The most important difference between systematic review and traditional narrative review lies in their respective quality, namely the degree of bias control. Generally speaking, the sources of bias include the process of literature searching, study selection, data extraction and original studies. A systematic review may greatly reduce bias, as it takes effective steps such as developing search strategies, undertaking funnel plot analysis, using established criteria for study selection, and assessment of the methodology quality of studies. All these help to control, identify and, describe the possible bias.
Objective To conduct bibliometric analysis of systematic review and meta-analysis published in the Chinese Journal of Evidence-based Medicine. Methods Based on the Chinese academic periodical network as a data pool, literature on systematic reviews (involving meta-analysis) and clinical decision-making researches were retrieved in the Chinese Evidence-Based Medicine Magazine from 2001 to 2010, screened and categorized by the medical and hygienic standards of Chinese Library Classification (fourth edition), and then were counted and sorted. Results There were 425 articles about systematic reviews (involving meta-analyses) and clinical decision-making studies in the Chinese Evidence-Based Medicine Magazine, with an yearly increasing number. Basically, those articles involved all subjects such as clinical medicine, preclinical medicine, hygenics, pharmacy, and traditional Chinese medicine. Conclusion Development levels of evidence-based research in medical subjects are different, each of which has its own feature. Also, some systematic reviews do not strictly follow the Cochrane Handbook. Therefore, high-quality systematic review is still needed in each subject.
Objective To determine the effectiveness of statins in reducing C-reactive protein in patients with cerebral infarction and the potency of C-reactive protein as an indicator for preventing cerebrovascular events. Methods We searched PubMed, EMbase, Central Register of Controlled Trials, CBMdisc and CNKI from the date of establishment through August 2008. Bibliographies of the retrieved articles were also checked. Data was extracted and evaluated by two reviewers independently with a designed extraction form. The RevMan 5.0 software was used to carry out meta-analysis. Results Twenty-three randomized trials involving 1946 patients were included. The results of meta-analyses showed the following: statins reduced C-reactive protein compared to the control group (WMD= –5.79, 95%CI –7.32 to –4.26); statins were associated with a reduction of carotid intima-media thickness (IMT) (WMD= –0.21, 95%CI –0.25 to –0.17); atorvastatin greatly reduced C-reactive protein than the simvastatin control group (WMD= –1.78, 95%CI –3.92 to 0.36); statins were associated with a slight improvement in neurological deficit (OR= 2.22, 95%CI 0.94 to 5.21). Conclusion The evidence currently available shows that statins can reduce C-reactive protein and carotid IMT in the patients with cerebral infarction compared to the control group. However, it is not clear whether statins reducing C-reactive protein is correlated to the improvement of neurological deficit and prognosis. Similar trials in future should focus on the relationship between the change of C-reactive protein and clinical outcomes.
Objective To evaluate prognostic impact of treatment with Continuous Positive Airway Pressure (CPAP) or upper airway surgery on the patients with obstructive sleep apnea (OSA) and coronary heart disease (CHD). Methods Database search in The Cochrane Library, PubMed, OVID and CBM (from establishment dates to October 2009) were conducted. Cohort studies and randomized controlled trials of OSA with CPAP or upper airway surgery in CHD patients were identified. We assessed the quality of the included trials and extracted the relevant data. Statistical analysis was performed using RevMan 4.3.2 software. Results A total of 4 cohort studies involving 945 participants were included. The results of meta-analysis were as follows: a) there were no significant differences in the rate of late lumen loss and 10-year mortality between CHD patients with OSA treated by CPAP and those without OSA (RR=1.84, 95%CI 0.73 to 4.68, P=0.20; RR=0.80, 95%CI 0.24 to 2.64, P=0.71). b) CPAP or uvulopalatopharyngoplasty used in the treatment of OSA on CHD patients after PCI had a significant decrease in the rate of 5-year cardiac death when compared with those untreated OSA patients (RR=0.34, 95%CI 0.14 to 0.82, P=0.02). But there were no differences in the rate of 5-year all-cause mortality, major adverse cardiac events (MACE) between the two groups respectively (RR=0.66, 95%CI 0.39 to 1.10, P=0.11; RR=0.97, 95%CI 0.81 to 1.15, P=0.69). c) CPAP or upper airway surgery in treating OSA significantly reduced the risk of MACE occurrence during the 86.5±39 months follow-up period (RR=0.22, 95%CI 0.07 to 0.72, P=0.01). Conclusion Current evidence indicates that treating OSA with CPAP or upper airway surgery in CHD patients might be associated with a decrease in the risk of cardiac death. But more studies are necessary to evaluate prognostic impact of treatment with CPAP or upper airway surgery on the patients with OSA and CHD. However, due to the limited quantity and quality of the included studies, more high-quality studies are need.
