Diagnostic tests used in the investigation of adult haematuria: A systematic review.
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Biomedical subjects
Publications and source records attributed to Jos Kleijnen.
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BACKGROUND: Slower rates of infant growth are associated with increased rates of death from ischaemic heart disease (IHD) in later life. We carried out a systematic review to assess the association between infant size or growth and leading causes of adult burden of disease to contribute to the debate on the potential of the promotion of infant growth to prevent ischaemic heart disease. METHODS: We searched Medline, Embase, CINAHL, PsycINFO, and bibliographies of included studies. First authors of included studies and other experts were contacted to locate unpublished analyses. Outcome measures for the review were leading causes of adult burden of disease selected from the Global Burden of Disease study. We included studies that assessed the relationship between infant size or growth during the first 2 years and the leading causes of adult burden of disease. RESULTS: Nineteen studies relating to 10 causes of burden of disease met inclusion criteria. Most studies reported data on infant size. Larger size in infancy was associated with increased risk of insulin-dependent diabetes. Larger infant size was associated with reduced rates of IHD in men but not in women. There were considerable gaps in the evidence and many conditions that account for a high burden of disease, such as cancer, mental illness, stroke, chronic obstructive pulmonary disease, and non-insulin-dependent diabetes, had few or no studies associating them with infant size or growth. CONCLUSIONS: Our findings suggest that there is no single optimal pattern of infant growth that is associated with beneficial adult health outcomes. There is insufficient evidence to recommend prevention of adult disease through strategies to alter infant growth.
BACKGROUND: A quality assessment tool for diagnostic accuracy studies, named QUADAS, has recently been developed. Although QUADAS has been used in several systematic reviews, it has not been formally validated. The objective was to evaluate the validity and usefulness of QUADAS. METHODS: Three reviewers independently rated the quality of 30 studies using QUADAS. We assessed the proportion of agreements between each reviewer and the final consensus rating. This was done for all QUADAS items combined and for each individual item. Twenty reviewers who had used QUADAS in their reviews completed a short structured questionnaire on their experience of QUADAS. RESULTS: Over all items, the agreements between each reviewer and the final consensus rating were 91%, 90% and 85%. The results for individual QUADAS items varied between 50% and 100% with a median value of 90%. Items related to uninterpretable test results and withdrawals led to the most disagreements. The feedback on the content of the tool was generally positive with only small numbers of reviewers reporting problems with coverage, ease of use, clarity of instructions and validity. CONCLUSION: Major modifications to the content of QUADAS itself are not necessary. The evaluation highlighted particular difficulties in scoring the items on uninterpretable results and withdrawals. Revised guidelines for scoring these items are proposed. It is essential that reviewers tailor guidelines for scoring items to their review, and ensure that all reviewers are clear on how to score studies. Reviewers should consider whether all QUADAS items are relevant to their review, and whether additional quality items should be assessed as part of their review.
The international review board was set up as the scientific advisory body of the Swiss Complementary Medicine Evaluation Programme (PEK) in 2002. It has met several times and has given advice with respect to the most important aspects of the programme. It would have been the normal procedure for the review board to have had the opportunity to comment on the drafts of the final scientific products as well as the draft of the summary report, in order to advise on them, before the documents became publicly available and formed the basis for political decision making. But the responsible authorities changed this process. In the following, the review board comments both on this process and on the products.
PURPOSE: Several new extended prostate biopsy schemes (greater than 6 cores) have been proposed. We compared the cancer detection rates and complications of different extended prostate biopsy schemes for diagnostic evaluation in men scheduled for biopsy to identify the optimal scheme. MATERIALS AND METHODS: In a systematic review we searched 13 electronic databases, screened relevant urological journals and the reference lists of included studies, and contacted experts. We included studies that compared different systematic prostate biopsy methods using sequential sampling or a randomized design in men scheduled for biopsy due to suspected prostate cancer. We pooled data using a random effects model when appropriate. RESULTS: We analyzed 87 studies with a total of 20,698 patients. We pooled data from 68 studies comparing a total of 94 extended schemes with the standard sextant scheme. An increasing number of cores were significantly associated with the cancer yield. Laterally directed cores increased the yield significantly (p = 0.003), whereas centrally directed cores did not. Schemes with 12 cores that took additional laterally directed cores detected 31% more cancers (95% CI 25 to 37) than the sextant scheme. Schemes with 18 to 24 cores did not detect significantly more cancers. Adverse events for schemes up to 12 cores were similar to those for the sextant pattern. Adverse event reporting was poor for schemes with 18 to 24 cores. CONCLUSIONS: Prostate biopsy schemes consisting of 12 cores that add laterally directed cores to the standard sextant scheme strike the balance between the cancer detection rate and adverse events. Taking more than 12 cores added no significant benefit.
