Language bias in orthodontic systematic reviews: A meta-study

Ref ID 1044
First Author S. Mheissen
Journal PLOS ONE
Year Of Publishing 2024
URL https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0300881
Keywords • Language
• Dentistry
Problem(s) • Literature searches not validated by information specialist
• Language restriction
Article Type Empirical
Article Subtype Meta-epidemiological analysis
First Author Country Syria
Aim To explore whether including non-English language studies in orthodontic systematic reviews (SRs) published in high-impact orthodontic journals between 2017 and 2021, may affect meta-analyses results and to estimate the extent of language bias in orthodontic SRs.
Level of Investigation Analytical
Summary of Findings From 174 systematic reviews (SRs) published in high-impact orthodontic journals between 2017 and 2021. Non-English studies were included in around one quarter (n = 45/174, 26%) of the SRs, representing 3.78% of the total included studies in orthodontic SRs (98/2568). There were explicit language restrictions in 39 of the reviews (22%). Only 37 (21%) SRs involved a librarian or/and search specialist. Meta-epidemiological analysis revealed that non-English studies tended to overestimate the summary SMD by approximately 0.30, but this was not statistically significant when random-effects model was employed due to substantial statistical heterogeneity (SMD = -0.29, 95%CI: -0.63 to 0.05, P = 0.37).
Number of systematic reviews included 174
Number of eligible systematic reviews assessed 185
Treatment impacted No
Treatment impacted description Meta-epidemiological analysis revealed that non-English studies tended to overestimate the summary SMD by approximately 0.30, but this was not statistically significant when random-effects model was employed due to substantial statistical heterogeneity (SMD = -0.29, 95%CI: -0.63 to 0.05, P = 0.37).
Interpretation impacted No
Interpretation impacted description