Article 1: Excluding non-English publications from evidence-syntheses did not change conclusions: a meta-epidemiological study. Nussbaumer-Streit B et al. 2019 Nov 4.

Conclusion: Exclusion of non-English publications from systematic reviews on clinical interventions had a minimal effect on overall conclusions and could be a viable methodological shortcut, especially for rapid reviews.

Comment: Nice to see (not) that the systematic review world appear to care little for cost when they’ll happily carry on with their philosophical ‘purity’ of trying to get ‘all’ evidence – even when it’s unlikely to make a difference. Have a massive pat on the back (again, not).

Article 2: An ultra-rapid review approach: an innovative solution to make evidence more relevant for time-sensitive policy-making and providing guidance for health systems? Affengruber L et al. Oral Presentation. BMJ EBM 2019 Volume 24, Issue Suppl 1

Conclusions: For oncological topics, the conclusions of the ultra-rapid review approach changed less often compared to the public health topic. Based on these three case studies, an ultra-rapid review approach seems to be viable for narrow questions that can be answered with RCTs. However, to assess whether an ultra-rapid review approach could be an expedited solution for evidence-based decisions for policy or health care professionals further research with a larger sample size is necessary to confirm our findings.

Comment: Interesting finding that narrow topics seemed more likely to get better, rapid, results. It seems to crop up a fair bit from my experience. For instance, using machine learning based screening tools work better on narrow topics and can be poor on broad – public health – topics. Again, it reinforces the need to understand when rapid methods work well and when less well.  Then you do reviews of narrow topics (say) as rapid reviews and that leaves more resources to (a) do more rapid reviews (b) do broad reviews. This seems so obvious to me!

Article 3: Pragmatic methods for reviewing exceptionally large bodies of evidence: systematic mapping review and overview of systematic reviews using lung cancer survival as an exemplar. Lewis R et al. Syst Rev. 2019 Jul 16;8(1):171

Conclusions: The study utilised a novel approach for reviewing an extensive and complicated body of research evidence. It enabled us to address a broad research question and focus on a specific area of priority. The staged approach ensured the review remained relevant to the stakeholders throughout, whilst maintaining the use of objective and transparent methods. It also provided important information on the needs of future research. However, it required extensive planning, management, and ongoing reviewer training.

Comment: Not a massive fan of overviews of overviews (as may miss important research that has yet to be reviewed), but it’s a pragmatic solution to attempt to rapidly derive an answer. Also, one of the authors – Dyfed W. Huws – is a colleague of mine at Public Health Wales!