American Journal of Epidemiology Advance Access originally published online on November 13, 2006
American Journal of Epidemiology 2007 165(2):222-230; doi:10.1093/aje/kwk004
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PRACTICE OF EPIDEMIOLOGY |
Comparison of Self-reported Lifetime Sun Exposure with Two Methods of Cutaneous Microtopography
1 Department of Public Health Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
2 Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
3 Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, Ontario, Canada
4 Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
Correspondence to Dr. Julia Knight, Samuel Lunenfeld Research Institute, Mount Sinai Hospital, 60 Murray Street, Box 18, Toronto, Ontario M5T 3L9, Canada (e-mail: knight{at}mshri.on.ca).
There is currently no "gold standard" for measuring lifetime sun exposure. Exploration of alternatives to self-reports is important for examining illnesses related to ultraviolet light exposure. Using skin replicas obtained from 184 controls in a breast cancer case-control study (Toronto, Ontario, Canada, 2004–2005), the authors compared self-reported indicators of lifetime sun exposure with two measures of cutaneous microtopography, the Beagley-Gibson system and skin line counts. With the Beagley-Gibson system, significantly increased odds ratios were found for age (odds ratio (OR) = 1.10, 95% confidence interval (CI): 1.05, 1.16), spending 7 days outside per week during the summer (OR = 3.33, 95% CI: 1.48, 7.50), and lifetime number of sunlamp sessions. Significantly decreased odds ratios were found for having darker skin, ever giving birth, and ever using sunlamps. With the skin line count approach, significant positive associations were found for age (OR = 2.31, 95% CI: 1.23, 4.35), age squared, duration of working in outdoor jobs (OR = 0.88, 95% CI: 0.79, 0.98), and average number of outdoor activities per week at ages 20–29 years (OR = 1.05, 95% CI: 1.00, 1.10). While the Beagley-Gibson method was associated with more variables than the skin line count method, both methods require further refinement before graded skin replicas can be recommended as a substitute for self-report measures.
data collection; questionnaires; skin; sunlight; validation studies [publication type]
Abbreviations: CI, confidence interval; ICC, intraclass correlation coefficient; OR, odds ratio