Mammography requests in general practice during the introduction of nationwide breast cancer screening, 1988-1995

Introducing an organised breast cancer screening programme for certain age groups in a population might induce opportunistic screening in adjacent (no n-invited) age groups and influence health behaviour in the target populati on. We analysed the effect of the start of the Dutch national screening pro gramme on the number of mammographies requested by 43-45 general practices for the age groups 30-39, 40-49, 50-69 and 70+ years, using logistic regres sion analysis. In all age groups an immediate increase was observed in the number of mammography requests after the start of the screening, which was largest and statistically significant in the target population of the scree ning programme (age 50-69 years), More than 2 years after the start of scre ening, the number of mammography requests in all age groups had decreased t o the level before the start and in the age group 50-69 years the number of mammographies was significantly lower than before the screening started. T he unexpected increase in mammographies after the start of the breast cance r screening programme might be related to registry problems or to the proce ss of building up the screening programme. Eventually there was a decrease in the number of mammographies in the target: population, probably an effec t of the introduction of the national screening programme. Opportunistic sc reening was not clearly demonstrated in adjacent age groups. (C) 1999 Publi shed by Elsevier Science Ltd. All rights reserved.