SERIES: Living Evidence Syntheses in Practice: Methodology, Standards, dissemination and publication challenges....

This is the second paper in a three-part series assessing how living evidence synthesis (LES) products (systematic reviews, rapid reviews, network meta-analyses, overviews of reviews, and scoping reviews) are defined, implemented, reported, and updated over time. Here, we evaluate compliance to methodological and reporting standards and the consistency of application of key living review principles across updates.

We conducted a methodological literature-based survey of any type of evidence syntheses that explicitly stated the use of a living evidence approach. All eligible LES were prospectively monitored by two years to capture all updates to achieve our assessment objectives. Adherence to conduction and reporting standards was assessed using the Bendersky's checklist, which compiles previously described living review requirements. In a post hoc analysis, we used a subsample of LES to assess compliance with the reporting elements included in the PRISMA-LSR extension.

Compliance with the Bendersky checklist was assessed in 119 baseline reports and up to three subsequent updates or surveillance reports per LES (93 reports). Baseline report compliance with general systematic review items was acceptable (>70%), but living-specific reporting was limited: 52% reported a monitoring plan but <30% reported most key elements, and only 5% specified discontinuation criteria. Among 73 updates, <50% reported previous updates and 35.6% reported changes in monitoring; all reported changes in screening or selection frequency. Among 20 surveillance reports, 20.0% reported previous updates and none reported changes in monitoring. In 20 LES assessed using new PRISMA-LSR extension, compliance was 57.5% at baseline, declining to 40.7% and 42.3% in intermediate and final updates, respectively.

Despite growing adoption of the living evidence approach, substantial gaps remain in implementing and reporting living-specific standards. Update triggers, surveillance strategies, discontinuation criteria, and version control were frequently underreported, with PRISMA-LSR compliance declining over successive updates.