Table 3.

Multivariate Logit Models (Unpaired and Paired Data) Assessing the Association Between Correct Response and Other Study Variables

Variable, Coding	Unpaired Analysis		Paired Analysis
	OR (95% CI)	P Value	OR (95% CI)	P Value
Image type
Gray-scale	1 [Reference]		1 [Reference]
Color	1.0 (0.8–1.4)	.99	1.2 (0.9–1.6)	.82
Lesion diagnosis
Nevus	1 [Reference]
Melanoma	1.0 (0.7–1.3)	.98	1.2 (0.3–4.3)	.82
BCC	1.2 (0.9–1.6)	.31	0.6 (0.1–2.0)	.34
SCC	0.1 (0.1–0.1)	<.001	0.1 (0.02–0.4)	.002
DF	1.2 (0.8–1.7)	.40	0.6 (0.1–2.4)	.43
SK	0.7 (0.5–0.9)	.01	0.5 (0.1–1.6)	.21
Hemangioma	1.9 (1.1–3.1)	.01	1.3 (0.2–5.2)	.83
Interaction: color by diagnosisa
Color × nevus	1 [Reference]	1 [Reference]
Color × melanoma	0.4 (0.2–0.5)	<.001	1.2 (0.8–1.8)	.41
Color × BCC	0.4 (0.3–0.6)	<.001	0.8 (0.6–1.2)	.38
Color × SCC Drops out	2.5 (1.6–3.9)	<.001
Color × DF	0.1 (0.1–0.2)	<.001	0.2 (0.1–0.3)	<.001
Color × SK	0.7 (0.5–1.1)	.13	0.8 (0.6–1.1)	.23
Color × hemangioma	1.7 (1.0–3.1)	.07	3.3 (1.9–5.6)	<.001
Sex
Female	1 [Reference]	1 [Reference]
Male	1.0 (0.8–1.3)	.88	1.0 (0.8–1.1)	.51
Age, y
21–30	1 [Reference]	1 [Reference]
31–50	1.4 (1.1–1.8)	.003	1.5 (1.3–1.8)	<.001
≥51	1.4 (1.1–1.9)	.02	1.6 (1.3–1.9)	<.001

Abbreviations: BCC, basal cell carcinoma; DF, dermatofibroma; OR, odds ratio; SCC, squamous cell carcinoma; SK, seborrheic keratosis.

^aThe interaction term depicts the differential effect of color on the proportion of correct responses by lesion diagnosis.