Letter 2: Meta‐analysis of randomized controlled trials comparing laparoscopic with open mesh repair of recurrent inguinal hernia (Br J Surg 2010; 97: 4–11)

Background: To compare the clinical efficacy and safety of phloroglucinol (PHL) and magnesium sulfate (MS) in the treatment of threatened abortion through systematic review. Methods: Foreign databases, such as the Cochrane Library, PubMed and EMBASE, and Chinese databases, including the China Biology Medicine disc (SinoMed), China National Knowledge Infrastructure (CNKI), Chongqing VIP (VIP) and WanFang Data, were searched. Published randomized controlled trials (RCTs) documents obtained from thesedatabaseswere included if theywere associated with the research objective. The search timeframewas from the beginning of the establishment of each database toMay 2018. Document selection, data abstraction and document quality evaluation were independently performed by 2 investigators. A combined analysis of the datawasperformed for thosedocuments that fulfilled the study requirements;RevMan5.3 andStata 12.0 softwarewere used to compare and analyze the 2 drugs in terms of the total effective rate (TER), rate of adverse events, time required to relieve uterine contractions, onset time, time of complete relief of uterine contraction symptoms, medication duration and length of hospital stay. Results:A total of 21 RCT trials were included in the present research, according to the inclusion criteria. However, the quality of the included studies was low. The meta-analysis suggested that the TER and drug onset time of PHL were higher than those for MS, while the rate of adverse events, the time required to relieve uterine contractions, time to complete relief of uterine contraction symptoms, drug continuous treatment time and length of hospital stay were shorter than those for MS. Conclusion: The clinical efficacy of PHL is better than that of MS, and PHL obviously results in fewer adverse reactions than MS. However, due to poor quality of evidence, high quality, multi-center RCTs with large samples are required for further verification. Abbreviations: CG = control group, CNKI = China national knowledge infrastructure, GI = glucose injection, MD = mean deviation, MS =magnesium sulfate, PHL = phloroglucinol, RCTs = randomized controlled trials, RG = research group, RR = relative risk, SCI = sodium chloride injection, SMD = standardized mean difference, TER = total effective rate, VIP = Chongqing VIP.