An overview of the characteristics and methodological standards across systematic reviews with Meta-analysis of efficacy/effectiveness of influenza antiviral drugs

Background Influenza antiviral drugs remain controversial and it is not clear if conclusions on their efficacy/effectiveness are based on high quality systematic reviews (SRs). We systematically identified, critically appraised, and summarized the characteristics and adherence to methodological standards in SRs with meta-analysis of efficacy/effectiveness of influenza antiviral drugs for prevention and/or treatment of influenza. Methods We searched MEDLINE, Embase, Scopus, CINAHL, Global Health, and CDSR for English-language SR publications up to July 2020. We summarized the characteristics, adherence to methodological standards and SR quality (AMSTAR 2). Results From a total 3,898 citations after removal of duplicates from all identified citations, we included 24 SRs. Seventy-five percent (n = 18) were of a critically low quality, 8% (n = 2) of a low quality, 17% (n = 4) of a moderate quality, and none were of a high quality. Seventeen percent (n = 4) were industry-funded, 4% (n = 1) coauthored by industry employee(s), and 33% (n = 8) commissioned by an organization or authority. Only 33% percent (n = 8) reported protocol registration, 4% (n = 1) reported collaboration with a knowledge synthesis librarian/information specialist, and 17% (n = 4) utilized a systematic review reporting checklist. Conclusions The evidence suggests that SRs of efficacy/effectiveness of influenza antiviral drugs are mostly of critically low quality and do not follow current best SR practices. These findings are significant in view of the important role of SRs in decision-making and the controversies that surround the use of the influenza antiviral drugs. However, the findings should not be interpreted to mean curtailment/cessation of use of antiviral drugs for influenza.