Improvement needed in the network geometry and inconsistency of Cochrane network meta-analyses: a cross-sectional survey

Article type
Authors
Gao Y1, Ge L2, Ma X3, Tian J1
1Evidence-Based Medicine Center, School of Basic Medical Sciences, Lanzhou University, Lanzhou
2School of Public Health, Lanzhou University, Lanzhou
3The Second Clinical Medical College of Lanzhou University, Lanzhou
Abstract
Background:
With the popularity of network meta-analyses (NMAs), more and more NMAs were published on Cochrane library, but there were no previous studies that evaluate the quality of all NMAs published in the Cochrane library.

Objectives:
To investigate the general characteristics, methodological and reporting quality of network meta-analyses (NMAs) published in the Cochrane library.

Methods:
We conducted a comprehensive search of the Cochrane library in April 2018 and included 42 NMAs. We used AMSTAR 2 to assess methodological quality and PRISMA-NMA for reporting quality. Stratified analysis and correlation analysis were conducted to explore the factors that might affect quality.

Results:
42 NMAs investigated 29 topics. The compliance of PRISMA-NMA was moderate. Only 26.2% NMAs described the geometry of network, 64.3% presented the network plot, and 33.3% assessed the inconsistency. The overall methodological quality was low. Only 11.9% NMAs explained the selection of study designs, and 40.5% investigated the publication bias. The compliance of PRISMA-NMA was higher with the increase of the AMSTAR 2 compliance rates (Spearman’s ρ = 0.630, P=0.000). NMAs with statistical or epidemiological authors often better reported the titles (P=0.032). Compared with non-funding NMAs, non-industry funding NMAs often better reported data collection process (P=0.028), planned methods of analysis (P=0.034), and synthesis of results (P=0.028).

Conclusions:
The quality still needs to be further improved, especially referring to the assessment of publication bias, the geometry of network, assessment and exploration of inconsistency.

Patient or healthcare consumer involvement: No.