Is there evidence for recommending silver-coated urinary catheters in guidelines?

We evaluated the available literature on effectiveness of silver-coated versus uncoated catheters for the prevention of urinary tract infections in catheterized patients stratified by sex, systemic antibiotic use, renal function and duration of catheterization. Controlled clinical trials, randomized clinical trials and systematic reviews/meta-analysis were identified by a search strategy in Medline (1966-August 2001) and in the Cochrane Controlled Trials Register. Keywords were urinary catheterization, silver and infection. Trials using silver-coated catheters in the treatment group and uncoated catheters in the control group, with bacteriuria as the outcome measure, were selected. The quality of the methods used of all selected publications was assessed by using a quality assessment scale for randomized clinical trials. In addition we looked critically at subject-specific aspects. Data from the original publications were used to calculate the overall relative risk of bacteriuria in patients with silver-coated versus uncoated catheters, as well as the effect in subgroups. Thirteen trials and one meta-analysis were identified. Seven reports satisfied the selection criteria with only one achieving a high-quality score. Confounding variables were not considered in any trial. Additional studies with a high standard of internal quality and careful specification of the clinical question with regard to subject-specific critical points are necessary to decide whether the use of silver-coated catheters can be recommended.     

重症急性胰腺炎经鼻胃管营养支持的Meta-分析

目的 系统性评价经鼻胃管肠内营养支持在重症急性胰腺炎患者中应用的安全性和有效性.方法 检索中国生物医学文献数据库、Cochrane图书馆、Medline数据库和EMBASE数据库,按Cochrane Handbook手册5.0评定文献质量,用RevMan 4.2软件进行Meta-分析.结果 441篇相关文献中,4篇文献被纳入,共157例患者.Meta-分析显示:经鼻胃管与经鼻窄肠管肠内营养的安全性和可耐受性差异无显著性.结论 现有证据表明经鼻胃管肠内营养对于重症急性胰腺炎患者是安全、有效和可耐受的,但同时需要进行更多大样本、高质量的随机对照研究.     

The role for vitamin B-6 as treatment for depression: a systematic review

BACKGROUND: Major depression is the leading cause of disability worldwide, and among the 10 most frequent indications for using alternative medicine therapies, especially dietary supplements. OBJECTIVE: To assess the evidence evaluating vitamin B-6 supplementation as treatment for depression. METHODS: Medline, Psychinfo, AMED, and Cochrane Controlled Trials Register were searched from database inception through September 2001. All randomized controlled trials, controlled clinical trials, intervention studies, case-control studies, reviews, and case reports examining the evidence behind vitamin B-6 in depression among humans were selected. No limits were placed for demographics or co-morbidities. Only English language papers were abstracted and assessed for trial quality. Two abstractors independently evaluated each study, then reconciled findings. As data were available, between group treatment effect size was noted or, as needed, calculated. When studies reported outcome effects using multiple measures, data were abstracted to permit the greatest possible comparisons among papers. RESULTS: Ten articles met inclusion criteria; three reviews, one case report, five RCTs, and one intervention study. There was no common outcome measure among all studies, eliminating opportunity for direct comparison of effect sizes. As an alternate means of comparison, effects were plotted as they related to the null hypothesis. CONCLUSION: Viewed as a whole, meaningful treatment effect of vitamin B-6 for depression in general was not apparent. However, examination of papers addressing depression in pre-menopausal women only, reveals a consistent message about the value of using vitamin B-6 supplementation. Further study of vitamin B-6 as independent and adjuvant therapy for hormone related depression in women is indicated.     

The contribution of handsearching European general health care journals to the Cochrane Controlled Trials Register

A fundamental aim of any systematic review is that all relevant studies should be identified and considered for inclusion. Limitations with searching bibliographic databases led the Cochrane Collaboration to search journals by hand for reports of trials. This article presents the results of a 3-year project to identify and make accessible reports of randomized trials published in European general health care journals. Overall, 21,620 reports of controlled trials were identified from 119 journals from 16 countries. More than three quarters (76%) were published in U.K. or German journals. Only 3,640 (17%) reports were indexed in MEDLINE as controlled trials, and 6,554 (30%) were not indexed in MEDLINE at all. Bibliographic details for all reports are available by searching The Cochrane Controlled Trials Register in The Cochrane Library. This project has ensured that a large proportion of trial reports not previously identifiable has been made accessible to those preparing systematic reviews.     

Should systematic reviews include non-randomized and uncontrolled studies? The case of acupuncture for chronic headache.

