Skin cancer is the most common form of cancer, with over a million new cases diagnosed annually in the United States [
1]. The prevalence of melanoma, the deadliest form of skin cancer, has been increasing over the past 30 years [
2] and is now the second most common cancer among women in their twenties [
3]. However, skin cancers are largely preventable with engagement in recommended protective practices, such as limiting ultraviolet radiation (UV) exposure, wearing sun-protective clothing, and using sunscreen. Long-term use of sunscreen is associated with decreased risk of non-melanoma skin cancers [
4]. Results of research studies examining the association between sunscreen use and melanoma risk have been mixed [
4,
5]. However, these studies have typically been limited by a number of methodological issues, including retrospective reports of sunscreen use and the use of non-randomized designs. The results of a recent prospective randomized controlled trial of sunscreen use found a lower incidence of invasive melanoma among individuals assigned to a sunscreen intervention compared to those in the control condition [
6]. Promoting routine sunscreen use as a component of skin protection is a critical aspect of public health approaches designed to reduce the incidence of skin cancer [
7].
Skin protection is especially important for children and adolescents. Early intense exposure to UV radiation is associated with higher rates of skin cancer [
8-
12], and regular sunscreen use during childhood and adolescence could reduce lifetime incidence of non-melanoma skin cancers by approximately 78% [
13]. Adolescence, in particular, is a critical period for skin cancer prevention because adolescents and young adults have the lowest skin protection rates of all age groups [
14], receive large amounts of UV radiation [
15-
17], and increase their UV exposure habits as they move into adulthood and are less influenced by their parents [
10,
18]. In 2003, only 14% of US high school students reported routine sunscreen use [
19]. In some cases, higher risk adolescents are less likely to protect their skin. For example, White Hispanic high school students in Miami, Florida were twice as likely to never or rarely wear sunscreen as non-White Hispanics [
20]. While several interventions have been found to produce short-term increases in sunscreen use among children, their long-term effect among adolescents is questionable [
18]. Thus, it is important to better understand the factors underlying adolescents' use of sunscreen and other skin protection behaviors so that we can intervene more effectively with those at highest-risk of developing skin cancer.
Fishbein's Integrative Model (IM; [
21]) provides a comprehensive theoretical framework to describe the relationships among variables predicting adolescents' skin protection intentions and behavior. Drawing from several empirically-validated health behavior theories, the IM includes multiple categories of predictor variables, including: background/individual difference variables, beliefs, norms, self-efficacy, intentions, contextual factors, and behavior. The beliefs category includes behavioral outcome beliefs, defined as beliefs about the consequences of performing the behavior (i.e., what will happen if I apply sunscreen), and outcome evaluations, defined as subjective evaluations or favorability of these consequences. Norms can include prototypes (evaluation of the typical person who engages in the behavior) and subjective norms (the extent to which associates engage in the behavior), as well as motivation to comply with these norms. Self-efficacy includes perceived control over the behavior and self-efficacy to perform the behavior. Contextual factors include environmental cues to engaging in the behavior. These beliefs, norms, self-efficacy, and cues contribute to behavioral intentions, which in turn influence behavior.
Prior research studies have identified associations between adolescent skin protection including sunscreen use and several variables drawn from the IM; however, no prior study has evaluated the full IM within the same study and sample. In terms of
background and individual difference variables, factors that have been found to be associated with greater sunscreen use among adolescents include white race, female gender, younger age, higher skin sensitivity, greater knowledge of sun protection recommendations, and a family history of skin cancer [
22-
25].
Behavioral beliefs associated with adolescent sunscreen use include a preference for natural/light skin, greater perceived benefits of sun protection, believing that it is not worth burning to get a tan, and perceiving shorter sun exposures as "safer" than longer ones [
24].
Normative factors linked with adolescents' use of sunscreen include sunscreen information and modeling by friends, parental information provision and insistence on sunscreen use, and receipt of sun protection advice from health care providers [
24].
Self-efficacy for skin protection is one of the variables that has been found to be most strongly associated with engagement in skin cancer protection, including among adolescents and young adults [
26-
29]. Perceived behavioral control over skin protection has also been found to be associated with skin protection [
30]. No prior study has examined the association between sunscreen use and sunscreen-related
cues or availability. The only IM construct that we did not include in this study was skills, since we did not expect there to be much variability in perceived skill level for sunscreen application. Among adolescents and young adults, skin protection
intentions are associated with skin protection
behaviors including sunscreen use [
31-
35].
The purpose of the current study was to determine which of the IM constructs are most closely associated with sunscreen use among adolescent high school students. Based on prior research, we expected that background/individual differences, beliefs, norms, and self-efficacy would all contribute to adolescent sunscreen use. However, in the current study, we included several novel variables within these domains that have not been investigated previously among high school students. These variables included beliefs about general health (i.e., health consciousness), sunscreen user prototype, as well as body image self-efficacy and emotional coping self-efficacy. Additionally, although not previously included in sun protection research, we expected cues and availability to be related to sunscreen use. Finally, we expected that intentions to use sunscreen would mediate the relationships between the IM variables and sunscreen use.