Objective To systematically evaluate impact of perioperative use of clopidogrel on coronary bypass grafting (CABG) patients for anti-platelet treatment, in order to provide evidence for the rational drug use of such patients in the perioperative period. Methods PubMed, EMbase, HighWire, CENTRAL and its affiliated clinical trial registered data center, CBM and CNKI were electronically searched from 2003 to November, 2012. Randomized controlled trials (RCTs) and non-randomized clinical trials on perioperative use of clopidogrel of CABG patients were collected. References of included studies were also retrieved. Two reviewers independently screened studies according to exclusion and inclusion criteria, extracted data, and assessed the methodological quality. Then, meta-analysis was performed using RevMan 5.0 software. Results 18 studies (including 10 RCTs and 8 non-randomized clinical trials) involving 14 592 patients were included. The results of meta-analysis showed that: a) Among 10 included RCTs, preoperative use of clopidogrel for anti-platelet treatment reduced the incidence of myocardial infarction obviously, compared with the blank control group (RR=0.63, 95%CI 0.48 to 0.83, P=0.000 9), but there is no significant difference between the two groups in blood loss amount within 24 hours after operation (MD=130, 95%CI –6.21 to 266.22, P=0.06), the number of reoperation patients because of bleeding (RR=1.42, 95%CI 0.92 to 2.20, P=0.12), and risk of postoperative short-term death (RR=1.19, 95%CI 0.89 to 1.58, P=0.24); b) Among 8 non-randomized clinical trials, there was no significant difference between the two groups in reducing the incidence of myocardial infarction (RR=0.83, 95%CI 0.30 to 2.26, P=0.71), but preoperative use of clopidogrel for anti-platelet treatment significantly increased blood loss amount within 24 hours after operation (MD=82.42, 95%CI 35.18 to 129.66, P=0.000 6), the number of reoperation patients because of bleeding (RR=1.71, 95%CI 1.07 to 2.75, P=0.03), and risk of postoperative short-term death (RR=1.89, 95%CI 1.15 to 3.12, P=0.01). Conclusion Current evidence shows that, perioperative use of clopidogrel can reduce the incidence of myocardial infarction, but doctors should consider cautiously the increased risk of bleeding, re-operation and postoperative short-term death. There is contradiction between the results of RCTs and those of non-randomized clinical trials, which may result from the argument intensity, quantity and sample size bias of the included studies. The above conclusion should be proved by large-scale high-quality RCT results in future.