We aimed to investigate: (1) whether patient and intervention characteristics, design-independent quality aspects, and response rates differ between randomized and non-randomized trials of acupuncture for chronic headache; (2) whether non-randomized studies provide useful additional information (regarding long-term effects, prognostic factors, adverse effects, and generalizability); (3) reasons for potential differences in response rates. Studies including at least five patients and reporting clinical outcome data were identified through searches in Medline, Embase, the Cochrane Controlled Trials Register, other databases and checking of bibliographies. Twenty-four randomized trials and 35 non-randomized studies (five non-randomized controlled cohort studies, 10 prospective uncontrolled studies, 10 case series, and 10 cross-sectional surveys) met the inclusion criteria. Studies were heterogeneous regarding patients, interventions, outcome measurements and results. On average, randomized trials had smaller sample sizes, met more quality criteria, and had lower response rates (0.59 [95% confidence interval 0.48-0.69] vs. 0.78 [0.72-0.83]). Whether randomized or not, studies meeting more quality criteria had lower response rates. Non-randomized studies did not have significantly longer follow-up periods, three included an analysis of prognostic variables, only one reported on adverse effects, and the degree of generalizability was unclear. In the case of acupuncture for chronic headache, non-randomized studies confirmed the finding of a systematic review of randomized trials that the treatment is likely to be effective but provided little relevant additional information on long-term effects, prognostic factors, and adverse effects.     

Literature searching for randomized controlled trials used in Cochrane reviews: rapid versus exhaustive searches

OBJECTIVES: To analyze sources searched in Cochrane reviews, to determine the proportion of trials included in reviews that are indexed in major databases, and to compare the quality of these trials with those from other sources. METHODS: All new systematic reviews in the Cochrane Library, Issue1 2001, that were restricted to randomized controlled trials (RCTs) or quasi-RCTs were selected. The sources searched in the reviews were recorded, and the trials included were checked to see whether they were indexed in four major databases. Trials not indexed were checked to determine how they could be identified. The quality of trials found in major databases was compared with those found from other sources. RESULTS: The range in the number of databases searched per review ranged between one and twenty-seven. The proportion of the trials in the four databases were Cochrane Controlled Trials Register = 78.5%, MEDLINE = 68.8%, Embase = 65.0%, and Science/Social Sciences Citation Index = 60.7%. Searching another twenty-six databases after Cochrane Controlled Trials Register (CCTR), MEDLINE, and Embase only found 2.4% additional trials. There was no significant difference between trials found in the CCTR, MEDLINE, and Embase compared with other trials, with respect to adequate allocation concealment or sample size. CONCLUSIONS: There was a large variation between reviews in the exhaustiveness of the literature searches. CCTR was the single best source of RCTs. Additional database searching retrieved only a small percentage of extra trials. Contacting authors and manufacturers to find unpublished trials appeared to be a more effective method of obtaining the additional better quality trials.     

Not only randomized controlled trials,but also case series should be considered in systematic reviews of rapidly developing technologies

ObjectiveCase series can influence clinical practice but are often omitted from systematic reviews. We evaluated the contribution of case series to a systematic review of radiofrequency catheter ablation (RFCA) for treatment of atrial fibrillation (AF).Study Design and SettingAnalysis of the results of a systematic review based on a search of 25 electronic databases and Internet sources.ResultsWe included eight controlled trials and 53 case series. Case series provided most patients longest follow-up and data on adverse events and complications. Rates of freedom from arrhythmia were comparable between case series, RFCA arms of controlled trials, and a survey of RFCA centers.ConclusionIn the case of RFCA for AF, the case series make a useful contribution to the systematic review. Inclusion of case series can increase the evidence base and strengthen the credibility of a review of an emerging health technology. These advantages must be balanced against the risk of bias associated with the lack of a control group, potential publication bias, overrepresentation of results from specialist centers, and overlap of patients across series. Specification in the review protocol of inclusion criteria for outcomes and quality criteria is recommended to make optimum use of case series.     

