This document represents WHO’s normative support for using evidence-informed policies and practices in all countries. The guideline was developed following standardized operating procedures in accordance with the process described in the WHO handbook for guideline development (8). In summary, the process included: (i) identification of the priority question and critical outcomes; (ii) retrieval of the evidence; (iii) assessment and synthesis of the evidence; (iv) formulation of the recommendation; and (v) planning for the dissemination, implementation, impact evaluation and updating of the guideline.
The guideline development process involved the formation of four main groups to guide and implement the process. Their specific roles are described in the next subsection. The members of all these groups and other contributors are listed in Annex 1.
2.1. Contributors to the guideline
WHO Steering Group
The WHO Steering Group, comprising WHO staff members from the Departments of Reproductive Health and Research (RHR) and Maternal, Newborn, Child and Adolescent Health (MCA), guided and managed the entire guideline development process. The Steering Group drafted the initial scope of the guideline and drafted the priority question in PICO format, and also identified members for the Guideline Development Group (GDG), the External Review Group and the Systematic Review Team, including the guideline methodologists. In addition, the Steering Group supervised the retrieval and synthesis of evidence, organized the GDG meeting (the WHO Technical Consultation on Duration of Catheterization after Surgical Repair of Simple Obstetric Fistula, held in May 2017 in Geneva, Switzerland), drafted and finalized the guideline document and managed the guideline dissemination, implementation, and impact assessment.
Guideline Development Group
The Steering Group identified 11 external experts and relevant stakeholders from the WHO African Region, the Region of the Americas, the East Mediterranean Region and the European Region to constitute the GDG. This diverse group of individuals had expertise in research, guideline development methods, and clinical policy and programmes relating to obstetric fistula. The group also included representatives of women who will be affected by the recommendation. The GDG members were selected in a way that ensured geographic representation and gender balance, and there were no important conflicts of interest. Selected members of this group provided input into the drafting of the guideline scope and the PICO question, and participated in prioritization of outcomes that guided the evidence reviews. Additionally, the group appraised the evidence that was used to inform the guideline, advised on the interpretation of this evidence, formulated the final recommendation based on the draft prepared by the WHO Steering Group, and reviewed and approved the final guideline document.
External Review Group
The External Review Group (ERG) included four technical experts with sufficient experience in the provision of evidence-based fistula care from the WHO African, European and South-East Asia Regions. None of the ERG members declared a conflicting interest. The ERG reviewed the final guideline document to identify any errors of fact and commented on clarity of the language, contextual issues and implications for implementation. The group ensured that the guideline decision-making processes had considered and incorporated contextual values and preferences of potential users of the recommendations (i.e. patients), as well as health-care professionals and policymakers. The ERG did not change the recommendation that was formulated by the GDG.
Systematic Review Team, led by guideline methodologists
A systematic review was conducted by the Systematic Review Team, led by two guideline methodologists, and with input from members of the WHO Steering Group (9). The Steering Group worked closely with the guideline methodologists to appraise the evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology (10).
External partners and observers
Representatives of the International Federation of Gynecology and Obstetrics (FIGO), the United Nations Population Fund (UNFPA) and the United States Agency for International Development (USAID) attended the GDG meeting as observers. All these organizations are potential implementers of the proposed guideline with a long history of collaboration with WHO’s RHR Department in the area of guideline dissemination and implementation. The names of observers who participated at the GDG meeting are also provided in Annex 1.
2.2. Identification of the priority question and critical outcomes
In consultation with members of the GDG, the Systematic Review Team and the guideline methodologists, the WHO Steering Group first drafted the priority question and the potential “critical” and “important” outcomes related to the management of the catheter after surgery for simple obstetric urinary fistula. The priority question was written in the PICO format, mentioning the population, intervention, comparator and outcome in turn. The potential critical and important outcomes were identified through a search of key sources – relevant published articles. This exercise generated a total of nine outcomes, which were then ranked by the Steering Group. Five outcomes were rated as critical and four were rated as important. All nine outcomes were included within the scope of this document for the purposes of evidence searching, retrieval and grading and for formulation of the recommendation. The priority/PICO question and the list of critical and important outcomes are provided in Annex 2.
2.3. Evidence identification and retrieval
To gather evidence on the priority question, the Steering Group and the guideline methodologists collaboratively screened Cochrane and non-Cochrane reviews of randomized controlled trials (RCTs). No systematic review of RCTs relevant to the question was found, so they decided to conduct a new systematic review. For this purpose, the Steering Group provided the methodologists with the standard operating procedures, the terms of reference enumerating the desired output of the systematic review, as well as the format for reporting and timelines.
The guideline methodologists, together with members of the Steering Group, developed a protocol with clear criteria for the identification and selection of studies for the systematic review, including methods for assessing risk of bias, and also developed a data analysis plan before embarking on the review. The protocol of the systematic review has been registered in PROSPERO, an international database of prospectively registered systematic reviews (CRD42017056320). The systematic review process followed standard methods recommended by the Cochrane handbook for systematic reviews of interventions and the PRISMA reporting guidelines (11,12). The WHO librarian prepared the search strategy (presented in Annex 3). The search was run in five electronic databases (MEDLINE, Embase, CINAHL, GIM and POPLINE) and two trial register platforms. The entire systematic review development process was interactive, with the systematic reviewers and guideline methodologists constantly communicating with the members of the WHO Steering Group to discuss challenges and agree on solutions.
Evidence for the recommendation presented in this guideline was sourced from the systematic review (9).
