Single-modality versus combination tanning. Frequency histogram of the study population (N = 1942). Gray bars represent single-modality tanners, black bars represent combination tanners. Of the single-modality tanners, 506 (69.7%) reported outdoor tanning (OT), 203 (28.0%) reported indoor tanning (IT), and 17 (2.3%) reported spray tanning (ST). Among combination tanners, the majority reported OT + IT (667 [54.9%]). OT + ST was used by 66 (5.4%), whereas IT + ST was used by 39 (3.2%). Of the combination tanners, 444 (36.5%) reported using all 3 tanning modalities (OT + IT + ST).