title: Associations of objectively assessed physical activity and sedentary time with health-related quality of life among colon cancer survivors.
abstract: BACKGROUND
  The primary purpose of this study was to determine associations of accelerometer-assessed moderate- to vigorous-intensity physical activity (MVPA) and sedentary time with health-related quality of life (HRQoL) and physical function and well-being in colon cancer survivors.
  
  
  METHODS
  Colon cancer survivors (N = 178) from Alberta, Canada (n = 92) and Western Australia (n = 86) completed a mailed survey that assessed HRQoL (Functional Assessment of Cancer Therapy-Colorectal), physical function and well-being (Trial Outcome Index-Colorectal), and relevant covariates. MVPA and sedentary time were assessed using the Actigraph GT3X+ accelerometer (60-second epochs) via a 7-day monitoring protocol. Average daily MVPA and sedentary time was corrected for wear time and then examined as quartiles.
  
  
  RESULTS
  Adjusting for relevant demographic, behavioral, and clinical covariates, a significant difference in HRQoL scores emerged between quartile 1 (Q1) and Q4 (M(diff) = 11.5, P = .038). For physical function and well-being, a significant difference emerged between Q1 and Q4 (M(diff) = 9.1, P = .009). For fatigue, a significant difference emerged between Q1 and Q4 (M(diff) = 7.1, P = .05). Significant differences were also observed for between Q1 and Q3 (M(diff) = 2.4, P = .041), and Q1 and Q4 (M(diff) = 3.5, P = .002) for colorectal cancer-specific symptoms. There were no statistically significant associations of sedentary time with HRQoL, physical function and well-being, fatigue, or colorectal cancer-specific symptoms.
  
  
  CONCLUSIONS
  Objectively measured MVPA, but not sedentary time, was associated with better HRQoL, physical function and well-being, and colorectal cancer-specific symptoms in colon cancer survivors. For MVPA, differences met or exceeded contemporary cutpoints for determining clinically important differences.
authors.affiliation: Faculty of Health Disciplines, Athabasca University, Athabasca, Canada.
authors.forename: Jeff K
authors.initials: JK
authors.lastname: Vallance
authors.forename: Terry
authors.initials: T
authors.lastname: Boyle
authors.forename: Kerry S
authors.initials: KS
authors.lastname: Courneya
authors.forename: Brigid M
authors.initials: BM
authors.lastname: Lynch
mesh_terms: D000368:Aged; D001315:Australia / Q000453:epidemiology; D015992:Body Mass Index; D002170:Canada / Q000453:epidemiology; D003110:Colonic Neoplasms / Q000473:pathology / Q000523:psychology* / Q000628:therapy; D015444:Exercise / Q000502:physiology*; D005221:Fatigue / Q000209:etiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D011379:Prognosis; D011788:Quality of Life / Q000523:psychology*; D012042:Registries; D012307:Risk Factors; D057185:Sedentary Behavior; D011795:Surveys and Questionnaires; D017741:Survivors
keywords: accelerometer; health-related quality of life; physical activity; sedentary time