The Impact of the COVID ‐19 Pandemic on Oral Cancer Screening: Real‐World Data From Taiwan

BACKGROUND: The COVID-19 pandemic disrupted cancer screening services worldwide, but its impact across multiple screening indicators remains unclear. METHODS: This population-based interrupted time series study evaluated the impact of COVID-19 on oral cancer screening in Taiwan. Two intervention points were defined: January 2020 and May 2021. Four indicators were assessed: screening rate, screening positivity rate, incidence, and mortality. Segmented regression analyses were performed across six National Health Insurance divisions, and changes in stage at diagnosis (2018-2022) were examined. RESULTS: At baseline, screening rates declined, screening positivity rate and mortality increased modestly, and incidence remained stable. After the first outbreak, screening positivity rate showed a significant immediate decrease (OR = 0.86, 95% CI: 0.81-0.92, p < 0.001), whereas screening rate, incidence, and mortality showed no significant changes. Advanced-stage diagnoses increased, while early-stage diagnoses declined. Regional analyses demonstrated similar patterns. No significant slope changes after the first outbreak or level/trend changes after the second outbreak were observed. Incidence and mortality remained stable throughout the study. CONCLUSIONS: The first outbreak had the greatest impact on screening-related indicators, with findings consistent with possible delays in cancer detection. Maintaining organized screening services during public health emergencies is essential to minimize delayed cancer detection.