Fig. 1
From: Observational studies: goldmines of information on rare diseases
The shape of the survival curves and the hazard ratio are similar in both studies, indicating a clear survival advantage for combination chemotherapy over single-agent doxorubicin. a. Survival of patients with soft-tissue sarcomas receiving combination chemotherapy or single-agent doxorubicin. The hazard ratio was 0.83 (95% CI 0.67–1.03); P = 0.076. Reprinted from Judson et al. [8] (copyright 2017) with permission from the primary author and Elsevier. b. The hazard ratio was 0.822 (95% CI 0.724–0.932); P = 0.0003. Reprinted from Savina et al. [3]