Participants rated how often they engaged in four behaviors when outside on a sunny day: wearing sun screen with an Sun Protection Factor ≥ 30, wearing a long-sleeved shirt, wearing a wide-brimmed hat, and staying in the shade. Items were rated on a five-point Likert scale (1=never, 2= rarely, 3= sometimes, 4= often, 5=always). In this case, higher values are associated with more protection behaviors. Subscales were averaged to compute the total index score.

Defined as thoroughly examining each area of the body during the most recent skin self-check in the last 2 months.

Defined as thoroughly examining each area of the body during the most recent skin self-check in the past 4 months

Defined as thoroughly examining each area of the body during the most recent skin self-check in the past 6 months

Total number of SSEs performed (regardless of their thoroughness)

Total number of body areas examined during the most recent SSE in the last 2 months

Use of a mirror, having someone else help, or using a body mole map during the most recent SSE

Frequency (from 1 = never to 5 = always) of wearing sunscreen with an SPF ≥ 30, wearing a long-sleeved shirt, wearing a wide-brimmed hat, and staying in the shade

Total number of sunburns received

Frequency (from 1 = never to 5 = always) of wearing long pants

Frequency (from 1 = never to 5 = always) of wearing sunglasses

Frequency (from 1 = never to 5 = always) of spending time in the sun in order to get a tan

Level of distress (from 1 = not at all distressed to 10 = extremely distressed)

Mean rating of four questions regarding worry about melanoma recurrence

Mean rating of four questions regarding perceived risk of melanoma recurrence

Number of biopsies conducted

Number of times indoor tanned in the past year

Whether a new or recurrent skin cancer was diagnosed

Ineligibility rate and reasons, recruitment rate and reasons for refusal, differences in sociodemographic factors between study decliners and those recruited, dropout rate and reasons.

Receipt of a physician skin examination and the reason for the visit

Perceived Internet Impact and Effectiveness Questionnaire was used. This 20-item survey was used to measure the degree to which MSS helped the participant learn how to be prepared to conduct SSE and engage in sun protection behaviors as well as feel in control of his/her health and feel less worried about melanoma. A Likert scale was used for each question (1=not at all, 2=slightly, 3=somewhat, 4=mostly, 5=very). The scores from each question were averaged to compute the total scale score for each participant. The total scores for each participant were also averaged to find the overall average across MSS participants. Higher values represent greater effectiveness of the program.

This survey was only conducted among those who were randomized to MSS

Number of visits to the website, the number of monthly skin self-checks completed, the number of updates to the sun-safe action plan, and starting/completing the remaining sections of the website (Introduction; Getting Ready to Do a Skin Self-Check; Practice Sun-Safe Behaviors).

Internet Evaluation and Perceived Utility Questionnaire and the Internet Adherence Questionnaire was used. This 15-item survey assessed the program characteristics, including usefulness, convenience, ease of use, worry about privacy, ease of navigation, and satisfaction with the program. A Likert scale was used for each question (1=not at all, 2=slightly, 3=somewhat, 4=mostly, 5=very). The scores from each question were averaged to compute the total scale score for each participant. The total scores for each participant were also averaged to find the overall average across MSS participants. Higher values represent higher scores in terms of utility and evaluation of the program.

Only the participants randomized to the intervention arm completed this survey

Participants rated how often they engaged in four behaviors when outside on a sunny day: wearing sun screen with an Sun Protection Factor ≥ 30, wearing a long-sleeved shirt, wearing a wide-brimmed hat, and staying in the shade. Items were rated on a five-point Likert scale (1=never, 2= rarely, 3= sometimes, 4= often, 5=always). In this case, higher values are associated with more protection behaviors. Subscales were averaged to compute the total index score.

Participants rated how often they engaged in four behaviors when outside on a sunny day: wearing sun screen with an Sun Protection Factor ≥ 30, wearing a long-sleeved shirt, wearing a wide-brimmed hat, and staying in the shade. Items were rated on a five-point Likert scale (1=never, 2= rarely, 3= sometimes, 4= often, 5=always). In this case, higher values are associated with more protection behaviors. Subscales were averaged to compute the total index score.

Participants rated how often they engaged in four behaviors when outside on a sunny day: wearing sun screen with an Sun Protection Factor ≥ 30, wearing a long-sleeved shirt, wearing a wide-brimmed hat, and staying in the shade. Items were rated on a five-point Likert scale (1=never, 2= rarely, 3= sometimes, 4= often, 5=always). In this case, higher values are associated with more protection behaviors. Subscales were averaged to compute the total index score.