2.4. Quality assessment and grading of the evidence
Quality assessment of the body of evidence for each outcome was performed using the GRADE approach (10). Using this approach, the quality of evidence for each outcome was rated as “high”, “moderate”, “low” or “very low”, based on a set of established criteria. The final rating of quality of evidence was dependent on the factors described briefly below.
Study design limitations: The risk of bias was first examined at the level of individual study and then across studies contributing to the outcome. For the review of RCTs, quality was first rated as “high” and then downgraded by one level (to “moderate”) or by two or three levels (to “low” or “very low”), depending on the minimum quality criteria met by the majority of the studies contributing to the outcome.
Inconsistency of the results: The similarity in the results for a given outcome was assessed by exploring the magnitude of differences in the direction and size of effects observed from different studies. The quality of evidence was not downgraded when the directions of the findings were similar and confidence limits overlapped, whereas quality was downgraded when the results were in different directions and confidence limits showed minimal or no overlap.
Indirectness: The quality of evidence was downgraded where there were serious or very serious concerns regarding the directness of the evidence, i.e. if there were important differences between the research reported and the context for which the recommendation was being prepared. Such differences were related, for instance, to populations, interventions, comparators or outcomes of interest.
Imprecision: This assessed the degree of uncertainty around the estimate of effect. As this is often a function of sample size and number of events, studies with relatively few participants or events – and thus wide confidence intervals around effect estimates – were downgraded for imprecision.
Publication bias: The quality rating could also be affected by perceived or statistical evidence of bias leading to underestimation or overestimation of the effect of an intervention as a result of selective publication based on study results. We considered downgrading evidence by one level for strong suspicion of publication bias.
GRADE profiler software was used to construct “summary-of-findings” tables for the priority question. These tables included the assessment and judgements on the above-described elements for each outcome, and the estimated risks. Relevant information and data were extracted in a consistent manner from the systematic review relating to the priority question by applying the following procedures. First, up-to-date review documents and/or data (e.g. RevMan file) were obtained from the review authors. Secondly, analyses relevant to the critical and important outcomes were identified and selected. The data were then imported and manually entered into the GRADE profiler software. For each outcome, GRADE assessment criteria (as described above) were applied to evaluate the quality of evidence. In the final step of the assessment process, GRADE evidence profiles were generated for the guideline question.
2.5. Formulation of the recommendation
The GRADE framework was applied to formulate the recommendation based on the synthesized evidence. The WHO Steering Group used the summary of evidence for the critical outcomes, the overall quality of the evidence, and information on the balance between benefits and harms, values and preferences, and cost/ resource implications, to draft the recommendation. The draft recommendation, the evidence summary, the corresponding GRADE table, and other related documents were provided to members of the GDG. The GDG members and other participants were then invited to attend a Technical Consultation at WHO headquarters in Geneva, Switzerland, in May 2017. At the Technical Consultation (or GDG meeting), the GDG members thoroughly reviewed and discussed the documents to finalize the recommendation.
2.6. Declaration of interests by external contributors
According to WHO regulations, all external experts must declare their relevant interests prior to participation in the WHO guideline development process and meetings. All GDG members and external contributors were therefore required to complete a standard WHO Declaration of Interest (DOI) form before engaging in the guideline development process and before participating in guideline-related meetings. The WHO Steering Group reviewed all DOI forms before finalizing the invitations for experts to participate in the development of the guideline. Where any conflict of interest was declared, the Steering Group determined whether it was serious enough to affect the expert’s objective judgement relating to the guideline development process and formulation of the recommendation. To ensure consistency, for each expert, the Steering Group applied the criteria for assessing the severity of conflicts of interest in the WHO handbook for guideline development (8). All findings from the received DOI statements were managed in accordance with the WHO DOI guidelines on a case-by-case basis and communicated to the experts. Where a conflict of interest was not considered significant enough to pose any risk to the guideline development process or reduce its credibility, the experts were only required to openly declare such conflict at the beginning of the GDG meeting and no further actions were taken.
Annex 4 provides a summary of the experts’ declared interests and information on how any conflicts of interest were managed by the WHO Steering Group.
2.7. Decision-making during the WHO Technical Consultation
The GDG, during the Technical Consultation, discussed the draft recommendation prepared by the WHO Steering Group. In addition to evaluating the scientific evidence and its quality, the GDG considered values and preferences, the balance between benefits and harms, cost/resource implications, as well as issues of equity, acceptability and feasibility, when formulating the final recommendation. The consideration of values and preferences and the evaluation of cost/resource implications were based on the experience and opinions of the GDG members and supported by evidence from the literature, where available. “Evidence-to-decision” tables were used to note and synthesize these considerations.
The decision on the wording and strength of the recommendation was based on consensus, defined as the agreement of at least three quarters of the participants. None of the GDG members expressed strong opposition to the final wording of the recommendation or the remarks.
2.8. Document preparation
Prior to the Technical Consultation, the WHO Steering Group prepared a draft of the evidence summary and the recommendation. The draft document was made available to the participants of the Technical Consultation two weeks before the meeting. During the meeting, the draft recommendation was modified in line with participants’ deliberations and remarks. Following the meeting, members of the WHO Steering Group prepared a draft of the full guideline document including revisions that accurately reflected the deliberations and decisions of the GDG members. The draft guideline document was sent electronically to GDG members for further comments before it was sent to the External Review Group for peer review.
2.9. Peer review
The draft guideline and recommendation document, as prepared by the GDG members and WHO Steering Group, was sent to the four External Review Group (ERG) members for peer review. The WHO Steering Group subsequently carefully evaluated the inputs of the peer reviewers for inclusion in the guideline document. After the Technical Consultation and peer review were completed, any further modifications made by the Steering Group to the guideline were limited to correction of factual errors and improvement in language to address any lack of clarity.
