Fig. 4

Quality of reporting by impact factor of publication venue. a Overall scores by 2016 impact factor of the publication venue in the independent samples comparison. Spearman’s correlation: ρ = − 0.11, 95% C.I. [− 0.35, 0.13], p = 0.35, n = 69. b Change in score from peer-reviewed to preprint version by impact factor of the peer-reviewed publication year in the paired sample. Spearman’s correlation: ρ = 0.16, 95% C.I. [− 0.13, 0.43], p = 0.25, n = 53. Impact factor was unavailable for 7 articles in the independent sample and 3 in the paired one