Background: Women residing in Oslo have had lower attendance in BreastScreen Norway than the national average. We explored attendance in BreastScreen Norway among immigrant versus Norwegian-born women in Oslo, compared to other counties in Norway.
Material and method: We linked attendance data from BreastScreen Norway to sociodemographic data from Statistics Norway for 885 979 women offered mammographic screening in the period 1996-2015. We undertook descriptive analyses of attendance in the different counties for the group of invitees as a whole, and for Norwegian-born and immigrants by country of birth ('Western Europe, Northern America, Australia and New Zealand' and 'other countries'). Furthermore, we estimated the predicted likelihood of attendance with the aid of logistic regression, using attendance (yes/no) as the outcome variable. Independent variables in the model included place of residence (Oslo/other counties), country of birth and interaction between these variables. In addition, we adjusted for age at the time of the invitation, education and marital status.
Results: Among women residing in Oslo, attendance was 67 % among Norwegian-born women, 61 % among women born in Western Europe, Northern America, Australia and New Zealand, and 39 % among women born in 'other countries'. Among women residing outside Oslo, the corresponding attendance was 79 %, 71 % and 50 % respectively.
Interpretation: Oslo as place of residence was associated with lower attendance in BreastScreen Norway, especially among immigrant women from 'other countries', and independently of adjustment for possible confounding variables.