Implementation rate and related factors of confirmatory tests following an abnormal Pap smear: a nationwide study from the National Health Insurance.

Objective: This study aims to investigate the implementation rate and influencing factors of confirmatory tests for women with abnormal cervical cytology results in the Korean nationwide cervical cancer screening program.

Methods: The National Health Insurance Service (NHIS) database was utilized to identify all Korean women who have participated in the Korean nationwide cervical cancer screening program from January 2011 and December 2021 using the NHIS database. Multiple logistic regression analysis was performed to estimate the multivariate odds ratio and evaluate the patients' characteristics.

Results: The rate of abnormal Papanicolaou (Pap) smears showed an initial increase from 2011 to 2015 and subsequently reached a plateau after 2016. When examining specific subcategories, cases of atypical squamous cells of undetermined significance (ASC-US) increased from 28,546 cases (1.1%) in 2011 to 62,850 cases (1.7%) in 2021. In contrast, cases of HSIL and SCC declined from 3,535 cases (0.14%) to 2,763 cases (0.07%) and from 383 cases (0.01%) to 179 cases (0.005%), respectively. Furthermore, the implementation rate of confirmatory tests for women with abnormal cytology increased from 8,865 cases (21.0%) in 2011 to 39,045 cases (51.2%) in 2021. Regarding the specific subcategory of ASC-US, the number of confirmatory tests exhibited a substantial increase from 4,101 cases (14.4%) in 2011 to 30,482 cases (48.5%) in 2021. For SCC, there was no significant change, with 216 cases (56.4%) in 2011 and 102 cases (57.0%) in 2021. The implementation rate of confirmatory tests was found to be significantly associated with results of abnormal Pap smear, age, and residence. Notably, economic status did not emerge as a significant factor affecting the likelihood of undergoing confirmatory tests.

Conclusions: The severity of abnormal Pap smear results is a reliable indicator of the probability of undergoing a confirmatory test. Additional endeavors are required to improve the implementation rate among women who have received abnormal Pap smear results.