Association between questionnaire- and accelerometer-assessed physical activity: the role of sociodemographic factors.
The correlation between objective and self-reported measures of physical activity varies between studies. We examined this association and whether it differed by demographic factors or socioeconomic status (SES). Data were from 3,975 Whitehall II (United Kingdom, 2012-2013) participants aged 60-83 years, who completed a physical activity questionnaire and wore an accelerometer on their wrist for 9 days. There was a moderate correlation between questionnaire- and accelerometer-assessed physical activity (Spearman's r = 0.33, 95% confidence interval: 0.30, 0.36). The correlations were higher in high-SES groups than in low-SES groups (P 's = 0.02), as defined by education (r = 0.38 vs. r = 0.30) or occupational position (r = 0.37 vs. r = 0.29), but did not differ by age, sex, or marital status. Of the self-reported physical activity, 68.3% came from mild activities, 25% from moderate activities, and only 6.7% from vigorous activities, but their correlations with accelerometer-assessed total physical activity were comparable (range of r 's, 0.21-0.25). Self-reported physical activity from more energetic activities was more strongly associated with accelerometer data (for sports, r = 0.22; for gardening, r = 0.16; for housework, r = 0.09). High-SES persons reported more energetic activities, producing stronger accelerometer associations in these groups. Future studies should identify the aspects of physical activity that are most critical for health; this involves better understanding of the instruments being used.
['Sabia|Séverine|S|', 'van Hees|Vincent T|VT|', 'Shipley|Martin J|MJ|', 'Trenell|Michael I|MI|', 'Hagger-Johnson|Gareth|G|', 'Elbaz|Alexis|A|', 'Kivimaki|Mika|M|', 'Singh-Manoux|Archana|A|']
D061725:Accelerometry D000368:Aged D000369:Aged, 80 and over D015331:Cohort Studies D003625:Data Collection D015444:Exercise D005260:Female D006306:Health Surveys D006801:Humans D008297:Male D008875:Middle Aged D057566:Self Report D012959:Socioeconomic Factors D011795:Surveys and Questionnaires D006113:United Kingdom
physical activity questionnaires accelerometry cohort studies elderly epidemiologic methods