Table 3. PFS and PSA response rate performance of the risk model in this study.

Risk group	No. (%)	PSA response rate (%)	Median PFS (months)	HR (95% CI)	P value
Low risk	65 (40.6)	42/65 (64.6)	3.6	1.619 (1.444–1.815)	Reference
Moderate risk	38 (23.8)	9/38 (23.7)	3.0		<0.001
High risk	57 (35.6)	0/57 (0)	1.4

Abbreviations: CI, confidence interval; HR, hazard rate; PFS, progression-free survival; PSA, prostate-specific antigen; PSADT, PSA doubling time.

Low risk denotes patients with 0–1 risk factor, moderate risk denotes 2 risk factors and high risk denotes 3–4 risk factors. The risk factors included a nadir PSA of ≥0.2 ng ml⁻¹, a baseline testosterone of <0.1 ng ml⁻¹, a baseline haemoglobin less than normal (<120 g l⁻¹) and a PSADT of <2 months. The PSA response rate was defined as the percentage of patients with a PSA decline of ≥50% compared with the baseline PSA level during the ketoconazole therapy.