# Table 3 Sensitivity (n = 390), specificity (n = 1043) and cost of various combinations of rapid HIV assays

S/N 1st Assay 2nd Assay Sensitivity % (95% CI) Specificity % (95% CI) Cost per algorithm (US\$)
1 SD Bioline First Response 100 (99.1–100) 99.9** (99.5–99.9) 0.47 + 0.65 = 1.12
2 First Response*** SD Bioline 99.5 (98.2–99.9) 100 (96–99.1) 0.65 + 0.47 = 1.12
3 SD Bioline Determine 100 (99.1–100) 100* (96–99.1) 0.47 + 0.80 = 1.27
4 Determine SD Bioline 100 (99.1–100) 100* (96–99.1) 0.80 + 0.47 = 1.27
5 SD Bioline Stat-Pak Dipstick 100 (99.1–100) 100* (96–99.1) 0.47 + 0.80 = 1.27
6 Stat-Pak Dipstick*** SD Bioline 97.9 (96–99.1) 100 (96–99.1) 0.80 + 0.47 = 1.27
7 Determine First Response 100 (99.1–100) 100* (96–99.1) 0.80 + 0.65 = 1.45
8 First Response*** Determine 99.5 (98.2–99.9) 99.9 (99.5–99.9) 0.65 + 0.80 = 1.45
9 First Response*** Stat-Pak Dipstick 99.5 (98.2–99.9) 100 (96–99.1) 0.65 + 0.80 = 1.45
10 Stat-Pak Dipstick*** First Response 97.9 (96–99.1) 100 (96–99.1) 0.80 + 0.65 = 1.45
11 Determine Stat-Pak Dipstick 100 (99.1–100) 100* (96–99.1) 0.80 + 0.80 = 1.60
12 Stat-Pak Dipstick*** Determine 97.9 (96–99.1) 100 (96–99.1) 0.80 + 0.80 = 1.60
13 SD Bioline Uni-Gold™ 100 (99.1–100) 100* (96–99.1) 0.47 + 1.80 = 2.27
14 Uni-Gold™ SD Bioline 100 (99.1–100) 100* (96–99.1) 1.80 + 0.47 = 2.27
15 Uni-Gold™ First Response 100 (99.1–100) 100* (96–99.1) 1.80 + 0.65 = 2.45
16 First Response*** Uni-Gold™ 99.5 (98.2–99.9) 100 (96–99.1) 0.65 + 1.80 = 2.45
17 Uni-Gold™ Stat-Pak Dipstick 100 (99.1–100) 100* (96–99.1) 1.80 + 0.80**** = 2.6
18 Stat-Pak Dipstick*** Uni-Gold™ 97.9 (96–99.1) 100 (96–99.1) 0.80 + 1.80 = 2.60
19 Determine Uni-Gold™ 100 (99.1–100) 100* (96–99.1) 0.80 + 1.80 = 2.60
20 Uni-Gold™ Determine 100 (99.1–100) 100* (96–99.1) 1.80 + 0.80 = 2.60
1. *Combination of the two assays had no concordant false positive results.
2. **One sample was repeatedly concordantly false positive in the two assays.
3. ***The first test had initial suboptimal sensitivity (< 100%).
4. ****Cost of Stat-Pak Dipstick is indicated as a range 0.8–0.95 US\$. The best case scenario of the lowest possible cost for this test was assumed in computing the cost for algorithms involving use of Stat-Pak Dipstick.