Figure 1. Meta-analysis of placebo-controlled trials of glucosamine and chondroitin in osteoarthritis. The white circles represent the effect size of each glucosamine trial; 0 represents no effect relative to placebo. Horizontal lines represent 95% CIs. The white diamond represents aggregate results (with 95% CI) for glucosamine trials. The black circles and diamonds represent the same features for chondroitin. Data from reference 48.