title: Measures of physical activity and their correlates: the Swedish National March Cohort.
abstract: We compared the results of self-estimates of physical activity obtained with a novel instrument (the Energy Expenditure Questionnaire, EEQ) to those obtained from questions typically asked in epidemiological investigations (reference method) in a cohort of 42,150 Swedish men and women, aged 18-94. In the EEQ, participants were asked to report total physical activity by estimating the total time during a typical day and night spent on different physical activity intensity levels from the lowest (corresponding to lying in bed, 0.9 Metabolic Energy Turnover; MET) to the highest, (exceeding the intensity of to shovelling snow by hand, i.e., >6 MET). As a comparison, they also estimated hours per week devoted to household chores, commuting and leisure time physical activities classified as; light, moderate and heavy. The average physical activity estimated with the EEQ was 1.36 MET or 32.6 METh/day or 2,341 kcal/day. In comparison, physical activity estimated with the reference method represented no more than 17% of this amount. The Spearman's correlation coefficient between the two measures was 0.26. Using EEQ, men reported significantly more physical activity than women (mean = 36.3 vs. 30.6 METh/day). Body mass index (BMI) > or = 25, education > or = 12 years, and age > or = 60 years were significantly associated with lower physical activity. Questions focusing on leisure time exercise and a few other selected activities provide estimates of activity that correlate poorly with self-reported total energy output from all physical activity and inactivity. Investigators need to be more explicit about which component of activity they investigate.
authors.affiliation: Unit of Clinical Epidemiology, Karolinska Institutet, T2, 17176 Stockholm, Sweden. ylva.trolle@ki.se
authors.forename: Ylva Trolle
authors.initials: YT
authors.lastname: Lagerros
authors.forename: Rino
authors.initials: R
authors.lastname: Bellocco
authors.forename: Hans-Olov
authors.initials: HO
authors.lastname: Adami
authors.forename: Olof
authors.initials: O
authors.lastname: Nyrén
mesh_terms: D000203:Activities of Daily Living; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001835:Body Weight; D015331:Cohort Studies; D004734:Energy Metabolism; D015444:Exercise; D005260:Female; D006801:Humans; D007899:Leisure Activities; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D012015:Reference Standards; D015203:Reproducibility of Results; D012650:Self Disclosure; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D013548:Sweden; D055815:Young Adult