Unreported Cognitive Scores in a Cannabis-Spray Trial Were Not Negative Results
The review identified a cannabis-extract trial that administered cognitive tests without reporting the quantitative results needed for synthesis. Missing scores should not be counted as demonstrated absence of impairment.
Testing and reporting are separate facts
The Notcutt study discussed in the review used Trail Making and the Adult Memory and Information Processing Battery. The reviewers described the cognitive findings as equivocal and noted that relevant quantitative results were not reported. Knowing that a test was administered does not supply its effect estimate or uncertainty.
The gap limits both favorable and unfavorable claims
The missing information cannot be converted into a clear drug-placebo null, a cognitive benefit or a demonstrated deficit. A narrative statement that some testing improved is not an adequate substitute for the comparison and data needed to assess that interpretation.
Retain the reporting limitation in an evidence inventory
A review should distinguish an unmeasured endpoint, an administered but insufficiently reported endpoint and a reported nonsignificant comparison. They contribute different information. The present analysis relies on what the supplied review says about the report; it does not claim an independent reanalysis of unavailable scores. The limitation concerns interpretability, not a conclusion that the investigators’ overall clinical work was invalid. For a treatment or impairment claim, the actual cognitive result must be available rather than inferred from silence.
Related analysis: the review’s broader findings and limitations.
Research cited
This analysis draws on the supplied review: Eadie and colleagues (2021). Duration of Neurocognitive Impairment With Medical Cannabis Use: A Scoping Review. Frontiers in Psychiatry.
Study discussed in that review: DOI 10.1111/j.1365-2044.2004.03674.x.
