Figure 5.

Forest plots of study design characteristics of experiments in which treatments were assessed for antinociceptive efficacy in rat models of persistent or injury-related persistent pain. Model type (A), sex (B), strain (C), and outcome assessment type (D) account for a significant proportion of heterogeneity. The size of the square represents the weight (%). The weight is the influence that individual subgroup has on the pooled result. N denotes the number of animals that contribute to that subgroup. SMD, standardised mean difference