Document Classification

Section Type: METHODS

Text: Two groups were studied : (1) randomly selected nonclinical subjects (77 men, M + / - SD age : 44. 4 + / - 18. 3 years ; 140 women, M + / - SD age : 41. 9 + / - 15. 3 years) from Ann Arbor, Michigan (replication of an earlier shopping mall-based survey) ; and (2) women (N = 54) who were concerned about their aging appearance (18 women with mild to moderate skin aging, M + / - SD age : 41 + / - 4 years ; 36 women with moderate to severe skin aging, M + / - SD age : 62 + / - 6 years) and had volunteered for 24-week, prospective, controlled studies evaluating the efficacy of topical retinoic acid versus placebo for the treatment of aging skin.