Background: Living evidence (LE) approach permits new research findings to be continually incorporated into evidence synthesis. Methods for this type of synthesis are not completely defined. The approaches currently used by the authors are unknown.

Objectives: To identify, evaluate and summarize the current methods used by authors for conducting and reporting living evidence synthesis.

Methods: We conducted a methodological study based on a systematic literature search to identify any type of evidence synthesis such as systematic reviews, network meta-analyses and overviews that used the “living evidence” approach. A highly sensitive search was run in Medline and Epistemonikos databases. Hand searching was done aimed to identify unpublished update reports included in the organization's websites and repositories among others. Two reviewers independently assessed each article against the selection criteria and extracted data on methods and procedures from the baseline report and subsequent updates. Data was analyzed descriptively.

Results: Searches up to August 31st, 2021, retrieved 1,692 records. We assessed 246 articles in full text, 195 met the criteria of being a living evidence synthesis (LES), corresponding to a total of 89 studies. Out of them 54 reporting only the baseline synthesis and 35 reporting the baseline and at least one update. Methods used by authors for searching, screening, monitoring, and integrating new evidence during the living mode are summarized descriptively in tables. LES authors used different ways to communicate their updates. We present the sources and publication characteristics of updated reports not identified by electronic searches.

Conclusions: There is a significant number of authors who did not report most of the main methodological characteristics for the “Living Evidence” approach, which suggest a low compliance with current methodological standards. Therefore, more guidance and standardization are needed to ensure they are conducted using rigorous methods, which will serve to improve the report of living evidence synthesis.