Participation in the nationwide cervical cancer screening programme in Denmark during the COVID-19 pandemic: An observational study

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    This article shows how the COVID-19 pandemic affected cervical cancer screening participation in the organized screening program of Denmark. Through registry data covering the entire population, the study shows that while short-term (90 days) participation after invitation dropped, long-term (365 days) participation remained stable. These results will be of interest to public health specialists and researchers working on pandemic recovery efforts related to cancer screening worldwide.

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Abstract

In contrast to most of the world, the cervical cancer screening programme continued in Denmark throughout the COVID-19 pandemic. We examined the cervical cancer screening participation during the pandemic in Denmark.

Methods:

We included all women aged 23–64 y old invited to participate in cervical cancer screening from 2015 to 2021 as registered in the Cervical Cancer Screening Database combined with population-wide registries. Using a generalised linear model, we estimated prevalence ratios (PRs) and 95% CIs of cervical cancer screening participation within 90, 180, and 365 d since invitation during the pandemic in comparison with the previous years adjusting for age, year, and month of invitation.

Results:

Altogether, 2,220,000 invited women (in 1,466,353 individuals) were included in the study. Before the pandemic, 36% of invited women participated in screening within 90 d, 54% participated within 180 d, and 65% participated within 365 d. At the start of the pandemic, participation in cervical cancer screening within 90 d was lower (pre-lockdown PR = 0.58; 95% CI: 0.56–0.59 and first lockdown PR = 0.76; 95% CI: 0.75–0.77) compared with the previous years. A reduction in participation within 180 d was also seen during pre-lockdown (PR = 0.89; 95% CI: 0.88–0.90) and first lockdown (PR = 0.92; 95% CI: 0.91–0.93). Allowing for 365 d to participation, only a slight reduction (3%) in participation was seen with slightly lower participation in some groups (immigrants, low education, and low income).

Conclusions:

The overall participation in cervical cancer screening was reduced during the early phase of the pandemic. However, the decline almost diminished with longer follow-up time.

Funding:

The study was funded by the Danish Cancer Society Scientific Committee (grant number R321-A17417) and the Danish regions.

Article activity feed

  1. eLife assessment

    This article shows how the COVID-19 pandemic affected cervical cancer screening participation in the organized screening program of Denmark. Through registry data covering the entire population, the study shows that while short-term (90 days) participation after invitation dropped, long-term (365 days) participation remained stable. These results will be of interest to public health specialists and researchers working on pandemic recovery efforts related to cancer screening worldwide.

  2. Reviewer #1 (Public Review):

    This study examines how the COVID-19 pandemic impacted cervical cancer screening participation to invitations sent through the organized cervical cancer screening program of Denmark. I think the results are particularly enlightening in the context of pandemic recovery, as they show that while the short-term participation (90 days) dropped due to public health messaging emphasizing staying at home, the long-term participation (365 days) did not drop; this suggests that women did not completely miss the opportunity to screen during the pandemic, but simply postponed their screening to a later point in time. I think this has implications, especially for modeling the impact of the pandemic on cancer incidence, as many screening models have made the assumption that screenings missed during the pandemic would not be "caught up" later leading to higher cancer incidence in the long term; however, this study suggests that this is not the case and that there is a natural 'catch up' of screening that occurs over time. This is reassuring, as a short delay in cervical cancer screening would not be expected to lead to overly important long-term negative health outcomes.

    Particular strengths of this study include the population-based registry covering the whole target population, and the ability to link the data to socioeconomic variables of interest to examine whether there were particular groups of women which were more impacted than others. The models also accounted for seasonal and long-term trends in cancer screening participation, which bolsters the confidence that their results are not the result of trends in cervical screening participation over time and are most likely attributable to the COVID-19 pandemic. However, as the statistical methods do not include an interaction test for the overall effect of each socioeconomic variable, it is not clear whether the differences that are observed between women by age and socioeconomic status are significant.

  3. Reviewer #2 (Public Review):

    The study included all women aged 23-64 years invited for cervical cancer screening in Denmark in 2015-2021 (n=2,220,00). The Danish registries provide an ideal setting for the study. Classification of explanatory covariates followed Danish and international standards. The authors estimated the prevalence ratios using a generalised linear model with a log link for the Poisson family. Material and statistical methods are appropriate for the study's aims.

    As the authors write, several studies have demonstrated lower participation among immigrants and women with lower socioeconomic status. However, the authors wanted to evaluate whether divergence may have been exacerbated during the pandemic. Unfortunately, they do not provide any justification for why they would hypothesize that to happen.

    The authors write that women who unregistered from the screening programme within 1 year since invitation (n=56,920) were excluded. If those who are at higher risk of cancer and with lower participation rates unregister themselves, the compliance to screening could be overestimated.

    The authors find that some age groups i.e. women aged 40-49 and those aged 60-64 years had a lower participation rate and conclude that it could indicate that the restrictions within a society affect different age groups disproportionally. The authors do not try to explain the finding and it should be scrutinized to rule out a chance. Comorbidity is strongly associated with age so if this is attributed to self-isolation, there should be a gradient. Why 50-59 years old would be different from 60-64 years?

    In general, study results support the conclusions. The authors consider the inconsistent health messages as a reason for women not to participate. What about fear? In several countries, there was a clear decrease in emergency admissions to the hospital which suggest that people were avoiding hospital because they were nervous about catching COVID-19.