title: Comparison of Subjective and Objective Measures of Sedentary Behavior Using the Yale Physical Activity Survey and Accelerometry in Patients With Rheumatoid Arthritis.
abstract: Sedentary behavior is associated with increased risk of functional decline and disability. Individuals with rheumatoid arthritis (RA) spend more time sedentary than healthy adults. Self-reported assessment of sedentary behavior has not been well-developed in this patient population.
  
  
  
  172 adults with RA wore an accelerometer for 7 days and completed a modified version of the Yale Physical Activity Survey (YPAS). YPAS-derived sedentary estimates included 1) daily sitting categories (<3, 3 to 6, 6 to 8, >8 hours/day), 2) continuous daily sedentary time calculated by subtracting hours spent sleeping or in physical activity from a 24-hour day, and 3) rank order of YPAS-derived continuous daily sedentary time. Each estimate was compared with objective accelerometer-derived sedentary time using linear regression and Bland-Altman analysis.
  
  
  
  A significant relationship was observed between accelerometer-derived sedentary time and all 3 estimates. Bland-Altman plot demonstrated systematic bias, however Bland-Altman plot of rank-order demonstrated that the ranked YPAS-derived continuous estimate was an unbiased predictor of ranked accelerometer sedentary time though limits of agreement were wide.
  
  
  
  This patient-reported approach using the YPAS shows promise to be a useful tool to identify the most sedentary patients. Providing a practical and accurate tool may increase the frequency sedentary behavior is assessed by clinicians.
authors.affiliation: Division of Rheumatology, Northwestern University Feinberg School of Medicine, Chicago, IL.
authors.forename: Abigail L
authors.initials: AL
authors.lastname: Gilbert
authors.forename: Jungwha
authors.initials: J
authors.lastname: Lee
authors.forename: Madeleine
authors.initials: M
authors.lastname: Ma
authors.forename: Pamela A
authors.initials: PA
authors.lastname: Semanik
authors.forename: Loretta
authors.initials: L
authors.lastname: DiPietro
authors.forename: Dorothy D
authors.initials: DD
authors.lastname: Dunlop
authors.forename: Rowland W
authors.initials: RW
authors.lastname: Chang
mesh_terms: D061725:Accelerometry; D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy; D002641:Chicago; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D011237:Predictive Value of Tests; D011594:Psychometrics; D015203:Reproducibility of Results; D057185:Sedentary Behavior; D057566:Self Report; D011795:Surveys and Questionnaires; D013995:Time