A retrospective (N = 140) and a prospective (N = 102) observational Israeli study by Bar-Sela and colleagues about cannabis potentially adversely impacting the response to immunotherapy have together been cited 202 times, including by clinical practice guidelines. There have also been concerns on PubPeer outlining irregularities and unverifiable information in their statistics and numerous errors in calculating percentages. This reanalysis attempted to verify the data analysis while including non-parametric statistics. The corrected prospective report contained 22p-values, but only one (4.5%) could be verified despite the authors being transparent about the N and statistics employed. Cannabis users were significantly (p< 0.0025) younger than non-users, but this was not reported in the retrospective report. There were also errors in percentage calculations (e.g., 13/34 reported as 22.0% instead of 38.2%). Overall, these observational investigations, and especially the prospective, appear to contain gross inaccuracies which could impact the statistical decisions (i.e., significant findings reported as non-significant or vice-versa). Although it is mechanistically plausible that cannabis could have immunosuppressive effects which inhibit the response to immunotherapy, these two reports should be viewed cautiously. Larger prospective studies of this purported drug interaction that account for potential confounds (e.g., greater nicotine smoking among cannabis users) may be warranted.
Bar-Sela及其同事开展的一项关于大麻可能对免疫疗法反应产生不利影响的以色列回顾性研究（N=140）和前瞻性研究（N=102）共计被引用202次，其中包括临床实践指南的引用。PubPeer平台亦指出其统计数据存在不规范和不可验证信息，且百分比计算存在多处错误。本次再分析尝试在纳入非参数统计的同时验证其数据分析。修正后的前瞻性报告包含22个p值，尽管作者对样本量和所用统计方法保持透明，但仅有一个p值（4.5%）可被验证。大麻使用者的年龄显著低于非使用者（p<0.0025），但回顾性报告中未报告此发现。此外还存在百分比计算错误（例如将13/34报告为22.0%而非38.2%）。总体而言，这些观察性研究（尤其是前瞻性研究）似乎存在重大误差，可能影响统计结论（例如将显著性结果报告为非显著性，反之亦然）。尽管从机制上讲大麻可能具有抑制免疫疗法反应的免疫抑制作用，但应谨慎看待这两份报告。未来可能需要开展更大规模的前瞻性研究来验证这种药物相互作用的假设，并控制潜在混杂因素（例如大麻使用者中更高的尼古丁吸烟率）。
Immunotherapy and Cannabis: A Harmful Drug Interaction or Reefer Madness?
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