Letters to the Editor|Articles in Press

Numbers don’t lie – but tell only part of the story

Open AccessPublished:March 13, 2023DOI:
      We appreciate Reiffel’s interest in our paper and the opportunity it provides to reiterate important caveats when interpreting research findings.
      First Reiffel mentions a concern with possible misclassification of diagnostic codes in administrative datasets. We agree and mentioned this among our limitations. However, this concern is mitigated by the data being generated by trained medical personnel and that these data sets have been used in over in 2,700 peer-reviewed studies (
      Second Reiffel notes, again as we mentioned in the original article, that propensity score methods can only adjust for measured covariates. However, Reiffel’s specific concern about the impact of beta blockers was dealt with by exclusion, as both exposure groups were selected without any concomitant beta blockers. Similarly, SGLT-2 medication use was not unbalanced between the groups, as they were not on the market at the time of the data acquisition.
      Third, the choice of research question, and by consequence the chosen outcome remains an essential element in any study. Reiffel argues that only unplanned atrial fibrillation hospitalizations should have been considered as an outcome, but most readers would 1) find the definition of “unplanned” to be potentially arbitrary and subjective 2) consider that outcome to be of lesser importance than our a priori chosen total repeat cardiovascular outcome measure.
      Finally, as Reiffel suggests, different research questions including the effect of drug choice on AF symptoms or AF burden could have been chosen, but they quite simply were not our research question.
      Accordingly, we disagree with Reiffel’s assertion that “numbers can lie”, rather the issue is not with the numbers per se, but rather with how they are generated and interpreted. We feel that the generation and interpretation of these numbers supports our conclusion that “given the large burden of disease with atrial fibrillation, a pressing need remains to reproduce and expand these research findings in different settings.”

      Linked Article

      • Numbers Don’t Lie – Or Can They?
        CJC Open
        • Preview
          I read with interest the Brophy/Nadeau paper “seeking to determine the comparative drug effectiveness of” amiodarone vs dronedarone (1) -- although their primary outcome was only repeat cardiovascular hospitalization (CVH) or within-hospital death subsequent to an initial hospital discharge for which ICD codes indicated atrial fibrillation (AF) as primary diagnosis. Using analyses with several statistical adjustments and propensity-score matching, the authors reported more CVH in the dronedarone group (12.7% vs 8.4%).
        • Full-Text
        • PDF
        Open Access