.91-19.55; P <.001).

Likewise, the rate of in-hospital mortality was significantly higher for patients with delirium than for those without it — 45.3% and 11.0%, respectively (P <.001). Delirium was independently associated with an increased risk of in-hospital mortality (OR, 5.84; 95% CI, 4.03-8.46; P <.001).

“[O]ur analysis demonstrates that ICU delirium is very common in critically ill patients with cancer and is associated with increased ICU and hospital mortality and increased ICU and hospital LOS [length of stay],” the researchers wrote. “Critical care specialists should perform systematic screening for delirium in patients with cancer admitted to the ICU and implement early mitigating interventions to prevent delirium and shorten its duration.”

Disclosures: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.


Tao J, Seier K, Marasigan-Stone CB, et al. Delirium as a risk factor for mortality in critically ill patients with cancer. JCO Oncol Pract. Published online February 21, 2023. doi:10.1200/OP.22.00395