“Our results show that blood pressure lowering drugs prevent a significant proportion of headaches…This in turn indicates that high blood pressure is a cause of headache but this conclusion is not supported by observational studies of blood pressure and headache. The uncertainty over whether high blood pressure causes headache does not, however, detract from the practical use of blood pressure tablets in preventing headaches…”
“Both experts agreed that in this matter opinion can only be based on informed guess work together with indirect scientific evidence e.g. that on LVH regression because specific and direct evidence does not exist.”
“46 In my view one cannot draw a distinction between medical negligence cases and others. I would summarise the position in relation to cumulative cause cases as follows. If the evidence demonstrates on a balance of probabilities that the injury would have occurred as a result of the non-tortious cause or causes in any event, the claimant will have failed to establish that the tortious cause contributed. Hotson exemplifies such a situation. If the evidence demonstrates that ‘but for’ the contribution of the tortious cause the injury would probably not have occurred, the claimant will (obviously) have discharged the burden. In a case where medical science cannot establish the probability that ‘but for’ an act of negligence the injury would not have happened but can establish that the contribution of the negligent cause was more than negligible, the ‘but for’ test is modified, and the claimant will succeed.”