Level of scientific evidence underlying recommendations arising from the functional urology guidelines

Purpose: This study aimed to review the functional urology guidelines, relate the level of evidence (LOE) of their recommendations and highlight the discrepancies between the LOE and grade of recommendation. Materials and Methods: The electronic search was conducted in May 2019 and updated in February 2021. Three researchers separately reviewed the extracted guidelines based on the Appraisal of Guidelines for Research and Evaluation II instrument. We extracted recommendations from each guideline and ranked them into three Grades of A, B, and C; and their evidence into four levels of I to IV. Results: Among the published functional urology guidelines, 18 guidelines were published between 2014 and 2020. Overall, 592 recommendations were abstracted. Of these, 121 recommendations were related to evaluation or diagnosis, and the others (n = 471) on the disease management. These recommendations were in the field of urinary incontinence (UI) (n = 216), overactive bladder (OAB) (n = 172), lower urinary tract symptoms (LUTS) (n = 126), and neurogenic bladder (NGB) (n = 78). Subgroup analysis showed that most of the recommendations in relation to UI were Grade A (n = 111; 51.4%), and one-third were Grade C (n = 83; 38.4%). The remaining 22 recommendations were Grade B (10.2%). In OAB, most of the recommendations were Grade B (n = 67, 39.0%), 55 of them were Grade A (32.0%) and the rest were Grade C (n = 50, 29.1%). Among UI guidelines, 51 (45.9%) Grade A recommendations were supported by LOE I evidence, and 39 (47.0%) Grade C recommendations were supported by LOE IV evidence. Across OAB guidelines, 43 (78.2%) Grade A recommendations were supported by LOE I evidence, and 20 (40.0%) Grade C recommendations were supported by LOE IV evidence. Across LUTS guidelines, 34 (61.8%) Grade A recommendations were supported by LOE I evidence, and 14 (23.3%) Grade C recommendations were supported by LOE IV evidence. Among NGB guidelines, 21 Grade A recommendations were supported by LOE I evidence, and 9 Grade C recommendations were supported by LOE IV evidence. Conclusion: Most of the recommendations in the field of functional urology are not based on the systematic review and meta-analysis of randomized controlled trials (RCTs) and high quality RCTs; which indicates that more attention is still needed in making decisions based on the certainty and grade of recommendations.