L 163 - 2013-14 - Bilag 4: Opfølgende materiale modtaget af Kræftens Bekæmpelse og Børnerådet i forlængelse af foretræde den 10. april 2014

Determinants of sunbed use in a population of DanishadolescentsJoan Bentzena, Anne F. Krarupa, Ida-Marie Castbergb, Poul D. Jensencand Anja PhilipaIn Denmark, melanoma is the most common type of cancerin individuals aged 15–34 years. Ultraviolet radiation fromsunbeds is a risk factor for melanoma. Knowledge of thecharacteristics of sunbed users is important in thedevelopment and implementation of prevention strategiesof sunbed use. The objective of this study was to examinesunbed use and its association with smoking, parentalsocioeconomic status (SES), friends’ attitudes towardsartificial tanning, and school environment amongadolescents aged 14–18 years at continuation schools inDenmark. We conducted a survey among adolescents inDanish continuation schools in 2011. We examined sunbeduse and its association with age, smoking, friends’attitudes towards artificial tanning, parental SES, andshared environment of the continuation school, usinglogistic regression. Within the past 12 months, 38% of thepupils had used a sunbed (70% girls and 28% boys). Therewas no difference in sunbed use according to age.Smoking and friends’ positive attitudes towards, andhigher use of sunbeds were associated with increased useof sunbeds. High SES of mothers’ was associated withlower odds for sunbed use among girls. The association ofschool environment with sunbed use was modestcompared with the other variables. Adolescents incontinuation schools report a higher use of sunbeds thanDanish adolescents as such. Educational interventionsshould be targeted at preteens, as sunbed use is commonin 14-year-olds. Special educational tools are tested in thecontinuation school environment and may prove effectivein this population.European Journal of Cancer Preventionc22:126–130 2013 Wolters Kluwer Health | LippincottWilliams & Wilkins.European Journal of Cancer Prevention2013,22:126–130Keywords: adolescents, continuation school, melanoma, risk factor,socioeconomic status, sunbedDanish SunSmart Campaign,bDocumentation Unit andcAdolescents &Smoking, Department of Prevention and Documentation, Danish Cancer Society,Copenhagen, DenmarkCorrespondence to Joan Bentzen, PhD, Danish SunSmart Campaign,Department of Prevention and Documentation, Danish Cancer Society,Strandboulevarden 49, DK-2100 Copenhagen, DenmarkTel: + 45 3525 7735; fax: + 45 3525 7701; e-mail: [email protected]Received6 June 2012Accepted2 July 2012a

IntroductionThe incidence of melanoma (world standardized inci-dence rate per 100 000) for men and women aged15–34 years in Denmark increased from 2.6 and 4.5 in1974–1978 to 8.1 and 18.8 in 2006–2010, respectively(Engholmet al.,2010). Consequently, melanoma hasbecome the most common type of cancer in this agegroup. Exposure to natural and artificial ultravioletradiation is an important risk factor for melanoma, and aworking group convened by the International Agency forResearch on Cancer (IARC) raised the classification ofthe use of ultraviolet radiation-emitting tanning devicesto ‘carcinogenic to humans’. The IARC reported recentlythat first exposure to sunbeds before the age of 35increases the risk for melanoma by 75% (IARC, 2006),and a study in Australia estimated that 76% of melanomasin individuals who had ever used a sunbed and receivedtheir diagnosis between 18 and 29 years of age wereattributable to sunbed use (Custet al.,2010).Sunbed use is highly prevalent in adolescents inDenmark and other countries, especially among girls(Cokkinideset al.,2002; Lazovichet al.,2005; Kosteret al.,2009; Krarupet al.,2011; Mayeret al.,2011). To developc0959-8278 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins

and implement prevention strategies towards the use ofsunbeds in adolescents, it is important to know moreabout the characteristics of the users. Previous studieshave found that sunbed use in adolescents is associatedwith an unhealthy lifestyle in terms of, for example,smoking and alcohol consumption (Schneideret al.,2010), a lower socioeconomic status (SES) (Demkoet al.,2003; Mayeret al.,2011), and peers’ attitudestowards artificial tanning (Lazovichet al.,2004; Mayeret al.,2011).In Denmark, continuation schools are an alternative tothe ordinary primary schools. Approximately 15% of thepupils in grades 8, 9, and 10 (aged 14–17 years) attendcontinuation schools each year in Denmark. Continuationschools offer a unique environment for social interactionas pupils live at the school. However, this schoolenvironment has also been shown to lead to a higher riskof smoking among the pupils (Jensenet al.,2010).It can be assumed that the same high-risk behaviorexists for sunbed use.The aim of this study was to examine the prevalence ofsunbed use among adolescents at continuation schools inDOI: 10.1097/CEJ.0b013e3283581934

