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 evaluate the effect and safety of Yinzhihuang injection for icteric viral hepatitis. Methods We searched MEDLINE (1966 to 2005), The Cochrane Library (Issue1, 2005), CBMdisk (1978 to 2004), CMCC (1994 to 2005), CMAC (1994 to 2005), CNKI (1994 to 2005), VIP (1989 to 2004). Data were extracted by two reviewers using a designed extraction form. The quality of included trials was critically assessed. RevMan 4.2.7 was used for data analysis. Results Four randomized controlled trials were included. It showed that Yinzhihuang injection could abate jaundice better than or the same as controlled western medicine in patients with hepatitis (WMD 19.70, 95%CI 32.69 to 6.71 and WMD 1.27, 95%CI 3.08 to 0.54, respectively), but less than S-adeanosyl methionine in patients with chronic hepatitis (WMD 106.00, 95%CI 189.05 to 22.95). There may be a dose-effect relationship in Yinzhihuang injection, higher doses had better effect (WMD 11.50, 95%CI 16.53 to 6.47). No fatal side effects were reported.Conclusions It is noted that Yinzhihuang injection can abate jaundice of icteric viral hepatitis. Due to low statistical power and high risk of selection bias, performance bias and measurement bias of the included trials, these conclusions need to be treated cautiously.
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.
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 evaluate the prognostic value of the level of serum neurone specific enolase (NSE) in patients with small cell lung cancer (SCLC). Methods We searched MEDLINE, EMbase, CBMdisc, and The Cochrane Central Register of Controlled Trials (1950 to December 2007). Studies meeting the eligibility criteria were retrieved and their bibliographies were checked for other relevant publications. The quality of included studies was evaluated by 2 reviewers independently. Meta-analyses were performed for the results of homogeneous studies using STATA 7.0 software. Results Nine studies involving 2 021 SCLC patients were included. About 66.0% of patients had high serum levels of NSE, according to the cut-off value defined by the authors. The hazard ratio (HR) of high levels of NSE for overall survival (OS) was 1.27 times of that of low levels of NSE for OS in SCLC patients (95% CI 1.19 to 1.35, P=0.281). Conclusion Patients with high levels of NSE appear to have a poorer OS compared with those with low levels of NSE, thus the level of NSE has a prognostic value in SCLC patients. Due to the potential publication bias, selection bias, and measurement bias among these studies, the conclusion should be interpreted carefully. More high-quality homogeneous studies are required to accurately evaluate the prognostic value of NSE.
Objective To systematically review the effectiveness and safety of Zhibitai vs. atorvastatin in the treatment of hyperlipidemia. Methods Randomized controlled trials (RCTs) about Zhibitai vs. atorvastatin for hyperlipidemia were electronically retrieved in databases of PubMed, CENTRAL (Issue 7, 2010), CBM,CNKI, VIP and WanFang Data from inception to July, 2012. Two reviewers independently screened literature, extracted data, and assessed methodological quality. Then, meta-analysis was conducted using RevMan 5.2 software. Results A total of 4 RCTs involving 519 cases were included. The results of meta-analysis showed, Zhibitai was superior to atorvastatin in reducing TG levels after 8-week treatment (MD= ?0.12, 95%CI ?0.23 to ?0.01, P=0.03) and increasing HDL-C levels after 8-week treatment (MD= ?0.16, 95%CI ?0.22 to ?0.11, P=0.000 01). But there was no significant difference in decreasing TC levels and LDL-C levels after 4-week treatment and 8-week treatment as well as decreasing TG levels after 4-week treatment between the two groups. No obvious adverse reaction occurred in the two groups, but atorvastatin may impair liver function. Conclusion Current evidence with weak strength shows that, Zhibitai is superior to atorvastatin in reducing TG levels, and increasing HDL-C levels after 8 weeks. However, they are alike in other blood-fat index and safety. Due to the limited quantity and quality of the included studies, more high quality RCTs are needed to verify the above conclusion.
Objective To evaluate the effect and safety of the conservative treatment for the protrusion of cervical vertebra intervertebral disc. Methods We searched CBM disk (1978~2007), CNKI (1979~2007), VIP (1989~2007). Telephone interviewed the original authors of claimed randomized controlled trials(RCTs) to identify whether they are truly RCTs. Only true RCTs and quasi-randomized controlled trials were included and the quality of them was critically assessed. Results Five RCTs and eleven quasi-randomized controlled trials were identified and included. It showed that lifting-massage, massage combining with traction or acupuncture, articulus mobilization combining with traction and electrotherapy, traction combining with computer intermediate frequency therapeusis and injectio ad acumen combining with massage have marked improvement. But it could hardly draw a conclusion that all the combining therapies had better curative effect. Conclusions Weak evidence shows that combining conservative treatment can improve the curative effect of the protrusion of cervical vertebra intervertebral disc. The results need to be supported by well designed and high quality trials.
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 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.
