Methodological aspects of international drug price comparisons

Drug prices have become an important issue in the last few years as concerns about constrained healthcare resources have increased. Healthcare authorities in all industrialised countries are questioning whether their country is carrying a heavier burden than others in paying for drugs. In view of this discussion, several price comparison studies have been conducted. However, there is no generally accepted methodology on how to conduct price comparisons, and many methodological issues remain unresolved. The results of most published studies are affected by moderately serious methodological flaws, which are never properly addressed. The purpose of this study is to discuss the methodological issue of international drug price comparison, in terms of 6 points that appear to this author to be necessary to conduct a methodologically sound study. A previous review of a large number of drug price comparisons revealed that they all fail to take into account some or all of these 6 basic methodological points. Studies that fulfil the methodological criteria outlined in this paper are therefore urgently needed before drug pricing studies can be fully utilised as a basis for important policy decisions in the healthcare arena.