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In many countries diagnostic tests compose a growing part of healthcare costs, although there are very low standards for their use and for diagnostic studies and evaluations. Reference standards often do not exist. Diagnostic research needs careful consideration of the clinical situation, and should take into account that diagnosis is a multivariable process. Various study designs to evaluate diagnostic procedures are presented.
OBJECTIVES: To assess the association between infant size or growth and subsequent obesity and to determine if any association has been stable over time. DESIGN: Systematic review. DATA SOURCES: Medline, Embase, bibliographies of included studies, contact with first authors of included studies and other experts. INCLUSION CRITERIA: Studies that assessed the relation between infant size or growth during the first two years of life and subsequent obesity. MAIN OUTCOME MEASURE: Obesity at any age after infancy. RESULTS: 24 studies met the inclusion criteria (22 cohort and two case-control studies). Of these, 18 assessed the relation between infant size and subsequent obesity, most showing that infants who were defined as "obese" or who were at the highest end of the distribution for weight or body mass index were at increased risk of obesity. Compared with non-obese infants, in those who had been obese odds ratios or relative risks for subsequent obesity ranged from 1.35 to 9.38. Ten studies assessed the relation of infant growth with subsequent obesity and most showed that infants who grew more rapidly were at increased risk of obesity. Compared with other infants, in infants with rapid growth odds ratios and relative risks of later obesity ranged from 1.17 to 5.70. Associations were consistent for obesity at different ages and for people born over a period from 1927 to 1994. CONCLUSIONS: Infants who are at the highest end of the distribution for weight or body mass index or who grow rapidly during infancy are at increased risk of subsequent obesity.
BACKGROUND: The use of systematic literature review to inform evidence based practice in diagnostics is rapidly expanding. Although the primary diagnostic literature is extensive, studies are often of low methodological quality or poorly reported. There has been no rigorously evaluated, evidence based tool to assess the methodological quality of diagnostic studies. The primary objective of this study was to determine the extent to which variations in the quality of primary studies impact the results of a diagnostic meta-analysis and whether this differs with diagnostic test type. A secondary objective was to contribute to the evaluation of QUADAS, an evidence-based tool for the assessment of quality in diagnostic accuracy studies. METHODS: This study was conducted as part of large systematic review of tests used in the diagnosis and further investigation of urinary tract infection (UTI) in children. All studies included in this review were assessed using QUADAS, an evidence-based tool for the assessment of quality in systematic reviews of diagnostic accuracy studies. The impact of individual components of QUADAS on a summary measure of diagnostic accuracy was investigated using regression analysis. The review divided the diagnosis and further investigation of UTI into the following three clinical stages: diagnosis of UTI, localisation of infection, and further investigation of the UTI. Each stage used different types of diagnostic test, which were considered to involve different quality concerns. RESULTS: Many of the studies included in our review were poorly reported. The proportion of QUADAS items fulfilled was similar for studies in different sections of the review. However, as might be expected, the individual items fulfilled differed between the three clinical stages. Regression analysis found that different items showed a strong association with test performance for the different tests evaluated. These differences were observed both within and between the three clinical stages assessed by the review. The results of regression analyses were also affected by whether or not a weighting (by sample size) was applied. Our analysis was severely limited by the completeness of reporting and the differences between the index tests evaluated and the reference standards used to confirm diagnoses in the primary studies. Few tests were evaluated by sufficient studies to allow meaningful use of meta-analytic pooling and investigation of heterogeneity. This meant that further analysis to investigate heterogeneity could only be undertaken using a subset of studies, and that the findings are open to various interpretations. CONCLUSION: Further work is needed to investigate the influence of methodological quality on the results of diagnostic meta-analyses. Large data sets of well-reported primary studies are needed to address this question. Without significant improvements in the completeness of reporting of primary studies, progress in this area will be limited.
