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Do pooled estimates from orthodontic meta-analyses change depending on the meta-analysis approach? A
Zacharias Tatas1, Ourania Koutsiouroumpa2, Jadbinder Seehra3
1Department of Orthodontics and Dentofacial Orthopedics, Dental School/Medical Faculty, University of Bern, Switzerland.
European Journal of Orthodontics
|July 12, 2023
Summary
The Hartung and Knapp (HK) correction significantly impacts meta-analysis results with few studies. Clinicians must consider heterogeneity and correction methods for accurate interpretation of pooled estimates.
Area of Science:
- Orthodontic research
- Biostatistics
- Evidence-based dentistry
Background:
- Meta-analyses with few studies require careful assessment of between-study heterogeneity.
- The Hartung and Knapp (HK) correction is recommended for meta-analyses with fewer than five studies exhibiting heterogeneity.
Approach:
- Systematic reviews (SRs) from orthodontic journals and the Cochrane Database (2017-2022) with ≥3 studies were analyzed.
- Meta-analyses were re-analyzed using eight heterogeneity estimators with and without HK correction.
- Pooled effect size, prediction intervals (PI), and confidence intervals (CI) were calculated.
Key Points:
- The HK correction altered statistical significance in 16.7%-25% of meta-analyses.
- Between-study variance was reported in most SRs, but heterogeneity estimators were rarely specified.
- Prediction intervals indicated that over half of statistically significant results may not be conclusive in the future.
Conclusions:
- Statistical significance in meta-analyses is sensitive to HK correction, heterogeneity estimators, and PIs.
- Clinicians must understand the impact of small study numbers and heterogeneity on meta-analysis interpretation.
- Inappropriate assessment can lead to misinterpretation of clinical implications.
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