A postal survey was conducted among 6059 pupils aged14–18 years attending 56 continuation schools inDenmark in September 2010 (the beginning of the newschool year). The survey was distributed to the schools,where the pupils used a school lesson to complete thequestionnaire, which was then collected and returned bythe school. Ninety-one percent of the pupils (n=5509)completed the survey. The 56 schools were chosenrandomly among schools, where smoking was eitherprohibited for both employees and pupils (n=26) orallowed indoors and/or outdoors for both employees andpupils (n=30). The schools were thus a representativesample of all Danish continuation schools with strong orweak smoking policies, but the pupils were not necessa-rily representative of all Danish adolescents. The samplesize was based on power calculations on smokingprogression in schools with different smoking policies.The survey covered the subjects of smoking habits,sunbed use, friends’ use and attitudes towards sunbeds,and parents’ SES, divided into nine categories accordingto the definitions prepared by R. Krølner and B.E.Hostein (2006, personal communication) (see Table 1 forcategories).The number of times the respondent had used a sunbedin the past 12 months was dichotomized into sunbed usein the past 12 months (number > 1) or no use in the past12 months (number = 0). The dichotomous variable wastreated as an outcome variable.Smokers were defined as those who smoked at least oncea week. Age was coded as 14, 15, 16, 17 or 18 years orolder. Pupils rated whether they ‘Strongly agree’, ‘Agree’,‘Disagree’, ‘Strongly disagree’ or ‘Do not know’ to thequestions ‘Most people I know use a sunbed’, and ‘Myfriends think that a sunbed tan is most attractive’. Thecategories ‘Strongly agree’ and ‘Agree’ were combinedinto a ‘Yes’ category and the categories ‘Strongly disagree’and ‘Disagree’ were combined into a ‘No’ category.Smoking status, age, mothers’ and fathers’ SES, andschool were used as independent variables.The study was approved by the Danish Data ProtectionAgency (registration number 2010-41-4450).Statistical analyses

SexGirlBoyMissingAge (years)1415161718> 18MissingSunbed use at least once the last 12 monthsYesNoMissingMother’s SESAcademic occupation, managers and owners of largecorporationsHighly skilled occupation, team leaders, business ownersOccupation requiring specialist knowledge, small businessownersSkilled manual occupation, low-level white collar workerUnskilled occupationEconomically active, but unclassifiable into codes 1–5Economically inactiveUnclassifiableMissingFather’s SESAcademic occupation, managers and owners of largecorporationsHighly skilled occupation, team leaders, business ownersOccupation requiring specialist knowledge, small businessownersSkilled manual occupation, low-level white collar workerUnskilled occupationEconomically active, but unclassifiable into codes 1–5Economically inactiveUnclassifiableMissingSmoking at least once a weekYesNoMissing

the past year. Sunbed use was more common among girls(70%) than boys (28%) (data not shown). Hence, furtheranalyses are stratified on sex.Table 2 shows the unadjusted and adjusted OR forsunbed use according to age, smoking, friends’ attitudestowards sunbed use, and parents’ SES stratified on sex.Smokers had a three- to four-fold risk of being sunbedusers compared with nonsmokers. The risk of being asunbed user for girl smokers was slightly higher than thatfor boys. Friends’ views on having a sunbed tan and havingpeers who use sunbeds were associated with a two- tothree-fold risk of using a sunbed. However, among girls,the association between having peers who use sunbedsand sunbed use was not significant after adjustment.The associations between mothers’ and fathers SES andsunbed use were different in boys and girls. Sunbed usewas not associated with parents’ SES after adjusting forother explanatory variables in boys. In girls, sunbed use wassignificantly associated with their mothers’ SES, whereasfathers’ SES was not associated with sunbed use afteradjustment. Age was not associated with sunbed use.The MOR for the random effect of schools on sunbed usewas 1.44 for boys and 1.49 for girls.

