Incidence of contrast-induced nephropathy in patients with CKD, normal kidney function and all patients. Incidence of contrast-induced nephropathy in patients with CKD, normal kidney function and all patients. The boxes and lines indicate the RRs and their CIs. Weights are from random-effects analysis. The size of the box indicates the relative weight of each estimate. Diamonds indicate the combined RRs (CKD, chronic kidney disease; IV, intravenous; PO, oral; RRs, relative risks). Shiv Kumar Agarwal et al. Open Heart 2015;2:e000317 ©2015 by British Cardiovascular Society