Viernes 3 de Octubre / Friday 3, October

15:00:00 a/to 16:30:00

325 INFORMACIÓN SOBRE EL IMPACTO DE LOS PROGRAMAS DE CRIBADO DE CÁNCER DE MAMA. INFORMATION ABOUT THE IMPACT OF BREAST CANCER SCREENING PROGRAMMES

Lola Salas Trejo*, Teresa Cerdá Mota**

*Unidad Prevención de Cáncer. D.G. Salud Pública, Conselleria Sanitat, Valencia, Spain. **Dirección Xeral de Saúde Pública, Conselleria de Sanidade, España.

Over the last few years Breast Cancer Screening Programmes have undergone tremendous growth both in Spain and in the rest of Europe. Fortunately, networks which coordinate these programmes have also been developed, these being the "European Breast Cancer Network (EBCN)" in Europe, and the "Annual Conference on Breast Cancer Screening Programmes" in Spain. Both these networks play a vital role through allowing professionals to exchange their experience and as regards the quality control of the processes involved, aspects which have determined the great impact that Breast Cancer Screening Programmes have had up to now and continue to have on the population, specifically among women.

326 COMPARACIÓN DE INDICADORES DE LOS PROGRAMAS INCLUIDOS

Nieves Ascunce Elizaga

Instituto de Salud Pública de Navarra, Departamento de salud Gobierno de Navarra, España.

In 1989 the European network of Breast Cancer Screening Programmes (EBCN) was got under way with the first pilot programmes that were being implemented in Europe at the time. Seventeen centres are involved in the network at the present time, and ten of these, from six different countries, have participated in an assessment project in order to jointly present their main results using impact-predicting indicators.

These indicators have been calculated as defined in "European guidelines for quality assurance in mammography screening" and their reference values have been used for comparative purposes. It was similarly examined if different organisational systems have an influence on the results in respect of these same indicators.

Data on the following aspects is given:

Participation

Detection rate

Characteristics of the tumours detected

327 INFORMACIÓN A LAS MUJERES SOBRE CRIBADO DE CÁNCER

Livia Giordano

Unit of epidemiology, CPO Piemonte Torino, Italia.

The past approach to screening information has mainly stressed benefits of screening for the population with the purpose of encouraging every eligible woman to participate, often glossing over detrimental side effects such as anxiety, false reassurance, false alarms, unnecessary biopsies, overdiagnosis and overtreatment.

There is now a general agreement that women cannot express informed participation in a population-based cancer screening programme unless they are given honest and balanced information, including explanations about advantages and disadvantages.

Although scientific literature stresses the importance of providing complete and truthful information to facilitate informed choice and participation in screening programmes, the question of how much information can or should be given to support (and not confuse or hinder) decisions is complex.

Some of the issues related to screening have to do with tensions between population and individual interests. While experts argue that more information on the disadvantages of screening would reduce uptake and thus reduce the benefits available at population level, very limited work has been done to test this hypothesis.

There is agreement that the information given about screening is inadequate and the recent revision of the written information material (first invitation letters and leaflets) on mammography provided to women by some European breast cancer screening programmes confirm this belief.

Even if satisfactory to disclose information about the examination modality and the screening aims, written information tools remain still inadequate in managing side effects and risks.

What possible suggestions to promote a real informed participation?

An important aspect of informed choice is that individuals must have access to relevant and appropriate information. Relevant not just from the health professional's point of view but also from the individual's point of view.

The starting point for good quality information to enable informed choice is to provide information about the issues of importance to those who are receiving it.

For this reason, researches on what women believe about the disease, what they understood and what they want to know should become a priority.

As far as the communication approach, a multifaceted and multi-level communication strategy should be adopted where differential information, different levels of deepening and the synergy with different communication tools can be tested.

328 EVALUACIÓN DEL IMPACTO EN LA MORTALIDAD MEDIANTE MODELOS EDAD-PERIODO-COHORTE

Marina Pollán Santamaría

Centro Nacional de Epidemiología, Instituto de Salud Carlos III, España.

Introduction: Decreasing of breast cancer mortality is the final indicator of effectiveness of any given population screening programme. The goal of this presentation is to estimate the reduction in breast cancer mortality in the Autonomous using age-cohort-period (APC) models.

Material and methods: Log-Poisson regression APC models estimate the variability in specific mortality rates associated with the age of death, the period of death and the birth-cohort. The variable period reflects changes produced in a specific moment affecting all age groups (such as changes in diagnosis, treatment and codification), while the cohort component mirrors variations mainly related with the generation (such as differences in the prevalence of risk factors). These models have been employed to forecast mortality not too far away from the last period available. Here, the reduction on mortality associated with the screening implantation is evaluated via APC models. Annual age-specific rates of breast cancer mortality during the period: 1980-1999 for age groups 30-34 until 85 and over were computed for every municipality (312). Numerators came from the Galician Mortality Registry and denominators were interpolated from censuses and municipal population registries. The impact of the screening program was evaluated in two ways: First, fitting an APC model including: age, quinquenium, birth-cohort, a socio-economic index, a variable reflecting rurality (population lower than 3000, 3000-10000 and towns greater than 10000) and the percentage of population covered by the programme as explanatory variables. The "screening" variable was 0 for those years and age-groups that were outside of the programme influence. Secondly, taking into account that the implantation of the screening programme has been progressively made between the years 1993 and 1998, the number of deaths expected in the age groups and towns already screened were computed from an APC model using only those strata outside the influence of the programme.

Results: The strata under the screening programme presented a lower though still not statistically significant mortality for breast cancer (RR per 10% of population covered = 0.98; p=0.074). In the second approach, the model used to estimate the number of breast cancer cases proved to be very consistent in the strata outside the influence of the program. There was a reduction of 13% in the observed mortality compared with the predicted.

Comments: Owing to the lack of enough data after the full implantation of the screening programme, it was not possible to consider a latency period in this analysis. We plan to extend it to the following years. For the next period, all Galician municipalities will be under the programme and a real extrapolation should be necessary to extend the APC model.