BMC Public Health 2009, 9:340 http://www.biomedcentral.com/1471-2458/9/340 Table 2: Prevalence of self-reported acne (quite a lot and very much) across mental distress, diet, lifestyle and socio-demographic factors among 1672 boys and 2103 girls in a cross-sectional study in Oslo, Norway (n = 3775). Whole sample Mental distress Diet Soft drinks with sugar Raw vegetables Fat fish Chocolate/sweets Potato chips Lifestyle Cigarette smoking Alcohol intake Socio-demographic factors Ethnicity Income 95% confidence interval No Yes Often Seldom Often Seldom Seldom Often Seldom Often Seldom Often Yes, daily Yes, but has quit or sometimes No, never Often Seldom Western Non-Western >1.0 million NOK 0.5-1.0 million NOK < 0.5 million NOK Acne Males N 1612 1371 229 405 1196 597 1011 1482 123 1124 484 1361 246 281 450 878 715 882 1143 322 335 729 282 14.4% (12.7-16.1) 13.4% (11.6-15.2) 20.5% (15.3-25.7) 13.8% (10.4-17.2) 14.7% (12.7-16.7) 12.7% (10.0-15.4) 15.2% (13.0-17.4) 14.1% (12.3-15.9) 16.3% (9.8-22.8) 13.0 (11.0-15.0) 17.3 (13.9-20.7) 13.6 (11.8-15.4) 18.3 (13.5-23.1) 13.2% (9.2-17.2) 14.4% (11.2-17.6) 14.8% (12.4-17.2) 12.7% (10.3-15.1) 15.6% (13.2-18.0) 14.5% (12.5-16.5) 14.0% (10.2-17.8) 13.1% (9.5-16.7) 14.5% (11.9-17.1) 14.9% (10.7-19.1) Females N 2043 12.8% (11.4-14.3) 1327 701 177 1836 999 1043 1918 115 1379 659 1804 234 418 577 1042 710 1294 1441 454 388 905 428 9,6% (8.0-11.2) 18.8% (15.9-21.1) 11.9% (7.1-16.7) 13.0% (11.5-14.5) 10.8% (8.9-12.7) 14.7% (12.5-16.9) 12.4% (10.9-13.9) 17.4% (10.5-24.3) 11.7 (10.0-13.4) 15.2 (12.5-17.9) 12.5 (11.0-14.0) 14.5% (10.0-19.0) 10.5% (7.5-13.5) 13.0% (10.3-15.7) 13.5% (11.4-15.6) 10.8% (8.5-13.1) 13.7% (11.8-15.6) 10.8% (9.2-12.4) 18.5% (14.9-22.1) 8.2% (5.5-10.9) 12.2% (10.1-14.3) 17.1% (13.5-20.7) ing the mean score of HSCL-10 in the four categories of acne, the mean score increased for each category when acne became more severe (Figure 1). Five different dietary variables were included in the anal- yses as possible confounders. In the crude analyses among the males, acne was associated with the consumption of chocolate/sweets with an OR = 1.40 (95%CI: 1.01-1.94) and the consumption of potato chips with an OR = 1.54 (95%CI: 1.03-2.29). However, these associations disap- peared in the adjusted model. In the crude analyses among the females, low consumption of raw vegetables was associated with acne with an OR = 1.41 (95%CI: 1.05- 1.90) and this association remained significant also in the adjusted model with OR = 1.38 (95% CI: 1.01-1.88). (Table 3). No other significant associations between acne and diet were identified, but there was a tendency that acne was more prevalent among those with a high intake of fatty fish. Regarding lifestyle factors, the prevalence of acne was a lit- tle lower among those who smoke cigarettes and among the adolescents who frequently consume alcohol. This was seen in both genders, but these findings are non-sig- nificant (Table 2). Socio-demographic factors were associated with acne among the females in the crude model, but not among the males. Among the females, a non-Western background was associated with acne with an OR = 1.77 (95%CI 1.27- 2.45), but this association did not remain significant in the adjusted model. Females from low-income families had more acne as seen in Table 2 and the association in the crude model showed an OR = 2.14 (95%CI: 1.36- 3.35). Other models with different combinations of the varia- bles used in the adjusted analyses were tried out, but none of these altered the estimated association between acne Page 4 of 8 (page number not for citation purposes)