Back to Annual Meeting Page		American Public Health Association 133rd Annual Meeting & Exposition December 10-14, 2005 Philadelphia, PA

Abstract #114194

Miguel Camões, Milton Severo, Ana C. Santos, Carla Lopes, and Henrique Barros. Hygiene and Epidemiology, University of Porto Medical School, Alameda Prof. Hernani Monteiro, Porto, 4200-319, Portugal, +351225507597, mcamoes@med.up.pt

BACKGROUND: Heterogeneity on reporting physical activity between seasons is a normal concern in epidemiological studies when the aim is obtain information representing the usual activity. OBJECTIVE: Evaluate seasonal variation on self-report physical activity behaviours of Porto adults. METHODS: A random digit dialling sample of 953 participants of EpiPorto study in 2001-2004, habitants of Porto (347 males and 606 females) aged 18-92 years, was evaluated using a structured questionnaire reporting social, demographic and anthropometric characteristics. Physical activity was assessed using a questionnaire designed to estimate usual individual daily energy expenditure, detailing the intensity and duration of sleeping hours, professional, domestic and leisure-time activities during the previous year, and was quantified as metabolic equivalent per hour (MET-hours/day). Trigonometric linear models were used to estimate the amplitude (A) in reporting activity during the different months of the year. 95% Credibility intervals (CI) were calculated: Bayesian inference. RESULTS: In both genders, after adjustment for trend, age, body mass index and education, no yearly variation was found for different types of activities evaluated, except for leisure time and professional activities in males (A=1.8, 95%CI: 0.7-2.9 and A=5.1, 95%CI: 1.3-9.3, respectively). For total physical activity, a higher variation was found for males (A=3.0, 95%CI: 0.7-5.8) than for females (A=1.6, 95%CI: 0.4-3.0) and the variation coefficient (amplitude/median value) represented 8.0% in males and only 4.0% in females. CONCLUSION: These data suggest no different yearly variation on reporting usual total physical activity with the exception of leisure time activities in males, which need to be considered carefully.

Learning Objectives:

• Discuss the importance of evaluate seasonal variation on reporting usual physical activity
• Describe the statistical model applied to detect the yearly variation on physical activity assessment

Keywords: Physical Activity, Assessments

Presenting author's disclosure statement:

Not Answered

Recorded presentation