World Health Organization recommendations for guideline development

The BioMed Central journal Health Research Policy and Systems is publishing a new series of reviews from the World Health Organization, outlining a WHO subcommittee's recommendations for the components of the practice guideline development process.

From the introductory article by Oxman et al:

In 2005 the World Health Organisation (WHO) asked its Advisory Committee on Health Research (ACHR) for advice on ways in which WHO can improve the use of research evidence in the development of recommendations, including guidelines and policies. The ACHR established the Subcommittee on the Use of Research Evidence (SURE) to collect background documentation and consult widely among WHO staff, international experts and end users of WHO recommendations to inform its advice to WHO. We have prepared a series of reviews of methods that are used in the development of guidelines as part of this background documentation.

The series will eventually include 16 reviews; currently, seven are posted on the journal's site:
1. Guidelines for guidelines
2. Priority setting
3. Group composition and consultation process
4. Managing conflicts of interests
5. Group processes
6. Determining which outcomes are important
7. Deciding what evidence to include

The 7th installment is probably closest to the decisions we're making in answering the question for this issue's case. The authors' prompts for deciding how to select evidence to address guideline topics include:

* The most important type of evidence for informing global recommendations is evidence of the effects of the options (interventions or actions) that are considered in a recommendation. This evidence is essential, but not sufficient for making recommendations about what to do. Other types of required evidence are largely context specific.
* The study designs to be included in a review should be dictated by the interventions and outcomes being considered. A decision about how broad a range of study designs to consider should be made in relationship to the characteristics of the interventions being considered, what evidence is available, and the time and resources available.
* There is uncertainty regarding what study designs to include for some specific types of questions, particularly for questions regarding population interventions, harmful effects and interventions where there is only limited human evidence.
* Decisions about the range of study designs to include should be made
explicitly.
* Great caution should be taken to avoid confusing a lack of evidence with evidence of no effect, and to acknowledge uncertainty.
* Expert opinion is not a type of study design and should not be used as evidence. The evidence (experience or observations) that is the basis of expert opinions should be identified and appraised in a systematic and transparent way.

Future installments in the series will address other components relevant to our question, including searching for evidence, synthesizing research, presenting results, and evidence grading strategies.