Demographic, medical and behavioral characteristics according to photoaging severity.

Values are expressed as means (SD) or percentages. Differences in demographic, medical and behavioral characteristics between photoaging grades were examined using analysis of variance for continuous variables (age) and the chi2 test for categorical variables.*Due to possible missing values the sum of the cell frequencies can be smaller than the total indicated in the top of the columns.†France has been arbitrarily divided in north and south using the northern frontier of Aquitaine, Limousin, Auvergne, and Rhône-Alpes regions.‡MHT: menopausal hormone therapy.