The Use of Coronary Computed Tomography Angiography for Patients Presenting with Acute Coronary Syndrome

A comprehensive search for guidelines was undertaken to identify the most relevant guidelines to consider for adaptation.

Inclusion/ exclusion criteria were followed in the search and retrieval of guidelines to be adapted:

• Selecting only evidence-based guidelines (guidelines must include a report on systematic literature searches and explicit links between individual recommendations and their supporting evidence)

·       Selecting only national and/or international guidelines

·       Selecting peer-reviewed publications only

·       Selecting guidelines written in the English language

·       Excluding guidelines written by a single author, not on behalf of an organization, to be valid and comprehensive, a guideline ideally requires multidisciplinary input

·       Excluding guidelines published without references, as the panel needs to know whether a thorough literature review was conducted and whether current evidence was used in the preparation of the recommendations

The following characteristics of the retrieved guidelines were summarized in:

·       Developing organization/authors

·       Date of publication, posting, and release

·       Country/language of publication

·       Date of posting and/or release

·       Dates of the search used by the source guideline developers

All retrieved Guidelines were screened and appraised using AGREE II instrument (www.agreetrust.org) by at least three members. The panel decided on a cut-off point or ranked the guidelines (any guideline scoring above 50% on the rigor dimension was retained).

The guidelines development group decided to adopt this guidline from the Society of Cardiovascular Computed Tomography (SCCT), American College of Radiology (ACR) and North American Society for Cardiovascular Imaging (NASCI) (4, 5, 6).

➡️Evidence assessment

According to WHO Handbook for Guidelines, we used the GRADE (Grading of

Recommendations, Assessment, Development and Evaluation) approach to assess the quality of a body of evidence, develop and report recommendations. GRADE methods are used by WHO because they represent internationally agreed standards for making transparent recommendations. Detailed GRADE information is available on the following sites:

•  GRADE working group: https://www.gradeworkinggroup.org/

•   GRADE online training modules: http://cebgrade.mcmaster.ca/

  Table 1 Quality and Significance of the four levels of evidence in GRADE:

Table 2 Factors that determine How to upgrade or downgrade the quality of evidence

The strength of the recommendation

The strength of a recommendation communicates the importance of adherence to the recommendation.

Strong recommendations

With strong recommendations, the guideline communicates the message that the desirable effects of adherence to the recommendation outweigh the undesirable effects. This means that in most situations the recommendation can be adopted as policy.

Conditional recommendations

These are made when there is greater uncertainty about the four factors above or if local adaptation should account for a greater variety in values and preferences, or when resource use makes the intervention suitable for some, but not for other locations. This means that there is a need for substantial debate and involvement of stakeholders before this recommendation can be adopted as policy.

Good practice statements

Statements based on opinions of respected authorities and the guidelines development group.

When not to make recommendations

When there is lack of evidence on the effectiveness of an intervention, it may be appropriate not to make a recommendation.