Fig. 4.

Magnitude of collider and reporting biases, according to cancer site. The figure is interpreted as follows: The unbiased relative risk (approximated from that of the study of Fang et al.) is at the right end of the bar. The light grey part of the bar represents the magnitude of the collider bias. The odds ratio from simulation #2 is at the junction between the light and the dark grey parts of the bar. The dark grey part of the bar represents the magnitude of the reporting bias. The observed odds ratio (obtained from French mortality data) is at the left end of the bar. For example, for breast cancer, the unbiased relative risk of suicide is 1.6. The collider bias divides this relative risk by 1.9. The odds ratio from simulation #2 is 0.85. The reporting bias divides this odds ratio by 24. The odds ratio observed from French mortality data are 0.04. The scale of the x-axis is logarithmic