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Pieper D.,Witten/Herdecke University | Buechter R.B.,Institute for Quality and Efficiency in Health Care IQWiG | Li L.,Lanzhou University | Prediger B.,Witten/Herdecke University | Eikermann M.,Witten/Herdecke University
Journal of Clinical Epidemiology | Year: 2015

Objectives To summarize all available evidence on measurement properties in terms of reliability, validity, and feasibility of the Assessment of Multiple Systematic Reviews (AMSTAR) tool, including R(evised)-AMSTAR. Study Design and Setting MEDLINE, EMBASE, Psycinfo, and CINAHL were searched for studies containing information on measurement properties of the tools in October 2013. We extracted data on study characteristics and measurement properties. These data were analyzed following measurement criteria. Results We included 13 studies, four of them were labeled as validation studies. Nine articles dealt with AMSTAR, two articles dealt with R-AMSTAR, and one article dealt with both instruments. In terms of interrater reliability, most items showed a substantial agreement (>0.6). The median intraclass correlation coefficient (ICC) for the overall score of AMSTAR was 0.83 (range 0.60-0.98), indicating a high agreement. In terms of validity, ICCs were very high with all but one ICC lower than 0.8 when the AMSTAR score was compared with scores from other tools. Scoring AMSTAR takes between 10 and 20 minutes. Conclusion AMSTAR seems to be reliable and valid. Further investigations for systematic reviews of other study designs than randomized controlled trials are needed. R-AMSTAR should be further investigated as evidence for its use is limited and its measurement properties have not been studied sufficiently. In general, test-retest reliability should be investigated in future studies. © 2015 Elsevier Inc. All rights reserved. Source


Buechter R.B.,Institute for Quality and Efficiency in Health Care IQWiG
German medical science : GMS e-journal | Year: 2011

To summarize the best available evidence on effectiveness of therapeutic or sport climbing in preventing or treating health problems. We searched Medline, Embase, CENTRAL, PsycINFO, PEDro, OTseeker and SportDiscus for randomized controlled trials published up to December 26, 2010. We included all trials assessing patient-relevant outcomes. Two reviewers independently selected relevant studies, assessed their methodological quality and extracted data. Quality of evidence was rated using the GRADE system. Data were entered into RevMan 5 to calculate effect sizes and 95% confidence intervals where appropriate. Eligible for inclusion were four RCTs studying the effectiveness of climbing in (a) geriatric patients, (b) adults with multiple sclerosis, (c) adults with chronic low-back pain and (d) children with disabilities and poor motor function. The sample sizes ranged between 20 and 95. All trials had major methodological limitations. We found very low quality evidence that therapeutic climbing may improve activities of daily living in geriatric patients compared to physiotherapy as measured by the Barthel index (difference in mean change score: 2.32 [95%-CI: 0.45 to 4.19]). We found very low quality evidence that therapeutic climbing compared to standard exercise therapy may improve physical functioning (difference in mean change score: 16.15 [95%-CI: 4.45 to 27.85]) and general physical health (13.14 [95%-CI: 3.61 to 22.67]) as measured by the SF-36 in adults with chronic low back-pain. Evidence for the effectiveness of therapeutic climbing is limited to small trials at high risk of bias. The effects of therapeutic climbing are therefore unclear. Source


Sauerland S.,Institute for Quality and Efficiency in Health Care IQWiG
Cochrane database of systematic reviews (Online) | Year: 2011

