COVID-19 control measures and the response rate in the organized breast cancer screening in Croatia

Background In order to reduce breast cancer mortality, decades of effort have been dedicated to continuous improvements of the organized breast cancer screening program (BCSP). The aim of this research was to analyse effect of the pandemic control measures on BCSP in Croatia, by comparing first (before the pandemic) and the second half of the sixth invitation round (during the pandemic). The implementation of the BSCP in Croatia was paused from March 16th- May 5th 2020). It is challenging to return the BSCP to the pre-pandemic rates. Methods Data on 699,877 women who were scheduled to be invited in the sixth invitation round in BCSP were analysed. Measure of government policy response, Stringency Index (SI) was analysed along with number of women invited in BCSP, responded to invitation and response rate. Results Of all women invited in the sixth invitation round of BCSP, response rate was 5.7% lower than in the fifth round. Fewer mammograms in the BCSP program and on the doctor's referral were recorded. In comparison of the monthly data, pause of the BCSP and the usual oscillations during the year, such as summer and winter holidays, were observed. Increase in response rate was occurred after the restart of the BCSP (May/June 2019, 41.0%/42.8% vs. May/June 2020, 67.2%/60.1%). Conclusions The number of monthly invited and responded women in BCSP did not return to the pre-pandemic values yet, but better response rate after the restart of the program (40% vs. 60%) was observed. Women were less motivated to respond to the invitation during the period of strict measures. Fear of COVID-19 could be addressed with an intensive public health campaign and vaccination of women invited to BCSP. Key messages The response rate in the BCSP was 5.7% lower during the COVID-19 pandemic measures. Vaccination against COVID-19 of women involved in the BCSP could improve the response rate.