拓普替康治疗卵巢癌的循证评价

目的采用循证医学的方法评价拓普替康治疗卵巢癌的效果和安全性。方法采用Cochrane系统评价方法，检索Cochrane图书馆，MEDLINE，CENTRAL，CNKI，VIP，CBMDISC等电子资料库，搜集关于拓普替康治疗卵巢癌的系统评价、临床随机对照试验等，并对所获取的证据进行质量评价。结果检索并纳入7篇临床随机对照试验，1篇系统评价。根据临床问题，对所查证据进行了评价。结论拓普替康与紫杉醇、甲基化脂质体阿霉素、吉西他滨等化疗药具有相似的治疗作用，是一种有效的治疗卵巢癌的二线化疗药物。     

A review of blinding in randomized controlled trials found results inconsistent and questionable

BACKGROUND AND OBJECTIVE: To determine methods to assess the success of blinding in randomized controlled trials (RCTs). METHODS: We searched MEDLINE, the Cochrane Controlled Trials Register, and the Cochrane Method Register and performed a manual search to target studies that attempt to assess blinding and describe the methods used in those studies. RESULTS: A total of 90 reports were selected. Reports assessed the success of blinding participants (n = 58), care providers (n = 36), and outcome assessors (n = 15). Of the 58 reports assessing the success of blinding participants, 54 (93%) reported asking participants to guess their treatment assignment. There was no consistency in timing of assessment (e.g., once at the end of the trial, 57%, or several times during the trial, 26%) or modalities of answering (e.g., "do not know" answers, 43%, or participants forced to guess, 31%). A statistical analysis was performed in 57% of reports. The statistical analysis mainly compared the proportion of correct guesses to those produced by chance (32%) or checked for a relation between participants' guesses and treatment assignment (23%). CONCLUSIONS: Methods of assessing the success of blinding, analysis and reporting the results were inconsistent and questionable.     

The role of a Prospective Public Health Intervention Study Register in building public health evidence: proposal for content and use

Evidence-informed practice is a key component of public health and the focus of much discussion, of which the nature of evidence and how it is best gathered and appraised has formed a large part. Prospective registration of trials is now a key component of rigour and quality in clinical research and has been supported at an international level through the WHO International Clinical Trials Registry Program. This paper discusses the scope and benefits of trial registration in clinical research, including greater transparency and reduced publication bias. It then considers the potential for a Prospective Public Health Intervention Studies Register specific to the needs of public health and aspects to be included in such a register. It is argued that this initiative has the potential to facilitate increased global cooperation and efficiency in the production of high quality evidence and ultimately in improved health outcomes for populations.     

Placebo-controlled trials of Chinese herbal medicine and conventional medicine comparative study

BACKGROUND: Chinese herbal medicine (CHM) is increasingly used in the West, but the evidence on its effectiveness is a matter of debate. We compared the characteristics, study quality and results of clinical trials of CHM and conventional medicine. METHODS: Comparative study of placebo-controlled trials of CHM and conventional medicine. Eleven bibliographic databases and searches by hand of 48 Chinese-language journals. Conventional medicine trials matched for condition and type of outcome were randomly selected from the Cochrane Controlled Trials Register (issue 1, 2003). Trials described as double-blind, with adequate generation of allocation sequence and adequate concealment of allocation, were assumed to be of high quality. Data were analysed using funnel plots and multivariable meta-regression models. RESULTS: 136 CHM trials (119 published in Chinese, 17 published in English) and 136 matched conventional medicine trials (125 published in English) were analysed. The quality of Chinese-language CHM trials tended to be lower than that of English-language CHM trials and conventional medicine trials. Three (2%) CHM trials and 10 (7%) conventional medicine trials were of high quality. In all groups, smaller trials showed more beneficial treatment effects than larger trials. CHM trials published in Chinese showed considerably larger effects than CHM trials published in English (adjusted ratio of ORs 0.29, 95% confidence intervals 0.17-0.52). CONCLUSIONS: Biases are present both in placebo-controlled trials of CHM and conventional medicine, but may be most pronounced in CHM trials published in Chinese-language journals. Only few CHM trials of adequate methodology exist and the effectiveness of CHM therefore remains poorly documented.     

A Hungarian example for handsearching specialized national healthcare journals of small countries for controlled trials. Is it worth the trouble?

The objective of this study was to determine whether a Hungarian language journal of clinical neuroscience, which is not indexed in MEDLINE, contains any reports of randomized or quasi-randomized clinical trials that are not also reported in MEDLINE-indexed publications. A cover-to-cover handsearch was performed of the journal Clinical Neuroscience/Ideggyógyászati Szemle, the official journal of Hungarian societies of neurology, neurosurgery, psychiatry and related clinical neurosciences, from its first volume in 1950 to the end of 1998; and a search of MEDLINE for other reports of the trials identified. Clinical trials in which patients were allocated to interventions by randomized, quasi-randomized or possibly randomized means were identified. Controlled trials were tabulated and coded as randomized controlled trials or controlled clinical trials according to the definitions of the Handsearch Manual of the Cochrane Collaboration. We identified three randomized and eight quasi-randomized trials. Six of the 11 trials were not reported in MEDLINE indexed publications. In conclusion, to obtain a comprehensive controlled trials register, specialized healthcare journals printed in small numbers in the national languages of small countries should be searched.     

