Table 4.

Analysis of injury occurrence (prevalence) via logistic regression and injury frequency via negative binomial regression by anogenital region before (models 1) and after (models 2) adding skin color values (N = 120)

Anogenital region	Model	Predictor	Logistic			Negative binomial
			AOR	95% CI	P	ARR	95% CI	P
External genitalia	1	Race/ethnicity	3.15	1.38–7.44	.0073	2.94	1.52–5.80	.0012
		Age	0.91	0.60–1.35	.6474	1.02	0.74–1.42	.8795
		Hours since intercourse	0.89	0.68–1.15	.3813	0.84	0.68–1.03	.0996
		No contraceptive vs condom	1.42	0.33–5.89	.6302	2.24	0.75–6.86	.8795
		No contraceptive vs other Method	2.52	0.93–7.36	.0772	2.51	1.09–6.07	.0350
	2	Race/ethnicity	1.14	0.31–4.18	.8422	1.01	0.38–2.69	.9885
		Age	1.00	0.65–1.51	.9975	1.03	0.76–1.40	.8193
		Hours since intercourse	0.86	0.64–1.14	.3119	0.83	0.67–1.01	.0641
		No contraceptive vs condom	1.22	0.26–5.51	.7990	1.67	0.56–5.09	.3709
		No contraceptive vs other method	2.42	0.82–7.68	.1166	2.62	1.14–6.50	.0275
		Skin L* value	1.06	1.01–1.11	.0192	1.04	1.00–1.08	.0364
		Skin b* value	0.94	0.89–0.99	.0268	0.94	0.89–0.99	.0067
		Skin a* value				1.10	1.02–1.19	.0148
Internal genitalia	1	Race/ethnicity	1.37	0.55–3.46	.5052	1.64	0.76–3.59	.2047
		Age	0.97	0.63–1.46	.8804	1.03	0.70–1.50	.8534
		Hours since intercourse	0.97	0.73–1.28	.8468	0.97	0.76–1.24	.8171
	2	Race/ethnicity	2.30	0.85–6.54	.1073	2.10	0.99–4.57	.0508
		Age	1.14	0.72–1.77	.5746	1.11	0.77–1.58	.5642
		Hours since intercourse	1.04	0.75–1.41	.8301	1.01	0.78–1.27	.9747
		Skin a* value	0.80	0.71–0.89	.0002	0.89	0.82–0.95	.0010

ARR, adjusted rate ratio. Model 1 does not include skin color variables as predictors. Model 2 includes skin color variables as predictors.