Methodological approaches to estimate physical resilience in older adults: a comparison across two clinical settings.

Agreement between the three physical resilience methodological approaches was poor to moderate across both clinical settings.

• Agreement was assessed using Cohen's kappa across the phenotype, expected recovery, and adapted ageing approaches.
• Cohen's kappa values ranged from κ = -0.10 to 0.64 across comparisons.
• The range indicates that different approaches identified substantially different patient groups as physically resilient.
• The two cohorts studied were older adults receiving chemotherapy (TENT, n=330) and those presenting with acute illness at the emergency department (APOP, n=2111).

All three physical resilience approaches showed only moderate discriminative ability for 12-month mortality.

• AUC values for 12-month mortality ranged from 0.55 to 0.69 across approaches and cohorts.
• Performance was assessed across both the TENT cohort (median age 75 years; 43% female) and the APOP cohort (median age 78 years; 54% female).
• Discriminative ability was measured using area under the curve (AUC).
• The moderate AUC values indicate limited ability to distinguish patients who would die within 12 months from those who would not.

All three physical resilience approaches showed only moderate discriminative ability for a composite endpoint of functional decline, quality of life decline, or mortality at 12 months.

• AUC values for the composite outcome ranged from 0.52 to 0.66 across approaches and cohorts.
• The composite endpoint included functional decline, quality of life decline, or mortality at 12 months.
• Physical functioning was assessed using Katz Activities of Daily Living and Lawton Instrumental Activities of Daily Living scales.

Physical resilience approaches provided limited added discrimination beyond simple predictors such as functional score at follow-up and age.

• Functional score at follow-up achieved AUC values of 0.65–0.69 for the outcomes studied.
• Age alone achieved AUC values of 0.48–0.67.
• The physical resilience approaches (AUC 0.52–0.69) did not substantially outperform these simple predictors.
• This finding suggests the resilience approaches do not add meaningful prognostic information beyond basic clinical variables.

The TENT cohort comprised 330 older adults receiving chemotherapy and the APOP cohort comprised 2111 older adults presenting with acute illness at the emergency department.

• TENT cohort: median age 75 years, 43% female.
• APOP cohort: median age 78 years, 54% female.
• The two cohorts represented distinct clinical contexts to enable cross-setting comparison of resilience approaches.
• Outcomes were assessed at 12 months in both cohorts.

The authors concluded that current physical resilience approaches may inadequately capture the dynamic construct of physical resilience, and that higher-frequency longitudinal measures may better quantify physical resilience for clinical practice.

• The phenotype approach measured functional change after the health stressor.
• The expected recovery approach compared actual to predicted recovery based on clinical characteristics.
• The adapted ageing approach assessed baseline function relative to expected levels given clinical risk profile.
• The authors suggested higher-frequency longitudinal measures as a potential methodological improvement.