DiscussionIn our study of pupils aged 14–18 years in continuationschools in Denmark, we found that 38% had used asunbed at least once in the past year (70% girls and 28%boys). This number is in agreement with two previousDanish studies from 2008, where 43–44% in the agegroups 15–18 and 15–19 years had used a sunbed in theprevious year (Kosteret al.,2011; Krarupet al.,2011), witha much higher prevalence among girls than boys.However, sunbed use has decreased in this age groupsince 2008 in Denmark. In 2009, 33% of 15–19 year oldshad used a sunbed in the previous year (Kosteret al.,2011) and in 2010 this number decreased to 21% (Darsøet al.,2011, summary in English). Apparently, this markeddecrease in sunbed use has not occurred amongadolescents in continuation schools. This indicates thatpupils at continuation schools may have a special andunhealthy lifestyle compared with the rest of the youthpopulation in Denmark. Continuation schools have beenconsidered a high-risk environment for smoking andsmoking initiation (Jensenet al.,2010), and this high-riskenvironment may even include sunbed use.In contrast to other studies, we did not find that older agewas associated with a higher prevalence of sunbed use in

Odds for sunbed use stratified according to sexGirlsUnadjusted OR[95% CI]Adjusted OR[95% CI]1.1 [0.9–1.6]Reference1.1 [0.9–1.4]0.6 [0.3–1.2]Reference4.5 [3.2–6.1]Reference1.9 [1.5–2.5]Reference1.2 [1.0–1.5]Reference2.2 [1.2–4.4]2.3 [1.1–4.6]2.8 [1.4–5.5]2.7 [1.3–5.4]2.3 [1.1–4.7]2.5 [1.3–5.0]2.7 [1.0–6.9]Reference1.2 [0.7–2.0]1.5 [0.8–2.5]1.6 [0.9–2.7]1.3 [0.7–2.2]1.5 [0.8–2.7]1.0 [0.5–1.8]1.3 [0.7–2.4]Unadjusted OR[95% CI]1.1 [0.8–1.6]Reference1.0 [0.8–1.2]0.9 [0.6–1.5]Reference2.8 [2.2–3.5]Reference3.2 [2.4–4.3]Reference2.8 [2.3–3.5]Reference1.2 [0.7–2.0]0.9 [0.5–1.7]1.7 [1.0–2.9]1.5 [0.8–2.6]1.6 [0.9–2.7]1.3 [0.8–2.4]1.8 [0.9–3.8]Reference2.1 [1.1–4.0]2.2 [1.2–4.3]2.9 [1.5–5.3]2.1 [1.1–4.0]2.1 [1.1–4.1]2.5 [1.2–4.9]3.2 [1.6–6.5]BoysAdjusted OR[95% CI]1.2 [0.7–1.8]Reference1.1 [0.8–1.4]1.1 [0.6–2.0]Reference2.9 [2.2–4.0]Reference2.5 [1.8.-3.6]Reference1.8 [1.4–2.4]Reference0.9 [0.5–1.7]0.8 [0.4–1.8]1.1 [0.5–2.1]1.0 [0.5–2.1]1.3 [0.6–2.6]0.9 [0.4–1.9]1.1 [0.4–3.1]Reference1.4 [0.7–2.9]1.3 [0.6–2.7]1.7 [0.8–3.4]1.4 [0.7–2.9]1.2 [0.6–2.6]1.4 [0.6–3.2]1.5 [0.7–3.5]

Age14151617 +Smoking at least once a weekNoYesMy friends think a sunbed tan is most attractiveNoYesMost people I know use a sunbedNoYesMother’s SESAcademic occupation, managers and owners of large corporationsHighly skilled occupation, team leaders, business ownersOccupation requiring specialist knowledge, small business ownersSkilled manual occupation, low level white collar workerUnskilled occupationEconomically active, but unclassifiable into codes 1–5Economically inactiveUnclassifiableFather’s SESAcademic occupation, managers and owners of large corporationsHighly skilled occupation, team leaders, business ownersOccupation requiring specialist knowledge, small business ownersSkilled manual occupation, low-level white collar workerUnskilled occupationEconomically active, but unclassifiable into codes 1–5Economically inactiveUnclassifiableCI, confidence interval; OR, odds ratio; SES, socioeconomic status.

