TABLE 3.

Association between quartiles of kidney transplant center numbers and incidence of kidney transplant

Transplant center quartile	n	Incidence of kidney transplant (pmp), median (IQR)	IRR (95% CI)
First quartile	20	4.45 (1.75–11.53)	1 [Reference]	–	–
Second quartile	24	7.42 (5.27–22.56)	1.35 (1.14, 1.60)	1 [Reference]	–
Third quartile	26	28.49 (11.74–45.09)	2.75 (2.37, 3.19)	1.99 (1.75, 2.26)	1 [Reference]
Fourth quartile	22	26.80 (15.83–42.00)	2.68 (2.31, 3.12)	2.04 (1.80, 2.31)	0.98 (0.88, 1.08)

CI, confidence interval; IQR, interquartile range; IRR, incidence rate ratio; pmp, per million population.