Example of network of direct comparisons for the multiple-treatments meta-analysis for the outcome of interest that will be used. The thickness of the connecting lines is proportional to the number of available direct comparisons. The size of each node is proportional to the number of trials that investigated each treatment. The information in this figure is preliminary and will be updated after the search and analysis. AC = anticonvulsant; ARI = aldose reductase inhibitor; SSRI = selective serotonin reuptake inhibitor.