Table 4.

Estimates for differences between intervention and control groups and mean ratings, standard errors and sample sizes by condition on measures of knowledge, attitudes, social norms, and self-efficacy expectations.

Variable	Control	Intervention	Estimate	pvalue	Effect size
Knowledge:
Number correct out of 10 items	6.65	8.07	−1.42	<0.0001	0.84
	0.14	0.14	0.18
	733	879
Attitudes toward suntanning:
Importance of a tan	2.02	1.92	0.10	0.0013	0.16
	0.027	0.024	0.037
	787	938
Perceived attractiveness of a tan	3.28	3.07	0.21	<0.0001	0.22
	0.035	0.032	0.047
	772	916
Desire to have a tan	3.22	2.94	0.28	0.0026	0.27
	0.045	0.042	0.061
	767	917
I think I have a chance of getting skin Cancer	2.83	2.79	0.04	0.4321	0.04
	0.033	0.030	0.046
	779	926
Barriers to sun protection:
It is hard to choose the right sunscreen	2.53	2.36	0.17	0.0317	0.17
	0.050	0.047	0.067
	778	928
Sunscreens irritate my skin	2.11	1.96	0.15	0.0771	0.15
	0.057	0.055	0.076
	772	912
Sunscreens are messy	2.93	2.69	0.24	0.0035	0.23
	0.051	0.048	0.069
	782	929
Sunscreens aren’t in a place that’s easy to get to	2.48	2.39	0.07	0.2267	0.09
	0.051	0.048	0.069
	781	926
I have to stop what I’m doing to put on sunscreen	3.34	3.28	0.06	0.2937	0.05
	0.040	0.37	0.056
	781	925
Barriers to sunscreen use composite (α =0.47)	2.51	2.36	0.15	0.0046	0.24
	0.035	0.034	0.047
	792	941
Don’t like how I look in a hat	2.71	2.55	0.16	0.0024	0.15
	0.039	0.036	0.054
	775	924
It’s too hot to wear long sleeves & pants in the summer	4.25	4.09	0.16	0.0055	0.14
	0.041	0.037	0.056
	776	914
There aren’t enough places that provide Shade	2.96	2.88	0.08	0.3544	0.08
	0.066	0.064	0.087
	784	929
If I stay out of the sun I will miss out on activities	3.43	3.38	0.05	0.5167	0.04
	0.052	0.049	0.070
	786	933
A hat messes up my hair	3.44	3.35	0.09	0.2508	0.08
	0.054	0.051	0.073
	781	925
Barriers to other sun protection composite	3.42	3.34	0.08	0.0662	0.14
	0.028	0.026	0.038
	793	941
Social norms for sun protection:
If I stay out of the sun, my friends will think I’m weird	2.65	2.54	0.09	0.1547	0.09
	0.051	0.048	0.070
	779	919
My friends will think I’m weird if I wear a hat	1.86	1.83	0.03	0.6352	0.03
	0.034	0.032	0.047
	764	916
If I wear long sleeves/pants, my friends will think I’m weird	3.26	3.27	−0.01	0.9261	0.01
	0.049	0.045	0.067
	772	924
My friends will make fun of me if I wear a hat	1.98	1.94	0.04	0.4943	0.05
	0.046	0.043	0.062
	782	927
Social norms composite (mean of above 4 items)	2.44	2.40	0.04	0.4331	0.05
	0.030	0.029	0.042
	793	941
Self-efficacy expectations for sun protection:
I can use a sunscreen of SPF 15 or more	2.38	2.57	−0.19	0.0069	0.29
	0.044	0.043	0.058
	778	928
I can stay out of the sun between 10 and 3	1.75	1.81	−0.04	0.2929	0.08
	0.037	0.035	0.050
	783	930
I can wear long sleeves and pants	1.53	1.56	−0.03	0.5442	0.05
	0.044	0.042	0.057
	754	919
I can tell my friends if I don’t want to Sunbathe	2.43	2.46	−0.03	0.5841	0.04
	0.035	0.034	0.048
	780	930
Self efficacy composite (mean of above 4 items)	2.02	2.10	−0.08	0.0577	0.18
	0.029	0.028	0.038
	785	932