Table 3.

Final model for predicting symptomatic recurrence using all stone formers and the subset with CT imaging

Predictor	All Stone Formers (n=2239, C Statistic=0.661)		Stone Formers with CT Imaging (n=765, C Statistic=0.687)
	Hazard Ratio (95% CI)	P Value	Hazard Ratio (95% CI)	P Value
Age, per decade	0.89 (0.84 to 0.94)	<0.001	0.95 (0.86 to 1.05)	0.31
Male sex	1.29 (1.09 to 1.52)	0.003	1.45 (1.07 to 1.97)	0.02
White	1.32 (0.97 to 1.80)	0.07	1.34 (0.75 to 2.43)	0.33
Family history of stones	1.57 (1.34 to 1.86)	<0.001	1.73 (1.26 to 2.37)	<0.001
Prior asymptomatic stone on past imaging	1.34 (0.99 to 1.81)	0.06	1.46 (0.86 to 2.48)	0.16
Prior suspected stone episodea	1.93 (1.51 to 2.46)	<0.001	1.96 (1.26 to 3.05)	0.003
Gross hematuria	1.08 (0.90 to 1.29)	0.42	1.43 (1.02 to 1.99)	0.04
Any nonobstructing stone	1.66 (1.41 to 1.94)	<0.001	2.07 (1.54 to 2.77)	<0.001
Symptomatic pelvic or lower-pole stone	2.02 (1.67 to 2.45)	<0.001	1.69 (1.17 to 2.45)	0.006
Symptomatic ureterovesicular junction stone	0.87 (0.73 to 1.04)	0.12	0.93 (0.69 to 1.26)	0.64
Any known uric acid composition	2.37 (1.60 to 3.50)	<0.001	3.15 (1.43 to 6.92)	0.004

CI, confidence interval.

^aCharacteristic renal colic attributed to a stone but no stone seen on imaging or voided.