Prognostic significance of patient-physician disagreement about performance status in patients with advanced cancer
9021 Background: Physician-reported performance status (PS) is an important prognostic factor in advanced malignancies and is a commonly used stratification variable in cancer clinical trials. However, the extent, predictors, and prognostic importance of disagreement in PS assessment between physicians and patients have not been examined. Methods: Using NCCTG clinical trials from 1987–1990 (J Clin Oncol 19(15):3539–3546, 2001), we analyzed the difference and agreement of PS (ECOG and Karnofsky [KPS]) and nutritional status assessments reported by physicians and patients individually. The degree of disagreement was analyzed using paired t-test. Overall mortality was estimated by Kaplan-Meier method. The effect of disagreement on overall survival was analyzed by Cox regression. Independent predictors of disagreement were identified by logistic regression. Results: 1,636 patients with advanced lung and colorectal cancer had a median survival of 9.8 months (95% CI, 9.4 to 10.4). Percent agreement between patients and physicians about KPS, ECOG PS, and appetite/nutritional status was 32.9%, 43.4% and 42.0% respectively. Physicians were more likely to rate patients better than individual patients were to rate themselves: ECOG (Mean 0.91 vs 1.30, p<.0001), KPS (Mean 83.3 vs. 81.7, p<0.0001), appetite/nutritional status (Mean 1.6 vs. 2.1, p<0.0001). Inability to work, depression and less than a high school education were independently associated with disagreement. An increased risk of death was observed for patient and physician disagreement on KPS (HR=1.15, 95% CI, 1.03 to 1.27 p=0.01) and appetite/nutritional status (HR=1.39, 95% CI, 1.26 to 1.54 p<0.0001). Conclusions: Patients and physicians frequently disagree about patient PS, with physicians tending to rate patients higher than patients do themselves. Baseline patient demographic factors that independently predict disagreement have been identified. Disagreement confers an increased risk of death in the setting of advanced malignancies. These findings illustrate limitations of physician-only assessed PS. No significant financial relationships to disclose.