key: cord-0967401-wk71poh1
authors: Su, C.-W.; Liu, Y.-T.; Yen, A. M.-F.; Chiu, H.-M.; Chen, T. H.-H.; Hsu, T.-H.; Shih, M.-Y.; Su, W. W.-Y.; Chen, S. L.-S.
title: Population-based Oral Cancer Service Screening Disrupted by COVID-19 Pandemic: Observational and Simulation Study
date: 2022-05-03
journal: nan
DOI: 10.1101/2022.05.03.22274618
sha: 2a7605a465770a961c8c795b22c1a2734cb3b8c6
doc_id: 967401
cord_uid: wk71poh1

Background: It is important for understanding the impact of COVID-19 pandemic on the missing opportunity for the early detection of oral cancer. This study aimed to assess the impact of COVID-19 pandemic on the existing population-based oral cancer (OC) service screening program in Taiwan. Methods: Before and after COVID-19 pandemic design was used to assess the impact of COVID-19 on the reduction of screening rate, referral rate, and the effectiveness of this OC service screening. Data and analysis after pandemic covered non-VOC period in 2020 and VOC period in 2021 compared to the historical control before pandemic in 2019. Results: The screening rate decreased substantially from 26.6% before COVID-19 in 2019 to 16.7% in 2020 and 15.3% in 2021 after pandemic. The reduction of screening rate varied with months, being the most remarkable decline in March (RR=0.61, 95% CI (0.60-0.62)) and June (RR=0.09, 95% CI (0.09-0.10)) in 2021 compared with January. The referral rate was stable at 81.5% in 2020 but it was reduced to 73.1% in 2021. The reduction of screening and referral rate led to the attenuation of effectiveness of advance cancer and mortality attenuated by 4% and 5%, respectively. Conclusion: COVID-19 pandemic disrupted the screening and the referral rate and further led to statistically significant reduction in effectiveness for preventing advanced cancer and death. Appropriate prioritized strategies must be adopted to ameliorate malignant transformation and tumor upstaging due to deference from participation in the screening. Funding: This study was financially supported by Health Promotion Administration of the Ministry of Health and Welfare of Taiwan (A1091116).

The emerging SARS-COV-2 has resulted in global public health crisis since 69 mid-March, 2020 when the World Health Organization declared it as a pandemic infectious 70 disease. As of August 22, 2021, the disease has spread over to 220 countries and regions with 71 more than 212 million confirmed cases and 4.4 million deaths [1] . COVID-19 pandemic 72 gives an unprecedented challenge for healthcare system in every country worldwide with 73 many non-essential clinical visits and admissions that have been deferred [2] . The COVID-19 74 pandemic is still an ongoing transmission under the threaten of variant of concern (VOC) and 75 interest in many countries. Although available anti-virus therapy or vaccination is provided, 76 containment measures including the quarantine and the isolation of suspected individuals, 77 social distancing, and personal and environmental sanitation are still widely adopted in many 78 countries. In clinical settings, additional containment measures were applied to reducing the 79 wide spread of transmission. Taking an example of dental practice, except emergencies, other 80 dental activities have been suspended in most of affected countries [3, 4, and 5]. During the 81 COVID-19 pandemic, some important health issues, like early detection of oral cancer may 82 be neglected by the public attention. As screening with oral visual inspection for high-risk 83 subjects is an effective means for oral cancer prevention worldwide [6, 7] that has shown the 84 reduction of 21% advanced stage and 26% mortality of oral cancer. Thus, population-based 85 oral cancer screening program had been considered as an important secondary prevention 86 strategy due to the high disease burden of oral cancer. Although early detection of oral 87 . CC-BY 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted May 3, 2022. 108 In Taiwan, population-based screening for oral neoplasm with oral visual inspection   109 has been offered for subjects with habits of cigarette smoking and/or betel quid chewing since CC-BY 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review)

The copyright holder for this preprint this version posted May 3, 2022. ; https://doi.org/10.1101/2022.05.03.22274618 doi: medRxiv preprint each month were referred to have confirmatory diagnosis ( Table 2 ). The monthly referral 127 rates were steady in 2019. Based on these screening characteristics, we used a monthly series 128 of before and after quasi-experimental design to compare both screening rate and referral rate 129 in 2020 (non-VOC period) and from January to June in 2021 (VOC period) with those of the 130 historical control of the contemporaneous period in 2019 (non-COVID-19 period). 131 As we do not have the control group as seen in population-based randomized controlled 132 trial, it is very difficult to estimate the risks of advanced oral cancer or deaths in the absence 133 of screening. A multi-state Markov natural history model as an alternative approach was 134 applied to simulating the cancer risks for subjects with and without screening. The two major in relation to the outcomes of screening process used in this study were 139 screening rate and referral rate. Screening rate was defined as the rate of number of 140 participants to population aged over 30 years with cigarette smoking and/or betel nut chewing. 141 The referral rate was defined as number of positive cases with confirmatory diagnosis. 143 Those who had the clinical diagnosis with suspicious oral malignancy were referred to 144 confirm the diagnosis or oral cancer by tissue biopsy. Such a clinical diagnosis may include a 145 . CC-BY 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted May 3, 2022. ; https://doi.org/10.1101/2022.05.03.22274618 doi: medRxiv preprint persistent white or red lesion, a non-hearing ulcer for more than two weeks, an irregular 146 surface lesion inside the oral cavity, or any unexplained lymph adenopathy during the oral 147 visual inspection was defined as positive case. Needle or incisional biopsy would be needed 148 before a confirmed diagnosis. Individual screen data from clinics or hospitals are timely 149 uploaded and transferred to a centralized database via web-based information system to The chi-square test was used to assess the differences in both screening rate and referral 159 rate before and after COVID-19. The statistically significant level was set as 0.05. For the 160 calculation of relative rate for screening rate change, the monthly screening rate in 2020 was 161 compared with that in 2019. The relative ratio of screening rate change in the epidemic period 162 was reckoned on the basis of the relative rate of screening from pre-epidemic period in 163 January. The 95% confidence intervals of relative rate were calculated.

. CC-BY 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted May 3, 2022. 174 We firstly used a hypothetical cohort without any intervention to simulate and project 175 the expected number of advanced oral cancer and then changed the screening rate from 176 pre-pandemic period to pandemic period during 6-year follow-up to estimate oral cancer 177 deaths. The parameters used in the current simulation are shown in Supplementary Table 1 . 178 The statistical software used for the analysis was SAS 9.4. 179 180 . CC-BY 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. Table 1 ). The screening rate increased 202 from July onwards. The referral rate did not change for each month. (Table 2) (Table 3 ). The similar result shows that 216 the delayed screening and referrals may compromise the effectiveness by 5% in 2021. CC-BY 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted May 3, 2022. is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review)

The copyright holder for this preprint this version posted May 3, 2022. ; https://doi.org/10.1101/2022.05.03.22274618 doi: medRxiv preprint 

World Health Organization. Coronavirus Disease (COVID-19) Pandemic

Wuhan novel coronavirus (COVID-19): why global control is challenging? 283 Public Health

Impact of COVID-19 on the early 285 detection of oral cancer: A special emphasis on high risk populations

Consequences of the COVID-19 Pandemic and 289 Referral rate