Table 3.
Incidence of cervical intraepithelial neoplasia grade II or grade III or worse after three years of follow-up, by trial arm and period of follow-up
| Biopsy and recall | Immediate large loop excision | Relative risk* (95% CI), P value | ||||
|---|---|---|---|---|---|---|
| No (% of those in arm) | % of disease detected | No (% of those in arm) | % of disease detected | |||
| Total women randomised | 1000 (100) | — | 983 (100) | — | — | |
| Total person years of follow-up | 2731 | — | 2725 | — | — | |
| Cervical intraepithelial neoplasia grade II or worse | ||||||
| Total cases† | 216 (22) | 100 | 228 (23) | 100 | — | |
| At initial colposcopy | 160 (16) | 74 | 202 (21) | 89 | — | |
| At follow-up | 32 (3) | 15 | 18 (2) | 8 | — | |
| At exit examination | 24 (2) | 11 | 8 (1) | 4 | — | |
| Cumulative incidence per 1000 person years§ | 79 | — | 84 | — | 1.04 (0.86 to 1.25), P=0.687 | |
| Cervical intraepithelial neoplasia grade III or worse | ||||||
| Total cases† | 107 (11) | 100 | 113 (11) | 100 | — | |
| At initial colposcopy | 83 (8) | 78 | 102 (10) | 90 | — | |
| At follow-up | 19 (2) | 18 | 10 (1) | 9 | — | |
| At exit examination | 5 (1) | 5 | 1 (0.1) | 1 | — | |
| Cumulative incidence per 1000 person years§ | 39 | — | 41 | — | 1.03 (0.79 to 1.34), P=0.841 | |
*Relative risk (with biopsy and recall as reference) based on total number of cases and adjusted for age (20-29, 30-39, 40-49, 50-59), cytology at recruitment (mild dyskaryosis, borderline nuclear abnormalities), centre (Grampian, Tayside, Nottingham), and high risk human papillomavirus status (positive, negative, unknown).
‡Includes four women who had disease worse than cervical intraepithelial neoplasia grade III; three detected after initial colposcopy and treatment (one in biopsy and recall arm, two in immediate large loop excision arm), and one detected during follow-up in biopsy and recall arm.