title: The Functionality Assessment Flowchart (FAF): a new simple and reliable method to measure performance status with a high percentage of agreement between observers.
abstract: BACKGROUND
  Performance status (PS) assessment is an integral part of the decision-making process in cancer care. Karnofsky Performance Status (KPS) and Eastern Cooperative Oncology Group (ECOG) PS are the most widely used tools. In some studies, the absolute agreement rate of these tools between observers has been moderate to low. The present study aimed to evaluate the inter-observer reliability and construct validity of the new Functionality Assessment Flowchart (FAF) and compare it with ECOG PS and KPS in a sample of cancer patients.
  
  
  METHODS
  The patients were recruited by convenience from the waiting rooms of the Breast and Gynecology Ambulatory in a cross-sectional study. Two trained medical students (observer A) and five medical oncologists (observers B) independently rated women according to the ECOG PS, KPS and FAF. After the determining the PS scores, observer A administered the Functional Assessment of Cancer Therapy-Fatigue (FACT-F) questionnaire to the participants. The agreements between observers A and B were investigated using the absolute agreement rate (%), weighted and unweighted kappa and Spearman's correlation test. For construct validity, the PS scores were correlated with functional and fatigue scores by performing correlation analysis.
  
  
  RESULTS
  Eighty women with a median age of 57 years were included in the study (86% accrual rate). Among these women, 39 (48.8%) had advanced cancer. The overall absolute agreement rate between observers was 49.4% for KPS, 67% for ECOG PS, and 78.2% for FAF. When using unweighted kappa values, the inter-observer reliability was "fair", "moderate" and "substantial" for KPS, ECOG PS and FAF, respectively. However, when using weighted kappa statistics, "substantial" agreement was observed for KPS and ECOG PS and "nearly perfect" agreement was observed for FAF. All of the PS scales correlated very well with the functional and fatigue scores.
  
  
  CONCLUSIONS
  We present a new instrument with moderate to high inter-observer agreement and adequate construct validity to measure PS in cancer patients.
authors.affiliation: Department of Clinical Oncology, Barretos Cancer Hospital, Pio XII Foundation, Barretos, São Paulo, Brazil. drcarlosnap@gmail.com.|Health-Related Quality of Life Research Group (GPQual), Barretos Cancer Hospital, Pio XII Foundation, Barretos, São Paulo, Brazil. drcarlosnap@gmail.com.|Center for Research Support - NAP, Barretos Cancer Hospital, Pio XII Foundation, Barretos, São Paulo, Brazil. drcarlosnap@gmail.com.|Departamento de Oncologia Clínica, Divisão de Mama e Ginecologia, Rua Antenor Duarte Vilella, 1331, Bairro Dr Paulo Prata, CEP: 14784-400, Barretos, SP, Brazil. drcarlosnap@gmail.com.
authors.forename: Carlos Eduardo
authors.initials: CE
authors.lastname: Paiva
authors.affiliation: Barretos School of Health Sciences, Dr. Paulo Prata - FACISB, Barretos, São Paulo, Brazil. felipe_siquelli@hotmail.com.
authors.forename: Felipe Augusto Ferreira
authors.initials: FA
authors.lastname: Siquelli
authors.affiliation: Barretos School of Health Sciences, Dr. Paulo Prata - FACISB, Barretos, São Paulo, Brazil. henriqueamorim@alunos.facisb.edu.br.
authors.forename: Henrique Amorim
authors.initials: HA
authors.lastname: Santos
authors.affiliation: Department of Clinical Oncology, Barretos Cancer Hospital, Pio XII Foundation, Barretos, São Paulo, Brazil. marina_srs@hotmail.com.
authors.forename: Marina Moreira
authors.initials: MM
authors.lastname: Costa
authors.affiliation: Department of Clinical Oncology, Barretos Cancer Hospital, Pio XII Foundation, Barretos, São Paulo, Brazil. daniellaramone@gmail.com.
authors.forename: Daniella Ramone
authors.initials: DR
authors.lastname: Massaro
authors.affiliation: Department of Clinical Oncology, Barretos Cancer Hospital, Pio XII Foundation, Barretos, São Paulo, Brazil. domiciolacerda@hotmail.com.
authors.forename: Domício Carvalho
authors.initials: DC
authors.lastname: Lacerda
authors.affiliation: Department of Clinical Oncology, Barretos Cancer Hospital, Pio XII Foundation, Barretos, São Paulo, Brazil. joaosoaresnunes@gmail.com.|Health-Related Quality of Life Research Group (GPQual), Barretos Cancer Hospital, Pio XII Foundation, Barretos, São Paulo, Brazil. joaosoaresnunes@gmail.com.
authors.forename: João Soares
authors.initials: JS
authors.lastname: Nunes
authors.affiliation: Department of Clinical Oncology, Barretos Cancer Hospital, Pio XII Foundation, Barretos, São Paulo, Brazil. crispeixoto10@hotmail.com.
authors.forename: Cristiano
authors.initials: C
authors.lastname: de Pádua Souza
authors.affiliation: Health-Related Quality of Life Research Group (GPQual), Barretos Cancer Hospital, Pio XII Foundation, Barretos, São Paulo, Brazil. bsrpaiva@gmail.com.|Center for Research Support - NAP, Barretos Cancer Hospital, Pio XII Foundation, Barretos, São Paulo, Brazil. bsrpaiva@gmail.com.
authors.forename: Bianca Sakamoto Ribeiro
authors.initials: BS
authors.lastname: Paiva
mesh_terms: D000328:Adult; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000453:epidemiology* / Q000503:physiopathology; D003657:Decision Making; D005260:Female; D006801:Humans; D017567:Karnofsky Performance Status / Q000592:standards*; D008875:Middle Aged; D015588:Observer Variation; D011379:Prognosis; D011795:Surveys and Questionnaires / Q000592:standards