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Systematic reviews and meta-analyses now form a major source of evidence on clinical effectiveness. Despite the relative recency of this approach to synthesizing research findings, a reasonable consensus has emerged as to the desirable methodological characteristics of this secondary research. Understanding these basic tenets enables readers to take a balanced view of published review findings.
OBJECTIVE: To systematically assess imaging diagnostic tests for fatty liver and provide a decision-making basis for clinical diagnosis and screening. METHODS: Electronic searches were conducted on the Chinese Biomedical Database, PubMed, and EMBASE, combining with manually searching of Chinese literature. All searches were completed until November 2002. All studies which evaluated imaging diagnostic test of human fatty liver were included. Data of diagnostic accuracy in the included studies were extracted, and methodological quality of the studies was assessed independently by two reviewers according to the established quality standard. Quantitative analysis or qualitative description were performed based on available data. RESULTS: Of 13 studies that met the eligibility criteria, 10 studies evaluated the diagnostic accuracy of B-mode ultrasound, 3 studies evaluated contrast-enhanced (helical) CT. To assess 7 diagnostic test studies for fatty liver that used liver biopsy as reference test: the pooled sensitivity of B-mode ultrasound was 0.89 (95% confidence interval 0.87-0.92), specificity was 0.94 (95% confidence interval 0.92-0.96) and the Q value was 0.90 by adjusted SROC method. To assess 2 diagnostic test studies for fatty liver that used CT as reference test: the pooled sensitivity, specificity, and Q value were 0.92 (95% confidence interval 0.89-0.96), 0.88 (95% confidence interval 0.84-0.92), and 0.90 respectively by adjusted SROC method. CONCLUSIONS: B-mode ultrasound method can be regarded as an effective method for fatty liver diagnosis and screening. The methodologic quality of diagnostic test needs to be improved.
In this systematic review, we identified and evaluated studies of the cost effectiveness of spinal cord stimulation (SCS) for the treatment of chronic pain. Published reports were identified from a systematic search of a number of general medical electronic databases (Medline, CINAHL, and EMBASE), and specialist economic databases (NHS Centre for Reviews and Dissemination Economic Evaluation Database, and Health Economics Evaluation Database). Reference lists of retrieved reports were also searched, and contact was made with experts in the field. Of the 99 abstracts identified, 14 studies were considered to meet the inclusion criteria of the review. We found that across a range of medical indications, the initial healthcare acquisition costs of SCS implantation are consistently offset by a reduction in post-implant healthcare resource demand and costs. Further research is required to formally examine the cost effectiveness of SCS.
AIM: The aim of this paper is to present a systematic review assessing the effectiveness of timed voiding for the management of urinary incontinence in adults. BACKGROUND: Despite the widespread use of systematic voiding programmes, their effectiveness is unclear, and the evidence for timed voiding has not been subject to rigorous and systematic evaluation. The impact on psychosocial factors and cost is also untested. The physiological basis for timed voiding is also poorly established. METHODS: The systematic review incorporated the methodology of the Cochrane Collaboration. All randomized or quasi-randomized controlled trials that addressed timed voiding for the management of urinary incontinence in adults were searched, appraised, analysed and summarized. The date of the latest search was 2002. Data were extracted independently and appraised according to the level of concealment of random allocation prior to formal entry; few and identifiable withdrawals and dropouts and an analysis based on an intention to treat. The relative risk for dichotomous data was calculated with 95% confidence intervals. Where data were insufficient to support quantitative analysis, a narrative overview was undertaken. RESULTS: Two trials of timed voiding met the inclusion criteria. In both, timed voiding was combined with other strategies. Participants were predominantly cognitively and physically impaired older women who resided in nursing home settings. Within-group improvements for the intervention groups were reported for both trials. One trial additionally reported a statistically significant reduction in night-time incontinence for the intervention group. The quality of the trials was modest and interpretation was limited by the potential for bias associated with inadequate concealment, missing data and no analysis by intention to treat. CONCLUSION: Terms used to describe voiding programmes that involve a fixed interval of voiding are variable. No conclusions can be drawn at this point about the effectiveness of timed voiding for the management of urinary incontinence in adults.
