Objective To evaluate the efficacy of n-3 PUFAs (fish oil) for prevention of cardiovascular events. Methods Randomized controlled trials (RCTs) were searched from the following electronic databases: PubMed, EMbase, The Cochrane Library (Issue 1, 2009), CBM, and CNKI. Quality assessment and data extraction were conducted by two reviewers independently. Disagreement was resolved through discussion. All data were analyzed by using Review Manager 4.2 software. Results Five studies involving 37 689 participants met the inclusion criteria. Meta-analysis results showed that: 1) Compared with placebo, the incidence rates of the cardiovascular death (RR=0.91, 95% CI 0.84 to 0.98), cardiovascular events (RR=0.95, 95%CI 0.91 to 0.98), angina (RR=0.79, 95%CI 0.64 to 0.96), and myocardial infarction (RR=0.79, 95%CI 0.65 to 0.96) could be reduced by n-3 PUFAs (fish oil). 2) There were no significant differences in death from any cause, the hospitalization rates of cardiovascular disease, sudden death, and heart failure (RR=0.95, 95%CI 0.90 to 1.00; RR=0.97, 95%CI 0.93 to 1.02; RR=0.90, 95%CI 0.79 to 1.01; RR=0.98, 95%CI 0.91 to 1.06). 3) Compared with placebo, the incidence rates of the arrhythmia and stroke could be increased, but there were no significant differences (RR=1.14, 95%CI: 0.80 to 1.62; RR=1.12, 95%CI 0.97 to 1.30). Conclusion Compared with placebo, n-3 PUFAs (fish oil) has good effects on reducing the incidence rates of total cardiovascular events, cardiovascular death, myocardial infarction, and angina pectoris, and it has the same efficacy in death from all cause, sudden death, heart failure, and the hospitalization rates of cardiovascular disease. There are no significant differences in the increased rates of arrhythmia and stroke.
ObjectivesTo systematically review the prognostic value of plasma soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) level in predicting 28-day mortality in sepsis.MethodsPubMed, The Cochrane Library, EMbase, Web of Science, CBM, CNKI, VIP and WanFang Data databases were electronically searched to collect studies about the prognostic value of plasma sTREM-1 in early 28-day mortality in sepsis from inception to April 16th, 2018. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies, then, meta-analysis was performed by using Stata 14.0 software.ResultsA total of 13 studies involving 1 115 patients were included. The results of meta-analysis showed that the sensitivity and specificity were 79% and 77%, respectively. The positive likelihood ratio and the negative likelihood ratio were 3.4 and 0.28, respectively. The diagnostic ratio was 12. The overall area under the summary receiver operator characteristic (SROC) curve was 0.80.ConclusionsCurrent evidence shows that plasma sTREM-1, as a single index, may play a prognostic role in the early 28-day mortality of sepsis in patients. Due to limited quality and quantity of the included studies, more high quality studies are needed to verify the above conclusion.
ObjectivesTo systematically review the application of evidence-based medicine (EBM) combined with problem-based learning (PBL) method in clinical teaching.MethodsDatabases including WanFang Data, CNKI, VIP, CBM, PubMed and EMbase were searched to identify eligible randomized controlled trials that compared EBM plus PBL with traditional lecture based learning (LBL) method in clinical teaching from inception to March 28th, 2020. Two reviewers independently screened literature, extracted data and assessed risk bias of included studies. Statistical analysis was performed using Stata 14.0 software.ResultsA total of 33 randomized controlled trials with 2 855 students were included. The results showed that students in EBM combined with PBL group obtained better scores of specialized theory (WMD=6.87, 95%CI 5.08 to 8.66, P<0.001), skills examination (WMD=10.57, 95%CI 8.98 to 12.16, P<0.001) and case analysis (WMD=9.79, 95%CI 4.71 to 14.88, P<0.001), comparing with those in LBL group. Besides, EBM combined with PBL method improved students’ overall ability including independent learning capability, clinical thinking ability, problem-solving capability, literature exploring capacity, communication and presentation skills and team-work ability.ConclusionsApplication of EBM combined with PBL method can improve clinical teaching quality.
