| Level I | Good quality evidence |
Systematic review of RCTs with consistent findings High quality individual RCT |
| Level II |
Limited quality patient orientated evidence |
Systematic review of lower quality studies or studies with inconsistent findings Low quality clinical trial Cohort studies Case-control studies |
| Level III | Other |
Consensus guidelines, extrapolations from bench research, usual practice, opinion, disease-oriented evidence (intermediate or physiologic outcomes only), or case series |
[4] Prednisone, oral (iodine allergy): American College of Radiology. ACR Manual on Contrast Media, 2018, version 10.3. https://www.acr.org/Clinical-Resources/Contrast-Manual
Prednisone, oral: Tramèr MR, von Elm E, Loubeyre P, Hauser C. Pharmacological prevention of serious anaphylactic reactions due to iodinated contrast media: systematic review. BMJ. 2006 Sep 30;333(7570):675. https://www.ncbi.nlm.nih.gov/pubmed/16880193
Prednisone, oral: Lasser EC, Berry CC, Talner LB, Santini LC, Lang EK, Gerber FH, Stolberg HO. Pretreatment with corticosteroids to alleviate reactions to intravenous contrast material. N Engl J Med. 1987 Oct 1;317(14):845-9. https://www.ncbi.nlm.nih.gov/pubmed/3627208