Figure 6. Forest plot of hazard ratios (HR) of (A) all-cause hospitalization and (B) cardiovascular disease (CVD)-related hospitalization of patients under 40 years of age, (C) all-cause hospitalization and (D) CVD-related hospitalization of patients between 40 and 60 years of age, (E) all-cause hospitalization and (F) CVD-related hospitalization of patients over 60 years of age stratified by hemoglobin (Hb) concentration.