Amanda Burls

Professor of Public Health at City University London and a public health physician

Author of: What is critical appraisal?

From 1997 to 2008, Amanda founded and directed the West Midlands Health Technology Assessment Collaboration at the University of Birmingham which produced systematic reviews and economic evaluations to inform national and regional UK NHS policy decisions, such as the NICE appraisal process.

She is an experienced teacher and started running workshops for the Critical Appraisal Skills Programme (CASP) in 1993, later becoming its director. From 2008 to 2013 Amanda was a Senior Clinical Research Fellow, and Director of Post-Graduate Programmes in Evidence-Based Health Care (EBHC), at the University of Oxford where she ran and taught on the MSc in EBHC and supervised DPhil in EBHC students. She received several awards for teaching excellence during this period, including one awarded by the students themselves.

At City University Amanda directs ThinkWell , a novel internet-based research programme, which aims to help the public (a) understand health information so they can make informed health decisions and (b) set up and participate in research studies. In 2011 she co-organised a Conference on Enhancing Public Understanding of Health Research, which resulted in the formation of the international Network to Support Understanding of Health Research which she currently coordinates.

Summary: What is critical appraisal?

  • Research is the process by which we generate knowledge.
  • Different research questions require different study designs.
  • Bias is the systematic deviation of the findings of studies from the truth. All studies can be subject to bias, but some study designs are more prone to bias than others.
  • It is important that researchers take steps to reduce bias so that studies are valid and their results trustworthy. When testing whether a treatment is effective, a randomised controlled trial is the best design to minimise bias.
  • Odds ratios, risk ratios and number needed to treat are ways of expressing results in quantitative studies.
  • Critical appraisal is the process of carefully and systematically examining a research report to judge its trustworthiness, make sense of the results and assess the relevance of the findings in a particular context.
  • Systematic reviews systematically collect, appraise, report and, where appropriate, combine all the trustworthy scientific evidence from individual studies. They are therefore the best study design to choose to inform decisions.
  • The Critical Appraisal Skills Programme aims to help people develop the necessary skills to make sense of scientific evidence, and has produced appraisal checklists covering the validity, results and relevance of different study designs, including systematic reviews. You can download these free of charge at