For each of the high-priority questions identified, the nominated researcher (medical writer or working group member) develops a search strategy and runs searches in PubMed.
The following standard limits are applied: English language, Humans, publication date 1990 (or last search date) –present, limited to systematic reviews, meta-analyses or randomised controlled trials. For aetiology clinical questions, publication type is extended to include cohort studies.
Search findings are summarised in a report to the working group, which identifies the reference, year, country, type of study (study design), intervention and comparator, population, study description, outcome measures, results and comments on study quality or conclusions.
If a high-quality systematic review (e.g. a Cochrane review) is published after the search but during guideline development, the working group considers whether it alters interpretation of the body of evidence on which a recommendation was based.
Working groups develop recommendations according to a range of methods, depending on the category of clinical question:
- For ‘high-priority’ clinical questions for which structured literature searches are conducted, the working group develop recommendations based on this evidence.
- For clinical questions for which the working group has identified sufficient existing evidence and does not run formal literature searches, the working group adapts or adopts recommendations in existing guidelines, or formulates recommendations based on the findings of published systematic reviews.
- For clinical questions subject to structured literature searches or systematic review, but where insufficient evidence is identified, the working group develops consensus-based recommendations.
- For other clinical questions, the working group develops consensus recommendations.
Recommendations are revised over time by working group members in teleconferences and face-to-face meetings. Selected working group members check consistency between topic sections. All recommendations are reviewed by the Guidelines Committee.
An icon system is used throughout the Handbook to indicate the method used to develop each recommendation. The methodology details and, where relevant, key evidence considered for that recommendation is viewable by clicking the icon under the recommendation.
In this section
Quick guide to the recommendation type icons and their meanings