| 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 |
[12] Proton pump inhibitor (therapeutic class): National Department of Health: Affordable Medicines, EDP-Adult Hospital level. Medicine Review: Proton pump inhibitor therapeutic class review, May 2018. http://www.health.gov.za
Proton pump inhibitor (therapeutic class): McDonagh MS, Carson S, Thakurta S. Drug Class Review: Proton Pump Inhibitors: Final Report Update 5 [Internet]. Portland (OR): Oregon Health & Science University; 2009 May. http://www.ncbi.nlm.nih.gov/books/NBK47260/
Proton pump inhibitor (therapeutic class): National Institute for Health and Care Excellence: Clinical Guidelines: Gastro-oesophageal reflux disease and dyspepsia in adults: investigation and management. https://www.nice.org.uk/guidance/cg184
Proton pump inhibitor: Contract circular HP09-2014SD. http://www.health.gov.za
Proton pump inhibitor (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
Proton pump inhibitor (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 Pharmacol Ther. 2002 Nov;16(11):1945-53. http://www.ncbi.nlm.nih.gov/pubmed/12390104
Proton pump inhibitor (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