. Author manuscript; available in PMC: 2016 Oct 1.

Published in final edited form as: Mayo Clin Proc. 2015 Sep 6;90(10):1356–1365. doi: 10.1016/j.mayocp.2015.07.016

Table 1.

Second stone composition stratified by first stone composition among 343 first-time stone formers with two stone compositions a median of 3.2 years apart.

First stone	Second stone

	Majority calcium oxalate n=240	Majority hydroxyapatite n=65	Any brushite n=5	Any struvite n=4	Any uric acid n=29
Majority calcium oxalate n=240	208(87%) ^a	19	2	1	10
Majority hydroxyapatite n=68	25	41 (60%) ^a	1	1	0
Any brushite n=6	2	2	2(33%) ^a	0	0
Any struvite n=4	0	1	0	2(50%) ^a	1
Any uric acid n=25	5	2	0	0	18(72%) ^a

The proportion with no change in stone composition between first and second available compositions. Overall, 79% had no change in stone composition.