Harmonization: a methodology for advancing research in multiple sclerosis

Decreasing research funding is in conflict with the increasing need to conduct large studies to examine rare risk factors and interactions between risk factors. As a result, investigators are searching for strategies to stretch research funds and to design studies that will maximize investments already made. Multiple sclerosis (MS) is generally accepted as a multifactorial disease, and the assessment of interactions between risk factors and the desire to assess risk factors within particular sub-groups requires a large number of participants. Harmonization is a methodology that may help address this problem. Harmonization is a methodological approach that aims to systematize the process of combining individual data that are collected in several observational studies. Combining data will increase sample size, but the quality of the harmonized result is only as high as the quality of the individual studies and the comparability of the constructs measured. In this short report, we introduce the concept of harmonization and provide examples where harmonization may be advantageous in MS research.