Impact of treatment-related complications on overall survival. (A) Impact of grade 3 to 4 non-hematologic toxicity in whole population and within the different treatment groups within the first 6 months after the occurrence of event in the forest plot (results are shown, on a log10 scale, for analysis adjusted for age, gender, International Staging System and serum creatinine). Interaction test (heterogeneity) P=0.79. (B) Impact of grade 3 to 4 infections, cardiac, or gastrointestinal adverse events in whole population and within the different treatment groups within the first 6 months after the occurrence of event in the forest plot (results are shown, on a log10 scale, for analysis adjusted for age, gender, International Staging System and serum creatinine). Interaction test (heterogeneity) P=0.52. (C) Impact of drug discontinuation due to grade 3–4 adverse events in whole population and within the different treatment groups within the first 6 months after the occurrence of event in the forest plot (results are shown, on a log10 scale, for analysis adjusted for age, gender, International Staging System and serum creatinine). Interaction test (heterogeneity) P=0.14. Hazard ratios higher than 1 indicate a higher risk of death. The I bars represent 95% confidence intervals. MP: melphalan and prednisone; MPT: melphalan, prednisone and thalidomide; VMP: melphalan, prednisone and bortezomib; VTP/VMPT: bortezomib, thalidomide, prednisone/bortezomib, melphalan, prednisone, thalidomide.