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Efficacy and safety of ceftazidime–avibactam versus polymyxins in the treatment of carbapenem-resistant Enterobacteriaceae infection: a systematic review and meta-analysis
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  • Published on:
    Conducting systematic reviews of observational studies
    • Mical Paul, Infectious Diseases physician Rambam Health Care Campus

    Yang et al. published a systematic review and meta-analysis on the efficacy and safety of ceftazidime-avibactam versus polymyxins in the treatment of carbapenem-resistant Enterobacteriaceae infection. The meta-analysis compared and summarized crude numbers of deaths, clinical failure and other outcomes. Patients treated with a new, costly, promising antibiotic are very different from patients treated with the old, currently non-recommended, antibiotic.(1,2). Most original studies made an effort to adjust for this extreme indication bias using regression and propensity-based analyses. Values from these adjusted analyses should be used in a systematic review and meta-analysis (3). Summarizing crude, unadjusted values is no more acceptable in a meta-analysis that it was in the original observational studies. Rather it is much more harmful since pooling all studies narrows the confidence intervals surrounding the unadjusted results. Reporting the risk of bias score is meaningless when using the crude numbers, since these scores attempt to appraise how well indication bias was addressed in the original studies. From a systematic review addressing such a difficult comparison for observational studies, I would expect serious critical appraisal of the analyses attempting to reduce indication bias and the validity of the reported adjusted results. “All studies were considered to have low risk of bias” is an inappropriate appraisal of these observational studies. Finding better trea...

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    Conflict of Interest:
    None declared.