Table 2.

Performance of several risk scores for AHI^a

Column 1	2	3	4	5	6	7	8
Risk score	Cutoffb	Seroconversion visits among visits with a score of at least the cutoffc	Seroconversion visits among visits with a score below the cutoffc	Sensitivity % (95% CI)	Specificity % (95% CI)	Overall AUC (95% CI)	% to be tested
Development of a risk score in Amsterdam Cohort Studies
A. Initial risk scored,e   -CLAI a conditionf	2	80/1888	95/15555	45.7 (38.2–53.4)	89.5 (89.1–90.0)	0.70 (0.66–0.74)	10.8
B. 14 symptoms scored as beta coefficient in symptom based modeld,g   -CLAI a conditionf	0.1	90/2342	85/15101	51.4 (43.8–59.0)	87.0 (86.4–87.5)	0.71 (0.67–0.74)	13.4
C. 14 symptoms scored as beta coefficient in symptom based modelg,h   -CLAI not a condition	0.2	116/4430	59/13012	66.3 (58.8–73.2)	75.0 (74.4–75.7)	0.74 (0.70–0.78)	25.4
D. 14 symptoms and 3 risk factors, scored as beta coefficient in combined modeli,j	1.3	111/4334	24/10858	82.2 (74.7–88.3)	72.0 (71.2–72.7)	0.83 (0.80–0.87)	28.5
E. 4 symptoms and 3 risk factors scored as beta coefficient in combined modelk,j	1.5	103/3675	32/11517	76.3 (68.2–83.2)	76.3 (75.6–77.0)	0.82 (0.79–0.86)	24.2
Validation of optimal risk score in Multicenter AIDS Cohort Study
E. 4 symptoms and 3 risk factorsk, scored as beta coefficient	1.5	77/3779	60/29274	56.2 (47.5–64.7)	88.8 (88.4–89.1)	0.78 (0.74–0.82)	11.4

AHI acute HIV-1 infection, CI confidence interval, CLAI condomless anal intercourse

^aBased on imputed data using the last observation carried forward method

^bBased on Youden-index, with the exception for risk score A: pre-defined cutoff was 2

^cDue to missing values, the denominators of columns 3 and 4 do not add up to 17,446. Data were missing for the following variables: fever, 1 missing; genital ulcers, 3 missings; gonorrhea, 2072 missings; receptive condomless anal intercourse, 162 missings; >5 sexual partners, 56 missings.

^dDue to 3 records with missing values, these risk score evaluations are based on 17,443 records

^e14 symptoms scored as case definition, but genital warts and oral ulcers not included due to large number of missing variables; score of 1: fatigue, headache, myalgia, nausea, night sweats, pharyngitis, or rash; score of 2: diarrhea, fever, genital ulcers, lymphadenopathy, oral thrush, oral ulcers, vomiting, or weight loss

^f112/175 seroconverters reported condomless anal intercourse in the preceding 6 months

^gIn a multivariable model including 14 symptoms (Table 3, column 6): diarrhea, fatigue, fever, genital ulcers, headache, lymphadenopathy, myalgia, nausea, night sweats, oral thrush, rash, sore throat, vomiting, weight loss

^hDue to 4 records with missing values, these risk score evaluations are based on 17,442 records

ⁱIn a multivariable model including 14 symptoms and 3 risk factors (Table 3, column 8): diarrhea, fatigue, fever, genital ulcers, headache, lymphadenopathy, myalgia, nausea, night sweats, oral thrush, rash, sore throat, vomiting, weight loss, and in the preceding 6 months: gonorrhea, receptive condomless anal intercourse, >5 sexual partners

^jDue to 2254 records with missing values, these risk score evaluations are based on 15,192 records

^kFever, lymphadenopathy, oral thrush, weight loss, and in the preceding 6 months: gonorrhea, receptive condomless anal intercourse, >5 sexual partners