that the investigators were "hoping" to find an effect of the smoke-free laws on sudden cardiac death and that - although I believe subconsciously - they slanted their interpretation of the data in order to favor such a finding. I can understand this bias because as a lifelong supporter of smoke-free laws, I would love to see data showing that these laws have an immediate effect in reducing sudden death from heart attacks. But you can see how this kind of bias, which is natural, can affect one's interpretation of the data. In this case, the investigators are presented with identical findings of a non-significant 17% change in sudden cardiac death rates. In the case where the change is a decline (which they favor), the significance does not matter. In the case where the change is an increase (which they disfavor), the significance absolutely matters and the finding can be completely thrown out as if it doesn't exist. The rest of the story is that the conclusions of this study are invalid because there was no comparison group and one cannot rule out the possibility that secular declines in heart attacks were occurring in Minnesota during the study period anyway (independent of the Olmsted County smoking laws). In fact, when one examines heart attack incidence rates for the state as a whole, one finds that there were comparable rates of decline in heart attacks in Minnesota during the same time period, nullifying and rendering invalid the study's conclusion. Very clearly,