BACKGROUND: Compliance with conventional weight-management programs is notoriously poor, and a plethora of over-the-counter slimming aids are sold with claims of effectiveness. OBJECTIVE: The objective of the study was to assess the evidence from rigorous clinical trials, systematic reviews, and meta-analyses on the effectiveness of dietary supplements in reducing body weight. DESIGN: The study was a systematic review. Literature searches were conducted on Medline, Embase, Amed, Cinahl, and the Cochrane Library until March 2003. Hand searches of medical journals, the authors' own files, and bibliographies of identified articles were conducted. There were no restrictions regarding the language of publication. The screening of studies, selection, validation, data extraction, and the assessment of methodologic quality were performed independently by the 2 reviewers. To be included, trials were required to be randomized and double-blind. Systematic reviews and meta-analyses of dietary supplements were included if they were based on the results of randomized, double-blind trials. RESULTS: Five systematic reviews and meta-analyses and 25 additional trials were included and reviewed. Data on the following dietary supplements were identified: chitosan, chromium picolinate, Ephedra sinica, Garcinia cambogia, glucomannan, guar gum, hydroxy-methylbutyrate, plantago psyllium, pyruvate, yerba maté, and yohimbe. The reviewed studies provide some encouraging data but no evidence beyond a reasonable doubt that any specific dietary supplement is effective for reducing body weight. The only exceptions are E. sinica- and ephedrine-containing supplements, which have been associated with an increased risk of adverse events. CONCLUSIONS: The evidence for most dietary supplements as aids in reducing body weight is not convincing. None of the reviewed dietary supplements can be recommended for over-the-counter use.
BACKGROUND AND OBJECTIVE: To assess the effect of publication bias and country effect on the results and conclusion of a systematic review of wrist P6 acupoint stimulation for the prevention of postoperative nausea and vomiting. METHODS: Reanalysis of a systematic review of 26 randomized trials comparing P6 acupoint stimulation with sham published in the Cochrane Database of Systematic Reviews using the Copas' sensitivity approach. RESULTS: If it is assumed that all studies that have ever been carried out are included, or that those selected for review are truly representative of all such studies, then the estimated relative risk (RR) for nausea was 0.71 (95% CI: 0.58 to 0.88, P<.01) and for vomiting was 0.70 (95% CI: 0.56 to 0.88, P<.01) after adjusting for country effect. For nausea, adjustment for publication bias suggests that the risk has been overestimated. If around 33% of studies have been unpublished, the RR of nausea (0.92, 95% CI: 0.80 to 1.06, P=.25) is no longer significant. For vomiting, however, there is no strong evidence of publication bias. The number of unpublished studies required to substantially overturn the above significant result is implausibly large. CONCLUSION: Publication bias affects the published estimate of postoperative nausea, not vomiting.
PURPOSE: The purpose of this paper was to undertake a systematic review about the relationship between obesity in childhood, adolescence and/or adulthood and the prevalence of dental caries. METHODS: The authors searched Bireme, Medline, ISI, Cochrane Library and the internet for papers from 1984-2004. The main search terms were 'obesity' and 'dental caries'. The inclusion criteria were studies that defined obesity (body mass index) and dental caries (total number of decayed, and filled teeth - DFT/DFS/dft/dfs) in their subjects. The following were excluded from this paper: articles on reviews, dietary guidelines, policy statements, papers related to oral health and nutrition deficiency--underweight, and with no relation between obesity and dental caries prevalence or dental health problems. RESULTS: No systematic review has focused on correlating obesity and caries and only three stud ies had high levels of evidence. CONCLUSION: Only one study with high level of evidence showed direct association between obesity and dental caries. In view of the findings, further well-designed randomised studies are needed to demonstrate the relationship between dental caries and obesity.