ObjectiveTo compare the impact of early enteral nutrition (EN) and parenteral nutrition (PN) on the postoperative efficacy of esophageal cancer through meta-analysis of relevant randomized controlled trial (RCT).MethodsPubMed, Medline, EMbase, The Cochrane Library, Web of Science, China National Knowledge Infrastructure (CNKI), Wanfang Database, VIP, China Biology Medicine disc (CBMdisc) were searched by computer from inception to April 2018 to identify potential RCT which assessed clinical efficacy between EN and PN for postoperative patients with esophageal cancer. According to the inclusion and exclusion criteria, two researchers independently screened and evaluated literature. Meta-analysis was performed by RevMan 5.3 software.ResultsA total of 30 RCT studies were selected, including 3 969 patients. Meta-analysis results showed that: there was a significant difference between EN and PN in postoperative anastomotic fistulas (I2=0%, OR=0.67, 95%CI 0.45-0.99, P=0.04), postoperative pulmonary infections (I2=0%, OR=0.42, 95%CI 0.32-0.55, P<0.000 1), postoperative albumin levels (I2=38%, MD=0.78, 95%CI 0.51-1.06, P<0.000 01),time of first anal exhaust after operation (I2=0%, MD=–23.16, 95%CI –25.16-21.16, P<0.000 01) and postoperative incision infection (I2=0%, RR=0.36, 95%CI 0.21-0.64, P=0.000 5).ConclusionCompared with PN, early EN can significantly reduce the incidence of major postoperative complications and shorten the time of first anal exhaust after surgery. In addition, EN is superior to PN in improving nutritional status, increasing weight and reducing costs and side effects.
Objective To systematically review the efficacy and safety of totally laparoscopic total gastrectomy (TLTG) versus laparoscopic-assisted total gastrectomy (LATG) for patients with gastric cancer. Methods Databases including PubMed, EMbase, The Cochrane Library, CBM, WanFang Data and CNKI were searched to collect cohort studies about TLTG vs. LATG for gastric cancer from inception to February 28th 2017. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Meta-analysis was then performed using RevMan 5.3 software. Results A total of six cohort studies were included, of which 407 cases were in the TLTG group, and 315 cases were in the LATG group. The results of meta-analysis showed that compared with LATG group, patients in TLTG group had shorter operation time (MD=–8.97, 95%CI –16.21 to –1.73, P=0.02), and initial postoperative feeding time (MD=–0.30, 95%CI –0.57 to –0.03, P=0.03). However, the anastomic time, bleeding volume, the number of dissected lymph nodes, proximal resection margin, initial flatus time, postoperative hospital stay, overall postoperative complications, anastomotic fistula, and anastomotic stenosis were similar between two groups (all P values>0.05)． Conclusions Compared with LATG, TLTG has shorter operation and recovery time for patients with gastric cancer. Due to limited quality and quantity of the included studies, more high quality studies are required to verify above conclusions.
Objective To evaluate associations betweenMTHFD1 gene G1958A polymorphism and the risk of neural tube defects (NTDs). Methods We electronically searched databases including PubMed, The Cochrane Library, Web of Science, CNKI, VIP, and WanFang Data from inception to June 2016 to collect case-control studies of the correlation between the G1958A polymorphism inMTHFD1 and the risk of NTDs. Two reviewers independently screened the studies, extracted data and assessed the risk of bias of included studies, and then, meta-analysis was performed using Stata 12.0 software. Results Thirteen case-control studies were included, involving 1 724 NTDs infants, 1 485 mothers and 774 fathers with NTDs offspring. The results of meta-analysis showed that there was significant association betweenMTHFD1 gene G1958A polymorphism and increased risk of NTDs in infants (AAvs. GG: OR=1.437, 95%CI 1.100 to 1.878,P=0.008; AA+AGvs. GG: OR=1.187, 95%CI 1.031 to 1.367,P=0.017; Avs. G: OR=1.210, 95%CI 1.050 to 1.394,P=0.008). However, there was no association between biparentalMTHFD1 gene G1958A polymorphism and NTDs in the offspring. Conclusion The current evidence shows thatMTHFD1 gene G1958A polymorphism may be a genetic risk factor for NTDs. Due to the limited quantity and quality of the included studies, more high quality studies are needed to verify the above conclusion.