Objective To investigate the effects of two formulations of artesunate, and to provide evidence for the WHO Model List of Essential Medicines. Methods We searched The Cochrane Library (2006, Issue 4), MEDLINE ( 1966 to 2007), EMbase (1988 to 2007), CBM (1978 to 2007), VIP (1989 to 2007) and CNKI (1994 to 2007). Randomised trials comparing the two formulations of artesunate with other drugs were eligible for inclusion. We applied the methods of The Cochrane Collaboration to assess the effects of artesunate, compared to placebo and active controls. Results Eleven trials were included, of which 6 compared intravenous artesunate with intravenous quinine. The quality of each study was high, 6 out of the 11 studies were graded A according to the criteria of The Cochrane Collaboration. The other 5 were graded B. The meta-analysis suggested that the mortality rate was lower in the intravenous artesunate group than in the intravenous quinine group [RR 0.65, 95%CI (0.52, 0.80), Plt;0.0001]. Three trials compared intravenous artesunate with artemisinin suppositories. These trials generated similar estimates and confidence intervals for mortality rates, showing no significant difference between the two treatments [0.94 (0.35 to 2.56), 0.58 (0.19 to 1.74) and 2.00 (0.39 to 10.26)]. Two trials compared intravenous artesunate and intramuscular artesunate, and no significant difference in mortality rate was identified between the two treatment groups [RR 1.50, 95%CI 0.52 to 4.31]. Mortality rates were not statistically significantly different for intravenous artesunate compared to alternative drugs. No significant adverse drug reactions were observed. Conclusions Artesunate is effective and safe in the treatment of severe malaria.
ObjectiveTo systematically evaluate the efficacy of mirror therapy for phantom limb sensation and phantom limb pain in amputee. MethodsDatabases include PubMed, EMbase, The Cochrane Library (Issue 9, 2015), CBM, CNKI, VIP and WanFang Data were searched to collect randomized controlled trials (RCTs) about mirror therapy for phantom limb sensation and phantom limb pain in amputee from inception to 1st Sept. 2015. Two reviewers independently screened literature, extracted data and assessed the methodological quality of included studies. Then metaanalysis was performed using RevMan 5.3 software. ResultsA total of 5 RCTs involving 129 patients were included. The results of meta-analysis showed that, there was no significant difference between the mirror therapy group and the control group in relieving the phantom limb sensation and phantom limb pain in amputee (MD=-7.29, 95%CI -27.73 to 13.16, P=0.48). ConclusionMirror therapy could improve the control of phantom limb, however, there is no sufficient evidence to support the effect of mirror therapy on pain management in amputee. The long-term effect of mirror therapy is still under exploration. Due to the limited quantity and quality of the included studies, larger-sample, high quality designed RCTs are needed to verify the above conclusion.
Objective To systematically review the methodological quality of guidelines concerning infertility, so as to provide references for clinical practice. Methods Guidelines concerning infertility were electronically retrieved (from inception to Feb. 2013) in PubMed, EMbase, CBM, WanFang Data, CNKI, GIN guideline database guideline development websites (including NGC, NICE, SIGN, NZGG, SOGC, etc.), and medical associtation websites (including IFFS, FIGO, ESHRE, NFOG, RCOG, ASRM, ACOG, etc.). We also searched Chinese guideline websites including the website of the National Health and Family Planning Commission of People’s Republic of China, CGC (China Guideline Clearinghouse), and CPGN (Clinical Practice Guideline Net). Two reviews independently screened literature according to the inclusion and exclusion criteria, and assessed the quality of guideline development and reporting using the Appraisal of Guidelines for Research and Evaluation (AGREE II). Results a) A total of 16 guidelines concerning infertility were included, with development time ranging from 1998 to 2012. Among 16 guidelines, 10 guidelines were made by the USA, 3 by Britan, 1 by the Europe, and 1 by America and Europe. b) The scores of guidelines according to the domains of AGREE II decreased from “Clarity of presentations, scope and purpose”, “Participants”, “Applicability”, “Rigour of development”, and “Editorial independence”. 16 guidelines were generally low in quality. The levels of recommendations were Level A (5 guidelines), Level B (8 guidelines), and Level C (3 guidelines). c) Four evidence-based guidelines scored the top three in the domain of “Rigour of development”. d) The recommendations of different guidelines were fairly the same. e) No guidelines on infertility have been developed in China. Conclusion a) The guidelines on infertility should be improved in “Rigour of development” and “Applicability” in future. Conficts of interest should be addressed. b) Guidelines are recommended to be developed on the basis of the methods of evidence-based medicine, and best evidence is recommended. c) National organizations such as ASRM should be established in China, so as to develop biomedicine and TCM guidelines based on evidence and regulate the treatment. d) For the general assessment of guidelines, AGREE II should offer threshold criteria of suggestion.