BACKGROUND: We aimed to describe the approaches and characteristics of systematic reviews on three major complementary therapies and to assess their methodological quality. METHODS: Systematic reviews of clinical trials of acupuncture, herbal medicines, and homeopathy were identified from a database developed for the Cochrane Collaboration Complementary Medicine Field. Information on conditions, interventions, methods, results, and conclusions was extracted using a pre-tested form; methodological quality was assessed using the Oxman scale. RESULTS: 115 reviews were included (39 on acupuncture, 58 on herbal medicine, 18 on homeopathy). Research questions were most specific in herbal medicine, and tended to be very general in homeopathy. The main comparison in most reviews was with placebo. The methodological quality of reviews was highly variable. Deficiencies were most frequent for the description of the selection process and the summary of the results of primary studies. CONCLUSION: Systematic reviews tend to approach different complementary therapies in different manner. Compared to a set of reviews on analgesic interventions methodological quality was slightly better on the average, but there is ample room for improvement in future complementary medicine reviews.
Critical appraisal of a literature is an important part of Systematic Review(SR) of laboratory tests. In this process, the quality of the clinical study is evaluated by using knowledge of clinical epidemiology and biostatistics. In the critical appraisal of articles of diagnostic tests, estimation of the design related bias, such as selection bias, spectrum bias, work-up bias, and referral bias, is extremely important. This article introduces the checklist for a diagnostic test proposed by the EBD collaboration in Japan. The proposed checklist consists of 23 items which effect on quality and external validity of the clinical studies. It will become a useful tool for systematic review in laboratory medicine.
OBJECTIVE: To assess how general practitioners might interpret and apply the results of a systematic review relevant to general practice. DESIGN: Cross-sectional postal survey of general practitioners in August 1997. PARTICIPANTS: 51 general practitioners in the Southern Division of General Practice in Adelaide and 11 professors or heads of departments of general practice. MAIN OUTCOME MEASURES: Extent to which comments on the implications for practice and implications for research coincided with the evidence presented in a systematic review of antibiotics for the treatment of acute otitis media in children; and reported probability that respondents would prescribe antibiotics in three brief case scenarios. RESULTS: There was considerable variation in the comments made by general practitioners on the implications of the review for clinical practice. After reading the review, respondents with training in critical appraisal were more likely to state that children with acute otitis media would usually recover spontaneously and reported a lower probability of prescribing antibiotics in two of the three case scenarios. CONCLUSIONS: Providing systematic reviews is not sufficient for the results of such evidence to be translated into clinical practice. There is an association between critical appraisal skills and the application of evidence-based practice.
OBJECTIVE: Using an evidence-based technique, systematically review the literature to evaluate the accuracy of routine clinical history and physical examination in the diagnosis of obstructive sleep apnea/hypopnea syndrome (OSAHS) in the pediatric patient. STUDY DESIGN AND SETTING: The biomedical literature was systematically reviewed. Articles comparing the results of clinical evaluation to polysomnography (PSG) were selected. The level of evidence was assessed using established evidence-based medicine (EBM) guidelines. RESULTS: Twelve articles were identified using the search criteria. Eleven of 12 articles concluded that clinical evaluation is inaccurate in the diagnosis of OSAHS. The level of evidence was good to very good (Grade B/B+). CONCLUSION/SIGNIFICANCE: Clinical history and physical examination are not reliable for diagnosing OSAHS compared with overnight PSG. Complicating the interpretation of this work is the lack of a validated PSG threshold of clinically significant disease. There is an urgent need for the development of adequate screening tests with validated clinical outcomes. EBM RATING: B-3.
A systematic review was conducted to determine whether certain vascular access policies are better than others in terms of prevention of catheter-related infections. Publications were retrieved by a search of Medline, the Cochrane Library and Embase up to May 2005. All randomized trials and systematic reviews/meta-analyses of randomized trials evaluating the effect of vascular access policies (i.e. needleless closed systems, conventional closed systems or conventional open systems) on catheter-related infection in hospitalized patients with intravascular catheters in situ were selected. Two reviewers independently assessed trial quality and extracted data. Data from the original publications were used to calculate the relative risk or the incidence-density relative rate of catheter-related infection. Data for similar outcomes were combined in the analysis where appropriate using a random-effects model. Of the six studies reviewed, one was excluded. Five randomized controlled trials were included in the review. The quality of the trials and the way they were reported were generally unsatisfactory. Four trials compared needleless closed systems with conventional open systems. There was a trend for an advantage of the needleless closed devices in terms of less catheter-associated bloodstream infection, less catheter tip colonization and less hub inlet colonization. There were no possibilities for combining data because of clinical heterogeneity. One trial compared needleless closed systems with conventional closed systems and the evidence was inconclusive. From the point of view of infection prevention, there are no objections to use these new systems. However, there is insufficient evidence at this stage to recommend the needleless closed vascular devices.