Humidified air inhalation for treating croup: a systematic review and meta-analysis

BACKGROUND: Croup (laryngotracheobronchitis) is a common cause of upper airway obstruction in children. Treatment with humidified air was previously widely used and is still commonly recommended as home treatment. OBJECTIVE: To assess the efficacy of humidified air in the treatment of croup. DESIGN: Systematic review and meta-analysis. DATA SOURCES: We searched the Cochrane Central Register of Controlled Trials, MEDLINE and EMBASE. REVIEW METHODS: We included randomized controlled trials with or without blinding. All studies treating children with a clinical diagnosis of croup with warm or cool humidified air delivered by steam or humidified tent whether inpatients, attenders at the Emergency Department or in the community were eligible. MAIN RESULTS: Three studies in emergency settings provided data on 135 patients with moderate croup for the main outcome (croup score). The combined results from 20 to 60 minutes in the three studies marginally favoured the treatment group with a weighted standardized mean difference of -0.14 (95% confidence interval = -0.75 to 0.47). No outcomes were significantly different between the groups. CONCLUSIONS: The croup score of children managed in an emergency setting with mild to moderate croup probably does not improve greatly with inhalation of humidified air. There is insufficient evidence to exclude either a small beneficial or a harmful effect.     

Should children be screened to undergo early treatment for otitis media with effusion? A systematic review of randomized trials

BACKGROUND: Otitis media with effusion (OME) is the most common cause of acquired hearing loss in childhood and has been associated with delayed language development and behavioural problems. Some have argued that children should be screened and treated early if found to have clinically important OME. The aim of this review was to assess evidence from randomized controlled trials about the effectiveness of screening and treating children with clinically important OME in the first 4 years of their life. The primary outcome was language development. METHODS: We searched the Cochrane Controlled Trials Register, MEDLINE and EMBASE and reference lists of all included studies in February 2003. We also contacted the first authors of the studies included in this review. Search terms included otitis media; otitis media with effusion; glue ear; OME; screen; children; treatment; language; and behaviour. Data extraction and methodological quality assessment were performed by at least two of us for each study independently, using methods described in the Cochrane Collaboration Handbook. RESULTS: From the three included randomized controlled trials evaluating interventions among children with OME identified through screening, we found no evidence of clinically important benefit in language development. CONCLUSIONS: The identified randomized trials do not show an important benefit on language development from screening the general population of asymptomatic children in the first 4 years of life to undergo early treatment for OME. Screening asymptomatic children in the first 4 years of life for OME is not recommended.     

Are obsessive‐compulsive personality traits associated with a poor outcome in anorexia nervosa? A systematic review of randomized controlled trials and naturalistic outcome studies

OBJECTIVE: Obsessive-compulsive personality disorder (OCPD) traits are commonly associated with anorexia nervosa (AN). The aim of this review was to systematically search the literature to examine whether OCPD traits have an impact on the outcome of AN. METHOD: A systematic electronic search of the literature (using Medline, PsycINFO, and the Cochrane Central Register of Controlled Trials) was undertaken to identify relevant publications (randomized controlled trials (RCT's) and naturalistic studies), until February 2006. RESULTS: Eleven prospective longitudinal studies and 12 RCT's met criteria for inclusion. A meta-analysis was not feasible as the studies were too heterogeneous. Just over half of published longitudinal studies found that OCPD traits were associated with a negative outcome in AN. Additionally, results from three RCTs suggested that these traits may moderate outcome. OCPD traits were reduced after treatment in five RCTs. CONCLUSION: There is tentative support to suggest that individuals with AN and concomitant OCPD traits have a poorer prognosis, and that these traits moderate outcome. A reduction in these traits may mediate this change. An individualized case formulation with treatment tailored to OCPD traits may improve the outcome of AN.     

Inflated numbers of authors over time have not been just due to increasing research complexity

OBJECTIVE: To examine trends in and determinants of the number of authors in clinical studies. STUDY DESIGN AND SETTING: We analyzed determinants of the number of authors in 633 articles of randomized trials and 313 articles of nonrandomized studies included in large meta-analyses (seven and six topics, respectively). Analyses were adjusted for topic. We also evaluated 310 randomly sampled case reports that had an abstract and described a single case. RESULTS: After adjusting for topic and other determinants, for both randomized trials and nonrandomized studies, the number of authors increased by 0.8 per decade (P<0.001). Topic was a strong determinant of the number of authors; other independent factors included journal impact factor, multinational authorship, and (for randomized trials) article length and sample size. Trials from South Europe (+1.1 authors) and North America (+0.9) and nonrandomized studies from South Europe (+1.8) had more authors than studies from North Europe (P<0.001). For case reports, only geographic location and article length were significantly related with author numbers. CONCLUSION: The number of authors in articles of randomized and nonrandomized studies has increased over time, even after adjusting for the topic, size, and visibility of a study. The academic coinage of authorship may be suffering from inflation.     

