Life-sustaining therapy limitation in critical illness: unequal weights of demographics, disease severity, and comorbidities.

OBJECTIVE

To identify independent clinical predictors of life-sustaining treatment limitation in critically ill adults and to quantify their relative contribution across predefined conceptual domains.

METHODS

We conducted a retrospective cohort study including all adults admitted to a tertiary medical-surgical intensive care unit in Brazil between May 2016 and May 2020. Patients with documented life-sustaining treatment limitations (withholding or withdrawal) were compared with those who received full treatment. Multivariable logistic regression was used to identify independent predictors of life-sustaining treatment limitation, and predictors were grouped into conceptual domains to assess their relative contributions.

RESULTS

Among 6,725 intensive care unit admissions, 336 patients (5.0%) had documented life-sustaining treatment limitation. Compared with patients without limitation, those with life-sustaining treatment decisions were older (median 77 versus 67 years; p < 0.001), more frequently frail (Clinical Frailty Scale ≥ 5: 7.6% versus 3.1%; p = 0.002), and had more metastatic cancer (15.6% versus 5.8%; p < 0.001). Independent predictors of life-sustaining treatment limitation included age ≥ 80 years (OR 2.08; 95%CI 1.32 - 3.28), frailty (OR 2.37; 95%CI 1.53 - 3.71), metastatic cancer (OR 2.38; 95%CI 1.53 - 3.71), medical admission (OR 1.86; 95%CI 1.02 - 3.40), higher SAPS 3 scores (OR 1.02 per point; 95%CI 1.01 - 1.03), and prolonged mechanical ventilation (OR 5.78 for ≥10 days). The presence of any organ support was inversely associated with life-sustaining treatment limitation (OR 0.69; 95%CI 0.49 - 0.97). When predictors were aggregated into conceptual domains and evaluated using Wald χ² proportions, acute illness severity and life-suppor-related variables accounted for approximately 45% of the model signal, followed by demographic factors (≈38%) and chronic comorbidities (≈17%).

CONCLUSION

Life-sustaining treatment limitation decisions in critically ill adults are influenced by frailty, comorbidities, and acute severity. Grouping predictors into conceptual domains enhances interpretability and may support more structured and transparent decision-making frameworks in intensive care unit settings.