Thoughts on how to improve the quality of multicentre patch test studies.

Multicentre patch test studies (MPTSs) can contribute useful information for diagnostic and preventive measures. The aim of the present paper is to propose how to perform high-quality MPTSs. To this end, factors of significance for the patch test result are discussed with regard to the standardization and calibration of high-quality MPTSs. The 16 factors discussed are scored 0, 1, 2, or 3, depending on the relative importance of a particular factor for the patch test result. The total score of an MPTS allows it to be ranked as having doubtful, acceptable, high or excellent quality. A total score of 30 is possible. Depending on the total score the MPTSs are grouped into those with a doubtful, acceptable, high, and excellent quality. In conclusion, high-quality MPTSs can be performed and are facilitated if a guideline and check list are followed when the study is being planned. The scoring enables the calculation of a total score, which can be used for quality ranking.