The impact of regional screening policies on the diffusion of cancer screening participation in Belgium: time trends in educational inequalities in Flanders and Wallonia

BACKGROUND: We investigate whether the extent of educational inequalities in the use of Pap smears (cervical cancer screening) and mammograms (breast cancer screening) in Belgium has changed over time in accordance with the pattern predicted by diffusion of innovation theory, as well as how the regional cancer screening policies of Flanders and Wallonia influence this pattern. METHODS: Data were obtained from five successive cross-sectional waves (1997–2001–2004-2008-2013) of the Belgian Health Interview Survey. Final sample sizes consisted of 8988 women aged 25–64 years for cervical cancer screening and 4194 women aged 50–69 years for breast cancer screening. We calculated absolute and relative measures of inequality, more specifically, the slope index of inequality (SII) and the relative index of inequality (RII), and their development over time. RESULTS: In both Flanders and Wallonia, mammogram use increased greatly between 1997 and 2013, while Pap smear use has remained quite stable over time. Educational inequalities in cervical-cancer screening have been largely persistent over time in both regions. In contrast, educational inequalities in breast cancer screening fluctuated more between 1997 and 2013. Between 1997 and 2001, when the breast cancer screening programme was implemented in Flanders, RII reduced significantly by 45%. Inequality measures did not change significantly in Wallonia, where it is known that most women are screened opportunistically outside the programme. CONCLUSIONS: By focussing on Belgium, this study demonstrates that regional variations in the support of a national screening programme can result in regional variations in the pattern of diffusion for cancer screening, as well as to the development of inequalities in cancer screening participation. Moreover, the findings demonstrate that high visibility and awareness of the screening programme, as was more the case in Flanders than it was in Wallonia, are required in order to reduce or eliminate educational inequalities in cancer screening participation over time. General practitioners and gynaecologists can play a decisive role in this regard.