OBJECTIVE: To assess the accuracy and effectiveness of the screening of all newborn infants for developmental dysplasia of the hip (DDH) using ultrasound imaging, as is standard practice in some European countries but not in the United Kingdom, the United States, or Scandinavia. DESIGN: Systematic review. DATA SOURCES: Twenty three medical, economic, and grey literature databases (to March 2004), with no limitations of design or language; some references were provided by experts. SELECTION OF STUDIES: Only diagnostic accuracy studies and comparative studies conducted in an unselected newborn population were eligible for the review. Two reviewers independently selected the studies and performed the quality assessment. RESULTS: The review identified one diagnostic accuracy study, and this was of limited quality. In this study the reference standard was treatment up to age of 8 months or an abnormal ultrasound finding at age 8 months. Ultrasound screening had a sensitivity of 88.5% (95% confidence interval 84.1% to 92.1%), specificity of 96.7% (96.4% to 97.4%), a positive predictive value of 61.6% and a negative predictive value of 99.4%. Ten studies evaluated the impact of ultrasound in screening, but these too had various methodological weaknesses, limiting the reliability of their findings. Compared with clinical screening, general ultrasound screening in newborns may increase overall treatment rates, but ultrasound screening seems to be associated with shorter and less intrusive treatment. CONCLUSIONS: Clear evidence is lacking either for or against general ultrasound screening of newborn infants for DDH. Studies that investigate the natural course of the disorder, the optimal treatment for DDH, and the best strategy for ultrasound screening are needed.
BACKGROUND: There is a lack of consensus regarding the use of quality scores in diagnostic systematic reviews. The objective of this study was to use different methods of weighting items included in a quality assessment tool for diagnostic accuracy studies (QUADAS) to produce an overall quality score, and to examine the effects of incorporating these into a systematic review. METHODS: We developed five schemes for weighting QUADAS to produce quality scores. We used three methods to investigate the effects of quality scores on test performance. We used a set of 28 studies that assessed the accuracy of ultrasound for the diagnosis of vesico-ureteral reflux in children. RESULTS: The different methods of weighting individual items from the same quality assessment tool produced different quality scores. The different scoring schemes ranked different studies in different orders; this was especially evident for the intermediate quality studies. Comparing the results of studies stratified as "high" and "low" quality based on quality scores resulted in different conclusions regarding the effects of quality on estimates of diagnostic accuracy depending on the method used to produce the quality score. A similar effect was observed when quality scores were included in meta-regression analysis as continuous variables, although the differences were less apparent. CONCLUSION: Quality scores should not be incorporated into diagnostic systematic reviews. Incorporation of the results of the quality assessment into the systematic review should involve investigation of the association of individual quality items with estimates of diagnostic accuracy, rather than using a combined quality score.
BACKGROUND: A significant proportion of trial participants respond to placebos for a variety of conditions. Despite the common conduct of these trials and the strong emphasis placed on informed consent, very little is known about informing participants about their individual treatment allocation at trial closure. This study aims to address this gap in the literature by exploring treatment beliefs and reactions to feedback about treatment allocation in the participants of a placebo-controlled randomized clinical trial (RCT). METHODS: Survey of trial participants using a semi-structured questionnaire including close and open-ended questions administered as telephone interviews and postal questionnaires. Trial participants were enrolled in a double-blind placebo-controlled RCT evaluating the effectiveness of corticosteroid for heel pain (ISRCTN36539116). The trial had closed and participants remained blind to treatment allocation. We assessed treatment expectations, the percentage of participants who wanted to be informed about their treatment allocation, their ability to guess and reactions to debriefing. RESULTS: Forty-six (73%) contactable participants responded to our survey. Forty-two were eligible (four participants with bilateral disease were excluded as they had received both treatments). Most (79%) participants did not have any expectations prior to receiving treatment, but many 'hoped' that something would help. Reasons for not having high expectations included the experimental nature of their care and possibility that they may get a placebo. Participants were hopeful because their pain was so severe and because they trusted the staff and services. Most (83%) wanted to be informed about their treatment allocation and study results. Over half (55%) said they could not guess which treatment they had been randomized to, and many of those who attempted a guess were incorrect. Reactions to treatment debriefing were generally positive, including in placebo responders. CONCLUSION: Our study suggests that most trial participants want to be informed about their treatment allocation and trial results. Further research is required to develop measure of hope and expectancy and to rigorously evaluate the effects of debriefing prospectively.
