Differences in mammography screening attendance among non-Western immigrants in Denmark, Finland, Iceland and Norway

Several studies have shown that attendance rates are lower among non-Western immigrants than among natives. As the Nordic countries have quite similar health systems and populations but also differences in the organisation of their organised mammography screening programmes, differences in attendance rates could highlight organisational factors that might increase the attendance rates. Mammography screening is offered free of charge in Denmark and Finland, but not in Iceland and Norway. Contrarily to the other countries, Iceland do not send out pre-booked appointment. The study population included natives and non-Western immigrants aged 50-69 years, who had at least one invitation to the national mammography screening programmes in Denmark (2008-2017), Finland (2001-2017), Iceland (2001-2020) or Norway (2001-2015). Relative risks (RRs) of attendance were estimated and adjusted for age group and calendar period. The study population included 116.033 non-Western immigrants and more than 2 million natives. The attendance rates were significantly lower among non-Western immigrants than among natives, with an adjusted relative risk of 0.81/0.80 in Denmark and Finland, 0.62 in Norway, and 0.40 in Iceland. The lower attendance rates among immigrants in Norway and Iceland did not seem to be due to differences in birth country, immigration age, or educational level, but might be explained by organisational factors. Offering free-of-charge mammography screening in Norway and Iceland and/or including a pre-booked appointment in the invitation letters in Iceland might increase the attendance rate among non-Western immigrants.