Fig. 4From: Understanding the mental health of doctoral researchers: a mixed methods systematic review with meta-analysis and meta-synthesisForest plot and meta-analysis of correlation coefficients testing the relationship between stress and performance. Black diamond = total effect size (based on random effects model); r = Pearson’s r; Q = heterogeneity; Z = z score; I2 = proportion of variance due to between-study heterogeneity; p = exact p valueBack to article page