Meta-research metrics matter: letter regarding article "indirect tolerability comparison of Deutetrabenazine and Tetrabenazine for Huntington disease".

Here we discuss the report by Claassen and colleagues describing an indirect treatment comparison between tetrabenazine and deutetrabenazine for chorea in Huntington's disease using individual patient data. We note the potential for discrepancies in apparently statistically significant findings, due to the rank reversal phenomenon. We provide some cautionary observations and suggestions concerning the limitations of indirect comparisons and the low likelihood that good quality evidence will become available to guide clinical decision comparing these two agents.