Table 5. Regression coefficients for change in log benzophenone-3 concentrations according to frequency of sunscreen use, stratified by age (n=4412).

Frequency of sunscreen use	Age group
	20-29 years	30-39 years	40-49 years	50-59 years
Never	ref	ref	ref	ref
Rarely	0.0 (-0.3-0.4)	0.3 (-0.1-0.7)	0.3 (-0.1-0.8)	0.3 (-0.2-0.9)
Sometimes	0.8 (0.5-1.2)	0.8 (0.4-1.2)	1.2 (0.7-1.6)	0.8 (0.3-1.3)
Most of the time	1.1 (0.8-1.5)	1.2 (0.8-1.7)	1.9 (1.5-2.4)	1.9 (1.3-2.4)
Always	1.8 (1.2-2.3)	1.5 (1.0-2.0)	1.9 (1.2-2.5)	2.7 (2.0-3.4)
P-trend	<0.01	<0.01	<0.01	<0.01
Model R2	0.26	0.26	0.26	0.29
Sunscreen R2	0.08	0.06	0.11	0.14

Adjusted for sex, ethnicity, BMI, education, sun avoidance, and 6-month time period