Objective To evaluate the effectiveness and safety of treatment with Fuzheng Huayu capsule for liver fibrosis of chronic hepatitis B (CHB). Methods We searched MEDLINE, EMBASE, Cochrane Database of Controlled Trials (CCTR), CBMweb and CNKI up to March 2008. The references of retrieved literature were also hand searched. Randomized controlled trials (RCTs) which compared Fuzheng Huayu capsule with placebo or other drugs were collected. Data extraction and quality assessment were performed by two reviewers independently. The Cochrane Collaboration’ s software RevMan 4.2.10 was used for data analyses. Results Seven RCTs involving 590 cases of liver fibrosis of CHB were included. As for their methodological quality, one was graded A, one was graded B and the others were graded C. We carried out subgroup analyses based on treatment course and intervention measures. In terms of reducing haluronic acid, Fuzheng Huayu capsule was more effective than Huoluo Shugan capsule when the treatment course was 3 months (WMD=–61.75, 95%CI –105.20 to –18.30); significant differences were also noted between Fuzheng Huayu capsule and placebo (WMD=–187.72, 95%CI –244.23 to –31.21) or Huoluo Shugan capsule (WMD=–120.03, 95%CI –158.41 to –81.65) when the treatment course was 6 months. In terms of reducing IV-C, Fuzheng Huayu capsule was more effective than Gantaile when the treatment course was 6 months (WMD=–72.32, 95%CI –84.30 to –60.34). As for improving liver fibrosis at stage S, significant differences were observed between Fuzheng Huayu capsule and Gantaile (RR=2.33, 95%CI 1.37 to 3.96) or Huoluo Shugan capsule (RR=1.30, 95%CI 1.03 to 1.65). Except a very small number of gastrointestinal reactions, no significant adverse reactions were reported. Conclusion Fuzheng Huayu capsule is effective in reducing haluronic acid and improving liver fibrosis at stage S, especially when the treatment course is prolonged from 3 months to 6 months. No significant adverse reactions are reported. Because most of the included trials are of poor quality and small sample size, more high-quality RCTs are needed.
ObjectiveTo systematically review the health-related quality of life (QOL) based on EQ-5D instrument for disease population in China. MethodsWe searched databases including PubMed, The Cochrane Library (Issue 5, 2015), EMbase, CNKI, VIP and WanFang Data from inception to August 2015, to identify studies involving healthrelated QOL about different diseases in China. A descriptive analysis was used to analyze health utility by disease and the proportion of patients who having problem in five dimensions, as well as comparing health-related QOL in different diseases. ResultsA total of 26 studies were included, involving 15 kinds of diseases. The health utility in different studies about the same disease was different. Diabetes ranged from 0.79 to 0.94, liver disease infected by HBV was from 0 to 0.80, hypertension was from 0.78 to 0.93, coronary heart disease was from 0.75 to 0.90, and chronic obstructive pulmonary disease was from 0.64 to 0.73. After ranking the health utility of fifteen kinds of diseases, the utility of kashin-beck disease and rheumatoid arthritis were 0.45 and 0.56, respectively, and the utility of children cerebral palsy was 0.44, which was the lowest. "Pain/discomfort" was the dimension with highest proportion of patients who having problem for most diseases while atrial fibrillation and children cerebral palsy were the "Self-care" and "Usual Activities". ConclusionEQ-5D is widely used in health-related QOL studies among different diseases in China. Many factors including sample source, severity of disease, complication and value set have influence on the measurement results of health utility.