A nationally quasi-experimental study to assess the impact of partial organized breast and cervical cancer screening programme on participation and inequalities.

BACKGROUND: Organized breast and cervical cancer screening programme could only provide services at no cost for a fraction of socioeconomic-deprived women in China and other low-resource countries, however, little evidence exists for whether such a programme effectively affect the participation and inequalities at the population level. METHODS: We used individual-level data from a nationally cross-sectional survey in 2014-2015 for breast and cervical cancer screening participation. Data for intervention and comparison grouping were from 2009 to 2014 national breast and cervical cancer screening programme, and counties covered by the programme were divided into intervention group. We assessed the impact of the intervention on the participation rates and the magnitude of inequalities with two approaches: multivariable multilevel logistic regressions adjusting for individual- and region-level covariates; and a difference analysis combined with propensity score matching that estimated the average intervention effect. RESULTS: Of 69,875 included women aged 35-64 years, 21,620 were classified into the intervention group and 43,669 into the comparison group for breast cancer screening; and 31,794 into the intervention group, and 33,682 into the comparison group for cervical cancer screening. Participation rate was higher in intervention group than comparison group for breast cancer screening (25.3, 95% confidential interval [CI], 22.8-27.7%, vs 19.1, 17.4-20.7%), and cervical cancer screening (25.7, 23.8-27.7%, vs 21.5, 19.6-23.5%), respectively. Intervention significantly increased the likelihood of participation for both breast cancer and cervical cancer screening in overall women, rural women and urban women, whereas the effect was significantly higher in rural women than urban women. The average intervention effect on the participation rate was an increase of 7.5% (6.7-8.2%) for breast cancer screening, and 6.8% (6.1-7.5%) for cervical cancer screening, respectively. The inequalities were significantly decreased by 37-41% (P < 0.001) between rural and urban, however, were slightly decreased or even increased in terms of age, education status, and household income. CONCLUSIONS: Organized breast and cervical cancer screening programme targeting for a fraction of women could increase the participation rates at population level, however, it could not significantly affect socioeconomic-introduced inequalities. Further studies are need to conduct time-series analyses and strengthen the causal correlation.