From:
Glick M, Verdugo-Paiva F, Booth HA, Liu E, Vandvik PO, Guyatt G,
Carrasco-Labra A, When to conduct a new systematic review or continue updating an existing living systematic review: rationale and considerations, Journal of Clinical Epidemiology (2026), doi: https://
doi.org/10.1016/j.jclinepi.2026.112504.
3.3. Methodological refinements are incremental.
Small adjustments in framing the question or methods do not alter the fundamental approach. A redesigned search—for example, incorporating new databases, search filters, or terms due to changes in indexing, would not warrant a new review. Similarly, adding or removing an a priori hypothesized subgroup analysis to explain heterogeneity, conducting tests of interaction for all such hypotheses and applying ICEMAN to interaction tests with sufficiently low p-values would also constitute a small adjustment (10). A Cochrane review on exercise therapy for chronic fatigue syndrome has been updated eight times between 2004 and 2024. Over this period, new methodological standards emerged, and the authors adapted their methods accordingly. In one update, they explicitly noted aligning their approach with the recommendations from the 2011 Cochrane Handbook for Systematic Reviews of Interventions. These refinements improvedrigor but did not change the primary aim of the review—showing that such methodological updates do not justify creating an entirely new review (11).
11. Larun, L., Brurberg, K. G., Odgaard-Jensen, J., & Price, J. R. (2017). Exercise therapy for chronic fatigue syndrome. The Cochrane database of systematic reviews, 4(4), CD003200.
https://doi.org/10.1002/14651858.CD003200.pub7