The sensitivity and specificity of different PMN cut-offs in cervical smears for detection of chlamydial infection (total 138, prevalence of chlamydia 12.31%)
| PMN cut-off criteria | No of cervical smears | Positive chlamydia test | Sensitivity (%) | Specificity (%) | PPV† (%) | NPV‡ (%) |
|---|---|---|---|---|---|---|
| *High power field: ×1000 microscopy. | ||||||
| †Positive predictive value. | ||||||
| ‡Negative predictive value. | ||||||
| ⩾5 PMN/hpf* | 85 | 13 | 76 | 40 | 15 | 92 |
| ⩾10 PMN/hpf | 56 | 10 | 59 | 62 | 18 | 91 |
| ⩾15 PMN/hpf | 48 | 10 | 59 | 69 | 21 | 92 |
| ⩾20 PMN/hpf | 39 | 9 | 53 | 75 | 23 | 92 |
| ⩾25 PMN/hpf | 31 | 9 | 53 | 82 | 29 | 92 |