Factors influencing coverage, response and participation in a breast cancer screening program

BACKGROUND: The objective was to analyze sociodemographic, organizational and health care-related factors associated to level of enrolement in a breast cancer screening program developed in one area of Barcelona (Spain). MATERIAL AND METHODS: Three types of indicators were used: coverage, response and participation. The influence of age, educational level, previous clinical contacts, the person who received the citation and the reason for not attending after the first citation were studied. The odds ratio (OR) was used to estimate the magnitude of the association between variables. The OR were adjusted by age and education through unconditional logistic regression. RESULIS: The rates were: coverage 79.2%, response 74.6%, and participation 61%. The response after the first citation was influenced by the recipient of the letter (p < 0.001); when it was the target-woman, the response was 75%. The response after the successive citations was 50.5% if the reason for not attending previously was circumstantial, and 11.5% when it was lack of interest. Having had previous clinical contacts in the primary care centre or in the reference hospital multiplied by 4 to 7 times the response. Coverage decreased with age, and it presented a curvilinear pattern with respect to educational level. Multivariate analyses emphasized the importance of previous clinical contacts (ORs between 3.5 and 8.1; p < 0.001). CONCIUSIONS: Previous contacts with the health system, the method of citation and the reason for not attending after the initial pahse were factors clearly associated with participation in a breast cancer screening program. Research on factors influencing participation would contribute to improve the results of screening programs currently underway in Spain.