ROKS Nomogram of Rule et al for Risk of a Second Symptomatic Stone Episode

Rule et al reported the ROKS nomogram for predicting a second symptomatic stone episode. The authors are from the Mayo Clinic.

ROKS = Recurrence of Kidney Stone

Patient selection: history of a first episode with a symptomatic stone

Parameters:

(1) age in years from 20 to 100 years

(2) sex

(3) race

(4) family history of kidney stones

(5) gross hematuria with first symptomatic stone

(6) uric acid in first stone

(7) symptomatic stone at ureterovesical junction

(8) symptomatic stone in renal pelvis or lower renal pole

(9) any concurrent asymptomatic stones

(10) any prior asymptomatic incidental stones seen on imaging

(11) prior suspected stone event without an actual stone passed or seen

Parameter	Finding	Points
age in years		(-1.175 * (age)) + 117.5
sex	female	0
	male	27
race	White	30
	other	0
family history	no	0
	yes	48
gross hematuria	no	0
	yes	8
uric acid	yes	92
	no or unknown	0
symptomatic stone at ureterovesical junction	no	0
	yes	15
symptomatic stone in renal pelvis or lower renal pole	no	0
	yes	75
any concurrent asymptomatic stones	no	0
	yes	54
any prior asymptomatic incidental stones	no	0
	yes	31
prior suspected stone	no	0
	yes	70

score =

= SUM(points for all of the parameters)

X =

= (0.00942 * (score)) - 1.2797

risk of recurrence in Y years =

= 1 - ((y)^X)

Performance:

• The area under the ROC curve was 0.69.

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