A systematic review of the literature was undertaken comparing proton pump inhibitors with H2- receptor blockers for the prevention of gastro-intestinal bleeding in ICU patients.
The following figure was included:
- a) Name the type of graph illustrated in the above figure. (10% marks)
- b) What does it show? (25% marks)
- c) What are the benefits of this type of analysis? (25% marks)
- d) What are the disadvantages of this analysis? (40% marks)
Answer and interpretation
a) Name the type of graph illustrated in the above figure. (10% marks)
- Forest plot
b) What does it show? (25% marks)
- Combining the trials together, PPI use results in an odds ratio of 0.35 or reduction in the risk of bleeding compared to H2RA. Alternatively, PPI use results in 65% reduction (1- 0.35) in bleeding.
c) What are the benefits of this type of analysis? (25% marks)
- Combines small studies with limited power, increasing the number and thus the ability to pick up a positive effect. Small studies with low power (due to small effect, small numbers) run the risk of a Type II error.
d) What are the disadvantages of this analysis? (40% marks)
- Individual studies might have different patient populations (with different risk of bleeding) or different definitions of outcome.
- Individual studies might have been conducted with different degrees of rigour (blinding, etc.)
- There is publication bias to positive studies so that negative studies are not reported.
- Need full disclosure how the studies were selected, their scientific grading, subgroup analyses and assessment of heterogeneity.
- Pass rate: 83%
- Highest mark: 8.0
- Candidates who scored well showed an in-depth understanding of the applied physiology and consequences of the various therapeutic options. Candidates who scored poorly omitted key points.
Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.
After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.
He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE. He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.
His one great achievement is being the father of three amazing children.
On Twitter, he is @precordialthump.