Fig. 4
The forest plots for the prognostic factors with data available in two or more studies, including the age (a), visceral metastasis (b), ambulatory status (c), performance status (d), number of involved vertebrae (e), extraspinal bone metastasis (f), time developing motor deficit (g), time interval from primary PCa diagnosis (h), PSA level (i), and bisphosphonates treatment (j)