Measuring Total and Domain-Specific Sitting: A Study of Reliability and Validity

• Published in: Medicine and science in sports and exercise 2010-06, Vol.42 (6), p.1094-1102
• Main Authors: MARSHALL, Alison L, MILLER, Yvette D, BURTON, Nicola W, BROWN, Wendy J
• Format: Article
• Language: English
• Subjects: Aged; Biological and medical sciences; Female; Fundamental and applied biological sciences. Psychology; Humans; Leisure Activities - classification; Male; Medical Records; Middle Aged; Monitoring, Ambulatory; Sedentary Lifestyle; Space life sciences; Surveys and Questionnaires; Vertebrates: body movement. Posture. Locomotion. Flight. Swimming. Physical exercise. Rest. Sports
• ISSN: 0195-9131; 1530-0315
• DOI: 10.1249/MSS.0b013e3181c5ec18

Although independent relationships between sitting behaviors (mainly television viewing) and health outcomes have been reported, few studies have examined the measurement properties of self-report sitting questions. This study assessed gender-specific test-retest reliability and validity of a questionnaire that assessed time spent sitting on weekdays and weekend days: 1) traveling to and from places, 2) at work, 3) watching television, 4) using a computer at home, and 5) for leisure, not including television. Test-retest reliability of domain-specific sitting time (min x d(-1)) on weekdays and weekend days was assessed using data collected on two occasions (median = 11 d apart). Validity of domain-specific self-reported sitting time on weekdays and weekend days was assessed against log data and sedentary accelerometer data. Complete repeat questionnaire and log data were obtained from 157 women (aged 51-59 yr) and 96 men (aged 45-63 yr). Reliability coefficients were high for weekday sitting time at work, watching television, and using a computer at home (r = 0.84-0.78) but lower for weekend days across all domains (r = 0.23-0.74). Validity coefficients were highest for weekday sitting time at work and using a computer at home (r = 0.69-0.74). With the exception of computer use and watching television for women, validity of the weekend-day sitting time items was low. This study confirms the importance of measuring domain- and day-specific sitting time. The measurement properties of questions that assess structured domain-specific and weekday sitting time were acceptable and may be used in future studies that aim to elucidate associations between domain-specific sitting and health outcomes.