Gøtzsche and Olsen, members of the In addition, several research studies have Nordic Cochrane Collaboration Group, published updated results, and there have published the results of their systematic been active scientific debates about the age review of mammography screening in The at which screening should begin and about Lancet in 2000 [Gøtzsche and Olsen, 2000] the validity of many of the scree [...] Given these developments, the these reports, they raised a number of revised research questions addressed by this concerns about the validity of the published report are: randomized trials and the choice of breast 1) What is the strength of the scientific cancer mortality as a measure of efficacy. [...] Hence arise all sorts of variability in study or program The main features of a strong contrast are design such as the interval between screens, the quality of the performance of the study and also complexity in defining concepts intervention, the thoroughness of its such as participation rates, average interval application to the screening population and between screens, and total number of its a [...] Third, the duration of the contrast in A weak contrast will tend to bias a study's screening studies is very different from the results in the direction of the null duration of the mammography programs that hypothesis, which is the hypothesis that are proposed or in place in various screening and control interventions are of jurisdictions. [...] If the purpose of the study is to more benefit than the average member of the anticipate the effect of introducing a population invited to screening).