The aim of this paper is to provide a theoretical background for performing and reading systematic reviews of diagnostic studies. We first discuss items for assessment of methodological quality in diagnostic studies and then present methods on how to incorporate these quality measures in systematic reviews. The items of internal validity determine whether the presented results of the individual studies are unbiased and can be trusted. Items of external validity determine to what extent the results are applicable outside the population in which the study was performed. The issues concern the adequacy of the study population, the performance and interpretation of the diagnostic tests and the presentation of the results. Several methods exist for incorporation of issues of methodological quality into systematic reviews, such as subgroup analyses, meta-regression analysis, and methodological scores. Publications of diagnostic studies should provide sufficient information to enable assessment of the methodological quality. Furthermore, publication of results of subgroup analyses should be promoted. Methodological criteria lists might help to improve the quality of systematic reviews of diagnostic research. With the items of methodological quality in mind the general practitioner might be better equipped to critically read and interpret diagnostic reviews.
STUDY DESIGN: A systematic review of randomized controlled trials. BACKGROUND: Although several rehabilitation programs, physical fitness programs, or protocols regarding instruction for patients to return to work after lumbar disc surgery have been suggested, little is known about the efficacy of these treatments, and there are still persistent fears of causing reinjury, reherniation, or instability. OBJECTIVES: The objective of this systematic review was to evaluate the effectiveness of active treatments that are used in the rehabilitation after first-time lumbar disc surgery. METHODS: The authors searched the MEDLINE, Embase, and Psyclit databases up to April 2000 and the Cochrane Controlled Trials Register 2001, issue 3. Both randomized and nonrandomized controlled trials on any type of active rehabilitation program after first-time disc surgery were included. Two independent reviewers performed the inclusion of studies, and two other reviewers independently performed the methodologic quality assessment. A rating system that consists of four levels of scientific evidence summarizes the results. RESULTS: Thirteen studies were included, six of which were of high quality. There is no strong evidence for the effectiveness for any treatment starting immediately postsurgery, mainly because of the lack of good quality studies. For treatments that start 4 to 6 weeks postsurgery, there is strong evidence (level 1) that intensive exercise programs are more effective on functional status and faster return to work (short-term follow-up) as compared to mild exercise programs, and there is strong evidence (level 1) that on long-term follow-up there is no difference between intensive exercise programs and mild exercise programs with regard to overall improvement. For all other primary outcome measures for the comparison between intensive and mild exercise programs, there is conflicting evidence (level 3) with regard to long-term follow-up. Furthermore, there is no strong evidence for the effectiveness of supervised training as compared to home exercises. There is also no strong evidence for the effectiveness of multidisciplinary rehabilitation as compared to usual care. There is limited evidence (level 3) that treatments in working populations that aim at return to work are more effective than usual care with regard to return to work. Also, there is limited evidence (level 3) that low-tech and high-tech exercises, started more than 12 months postsurgery, are more effective in improving low-back functional status as compared to physical agents, joint manipulations, or no treatment. Finally, there is no strong evidence for the effectiveness of any specific intervention when added to an exercise program, regardless of whether exercise programs start immediately postsurgery or later. None of the investigated treatments seem harmful with regard to reherniation or reoperation. CONCLUSIONS: There is no evidence that patients need to have their activities restricted after first-time lumbar disc surgery. There is strong evidence for intensive exercise programs (at least if started about 4-6 weeks postoperative) and no evidence they increase the reoperation rate. It is unclear what the exact content of postsurgery rehabilitation should be. Moreover, there are no studies that investigated whether active rehabilitation programs should start immediately postsurgery or possibly 4 to 6 weeks later.
