title: Incidental and Planned Exercise Questionnaire for seniors: validity and responsiveness.
abstract: OBJECTIVE
  This study assessed the criterion validity and responsiveness of the Incidental and Planned Exercise Questionnaire (IPEQ) specifically developed for aging research.
  
  
  METHODS
  The sample comprised 315 community-dwelling inactive older adults (mean age = 73.2 yr) who participated in a trial investigating the effect of a walking program on falls. At baseline, a subsample (n = 177) also wore an accelerometer (ActiGraph GT1M) for 7 d, and 126 of those had four valid days or more of accelerometer data. Validity coefficients (Spearman ρ) were calculated between accelerometer counts per minute, average steps per day, average moderate- to vigorous-intensity physical activity (MVPA) using two cut points (760 and 1041 counts per minute), and IPEQ-MVPA (the sum of physical activity hours per week derived from nine IPEQ items excluding the indoor chores question). Responsiveness was the mean IPEQ change in the intervention group divided by the SD of the mean change in control group.
  
  
  RESULTS
  The correlation coefficients between IPEQ-MVPA and counts per minute per day and steps per day were 0.33 and 0.31, respectively. The coefficients with accelerometer MVPA at low and medium cut points were 0.29 and 0.33, respectively, and 0.26 and 0.35 for walking. The Bland-Altman plot showed increased errors with higher values of IPEQ-MVPA. IPEQ incidental physical activity questions and IPEQ as a whole were significantly correlated with accelerometer light intensity (100-760 counts per minute, ρ = 0.29 and 0.23). The 12-month responsiveness of total IPEQ was 0.30 and 0.44 for the "planned walking" item.
  
  
  CONCLUSIONS
  IPEQ provides a practical and valid measure of MVPA in surveillance and intervention studies. Incidental activities are mostly of a light-intensity nature, and their low ambulatory component may explain the lower correlation between IPEQ as a whole and accelerometer measures.
authors.affiliation: 1School of Science and Health, University of Western Sydney, Campbelltown, AUSTRALIA; 2Neuroscience Research Australia (NeuRA), University of NSW, Sydney, AUSTRALIA; 3School of Public Health, University of Sydney, Sydney, AUSTRALIA; 4Health Promotion Service, Clinical Support Division (Western), Sydney, AUSTRALIA; 5Centre for Health Advancement, NSW Health Department, Liverpool, AUSTRALIA; and 6Department of Public and Occupational Health, EMGO Institute for Health and Care Research, VU University Medical Centre, Amsterdam, THE NETHERLANDS.
authors.forename: Dafna
authors.initials: D
authors.lastname: Merom
authors.forename: Kim
authors.initials: K
authors.lastname: Delbaere
authors.forename: Robert
authors.initials: R
authors.lastname: Cumming
authors.forename: Alex
authors.initials: A
authors.lastname: Voukelatos
authors.forename: Chris
authors.initials: C
authors.lastname: Rissel
authors.forename: Hidde P
authors.initials: HP
authors.lastname: Van Der Ploeg
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Lord
mesh_terms: D061725:Accelerometry; D000203:Activities of Daily Living; D000368:Aged; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011795:Surveys and Questionnaires; D016138:Walking