There are many different techniques currently in use for ventral and incisional hernia repair. Laparoscopic techniques have become more common in recent years, although the evidence is sparse. We compared laparoscopic with open repair in patients with (primary) ventral or incisional hernia. We searched the following electronic databases: MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, metaRegister of Controlled Trials. The last searches were conducted in July 2010. In addition, congress abstracts were searched by hand. We selected randomised controlled studies (RCTs), which compared the two techniques in patients with ventral or incisional hernia. Studies were included irrespective of language, publication status, or sample size. We did not include quasi-randomised trials. Two authors assessed trial quality and extracted data independently. Meta-analytic results are expressed as relative risks (RR) or weighted mean difference (WMD). We included 10 RCTs with a total number of 880 patients suffering primarily from primary ventral or incisional hernia. No trials were identified on umbilical or parastomal hernia. The recurrence rate was not different between laparoscopic and open surgery (RR 1.22; 95% CI 0.62 to 2.38; I(2) = 0%), but patients were followed up for less than two years in half of the trials. Results on operative time were too heterogeneous to be pooled. The risk of intraoperative enterotomy was slightly higher in laparoscopic hernia repair (Peto OR 2.33; 95% CI 0.53 to 10.35), but this result stems from only 7 cases with bowel lesion (5 vs. 2). The most clear and consistent result was that laparoscopic surgery reduced the risk of wound infection (RR = 0.26; 95% CI 0.15 to 0.46; I(2)= 0%). Laparoscopic surgery shortened hospital stay significantly in 6 out of 9 trials, but again data were heterogeneous. Based on a small number of trials, it was not possible to detect any difference in pain intensity, both in the short- and long-term evaluation. Laparoscopic repair apparently led to much higher in-hospital costs. The short-term results of laparoscopic repair in ventral hernia are promising. In spite of the risks of adhesiolysis, the technique is safe. Nevertheless, long-term follow-up is needed in order to elucidate whether laparoscopic repair of ventral/incisional hernia is efficacious. Source


Pieper D.,Witten/Herdecke University | Buechter R.,Institute for Quality and Efficiency in Health Care IQWiG | Jerinic P.,Witten/Herdecke University | Eikermann M.,Witten/Herdecke University
Journal of Clinical Epidemiology | Year: 2012

Objective: To examine published overviews of systematic reviews in terms of descriptive and methodological characteristics. Study Design and Setting: MEDLINE, Database of Abstracts of Reviews of Effects, the Cochrane Database of Systematic Reviews, and several Health Technology Assessment databases were searched for overviews of reviews up to February 2012. We extracted data from the methods and results sections of the included overviews. These data were analyzed descriptively as frequencies or medians and interquartile ranges. Results: We included 126 overviews of reviews. According to our sample, publication rates for overviews have risen in the last decade. The quality of the included reviews was systematically appraised in 64% of the overviews. The most commonly used assessment tools were the Overview Quality Assessment Questionnaire (26%), Assessment of Multiple Systematic Reviews (11%), and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (5%). Only three of 18 overviews restricted to Cochrane reviews in our sample performed a quality assessment. Strategies to deal with discordant reviews were reported in 5% of the overviews. Searches for additional primary studies were conducted in 5% of the overviews. Conclusion: Overviews of reviews often lack methodological rigor. Methodological standards and reporting guidelines for overviews are needed to improve the quality of this new publication type. © 2012 Elsevier Inc. All rights reserved. Source


Laubendera R.P.,Ludwig Maximilians University of Munich | Bender R.,Institute for Quality and Efficiency in Health Care IQWiG | Bender R.,University of Cologne
Statistics in Medicine | Year: 2010

In medical research, risk difference (RD) and number needed to treat (NNT) measures for survival times have been mainly proposed without consideration of covariates. In this paper, we develop adjusted RD and NNT measures for use in observational studies with survival time outcomes within the framework of the Cox proportional hazards regression model taking the distribution of confounders into account. We consider the typical situation of a cohort study in which the effect of an exposure on a survival time outcome is investigated and important covariates have to be taken into account. The exposure effect described by means of the RD and NNT measures in dependence on whether the effect of allocating an exposure to unexposed persons (number needed to be exposed) or that of removing an exposure from exposed persons (exposure impact number) is considered. Estimation of these adjusted RD and NNT measures is performed by using the average RD approach recently developed for logistic regression. To determine standard errors and confidence intervals for these estimators we use two approaches, the delta method with respect to the regression coefficients of the Cox model and bootstrapping and compare each other. The performance of these estimators is assessed by performing Monte Carlo simulations demonstrating clear advantages of the bootstrap method. The proposed method for point and interval estimation of adjusted RD and NNT measures in the Cox model is illustrated by means of data of the Düsseldorf Obesity Mortality Study (DOMS). Copyright © 2010 John Wiley & Sons, Ltd. Source

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