Linda S Cook1, Bevin L Moon1, Yan Dong1, Heather K Neilson2. 1. 1 Division of Epidemiology and Biostatistics, Department of Internal Medicine, MSC10 5550, 1 University of New Mexico, Albuquerque, NM 87131-0001, USA. 2. 2 Alberta Health Services, Calgary, Alberta, Canada.
Abstract
OBJECTIVE: To assess the inter-method reliability of the Ovarian Cancer in Alberta (OVAL) survey developed to estimate adult vitamin D exposure from sun and diet for every tenth year, against the longer Geraldton Skin Cancer Prevention Survey (the assumed 'gold standard'). We also estimated total vitamin D exposure using the OVAL survey. DESIGN: A randomized crossover design to assess the inter-method reliability of sun exposure (OVAL v. Geraldton survey), using intra-class correlation and estimated total vitamin D exposure from sun and diet. SETTING: Calgary, Alberta, Canada. SUBJECTS:Randomly selected women (n 90) aged 40-79 years. RESULTS: The average lifetime sun exposure of 13,913 h (average 411 h/year) from the Geraldton survey was not significantly different from the 13,034 h (average 385 h/year) from the OVAL survey for periods with sufficient UV radiation to stimulate vitamin D production. The intra-class correlation coefficient for average lifetime sun exposure was 0.77 (95% CI 0.69, 0.86); the annual average was 0.60 (95% CI 0.47, 0.74). Estimated vitamin D from diet and supplements increased with age. CONCLUSIONS: Our OVAL survey reliably estimated adult sun exposure relative to the Geraldton survey, suggesting that assessing sun exposure every tenth year is a reliable and efficient method for estimating sun contributions to lifetime vitamin D exposure.
RCT Entities:
OBJECTIVE: To assess the inter-method reliability of the Ovarian Cancer in Alberta (OVAL) survey developed to estimate adult vitamin D exposure from sun and diet for every tenth year, against the longer Geraldton Skin Cancer Prevention Survey (the assumed 'gold standard'). We also estimated total vitamin D exposure using the OVAL survey. DESIGN: A randomized crossover design to assess the inter-method reliability of sun exposure (OVAL v. Geraldton survey), using intra-class correlation and estimated total vitamin D exposure from sun and diet. SETTING: Calgary, Alberta, Canada. SUBJECTS: Randomly selected women (n 90) aged 40-79 years. RESULTS: The average lifetime sun exposure of 13,913 h (average 411 h/year) from the Geraldton survey was not significantly different from the 13,034 h (average 385 h/year) from the OVAL survey for periods with sufficient UV radiation to stimulate vitamin D production. The intra-class correlation coefficient for average lifetime sun exposure was 0.77 (95% CI 0.69, 0.86); the annual average was 0.60 (95% CI 0.47, 0.74). Estimated vitamin D from diet and supplements increased with age. CONCLUSIONS: Our OVAL survey reliably estimated adult sun exposure relative to the Geraldton survey, suggesting that assessing sun exposure every tenth year is a reliable and efficient method for estimating sun contributions to lifetime vitamin D exposure.
Authors: Nigel T Brockton; Stephanie J Gill; Stephanie L Laborge; Alexander H G Paterson; Linda S Cook; Hans J Vogel; Carrie S Shemanko; David A Hanley; Anthony M Magliocco; Christine M Friedenreich Journal: BMC Cancer Date: 2015-07-10 Impact factor: 4.430