ObjectiveZero-events studies frequently occur in systematic reviews of adverse events, which consist of an important source of evidence. We aimed to examine how evidence of zero-events studies was utilized in the meta-analyses of systematic reviews of adverse events.MethodsWe conducted a survey of systematic reviews published in two periods: January 1, 2015 to January 1, 2020 and January 1, 2008, to April 25, 2011. Databases were searched for systematic reviews that conducted at least one meta-analysis of any healthcare intervention and used adverse events as the exclusive outcome. An adverse event was defined as any untoward medical occurrence in a patient or subject in healthcare practice. We summarized the frequency of occurrence of zero-events studies in eligible systematic reviews and how these studies were dealt with in the meta-analyses of these systematic reviews.ResultsWe included 640 eligible systematic reviews. There were 406 (63.45%) systematic reviews involving zero-events studies in their meta-analyses, among which 389 (95.11%) involved single-arm-zero-events studies and 223 (54.93%) involved double-arm-zero-events studies. The majority (98.71%) of these systematic reviews incorporated single-arm-zero-events studies into the meta-analyses. On the other hand, the majority (76.23%) of them excluded double-arm-zero-events studies from the meta-analyses, of which the majority (87.06%) did not discuss the potential impact of excluding such studies. Systematic reviews published at present (2015-2020) tended to incorporate zero-events studies in meta-analyses than those published in the past (2008-2011), but the difference was not significant [proportion difference=–0.09, 95%CI (–0.21, 0.03), P=0.12].ConclusionSystematic review authors routinely treated studies with zero-events in both arms as "non-informative" carriers and excluded them from their reviews. Whether studies with no events are "informative" or not, largely depends on the methods and assumptions applied, thus sensitivity analyses using different methods should be considered in future meta-analyses.
Objective To systematically review the prognostic value of perineural invasion (PNI) for patients with early-stage cervical cancer. Methods We searched PubMed, EMbase, The Cochrane Library (Issue 10, 2016), CNKI, WanFang Data, CBM and VIP databases to collect case-control studies about prognostic value of PNI in cervical cancer from inception to October, 2016. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Then meta-analysis was performed by using RevMan 5.3 software. Results Seven case-control studies from eight articles involving 1 218 patients were included. The results of meta-analysis showed that: (1) On Cox's model multivariate analysis, PNI was not identified as an independent risk factor for disease free survival (DFS) (HR=0.73, 95%CI 0.33 to 1.58,P=0.42) or overall survival (OS) (HR=0.89, 95%CI 0.41 to 1.94,P=0.77) with no significant difference; (2) On Kaplan-Meier-curves, DFS (HR=1.86, 95%CI 1.20 to 2.88,P=0.006) and OS (HR=2.43, 95%CI 1.63 to 3.62,P<0.000 1) were both significantly decreased in patients with PNI positive group. Conclusion PNI represents a decreasing disease-free survival and overall survival in patients with early-stage cervical cancer, and is one of the poor prognosis factors which be informed management decisions regarding adjuvant therapy. However, there is no evidence that PNI is an independent factor affecting the prognosis. In view of the limitation of the studies, a large sample prospective controlled trial is warranted to verify the above conclusion.
ObjectiveTo explore the correlation of pretreatment systemic immune inflammation index (SII) with prognosis in esophageal cancer patients.MethodsWe searched the PubMed, Web of Science, Embase, Cochrane Library, China National Knowledge Infrastructure, VIP, Chinese Biology Medicine, and Wanfang databases to identify eligible studies evaluating the relation between pretreatment SII and prognosis in patients with esophageal cancer from establishment of databases to December 2018. SII was defined as the absolute neutrophil count multiplied by the absolute platelet count divided by the absolute lymphocyte count. The primary endpoint was overall survival (OS), and the secondary endpoints were cancer-specific survival and disease-free survival. The Stata 12.0 software was applied for the meta-analysis, and the hazard ratio (HR) and 95% confidence interval (CI) were assessed.ResultsA total of six retrospective studies involving 2 376 esophageal cancer patients were included and all patients were from China or Japan. The results revealed that elevated pretreatment SII was significantly associated with poor OS in esophageal cancer [HR=1.50, 95%CI (1.15, 1.95), P=0.002]. Subgroup analyses of OS indicated that SII had a high prognostic value in patients who received surgery [HR=1.54, 95%CI (1.14, 2.08), P=0.005] and were diagnosed as esophageal squamous cell carcinoma [HR=1.50, 95%CI (1.11, 2.02), P=0.007]; however, no significant relation was observed between SII and prognosis in esophageal cancer patients who were treated with radiotherapy [HR=1.318, 95%CI (0.611, 2.841), P=0.482]. Furthermore, compared with neutrophil to lymphocyte ratio and platelet to lymphocyte ratio, SII showed a higher predictive value for the prognosis of esophageal cancer.ConclusionsPretreatment SII may serve as an independent risk factor for prognosis of Chinese and Japanese esophageal cancer patients, especially patients who were treated with surgery and with esophageal squamous cell carcinoma. However, more prospective studies with big samples from other countries or regions are still needed to verify our findings.
Sample size, mean and standard deviation are necessary when conducting meta-analysis for continuous outcomes. Advanced methods of data extraction were needed if the mean and the standard deviation couldn’t be obtained from a literature directly. Eight methods were introduced and two examples were given to illustrate how to apply the methods.