Inpatient management of children with severe acute malnutrition: a review of WHO guidelines

ObjectiveTo understand how the World Health Organization’s (WHO’s) guidelines on the inpatient care of children with complicated severe acute malnutrition may be strengthened to improve outcomes.MethodsIn December 2015, we searched Google scholar and WHO’s website for WHO recommendations on severe acute malnutrition management and evaluated the history and cited evidence behind these recommendations. We systematically searched WHO International Clinical Trials Registry Platform, clinicaltrials.gov and the Controlled Trials metaRegister until 10 August 2015 for recently completed, ongoing, or pending trials.FindingsWHO’s guidelines provide 33 recommendations on the topic. However, 16 (48.5%) of these recommendations were based solely on expert opinion – unsupported by published evidence. Another 11 (33.3%) of the recommendations were supported by the results of directly relevant research – i.e. either randomized trials (8) or observational studies (3). The other six recommendations (18.2%) were based on studies that were not conducted among children with complicated severe malnutrition or studies of treatment that were not identical to the recommended intervention. Trials registries included 20 studies related to the topic, including nine trials of alternative feeding regimens. Acute medical management and follow-up care studies were minimally represented.ConclusionWHO’s guidelines on the topic have a weak evidence base and have undergone limited substantive adjustments over the past decades. More trials are needed to make that evidence base more robust. If the mortality associated with severe malnutrition is to be reduced, inpatient and post-discharge management trials, supported by studies on the causes of mortality, are needed.     

Matched-pair study showed higher quality of placebo-controlled trials in Western phytotherapy than conventional medicine

OBJECTIVES: Herbal medicine (phytotherapy) is widely used, but the evidence for its effectiveness is a matter of ongoing debate. We compared the quality and results of trials of Western phytotherapy and conventional medicine. STUDY DESIGN AND SETTING: A random sample of placebo-controlled trials of Western phytotherapy was identified in a comprehensive literature search (19 electronic databases). Conventional medicine trials matched for condition and type of outcome were selected from the Cochrane Central Controlled Trials Register (issue 1, 2003). Data were extracted in duplicate. Trials described as double-blind, with adequate generation of allocation sequence and adequate concealment of allocation were assumed to be of higher methodological quality. RESULTS: Eighty-nine herbal medicine and 89 matched conventional medicine trials were analyzed. Studies of Western herbalism were smaller, less likely to be published in English, and less likely to be indexed in MEDLINE than their counterparts from conventional medicine. Nineteen (21%) herbal and four (5%) conventional medicine trials were of higher quality. In both groups, smaller trials showed more beneficial treatment effects than larger trials. CONCLUSIONS: Our findings challenge the widely held belief that the quality of the evidence on the effectiveness of herbal medicine is generally inferior to the evidence available for conventional medicine.     

A capture-recapture analysis demonstrated that randomized controlled trials evaluating the impact of diagnostic tests on patient outcomes are rare

ObjectiveTo estimate the number of randomized controlled trials (RCTs) published annually that evaluate the impact of diagnostic tests on patient outcomes to gauge the extent of available randomized evidence assessing the effectiveness of diagnostic tests.Study Design and SettingRelevant RCTs published in 2004–2007 were identified from electronic searches of the Cochrane Central Register of Controlled Trials (CENTRAL). Two search strategies were developed, one using diagnostic methodological terms and one using test names. Potentially relevant RCTs were identified by screening titles and abstracts. Final inclusion decisions were based on full-text review. A random 10% sample of all citations was independently screened by a second reviewer. Capture-recapture methodology was used to estimate the number of relevant RCTs missed by both searches.ResultsOne hundred thirty-five relevant RCTs were identified from the 23,888 records retrieved. Interobserver agreement was substantial. Capture-recapture methodology estimated that 148 (95% confidence interval: 140, 160) relevant RCTs were published in the 4-year period, an average of only 37 publications per year.ConclusionRCTs of diagnostic tests that evaluate patient outcomes are rare. Consequently recommendations on the use of diagnostic tests can rarely be made on the basis of randomized comparisons, lower grade evidence frequently being the best available.