Objectives To investigate calcium supplement in pregnancy for prevention of preeclampsia and relevant outcomes. Methods The Cochrane Library, PubMed, EMbase, CBM, WanFang Data, VIP and CNKI databases were searched online to collect randomized controlled trials (RCTs) of calcium supplement in pregnancy for prevention of preeclampsia and relevant outcomes from inception to July 2018. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Meta-analysis was then performed by RevMan 5.3 software. Results A total of 33 RCTs involving 29 234 subjects were included. The results of meta-analysis showed that: compared with control group, the calcium supplement group was associated with lower preeclampsia (RR=0.48, 95%CI 0.38 to 0.62, P<0.000 01) and gestational hypertension (RR=0.65, 95%CI 0.55 to 0.77,P<0.000 01) incidence. The incidence of premature delivery, intrauterine growth retardation and severe preeclampsia in calcium supplement group was lower than that in placebo group, and the neonatal weight in calcium was higher than that in placebo group. However, there was no significant difference in the pregnancy cycle between the two groups. Conclusions Current evidence shows that calcium supplement is associated with lower risk of preeclampsia and gestational hypertension. Due to limited quality and quantity of the included studies, more high quality studies are required to verify the above conclusion.
Evidence mapping is a new type of comprehensive evidence research method that systematically collects, evaluates, and synthesizes existing evidence to clarify research status and gaps, thereby promoting scientific research and decision-making. After nearly 20 years of development, the methodology of evidence mapping has been continuously improved, and has gained wide attention and recognition from the international community. China has paid much attention to evidence mapping at an early stage, but there are relatively few theoretical and practical researches, and the concept definition is inconsistent. This paper introduces the methodology of evidence mapping production and reporting for researchers to use for reference, with a view to further promoting the research and development of evidence mapping in China.
目的 探討脂多糖（LPS）、白細胞介素-6（IL-6）和血小板活化因子（PAF）與重癥胸腹創傷后凝血功能紊亂發生的相關性及可能的致病機理。方法 收集2009年1月至2011年12月期間在中國人民解放軍第二五三醫院急診科就診、創傷指數≥17分且除外合并顱腦損傷及在急診科內死亡的胸腹創傷患者62例，在予以搶救、治療的同時抽血檢查血小板計數（PLT）、血漿D-二聚體（D-D）、部分活化凝血酶原時間（APTT）、凝血酶原時間（PT）、LPS、IL-6和PAF，并對其結果進行相關性分析。結果 本組患者就診時檢測的PLT為（157.73±78.11）×109/L， D-D為（1 023.88±208.72） U/L，APTT為（46.95±17.85） s，PT為（19.44±6.95） s，TT為（58.27±12.44）s，除PLT降低外，其余4項指標均升高或延長； LPS為（322.85±104.54） U/L，IL-6為（285.51±81.46） ng/mL，PAF為 （14 714.70±4 427.95） ng/L， 三者均升高； PLT與LPS、IL-6和PAF之間呈負相關關系（P＜0.001），而D-D、APTT、PT和TT與LPS、IL-6和PAF之間均呈正相關關系（P＜0.001）。結論 LPS、IL-6及PAF可能參與了重癥胸腹創傷后凝血功能障礙的發生；重癥胸腹損傷后出現的微循環障礙及內毒素血癥是凝血功能障礙發生的重要機理。針對LPS、IL-6和PAF進行早期干預，有可能改善重癥胸腹創傷患者的凝血功能障礙。