PMID- 27749930 OWN - NLM STAT- MEDLINE DCOM- 20170531 LR - 20221207 IS - 1932-6203 (Electronic) IS - 1932-6203 (Linking) VI - 11 IP - 10 DP - 2016 TI - A Systematic Review of Methods for Handling Missing Variance Data in Meta-Analyses of Interventions in Type 2 Diabetes Mellitus. PG - e0164827 LID - 10.1371/journal.pone.0164827 [doi] LID - e0164827 AB - AIMS: Meta-analysis is of critical importance to decision makers to assess the comparative efficacy and safety of interventions and is integral to health technology assessment. A major problem for the meta-analysis of continuous outcomes is that associated variance data are not consistently reported in trial publications. The omission of studies from a meta-analysis due to incomplete reporting may introduce bias. The objectives of this study are to summarise and describe the methods used for handling missing variance data in meta-analyses in populations with type 2 diabetes mellitus (T2DM). METHODS: Electronic databases, Embase, MEDLINE, and the Cochrane Library (accessed June 2015), were systematically searched to identify meta-analyses of interventions in patients with T2DM. Eligible studies included those which analysed the change in HbA1c from baseline. RESULTS: Sixty-seven publications reporting on meta-analyses of change in HbA1c from baseline in T2DM were identified. Approaches for dealing with missing variance data were reported in 41% of publications and included algebraic calculation, trial-level imputation, and no imputation. CONCLUSIONS: Meta-analysis publications typically fail to report standardised approaches for dealing with missing variance data. While no particular imputation method is favoured, authors are discouraged from using a no-imputation approach. Instead, authors are encouraged to explore different approaches using sensitivity analyses and to improve the quality of reporting by documenting the methods used to deal with missing variance data. FAU - Batson, Sarah AU - Batson S AD - DRG Abacus, Bicester, United Kingdom. FAU - Burton, Hannah AU - Burton H AD - DRG Abacus, Bicester, United Kingdom. LA - eng PT - Journal Article PT - Meta-Analysis PT - Review PT - Systematic Review DEP - 20161017 PL - United States TA - PLoS One JT - PloS one JID - 101285081 RN - 0 (Glycated Hemoglobin A) RN - 0 (hemoglobin A1c protein, human) SB - IM MH - Analysis of Variance MH - Databases, Factual MH - Diabetes Mellitus, Type 2/*pathology MH - Glycated Hemoglobin/analysis MH - Humans PMC - PMC5066955 COIS- We have the following interests. This study was funded by DRG Abacus. Batson and Burton are employed by DRG Abacus. There are no patents, products in development or marketed products to declare. This does not alter our adherence to all the PLOS ONE policies on sharing data and materials, as detailed online in the guide for authors. EDAT- 2016/10/18 06:00 MHDA- 2017/06/01 06:00 PMCR- 2016/10/17 CRDT- 2016/10/18 06:00 PHST- 2016/07/17 00:00 [received] PHST- 2016/09/30 00:00 [accepted] PHST- 2016/10/18 06:00 [pubmed] PHST- 2017/06/01 06:00 [medline] PHST- 2016/10/18 06:00 [entrez] PHST- 2016/10/17 00:00 [pmc-release] AID - PONE-D-16-28537 [pii] AID - 10.1371/journal.pone.0164827 [doi] PST - epublish SO - PLoS One. 2016 Oct 17;11(10):e0164827. doi: 10.1371/journal.pone.0164827. eCollection 2016.