Objective: To review studies on the costs of diabetes and its complications through a scheme designed specifically for assessing the quality of cost-of-illness (COI) studies.
Design and setting: The methodology of COI studies in diabetes was analysed in order to assess the significance of quantitative results. The scheme adopted 7 items identified as the main points for discussing the methodological choices governing the results. We also used a checklist based on questions related to the 7 items.
Main outcome measures and results: The answers showed that many studies appear not to give technical details, so it is hard to understand the method. Methodological choices varied widely between the studies. This is probably due to the lack of consensus on the methodology of COI studies. Based on the findings of this review, we suggest also some specific points that could help produce more reliable results on the costs of diabetes.
Conclusions: Clearly, a general consensus on COI studies is still remote, making the value of any comparison of results questionable.