the adolescents (Boldemanet al.,2003; Demkoet al.,2003; Krarupet al.,2011; Mayeret al.,2011). Thisindicates that youths at continuation schools behavedifferently from their peers outside the continuationschool system and that the transition from nonusers tosunbed users may occur earlier in adolescents attractedby continuation schools. This could be a consequence or apremise of the increased demand for independence thatgoing to a continuation schools requires, that is, beingaway from parents and the home environment for aprolonged period of time.The differences in sunbed use between adolescents atcontinuation schools and other adolescents could also beascribed to differences in the mode of data collection andquestions used. In this study, data were collected usingtraditional surveys distributed and collected at therespondents’ schools and we had a very high responserate (91%). Data on sunbed use from adolescents inDenmark have mainly been collected using either websurveys or postal questionnaires, with lower response rates(around 30%). Data on sunbed use in these surveys werecollected using a question where the respondents shouldindicate their use of a sunbed in the previous 12 monthsby choosing one of seven different answers (‘Have used asunbed several times a week/once a week/several times amonth/once a month/four times or less in the previousyear/Not in the previous year, but have used a sunbedearlier/Have never used a sunbed’), whereas in this studyin the continuation school, pupils had to write the numberof times they had used a sunbed in the previous year. It ispossible that this study, with its higher response rate, hasgathered responses from adolescents not reached by ourweb and postal surveys, and that this study in continuationschools therefore monitors sunbed use among adolescentsmore precisely than the population-based surveys. How-ever, the previous population-based surveys were repre-sentative of the Danish population for the age group 15 +in terms of sex and geographical region of residence, whichthis continuation-based survey is not. Also, it is possiblethat the differences in how questions on sunbed use arephrased may have influenced the data collection.In our study, smoking was heavily associated with sunbeduse in both girls and boys, which is in agreement withearlier observations that have linked adverse healthbehavior in other areas to problematic UV exposure(Boldemanet al.,1997; Demkoet al.,2003; O’Riordanet al.,2006; Miyamotoet al.,2012). Sunbed use was alsoassociated with friends’ attitudes towards sunbed andtheir perceived behavior. Similar results have beenreported in other studies (Lazovichet al.,2004).This study uses detailed information about the SES ofboth mothers and fathers. We found differences in theassociation between SES and sunbed use between girlsand boys. Having a mother with a lower social class thanthe top (i.e. with academic occupation, managers, and

owners of large corporations) was associated with a two-fold risk of sunbed use among the adolescent girls. Weobserved no gradient in this risk; the OR for sunbed usein other social classes were all slightly above 2 anduniform among all seven groups. Fathers’ SES was notstatistically significantly associated with girls’ or boys’sunbed use after adjustment for other explanatoryvariables. In addition, mothers’ SES was not associatedwith sunbed use among boys either before or afteradjustment.Previous studies have also found parents’ social status to beassociated with sunbed use in children (Demkoet al.,2003; Strykeret al.,2004). For example, Mayeret al.(2011)found that children whose parents had a college degree hada 25% less risk of having used a sunbed in the past 12months compared with children of parents with lowereducation. Mayeret al.(2011) did not report on sexdifferences among parents or children. That girls’ sunbeduse is more strongly associated with their mothers’ SEScompared with their fathers may not be surprising, as girlsmost likely see their mother as the primary role model inthe family. What may seem more surprising is the lack of agradient in the association of sunbed use and SES. Onecould expect that the lowest SES (e.g. women outside thelabor market) would be more strongly associated withadolescent sunbed use as is seen in, for example, smoking,but this was not the case. This may indicate that sunbeduse is not considered as an unhealthy behavior that isavoided by the higher social classes as is the case withsmoking (Hiscocket al.,2012). There was no difference inthe OR for girls’ sunbed use between women with, forexample, highly skilled occupation, manual occupation, andno occupation. Only having a mother in the highest socialclass was associated with decreased sunbed use among thegirls. This may be because mothers with this SES has a lowlevel of sunbed use themselves and this reflects theirdaughters’ sunbed use [sunbed use by parents has beenassociated with sunbed use in their children in previousstudies (Cokkinideset al.,2002)]. The association may alsobe explained by families in this high social class going onvacations to sunny destinations more often than others andthat the girls therefore have a ‘natural’ tan and thus have noneed for using sunbeds to get a tan. However, this does notexplain why we did not observe the same effect for boys.School-level effect as measured by the MOR was modestcompared with the individual ORs for the explanatoryvariables, which makes sense, as the data were collectedat the beginning of the school year, where the commonenvironmental factors associated with the school may notyet have been overtly present.Strengths and limitations of study

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