Nation-wide mammography screening participation in Denmark during the COVID-19 pandemic: An observational study

ABSTRACT

BackgroundIn most of the world, the mammography screening programmes were paused at the start of the pandemic, whilst mammography screening continued in Denmark. We examined the mammography screening participation during the COVID-19 pandemic in Denmark. MethodsThe study population comprised all women aged 50-69 years old invited to participate in mammography screening from 2016-2021 in Denmark based on data from the Danish Quality Database for Mammography Screening in combination with population-based registries. Using a generalised linear model, we estimated prevalence ratios (PR) and 95% confidence intervals (CI) of mammography screening participation within 90, 180 and 365 days since invitation during the pandemic in comparison with the previous years adjusting for age, year and month of invitation. ResultsThe study comprised 1,828,791 invitations among 847,766 women. Before the pandemic, 80.2% of invitations resulted in participation in mammography screening within 90 days, 82.7% within 180 days and 83.1% within 365 days. At the start of the pandemic, the participation in screening within 90 days was reduced to 69.9% for those invited in pre-lockdown and to 76.5% for those invited in 1st lockdown. Extending the length of follow-up time to 365 days only a minor overall reduction was observed (PR=0.94; 95% CI 0.93-0.95 in pre-lockdown and PR=0.97; 95% CI 0.96-0.97 in 1st lockdown). A lower participation was; however, seen among immigrants and among women with a low income. ConclusionsThe short-term participation in mammography screening was reduced at the start of the pandemic, whilst only a minor reduction in the overall participation was observed with longer follow-up time indicating that women postponed screening. Some groups of women; nonetheless, had a lower participation indicating that the social inequity in screening participation was exacerbated during the pandemic.