Table 3.

Risk Score Variables for the Derivation and Validation Cohorts According to Diagnosis of Human Immunodeficiency Virus Infection, Denver, Colorado, 1996–2008

	Derivation Cohort				Validation Cohort
	HIV-Infected (n = 504)		Not HIV-Infected (n = 92,131)		HIV-Infected (n = 168)		Not HIV-Infected (n = 22,815)
	No.	%a	No.	%	No.	%	No.	%
Age group, years
<22 or >60	45	8.9	22,464	24.4	31	18.5	5,790	25.4
22–25 or 55–60	72	14.3	21,072	22.9	34	20.2	4,840	21.2
26–32 or 47–54	184	36.5	26,513	28.8	43	25.6	6,597	28.9
33–46	203	40.3	22,082	24.0	60	35.7	5,588	24.5
Gender
Female	74	14.7	35,611	38.7	33	19.6	11,196	49.1
Male	430	85.3	56,520	61.4	135	80.4	11,619	50.9
Race/ethnicity
Black	119	23.6	22,620	24.6	86	51.2	11,942	52.3
Hispanic	129	25.6	26,652	28.9	3	1.8	333	1.5
Otherb or white	256	50.8	42,859	46.5	79	47.0	10,540	46.2
Sexual practices
Sex with a male	404	80.6	42,721	46.4	111	66.1	11,672	51.2
Vaginal intercourse	178	35.3	80,334	87.2	117	69.6	18,519	81.2
Receptive anal intercourse	279	55.4	12,854	14.0	68	40.5	3,402	14.9
Other risk factors
Injection drug use	59	11.8	5,035	5.5	10	6.0	1,602	7.0
Past HIV testing	391	77.6	61,856	67.2	105	62.5	16,212	71.1

Abbreviation: HIV, human immunodeficiency virus.

^aPercentages may not add to 100% because of rounding.

^bAmerican Indian or Alaska Native, Native Hawaiian, or non-Hawaiian Pacific Islander.