ReacciónThis guideline was developed in accordance with the WHO evidence-informed guideline development procedures, as outlined in the WHO handbook for guideline development (1).
Advisory groups
A WHO Steering Committee for Nutrition Guidelines Development, led by the Department of Nutrition for Health and Development was established in 2009, with representatives from all WHO departments with an interest in the provision of scientific nutrition advice, including the Global TB Programme (GTB) and the Departments of Maternal, Newborn, Child and Adolescent Health, and Reproductive Health and Research. The steering committee guided the development of this guideline and provided overall supervision of the guideline development process (Annex 4). Two additional groups were formed: an advisory guideline group and an external experts’ and stakeholders’ panel.
The Nutrition Guidance Advisory Group was established in 2009 (Annex 5). A subgroup on nutrition in the life-course was established for the biennium 2010–2011. Its role was to advise WHO on the choice of important outcomes for decision-making and in the interpretation of the evidence. The Nutrition Guidance Advisory Group includes experts from various WHO expert advisory panels (57) and those identified through open calls for specialists. Efforts were made to include content experts, methodologists, representatives of potential stakeholders (such as managers and other health professionals involved in the health-care process) and consumers. Representatives of commercial organizations may not be members of a WHO guideline group.
The external experts’ and stakeholders’ panel was consulted on the scope of the guideline, the questions addressed, and the choice of important outcomes for decisionmaking, as well as with regard to review of the completed draft guideline (Annex 6). This was done through the WHO Nutrition and United Nations System Standing Committee on Nutrition (SCN) (58) mailing lists that together include over 5500 subscribers, through the WHO nutrition web site (59), and through contacting technical agencies involved in national and international TB control.
Scope of the guideline, evidence appraisal and decision-making
Since there were no internationally agreed recommendations on what nutrition care or food assistance TB patients should receive, or on how national TB programmes can contribute to improving a population’s nutritional status, the Department of Nutrition for Health and Development and the Global TB Programme (GTB) planned to develop such recommendations and guidelines jointly. A scoping meeting for the development of recommendations on nutritional support/food assistance to prevent TB and improve health status among TB patients was held in Geneva, 2–4 November 2009 (60). An initial set of questions (and the components of the questions) to be addressed in the guideline was the critical starting point for formulating the recommendation. The questions were drafted by technical staff at the Evidence and Programme Guidance Unit, Department of Nutrition for Health and Development, and the Policy, Strategy and Innovations unit, Global TB Programme, based on policy and programme guidance needs of Member States and their partners. The population, intervention, control, outcomes (PICO) format was used (Annex 3). The questions were discussed and reviewed by the WHO Steering Committee for Nutrition Guidelines Development, and feedback was received from five stakeholders.
A Nutrition Guidance Advisory Group meeting was held on 16–18 November 2010 in Amman, Jordan, to finalize the scope of the questions and rank the critical outcomes and populations of interest. The guideline development group discussed the relevance of the questions and modified them as needed. The guideline group scored the relative importance of each outcome. The final key questions on this intervention, along with the outcomes that were identified as critical and important for decision-making are listed in PICO format in Annex 3.
One Cochrane¹ review (27), and two supplementary reviews were used to summarize and appraise the evidence (62, 63). WHO technical staff, together with methods experts of the guideline group, prepared evidence summaries according to the Grading of Recommendations Assessment, Development and Evaluation (64) (GRADE) approach to assess the overall quality of the evidence (65).
Both the systematic reviews and the GRADE evidence profiles for each of the critical outcomes were used for drafting this guideline. However, GRADE tables were only developed for those questions for which there were published studies included in the reviews. Some recommendations were developed based on recommendations previously made by WHO on nutritional care and support. The draft recommendation was discussed by the WHO Steering Committee for Nutrition Guidelines Development and the guideline development group, at a second guideline development consultation, held in Geneva between 28 November and 1 December 2011. The procedures for decision-making were established at the beginning of the meetings, including a minimal set of rules for agreement and voting. At least two thirds of the guideline development group had to be present for an initial discussion of the evidence and proposed recommendation and remarks. The guideline development group secretly voted on the direction and strength of the recommendation, using a form designed for this purpose, which also included a section for documenting their views on (i) the desirable and undesirable effects of the intervention; (ii) the quality of the available evidence; (iii) values and preferences related to the intervention in different settings; and (iv) the cost of options available to health-care workers in different settings. Each member had one vote if not advised otherwise, after managing any potential conflict of interests. Abstentions were not allowed.
The WHO Secretariat collected the forms and disclosed the summary of the results to the guideline development group. If there was no unanimous consensus, more time was given for deliberations and a second round of voting was possible. If there was no full agreement, a two thirds vote of the guideline development group would have been required for the approval of the proposed recommendation. Divergent opinions, if any, were recorded in the guideline. Voting forms will be kept on file by WHO for 10 years. Consensus was reached for all recommendations. WHO staff present at the meeting, as well as other external technical experts involved in the collection and grading of the evidence, were not allowed to vote. There were no strong disagreements among the guideline group members.
A draft of the revised principles and recommendations was disseminated for external peer review in February 2012. Reviewers were asked to examine the principles and recommendations, to ensure that there were no important omissions, contradictions or inconsistencies with scientific evidence or programmatic feasibility; and to assist with clarifying the language, especially in relation to implementation and how policy-makers and programme staff might read them. Reviewers were advised that no additional recommendations could be considered and that they were being asked to undertake this exercise in their personal capacity and not as representatives of any agency or institution. External reviewers proposed several comments to make the recommendations clearer. There was no major disagreement. The draft principles and recommendations were circulated to all involved WHO technical staff; all TB regional advisers in all WHO regional offices; selected national TB programmes; several technical agencies working on TB control, including KNCV Tuberculosis Foundation, the Centers for Disease Control and Prevention and the International Union Against TB and Lung Disease; and a network of external experts for TB and nutrition, respectively. All interested stakeholders became members of the external experts’ and stakeholders’ panel but were only allowed to comment on the draft guideline after submitting a signed declaration of interests form. Feedback was received from these stakeholders. WHO staff addressed each comment and then finalized the guideline and submitted it for clearance by WHO before publication.
Management of conflicts of interest
According to the rules in the WHO Basic documents (66), all experts participating in WHO meetings must declare any interest relevant to the meeting, prior to their participation. The conflicts of interest statements for all guideline group members were reviewed by the responsible technical officer and the relevant departments before finalization of the group composition and invitation to attend a guideline group meeting. All guideline group members and participants of the guideline development meetings submitted a declaration of interests form along with their curriculum vitae, before each meeting. In addition, they verbally declared any interest at the beginning of each meeting and they agreed to the publication of their declaration, if relevant, in the guideline prior to their involvement. The procedures for management of conflicts of interests strictly followed WHO Guidelines for declaration of interests (WHO experts) (67). On reviewing the responses, none of the declared interests were likely to influence the discussions of the meeting. Therefore, no special provisions or mechanisms to deal with these interests were considered necessary. External experts representing partner organizations, representatives from the Department of Nutrition for Health and Development and Global TB Programme, and from selected national TB programmes, participated in the meeting and review processes. All external experts were also required to submit a curriculum vitae and complete a declaration of interest.
¹ The detailed methods used in each Cochrane systematic review, as well as their search date, are published and available through the Cochrane Library. As part of the Cochrane pre-publication editorial process, this review was commented on by external peers (an editor, and two referees external to the editorial team) and the group’s statistical adviser. The Cochrane handbook for systematic reviews of interventions (61) describes in detail the process of preparing and maintaining Cochrane systematic reviews on the effects of health-care interventions.