Design and methods for a cluster randomized trial of the Sunless Study: A skin cancer prevention intervention promoting sunless tanning among beach visitors

This cluster randomized trial will examine whether a beach-based intervention that promotes sunless tanning as a substitute for sunbathing and includes sun damage imaging and sun safety recommendations is superior to a questionnaire only control group in reducing sunbathing frequency. Female beach visitors (N = 250) will be recruited from 2 public beaches in eastern Massachusetts. Beach site will be the unit of randomization. Follow-up assessment will occur at the end of the summer (1-month following intervention) and 1 year later. The primary outcome is average sunbathing time per week. The study was designed to provide 90% power for detecting a difference of .70 hours between conditions (standard deviation of 2.0) at 1-year with an intra-cluster correlation coefficient of 0.01 and assuming a 25% rate of loss to follow-up. Secondary outcomes include frequency of sunburns, use of sunless tanning products, and sun protection behavior.Interventions might be improved by promoting behavioral substitutes for sun exposure, such as sunless tanners, that create a tanned look without exposure to UVR.NCT00403377Ultraviolet radiation (UVR) from the sun is linked to more cancers worldwide than any other carcinogen.[1] Because skin cancer, the most prevalent cancer in the US [2], is largely attributable to UV exposure, it is largely preventable [3,4]. Prevention via avoidance of UVR seems like a simple solution, but rates of unprotected sun exposure remain quite high [5].The belief that a suntan enhances physical attractiveness is a strong predictor of prolonged unprotected sun exposure [6-10]. Tanned images in the media play a big role in reinforcing the value of a tanned appearance [11]. The social norm for the attractiveness of a tanned appearance is difficult to change given the: 1) long history of this belief in the American culture, and 2) the number of tanned media images saturating the public [12]. Individuals who value being tan have been particularly resistant to educa