Table 2.

Multivariable associations of medulla on biopsy

Multivariable Risk Factors	Odds Ratio	95% Confidence Interval
Creatinine, loge mg/dl	1.21	1.00 to 1.46
Prior BK viremia	1.47	1.12 to 1.95
Maximal core length, mm	1.16	1.13 to 1.19
No. of cores	1.24	1.09 to 1.41
Glomeruli, no.	1.03	1.01 to 1.04

The determinants of sample medulla included all of the physical parameters of the biopsy core using binomial generalized estimating equation to adjust for repeated sampling (n=813 kidneys; estimate of common correlation =0.033) and remained significant despite correction for clinical dysfunction and prior (chronic) viremia, which could prompt increased sampling efforts (compete univariable results and other data are detailed in Supplemental Table 5).