title: Patient-reported outcomes are associated with patient-oncologist agreement of performance status in a multi-ethnic Asian population.
abstract: OBJECTIVE
  This study aims to compare the performance status assessed by breast cancer patients and their oncologist and investigate the factors associated with the patient-oncologist disagreement in a multi-ethnic Asian population.
  
  
  METHODS
  This is a cross-sectional study of 270 female breast cancer patients in Singapore. Patients' performance status was rated by the patients and their treating oncologists. Patients were also asked to complete two instruments regarding their health status and health-related quality of life. The proportions of patients with assessment of performance status the same as and different from their oncologist were calculated. The level of agreement was quantified by Kappa statistics together with the confidence interval (CI). Multinomial logistic regression analyses were performed to examine potential factors associated with the patient-oncologist disagreement.
  
  
  RESULTS
  Approximately half (136/270) of the patients agreed with the oncologist in assessing performance status. Among the disagreeing half, 48 (17.8 %) patients rated better and 86 (31.9 %) poorer than the oncologists. The unweighted and quadratic-weighted Kappa statistics were, respectively, 0.21 (95 % CI = 0.13 to 0.29) and 0.34 (95 % CI = 0.26 to 0.42). Multivariable multinomial logistic regressions showed that outpatient, language used, and evidence of disease were associated with patients' better assessment than the oncologists, while age, physical well-being, and pain/discomfort were associated with patients' poorer assessment.
  
  
  CONCLUSIONS
  The patient-oncologist agreement was weak to moderate. When discrepant, patients tended to rate themselves worse than the oncologists assessed. Poorer assessment rated by patients was associated with their physical well-being. Patients who self-rated poorer may require further evaluation of any unobserved symptoms.
authors.affiliation: Center for Quantitative Medicine, Duke-NUS Graduate Medical School, Singapore, Singapore, chunfan.lee@scri.edu.sg.
authors.forename: Chun Fan
authors.initials: CF
authors.lastname: Lee
authors.forename: Raymond
authors.initials: R
authors.lastname: Ng
authors.forename: Nan
authors.initials: N
authors.lastname: Luo
authors.forename: Yin Bun
authors.initials: YB
authors.lastname: Cheung
mesh_terms: D000328:Adult; D001943:Breast Neoplasms / Q000208:ethnology / Q000523:psychology / Q000628:therapy; D003430:Cross-Sectional Studies; D005006:Ethnicity; D005260:Female; D006801:Humans; D017567:Karnofsky Performance Status; D016015:Logistic Models; D008875:Middle Aged; D063868:Patient Outcome Assessment; D010817:Physician-Patient Relations; D011788:Quality of Life; D018434:Sickness Impact Profile; D012846:Singapore / Q000453:epidemiology; D012959:Socioeconomic Factors