Table 4. Performance characteristics of the 4Kscore in predicting GG ≥2 prostate cancer by population and biopsy status.

4Kscore studies	Population	Bx Status	N	GG ≥2 (%)	Cutoff value (%)	Sn (%)	Sp (%)	Bx avoided (%)	Unnecessary Bx avoided (%)	GG ≥2 missed (%)	Model Used
Parekh et al., 2015 (47)	Overall BxRef	Mixed (20% RBx)	1,012	23	6	94*	39*	30	39*	5.6*	Full 4K model
					9	90*	56*	43	56*	10*
					12	86*	67*	51	67*	14*
					15	79*	76*	58	76*	21*
Zappala et al., 2017 (52)	Overall BxRef	Mixed (20% RBx)	1,012	23	7.5	93*	47*	36	47*	7.4*	Full 4K model
					7.5	93*	46*	36	46*	6.9*	4K model without DRE
Punnen et al., 2018 (49)	Overall BxRef	Mixed (20% RBx)	366	36	6	99*	27*	17	27*	1.5	Full 4K model
					7.5	97*	34*	22	34*	3
					9	96*	39*	25	39*	4
					12	92*	49*	31	49*	8
					15	87*	57*	37	57*	13
Bryant et al., 2015 (53)	Overall BxRef	Mixed	4,765	13.3	4	96*	31*	27	31*	4.5*	4K panel and age
					6	90*	49*	43	49*	11*
					8	83*	64*	56	64*	17*
					10	77*	74*	64	74*	23*
Braun et al., 2016 (48)	Overall BxRef	Unknown	749	21	4	99*	11*	8.7	11*	1.4*	4K panel and age
					6	96*	21*	17	21*	3.8*
					8	94*	30*	24	30*	6.3*
					10	92*	39*	31	39*	7.7*
					12	89*	48*	38	48*	12*
Wysock et al., 2020 (51)	Overall BxRef	Unknown	50	44	7.5	96	32	–	32*	4.5*	Full 4K model
					12	90	54	–	54*	9.9*
Nordström et al., 2015 (37)	PSA 3-15	Bx-naive	531	25	10	90*	40*	30	40*	11	4K panel and age
					15	78*	61*	45	61*	22
					20	64*	77*	56	77*	37

Bx, biopsy; Overall BxRef, Overall biopsy referral; RBx, repeat biopsy; 4K panel, PSA, fPSA, iPSA, and hK2; Full 4K model, 4K panel, age, prior biopsy status, and DRE; Sn, sensitivity; Sp, specificity; PSA, ng/mL. Calculated values are labeled with an asterisk (*).