| 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 |
[18] PPI (high risk patients on chronic NSAID therapy): McQuaid KR ,Laine L . Systemic review and meta-analysis of adverse events of low-dose aspirin and clopidogrel in randomized controlled trials. Am J Med 2006;119:624–38. http://www.ncbi.nlm.nih.gov/pubmed/16887404
PPI (high risk patients on chronic NSAID therapy): Serrano P, Lanas A, Arroyo MT, Ferreira IJ. Risk of upper gastrointestinal bleeding in patients taking low-dose aspirin for the prevention of cardiovascular diseases. Aliment PharmacolTher. 2002 Nov;16(11):1945-53. http://www.ncbi.nlm.nih.gov/pubmed/12390104
PPI (high risk patients on chronic NSAID therapy): Lanza FL, Chan FK, Quigley EM; Practice Parameters Committee of the American College of Gastroenterology. Guidelines for prevention of NSAID-related ulcer complications. Am J Gastroenterol. 2009 Mar;104(3):728-38. http://www.ncbi.nlm.nih.gov/pubmed/19240698
PPI (high risk patients on chronic NSAID therapy): Narum S, Westergren T, Klemp M. Corticosteroids and risk of gastrointestinal bleeding: a systematic review and meta-analysis. BMJ Open. 2014 May15;4(5):e004587. https://www.ncbi.nlm.nih.gov/pubmed/24833682
PPI (high risk patients on chronic NSAID therapy): Scarpignato C, Gatta L, Zullo A, Blandizzi C; SIF-AIGO-FIMMG Group; Italian Society of Pharmacology, the Italian Association of Hospital Gastroenterologists, and the Italian Federation of General Practitioners. Effective and safe proton pump inhibitor therapy in acid-related diseases - A position paper addressing benefits and potential harms of acid suppression. BMC Med. 2016 Nov 9;14(1):179. https://www.ncbi.nlm.nih.gov/pubmed/27825371