School of Population Health

2011 Evidence-based practice and critical appraisal

Presentations and papers

In this section we provide a series of downloadable presentations on the EPIQ approach to evidence-based practice and critical appraisal and a paper we have published on the GATE approach to critical appraisal. 

  1. An introduction to evidence-based practice using the Graphic Appraisal Tool for Epidemiology (GATE) by Rod Jackson (February 2011): EPIQ approach to evidence-based practice (PDF)
  2. Rapid critical appraisal with GATE by Rod Jackson (February 2011)
    The EPIQ group has developed a series of 4-page excel-based Critically Appraised Topics (CATs) / critical appraisal checklists and 1-page ‘GATE-lite’ forms. Both sets of tools are based on GATE and are provided in the next 2 sections below. The GATE approach to critical appraisal used in these tools is described in this presentation: Critical appraisal with GATE & CATs (PDF)
  3. The GATE approach to critical appraisal is described in a paper published in 2006 entitled: The GATE frame - critical appraisal with pictures (PDF)
  4. The GATE approach to searching the literature by Sue Wells (February 2008): MESH-based rapid access to the evidence (XLS)

Critically appraised topics (CATs) checklists for quantitative studies:

In this section we provide a series of CAT checklists that have been developed by Rod Jackson, Shanthi Ameratunga, Adam Briggs, Joanna Broad, Jennie Connor, Anne Lethaby, Gill Robb and Sue Wells. The original excel versions of the CATs were designed by Joanna Broad. These were updated in 2008 by Adam Briggs, a British medical student, while on his elective with us in Auckland. The Systematic Review CAT was changed significantly in 2010 and 2011.

EPIQ checklists are MS Excel documents and are designed to generate CATs. Each CAT has four pages and is designed to model the five steps of evidence-based practice. CATs can be printed back-to-back on A3 paper to produce a booklet.

Page 1 documents the clinical /practice scenario, the question (Step 1) asked and the search strategy and search results (Step 2).

Page 2 documents the first part of critical appraisal (Step 3a) which involves hanging the study on the GATE frame. If you key the main study numbers into the GATE frame, it automatically calculates risk, risk ratios, risk differences and NNTs, as well as 95% confidence intervals for all estimates (note: the systematic review checklist does not include a calculator).

Page 3 documents the second part of critical appraisal (Step 3b) which is to assess the quality of the study (internal & external validity, precision and power).

Page 4 documents the integration and application of evidence (Step 4) and personal and clinical audit (Step 5).

There is also an instructions page at the front of each CAT and an overflow page at the back.

For the calculator on page 2 of the checklists to work, macros security settings may need to be set to medium before downloading the CAT.

  1. Intervention studies (2008): Intervention Studies CAT

    a. model answer of an intervention question CAT, based on a randomised controlled trial.
    Intervention CAT Model Answer

    b. model answer of an intervention question CAT based on a non-randomised study.
    Non-randomised Study Intervention CAT Model Answer
  2. Diagnostic Test Accuracy studies (2008): Diagnostic Test Accuracy Studies CAT
    A model answer of a diagnostic test accuracy question CAT
    Diagnostic CAT Model Answer

  3. Prognostic and risk factor studies (2008): Prognosis / Risk Factor Studies CAT

    A model answer of a prognostic study question CAT
    Prognostic CAT Model Answer

  4. Case-control studies (2008): Case Control Study CAT
    A model answer of the Case Control Study CAT
    Case Control Study CAT Model Answer

    A new Generic Systematic Review CAT has been designed for appraising reviews of all study types (updated December 2010).
  5. Systematic review studies (updated February 2011): Generic Systematic Review CAT



The GATE-lite forms provided here are one-page rapid critical appraisal tools that we have derived from the more comprehensive CATs described above.

GATE-lite forms are designed to be paper-based rather than electronic. GATE-lite forms (page 1) include a glossary (page 2) and a second ‘very-lite’ version of the forms (last page) that have the detailed appraisal questions removed. The 'GATE-very LITE' forms provide less direction but more space to write comments.

  1.  The GATE-lite tool for RCTs can be used to appraise intervention, risk, prognostic and cross-sectional studies (February 2011).
    GATE-lite for RCTs, Cohort & Cross-sectional Studies

  2.  The GATE-lite tool for Diagnostic studies is for appraising test accuracy studies (November 2010). 
    GATE-lite for Diagnostic Test Accuracy Studies

A CAT checklist for qualitative studies

Inspired by our Quantative CATS, Ann McKillop, a Senior Lecturer in Nursing at the University of Auckland, has developed:

CAT for Qualitative Studies
(244.7 kB, EXCEL)

This has now been tested on several classes of student nurses and we invite you to test it out. Ann has also produced a

If you have any questions or comments about this new CAT please contact Ann McKillop.