Predicting fitness for chemotherapy in older cancer patients.

Abstract

9516 Background: The Vulnerable Elders Survey-13 (VES-13) is increasingly used to screen for older patients who can proceed to intensive chemotherapy without further comprehensive assessment. This study compared the VES-13 determination of fitness for treatment with the oncologist's assessments of fitness. Methods: Sample: Consecutive series of solid tumour patients ≥65 years (n=175; M=72; range=65-86) from an Australian cancer centre. Patients were screened with the VES-13 before proceeding to usual treatment. Blinded to screening, oncologists concurrently predicted patient fitness for chemotherapy. A sample of 175 can detect, with 90% power, kappa coefficients of agreement between VES-13 & oncologists’ assessments >0.90 ("almost perfect agreement"). Separate backward stepwise logistic regression analyses assessed potential predictors of VES-13 & oncologists’ ratings of fitness. Results: Kappa coefficient for agreement between VES-13 & oncologists’ ratings of fitness was 0.41 (p<0.001). VES-13 & oncologists’ assessments agreed in 71% of ratings. VES-13 sensitivity = 83.3%; specificity = 57%; positive predictive value = 69%; negative predictive value = 75%. Logistic regression modelling indicated that the odds of being vulnerable to chemotherapy (VES-13) increased with increasing depression (OR=1.42; 95% CI: 1.18, 1.71) & decreased with increased functional independence assessed on the Bartel Index (OR=0.82; CI: 0.74, 0.92) & Lawton instrumental activities of daily living (OR=0.44; CI: 0.30, 0.65); RSquare=.65. Similarly, the odds of a patient being vulnerable to chemotherapy, when assessed by physicians, increased with increasing age (OR=1.15; CI: 1.07, 1.23) & depression (OR=1.23; CI: 1.06, 1.43), & decreased with increasing functional independence (OR=0.91; CI: 0.85, 0.98); RSquare=.32. Conclusions: Our data indicate moderate agreement between VES-13 & clinician assessments of patients’ fitness for chemotherapy. Current ‘one-step’ screening processes to determine fitness have limits. Nonetheless, screening tools do have the potential for modification & enhanced predictive properties in cancer care by adding relevant items, thus enabling fit patients to be immediately referred for chemotherapy.