From: Another look at Emergency Department HIV screening in practice: no need to revise expectations
 |  | Assuming X of the negatives were actually false positives | ||
---|---|---|---|---|
 |  | 0 (observed) | 2 (0.95% prevalence of positives overall) | 4 (1.1% prevalence of positives overall) |
False negatives | 0 | Pr(+|A) 100% (95% CI 75.3%-100%) | Pr(+|A) 100% (95% CI 75.3%-100%) | Pr(+|A) 100% (95% CI 75.3%-100%) |
 |  | Pr(-|N) 100% (95% CI 99.8%-100%) | Pr(-|N) 99.9% (95% CI 99.5%-100%) | Pr(-|N) 99.7% (95% CI 99.3%- 99.9%) |
 |  | Pr(A|+) 100% (95% CI 75.3%-100%) | Pr(A|+) 86.7% (95% CI 59.5%-98.3%) | Pr(A|+) 76.5% (95% CI 50.1%-93.2%) |
 | 1 | Pr(+|A) 92.9% (95% CI 66.1%-99.8%) | Pr(+|A) 92.9% (95% CI 66.1%-99.8%) | Pr(+|A) 92.9%(95% CI 66.1%-99.8%) |
 |  | Pr(-|N) 100% (95% CI 99.8%-100%) | Pr(-|N) 99.9% (95% CI 99.5%-100%) | Pr(-|N) 99.7% (95% CI 99.3%-99.9%) |
 |  | Pr(A|+) 100% (95% CI 75.3%-100%) | Pr(A|+) 86.7% (95% CI 59.5%-98.3%) | Pr(A|+) 76.5% (95% CI 50.1%-93.2%) |
 | 28 (1.2% false negatives) | Pr(+|A) 31.7% (95% CI 18.1%-48.1%) | Pr(+|A) 86.7% (95% CI 59.5%-98.3%) | Pr(+|A) 24.3% (95% CI 11.8%-41.2%) |
 |  | Pr(-|N) 100% (95% CI 99.8%-100%) | Pr(-|N) 100% (95% CI 99.8%-100%) | Pr(-|N) 99.7% (95% CI 99.3%-99.9%) |
 |  | Pr(A|+) 100% (95% CI 75.3%-100%) | Pr(A|+) 100%(95% CI 75.3%-100%) | Pr(A|+) 69.2% (95% CI 38.6%-90.9%) |