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Christian MS, Evans CE, Hancock N, Nykjaer C, Cade JE.Christian MS, et al.J Epidemiol Community Health. 2013 Apr;67(4):332-8. doi: 10.1136/jech-2012-201604. Epub 2012 Dec 19.J Epidemiol Community Health. 2013.PMID: 23254183Clinical Trial.