When the randomized trial from Malmö was analyzed as a case control study, a 58% reduction in mortality from breast cancer was found, whereas the real, observed reduction in the trial was only 4% (8% when the results were adjusted for non-compliance and contamination) [ 36].
Although the reduction within the trial intervention arms was greater for those trials with a higher baseline HbA1c we also observed a reduction in the trial control arms, perhaps attributable to regression to the mean [ 22].
Our findings of increased toxicity are in line with the POCHER trial investigating the same drugs in a chronomodulated schedule requiring a dose reduction during the trial [ 12].
The relative hazards of different factors, including lymph node status, have previously been validated against observed mortality reduction in the trial in different age-groups including women aged 40 49 (Tabar et al, 1995a).
This enables comprehensive analysis of the relationship between intervention use and symptom reduction following the trial, for instance, examining dose response curves and whether viewing some sections in particular appeared to be critical to beneficial outcome.
In brief, rosuvastatin was associated with a 44% (hazard ratio [HR], 0.56; 95% confidence interval [CI], 0.46 0.69; P<0.00001) reduction in the trial primary end point, a composite of nonfatal MI, nonfatal stroke, hospitalization for unstable angina, arterial revascularization, or death resulting from cardiovascular causes.
The mean (±SD) weight reductions during the trial were 4.6 ± 2.7 kg for the controls, 4.2 ± 3.2 kg for the ispaghula group and 4.6 ± 2.3 kg for the bran group (p > 0.05 for both groups).
Essentially, the RR reduction from the trials is regarded as approximately generalisable to the current UK screening programmes, and the corresponding absolute risk reduction is calculated by applying this RR reduction to the national rates of breast cancer mortality for an appropriate age group.
The yield reduction in the trials varied from 51% to 60%, indicating that the association panel was subjected to moderate to severe drought stress.
The panel's view is that to estimate the impact of the UK screening programmes on absolute risk of dying of breast cancer, it is necessary to consider the relevant underlying risk of breast cancer to which the RR reduction from the trials should apply.
