Living methods for living guidelines: Changes to evidence synthesis methods in the Australian National Clinical Evidence Taskforce COVID-19 living guidelines

Living evidence methods, such as those used to produce living guidelines, can evolve over time as the context or evidence changes. In Australia, the National Clinical Evidence Taskforce has been developing living guidelines for the management and care of people with coronavirus disease 2019 (COVID-19) since March 2020, undertaking daily searches, and producing over 130 updates of more than 200 recommendations. Over the 3 years of the guidelines, the methods have also been ‘living’. In this paper, we describe why, how and with what impact changes to our methods have been made. When changes were required to the methods, the Taskforce Evidence Team developed a ‘Methods Brief’ outlining the proposed changes, rationale and any risks. This was presented to the Guidelines Leadership Group for approval and to the Steering Committee for noting. Changes were then reflected in the online, publicly available description of our methods. Methods to develop the living guidelines evolved through five phases, reflecting changes in the availability of evidence, the degree and nature of clinical uncertainty and resource availability. Largely these changes were to the criteria we used to select evidence for inclusion, and our expected level of responsiveness to new evidence. In the initial phases, inclusion criteria were very broad, and as the evidence base stabilised our focus narrowed to areas of high clinical importance and evidence certainty. The rapidly evolving nature of the pandemic, understanding of the illness, clinical questions and evidence base during development of the living COVID-19 guidelines, necessitated multiple changes to the methods used to produce the guidelines. In this context, the ongoing revision of the methods for living guideline production was a necessity and a strength of the living approach. Questions remain about how best to ensure rigour is maintained while methods evolve.