If comparisons can be odious, so can assumptions

CORRESPONDENCE If comparisons can be odious, so can assumptions Dear Sir, We are writing in response to the article 'A cost minimization study comparing vigabatrin, lamot-rigine and gabapentin for the treatment of intractable partial epilepsy' that was published in Seizure 1996; 5: 89-95. There are some specific issues concerning the paper that we would like to raise. However, we would first like to contribute to the discussion from last month's editorial on the consideration of cost and the newer anti-epileptic drugs (AEDs). In the recent publication 'A Positive Approach to Epilepsy " the Department of Health recognizes that the new AED therapies may offer significant personal health gain and longer-term financial savings. We agree and believe that although the new AED therapies may appear initially to be more expensive than the older therapies, this increase in cost can produce real benefits to the patient, and the NHS, in terms of fewer side-effects, better compliance and improved patient quality of life. It is in the interests of patients, the health service and the pharmaceutical industry that resources are used to produce the maximum health gain. Therefore, decision-maker need evidence not just on the clinical effectiveness of medicines but also on the economic and quality of life outcomes of using them. Health economic evaluations need to be subjected to a similar level of scrutiny as clinical evidence. For the conclusions to be valid they need to be based upon robust clinical data and sound reasoning, and they should adhere to the British guidelines for economic evaluations*. The 'gold standard' economic evaluation may well be one that is run prospectively alongside a ran-domized controlled trial. However, observational approaches such as practice audits can also provide useful information for decision-makers. Economic analyses based upon secondary analysis of clinical data, such as the one published in the last issue3, are another useful method to consider. are heavily dependent upon the clinical evidence selected and the assumptions that are made. With this in mind, we wish to raise three particular aspects of the paper for discussion. The first is the choice of technique. The authors have proposed that in the absence of conclusive evidence to the contrary equal efficacy should be assumed. When interventions have equal efficacy, cost minimization is accepted-as an appropriate technique. However, it is questionable whether cost minimization should have been applied in this case as equal efficacy has not been proven. Indeed, …