Assessment of evidence underlying guidelines by the Society for Maternal-Fetal Medicine

BACKGROUND: The Society for Maternal-Fetal Medicine, sometimes together with the American College of Obstetricians and Gynecologists, publishes guidelines utilizing the Grading of Recommendations, Assessment, Development, and Evaluation system to rate the quality of evidence and assign the strength of its recommendations. The strength of recommendations is determined by the quality of evidence and 3 other strength determinants that are defined in this system. OBJECTIVE: This study aimed to assess all recommendations by the Society for Maternal-Fetal Medicine assessed by the Grading of Recommendations, Assessment, Development, and Evaluation system, determine the quality of evidence supporting them, evaluate the relationship between quality of evidence and strength of recommendations, and determine the extent to which the other 3 strength determinants were employed to assign recommendation strength. STUDY DESIGN: All publications from the Society for Maternal-Fetal Medicine Publications and Guidelines website were reviewed, but only the ones with Grading of Recommendations, Assessment, Development, and Evaluation recommendations were analyzed. These were aggregated by their rating for quality of evidence and strength. Quality and strength were first compared across all recommendations. Subsequently, they were compared with stratification by recommendation topic and type (eg, interventions, counseling, screening, and diagnosis). References supporting each recommendation were also summarized by type (eg, randomized trial, retrospective study). The quality of evidence for each recommendation was then compared with the supporting reference types. Other characteristics that may contribute to strength were also evaluated. Finally, we compared recommendations authored jointly by the Society for Maternal-Fetal Medicine and the American College of Obstetricians and Gynecologists with those by the Society for Maternal-Fetal Medicine alone. RESULTS: The Society for Maternal-Fetal Medicine published 24 documents containing 235 recommendations assessed by the Grading of Recommendations, Assessment, Development, and Evaluation system. There were 35 (15%) recommendations supported by high-quality evidence; 34 (97%) were determined to be strong. Recommendations supported by moderate-quality (n=102) and low-quality (n=75) evidence were also rated as strong in 78% and 68% of cases, respectively. Recommendations were supported by randomized trials 8% of the time and references that summarize primary data (eg, meta-analyses, reviews, previous guidelines) 64% of the time. Recommendations with higher quality evidence ratings were more likely to be supported by references that summarize primary data (69% high-quality, 74% moderate-quality, 49% low-quality). Topics with recommendations authored jointly by the Society for Maternal-Fetal Medicine and the American College of Obstetricians and Gynecologists were supported by higher quality evidence than those by the Society for Maternal Fetal Medicine alone (high quality, 26% vs 9%, respectively). CONCLUSION: Recommendations by the Society for Maternal-Fetal Medicine assessed by the Grading of Recommendations, Assessment, Development, and Evaluation system were supported by high-quality evidence in 15% of cases. This suggests that well-designed, high-quality clinical trials remain a priority in obstetrics. Strong recommendations were often made on the basis of Grading of Recommendations, Assessment, Development, and Evaluation strength determinants other than quality of evidence. Increased transparency of the Society for Maternal-Fetal Medicine's determination of strong recommendations based on strength determinants other than quality of the evidence may be useful to practicing clinicians.