BACKGROUND: Urinary tract infection (UTI) is one of the most common sources of infection in children under five. Prompt diagnosis and treatment is important to reduce the risk of renal scarring. Rapid, cost-effective, methods of UTI diagnosis are required as an alternative to culture. METHODS: We conducted a systematic review to determine the diagnostic accuracy of rapid tests for detecting UTI in children under five years of age. RESULTS: The evidence supports the use of dipstick positive for both leukocyte esterase and nitrite (pooled LR+ = 28.2, 95% CI: 17.3, 46.0) or microscopy positive for both pyuria and bacteriuria (pooled LR+ = 37.0, 95% CI: 11.0, 125.9) to rule in UTI. Similarly dipstick negative for both LE and nitrite (Pooled LR- = 0.20, 95% CI: 0.16, 0.26) or microscopy negative for both pyuria and bacteriuria (Pooled LR- = 0.11, 95% CI: 0.05, 0.23) can be used to rule out UTI. A test for glucose showed promise in potty-trained children. However, all studies were over 30 years old. Further evaluation of this test may be useful. CONCLUSION: Dipstick negative for both LE and nitrite or microscopic analysis negative for both pyuria and bacteriuria of a clean voided urine, bag, or nappy/pad specimen may reasonably be used to rule out UTI. These patients can then reasonably be excluded from further investigation, without the need for confirmatory culture. Similarly, combinations of positive tests could be used to rule in UTI, and trigger further investigation.
BACKGROUND: Further investigation of confirmed UTI in children aims to prevent renal scarring and future complications. METHODS: We conducted a systematic review to determine the most effective approach to the further investigation of confirmed urinary tract infection (UTI) in children under five years of age. RESULTS: 73 studies were included. Many studies had methodological limitations or were poorly reported. Effectiveness of further investigations: One study found that routine imaging did not lead to a reduction in recurrent UTIs or renal scarring. Diagnostic accuracy: The studies do not support the use of less invasive tests such as ultrasound as an alternative to renal scintigraphy, either to rule out infection of the upper urinary tract (LR- = 0.57, 95%CI: 0.47, 0.68) and thus to exclude patients from further investigation or to detect renal scarring (LR+ = 3.5, 95% CI: 2.5, 4.8). None of the tests investigated can accurately predict the development of renal scarring. The available evidence supports the consideration of contrast-enhanced ultrasound techniques for detecting vesico-ureteric reflux (VUR), as an alternative to micturating cystourethrography (MCUG) (LR+ = 14.1, 95% CI: 9.5, 20.8; LR- = 0.20, 95%CI: 0.13, 0.29); these techniques have the advantage of not requiring exposure to ionising radiation. CONCLUSION: There is no evidence to support the clinical effectiveness of routine investigation of children with confirmed UTI. Primary research on the effectiveness, in terms of improved patient outcome, of testing at all stages in the investigation of confirmed urinary tract infection is urgently required.
OBJECTIVE: To assess the accuracy with which antenatal maternal anthropometric measurements predict the risk spontaneous preterm birth. STUDY DESIGN: (1) DATA SOURCES: Studies were identified without language restrictions from MEDLINE, EMBASE, PASCAL, BIOSIS, the Cochrane Library, MEDION, National Research Register, SCISEARCH and Conference Papers, and manual searching of bibliographies of known primary and review articles, and contact with authors. (2) STUDY SELECTION AND DATA EXTRACTION: Studies were selected if they used antenatal maternal anthropometric features (pre-pregnancy weight, maternal pregnancy weight gain and maternal height) to predict spontaneous preterm birth. Two reviewers independently selected studies and extracted data on their characteristics, quality and accuracy. Accuracy data were used to form 2 x 2 contingency tables of the maternal anthropometric test results with spontaneous preterm birth as the reference standard. (3) DATA SYNTHESIS: Heterogeneity assessments were carried out to aid the decision regarding pooling of the accuracy results. Likelihood ratios for positive (LR+) and negative (LR-) test results were calculated, and summary estimates were produced in absence of heterogeneity of the accuracy results. RESULTS: There were eight primary accuracy articles that met the selection criteria, which included a total of 122,647 asymptomatic women. There were six studies on pre-pregnancy weight where five measured the body mass index (BMI) and one used an arbitrary measure. There were four studies on the adequacy of pregnancy weight gain and two studies on maternal height as a predictor for the risk of preterm birth. One article contributed three studies, while two articles provided two studies each. The commonest reference standard used was birth before 37 weeks' gestation. None of the studies fulfilled the ideal test accuracy study criteria. There was heterogeneity in the accuracy results of pre-pregnancy BMI but not in the adequacy of weight gain. All three maternal anthropometric features were poor predictors of preterm labour. Pre-pregnancy BMI is a poor predictor of preterm birth before 37 weeks' gestation (LR+ that ranged from 0.96 (95% confidence interval (CI) 0.66-1.40) to 1.75 (95% CI 1.33-2.31)) as are the adequacy of pregnancy weight gain (summary LR+ of 1.81, 95% CI 1.45-2.30) and short maternal height (LR+ of 1.79 (95% CI 1.27-2.52). CONCLUSION: Routine antenatal maternal anthropometric measurements are not useful in predicting the risk of preterm birth before 37 weeks' gestation. Further studies should address their use in combination with other test but need to use a more clinically appropriate reference standard of preterm birth, such as birth before 32-34 weeks' gestation, and improve on the quality of study design.