AIMS: This paper presents a systematic review whose aim was to describe the scope and methods of the current literature on preoperative patient education and to identify the effects of this education. BACKGROUND: Preoperative patient education is a common and important intervention in surgical nursing, yet there is very limited systematic evidence on its precise role. METHODS: The Medline, CINAHL, Eric, Psycinfo and Social Sciences Index databases and the Cochrane Library were searched, covering the period from the beginning of each database to April 2003. Studies were included if they concerned adult orthopaedic patients, preoperative nursing patient education and were based on randomized controlled or clinical trials. Meta-analysis was carried out where appropriate. RESULTS: We identified 11 articles involving 1044 participants. Most studies included one experimental and one control group; only two had more than one experimental and control group. The educational interventions varied widely, but the majority were based on written materials alone, or written materials in combination with other teaching methods. The most common outcome measures related to pain, knowledge, anxiety, exercises and length of stay, and the least common to self-efficacy and empowerment. The methodological quality of the studies varied. Almost all reported one or more statistically significant effects. Based on the findings of the meta-analysis, preoperative education appears to have some impacts on patients' anxiety and knowledge levels. CONCLUSIONS: The review clearly highlights the need for well-designed, methodologically sound research into the outcomes of patient education. It also points to the need to study patient education from the point of view of empowerment.
OBJECTIVE: To identify pressure ulcer research funding sources. DESIGN: A systematic review of the acknowledgment sections of pressure ulcer literature published between 2000 and 2002. RESULTS: Sixty-four papers were identified that acknowledged funding sources. Governmental funding sources were acknowledged in 53% (n = 34) of these papers, followed by manufacturers (30%, n = 19), consumer/professional organizations (17%, n = 11), provider organizations (11%, n = 7), philanthropic organizations (11%, n = 7), and academic institutions (9%, n = 6). CONCLUSION: Although various governmental organizations fund most pressure ulcer-related projects, this systematic review found that many other sources of funding are available. Researchers are encouraged to explore multiple sources for funding clinical research.
AIM: This systematic review aimed to evaluate the best available evidence regarding the effectiveness of topical skin care interventions for residents of aged care facilities. INTRODUCTION: Natural changes to skin, as well as increased predisposition to pressure sores and incontinence, means residents of aged care facilities readily require topical skin care. A range of interventions exist that aim to maintain or improve the integrity of skin of older adults. METHODS: Pubmed, Embase, Current Contents, CINAHL and The Cochrane Library databases were searched, as well as Health Technology Assessment websites up to April 2003. Systematic reviews and randomized or non-randomized controlled trials were evaluated for quality and data were independently extracted by two reviewers. RESULTS: The effectiveness of topical skin interventions was variable and dependent on the skin condition being treated. Studies examined the effectiveness of washing products on incontinence irritated skin. Disposable bodyworns may prevent deterioration of skin condition better than non-disposable underpads or bodyworns. Clinisan, a no-rinse cleanser may reduce the incidence of incontinence associated pressure ulcers when compared with soap and water. CONCLUSION: In general the quality of evidence for interventions to improve or maintain the skin condition in the older person was poor and more research in this area is needed. RELEVANCE TO CLINICAL PRACTICE: Skin care is a major issue for nurses working with older people. On the basis of this review no clear recommendations can be made. This lack of strong evidence for nurses to base effective practice decisions is problematic. However, the 'best' evidence suggests that disposable bodyworns are a good investment in the fight against skin deterioration. No rinse cleansers are to be preferred over soap and the use of the bag bath appears to be a useful practice to reduce the risk of dry skin (a risk factor for breaches in skin integrity).
The authors discuss 3 challenges in conducting and interpreting any systematic review that are particularly relevant for systematic reviews of therapeutic devices or surgical procedures: 1) inclusion or exclusion of grey literature, 2) the role of nonrandomized studies, and 3) issues in applying the results to clinical care that are unique to the surgical and therapeutic device literature. The authors also discuss empirical evidence related to these topics and illustrate how reviewers in the Agency for Healthcare Research and Quality's Evidence-based Practice Center program have dealt with these challenges in developing evidence reports for decision makers and clinicians about therapeutic devices or surgical procedures.