Impact of real-time OCR de-duplication on cervical cancer over-screening rates by age, screening strategy, and county cluster, 2021–2024
| Item | Pre-digital (%, n/N) | Post-digital (%, n/N) | Absolute delta (%, 95% CI)a | P | Adjusted Pb | ||
|---|---|---|---|---|---|---|---|
| 2022 (1-y) | 2023 (1-y) | 2023 (2-y cum) | 2024 (1-y-post) | ||||
| Age | |||||||
| 35–44 | 15.57 (1,610/10,338) | 14.97 (2,002/13,372) | 23.18 (3,100/13,372) | 0.18 (19/10,700) | 15.06 (14.59, 15.52) | < 0.001c | < 0.001 |
| 45–54 | 12.03 (2,013/16,735) | 13.34 (2,768/20,745) | 22.15 (4,596/20,745) | 0.20 (34/16,589) | 12.55 (12.21, 12.90) | < 0.001c | < 0.001 |
| 55–64 | 7.57 (661/8,736) | 8.80 (1,054/11,971) | 16.67 (1,996/11,971) | 0.13 (17/12,791) | 8.15 (7.77, 8.53) | < 0.001c | < 0.001 |
| Screening strategy | |||||||
| HPV | 6.29 (304/4,836) | 3.85 (126/3,269) | 12.97 (424/3,269) | 0.00 (0/2,470) | 5.31 (4.82, 5.79) | < 0.001 | < 0.001 |
| HPV + cytology | 1.62 (18/1,110) | 1.33 (156/11,769) | 3.62 (426/11,769) | 0.33 (31/9,318) | 1.02 (0.79, 1.25) | < 0.001c | < 0.001 |
| Cytology | 13.27 (3,962/29,863) | 23.79 (2,399/10,083) | 39.21 (3,954/10,083) | NA | NA | NA | NA |
| HPV + VIA/VILI triage | NA | 8.05 (747/9,278) | 16.74 (1,553/9,278) | 0.19 (9/4,667) | 7.86 (7.29, 8.43) | < 0.001c | < 0.001 |
| HPV + cytology triage | NA | 20.50 (2,396/11,689) | 28.53 (3,335/11,689) | 0.14 (23/16,435) | 20.36 (19.62, 21.09) | < 0.001c | < 0.001 |
| HPV + cytology + VIA/VILI | NA | NA | NA | 0.10 (7/7,190) | NA | NA | NA |
| VIA + cytology triage | NA | NA | NA | NA | NA | NA | NA |
| Manual de-duplication cluster | |||||||
| Zezhou County | 7.60 (330/4,342) | 1.56 (138/8,867) | 4.79 (425/8,867) | 0.06 (4/7,058) | 3.49 (3.17, 3.81) | < 0.001d | < 0.001 |
| Xiangyuan County | 5.43 (325/5,990) | 2.44 (128/5,246) | 8.41 (441/5,246) | 0.11 (6/5,646) | 3.93 (3.55, 4.30) | < 0.001c | < 0.001 |
| Xinping County | 5.17 (213/4,117) | 9.40 (747/7,943) | 19.55 (1,553/7,943) | 0.12 (10/8,506) | 7.84 (7.35, 8.33) | < 0.001c | < 0.001 |
| Yanting County | 0.06 (4/6,920) | 0.04 (3/7,003) | 0.07 (5/7,003) | 0.01 (1/7,621) | 0.04 (−0.01, 0.08) | 0.274d | 1.000 |
| Overall | 4.08 (872/21,369) | 3.50 (1,016/29,059) | 8.34 (2,424/29,059) | 0.07 (21/28,831) | 3.67 (3.50, 3.84) | < 0.001c | < 0.001 |
| No de-duplication cluster | |||||||
| Shimian County | 18.09 (724/4,002) | 31.92 (1,722/5,395) | 51.07 (2,755/5,395) | 0.00 (0/3,180) | 26.03 (25.14, 26.92) | < 0.001d | < 0.001 |
| Mangshi | 25.75 (2,688/10,438) | 26.53 (3,086/11,634) | 38.79 (4,513/11,634) | 0.61 (49/8,069) | 25.55 (24.95, 26.16) | < 0.001c | < 0.001 |
| Overall | 23.63 (3,412/14,440) | 28.23 (4,808/17,029) | 42.68 (7,268/17,029) | 0.44 (49/11,249) | 25.69 (25.18, 26.19) | < 0.001c | < 0.001 |
| Overall | 11.96 (4,284/35,809) | 12.64 (5,824/46,088) | 21.03 (9,692/46,088) | 0.17 (70/40,080) | 12.17 (11.94, 12.40) | < 0.001c | < 0.001 |
*Repeat screening within the ≤ 3-year guideline interval was defined as any woman who (i) had a documented negative cervical test in the relevant look-back window and (ii) underwent screening again in the index year. The look-back windows were 1 year for 2022 (records from 2021 only) and 2023 (records from 2022 only) and 2 years for 2023 (records from 2021–2022), and 2024 (records from 2023 after digital implementation). The over-screening rates were calculated as the number of such women (numerator) divided by the total number of negative (NEG) women screened in the same index year (denominator). aAbsolute delta was calculated as the overall over-screening rate in the pre-digital period minus that in the post-digital period. bAdjusted P-values were obtained using Bonferroni correction for 16 independent tests. cχ2 test comparing 2024 with pooled 2021–23 counts. dFisher exact test comparing 2024 with pooled 2021–23 counts due to expected cell counts < 5. CI, confidence interval; cum, cumulative; HPV, human papillomavirus; NA, not applicable; VIA, visual inspection with acetic acid; VILI, visual inspection with Lugol’s iodine; y, year.