BACKGROUND AND OBJECTIVE: To review existing quality assessment tools for diagnostic accuracy studies and to examine to what extent quality was assessed and incorporated in diagnostic systematic reviews. METHODS: Electronic databases were searched for tools to assess the quality of studies of diagnostic accuracy or guides for conducting, reporting or interpreting such studies. The Database of Abstracts of Reviews of Effects (DARE; 1995-2001) was used to identify systematic reviews of diagnostic studies to examine the practice of quality assessment of primary studies. RESULTS: Ninety-one quality assessment tools were identified. Only two provided details of tool development, and only a small proportion provided any indication of the aspects of quality they aimed to assess. None of the tools had been systematically evaluated. We identified 114 systematic reviews, of which 58 (51%) had performed an explicit quality assessment and were further examined. The majority of reviews used more than one method of incorporating quality. CONCLUSION: Most tools to assess the quality of diagnostic accuracy studies do not start from a well-defined definition of quality. None has been systematically evaluated. The majority of existing systematic reviews fail to take differences in quality into account. Reviewers should consider quality as a possible source of heterogeneity.
BACKGROUND AND OBJECTIVE: The use of randomized consent designs has been subject of methodologic and ethical controversy. In most Western countries, research ethics committees make the decision as to whether a randomized consent design can be applied. The purpose of the study is to assess to what extent a randomized consent design and a modification of this design is accepted by research ethics committees, in terms of ethics, health law, and methodology. METHODS: A postal survey was conducted among members of research ethics committees in the United Kingdom, and in The Netherlands, with professional competence in ethics, (health) law, methodology, or clinical practice. RESULTS: In both the UK and in The Netherlands, the modified randomized consent design appears to be statistically significantly more acceptable than the randomized consent design, with respect to ethical and judicial aspects. The overall rejection rate of the randomized consent design was 66% in the UK and 59% in The Netherlands. However, the modified randomized consent design was rejected by 47 and 41% in the two countries, respectively. CONCLUSION: the modified randomized consent design appears to be more acceptable than the randomized consent design. To increase consistency in the way research ethics committees handle study protocols, a discussion about the use of randomized consent designs appears necessary.
BACKGROUND: Hypertension occurs more frequently and is generally more severe in black persons than in white persons, leading to excess morbidity and mortality. PURPOSE: To systematically review the efficacy of different antihypertensive drugs in reducing blood pressure, morbidity, and mortality in hypertensive black adults. DATA SOURCES: The following databases were searched from their inception through November 2003: MEDLINE, EMBASE, LILACS (Literatura Latino-Americana y del Caribe en Ciencias de la Salud), African Index Medicus, and the Cochrane Library. PubMed was also searched from September 2003 through March 2004. Searches were conducted without language restriction. STUDY SELECTION: Randomized, controlled trials of drugs versus placebo (blood pressure outcomes) or drugs versus placebo or other drugs (morbidity and mortality outcomes). DATA EXTRACTION: 2 reviewers independently extracted data. DATA SYNTHESIS: The efficacy of beta-blockers in reducing systolic blood pressure and the efficacy of angiotensin-converting enzyme inhibitors in achieving diastolic blood pressure goals did not significantly differ from that of placebo (weighted mean difference for beta-blockers, -3.53 mm Hg [95% CI, -7.51 to 0.45 mm Hg]; relative risk for angiotensin-converting enzyme inhibitors, 1.35 [CI, 0.81 to 2.26]). In the pooled analyses, other reviewed drugs (calcium-channel blockers, diuretics, central sympatholytics, alpha-blockers, and angiotensin II receptor blockers) were more effective than placebo in reducing blood pressure, but only calcium-channel blockers remained effective in all prespecified subgroups, including patients with a baseline diastolic blood pressure of 110 mm Hg or greater. Main morbidity and mortality outcomes did not differ significantly between treatment groups when drugs were combined to reach blood pressure goals. However, trial results indicated a greater occurrence of diabetes with diuretics and a higher risk for cardiovascular events with drug regimens that included angiotensin-converting enzyme inhibitors. LIMITATIONS: This meta-analysis evaluated the blood pressure lowering-efficacy of monotherapy only. CONCLUSIONS: Drugs differ in their efficacy for reducing blood pressure in black patients, but there is no solid evidence that efficacy for reducing morbidity and mortality outcomes differs once patients achieve the blood pressure goal.