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Comment & Response
January 24, 2019

Methodology Flaws and Implications of a Complementary Medicine Study

Author Affiliations
  • 1Research Unit on Scientific Culture, CIEMAT, Madrid, Spain
JAMA Oncol. 2019;5(3):432-433. doi:10.1001/jamaoncol.2018.6640

To the Editor From my perspective, the work by Johnson et al1 has 3 problems. Two are genuinely methodological, whereas the third is more related with the ethics of research. The 3 problems severely undermine the study’s scientific rigor.

First, the authors show that the use of complementary medicine (CM) is an independent variable associated with a greater risk of death. The problem arises when, after also adjusting for treatment refusal and delay from diagnosis to treatment, CM no longer has a statistically significant association with the risk of death. This means that the supposed association between CM use and survival is a spurious one, ie, a false correlation between 2 variables that is caused by a third variable.

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