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OBJECTIVES: The study's aim was to assess the internal reliability for the nine domains of the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30) to evaluate homogeneity across clinical studies and whether sample characteristics predict coefficient heterogeneity.
STUDY DESIGN AND SETTING: A systematic literature review was undertaken. Internal reliability was assessed against Cronbach a coefficient >0.70. Reliability generalization was undertaken using fixed- and random-effects models. A weighted least squares regression model was applied to determine whether baseline sample characteristics (language, percentage of women, sample size, sample means and standard deviations, and cancer type) predicted variation in a coefficients.
RESULTS: A total of 33 studies were identified. Eight domains demonstrated good internal reliability (unweighted/weighted by sample variance). One domain, Cognitive Functioning, consistently performed poorly. In terms of moderating variables, none of the sample characteristic variables explained sample variance for the Physical or Role Functioning domains. For the other domains, language, percentage of women, and sample means and variances accounted for some of the heterogeneity observed.
CONCLUSION: Most domains on the EORTC QLQ-C30 are reliable and may therefore be used to help inform decision-making processes, such as those involving individual patients.
Recent systematic reviews have reported a positive, although modest, effect of probiotics in terms of preventing common cold symptoms. In this systematic review, the effect of probiotics, specifically Lactobacillus and Bifidobacterium strains, on the duration of acute respiratory infections in otherwise healthy children and adults was evaluated. To identify relevant trials, eight databases, including MEDLINE, Embase, the Cochrane Database of Systematic Reviews (CDSR), the Cochrane Central Register of Controlled Trials (CENTRAL), the Database of Abstracts of Reviews of Effects (DARE), Health Technology Assessment (HTA), Science Citation Index (SCI) and OAISTER, were searched from inception to 20 July 2012. Details regarding unpublished studies/databases were also obtained from probiotic manufacturers. Study selection, data extraction and quality assessment were carried out by two reviewers. Risk of bias was assessed using criteria adapted from those published by the Centre for Reviews and Dissemination. In this review, twenty randomised controlled trials (RCT) were included, of which twelve were considered to have a low risk of bias. Meta-analysis revealed significantly fewer numbers of days of illness per person (standardised mean difference (SMD) - 0·31 (95% CI - 0·41, - 0·11), I²= 3%), shorter illness episodes by almost a day (weighted mean difference - 0·77 (95% CI - 1·50, - 0·04), I²= 80%) (without an increase in the number of illness episodes), and fewer numbers of days absent from day care/school/work (SMD - 0·17 (95% CI - 0·31, - 0·03), I²= 67%) in participants who received a probiotic intervention than in those who had taken a placebo. Reasons for heterogeneity between the studies were explored in subgroup analysis, but could not be explained, suggesting that the effect sizes found may differ between the population groups. This systematic review provides evidence from a number of good-quality RCT that probiotics reduce the duration of illness in otherwise healthy children and adults.
This report presents the results of a systematic review and meta-analyses of studies on epithelium-off photochemical corneal collagen cross-linkage for the management of keratoconus and secondary ectasia. The literature search identified 3,400 records of which 49 were considered for inclusion in the meta-analyses. Eight papers reported 4 unique randomized controlled trials, 29 studies were prospective, and 12 were retrospective studies. The majority of the studies (39/49) were graded as very low quality evidence. Twenty-six studies described adverse events and were included in the safety analysis. Meta-analyses are presented for changes in four outcomes: visual acuity, topography, refraction and astigmatism, and central corneal thickness. Statistically significant improvements were found in all efficacy outcomes at 12 months after the operation. Common side effects were pain, corneal edema, and corneal haze, which resolved usually within a few days after the procedure. The remaining uncertainty is duration of benefit to establish the procedure's potential benefit in avoiding or delaying disease progression and possibly reducing the need for corneal transplantation.
BACKGROUND: Since 2005, International Committee of Medical Journal Editors (ICMJE) member journals have required that clinical trials be registered in publicly available trials registers before they are considered for publication.
OBJECTIVES: The research explores whether it is adequate, when searching to inform systematic reviews, to search for relevant clinical trials using only public trials registers and to identify the optimal search approaches in trials registers.
METHODS: A search was conducted in ClinicalTrials.gov and the International Clinical Trials Registry Platform (ICTRP) for research studies that had been included in eight systematic reviews. Four search approaches (highly sensitive, sensitive, precise, and highly precise) were performed using the basic and advanced interfaces in both resources.
RESULTS: On average, 84% of studies were not listed in either resource. The largest number of included studies was retrieved in ClinicalTrials.gov and ICTRP when a sensitive search approach was used in the basic interface. The use of the advanced interface maintained or improved sensitivity in 16 of 19 strategies for Clinicaltrials.gov and 8 of 18 for ICTRP. No single search approach was sensitive enough to identify all studies included in the 6 reviews.
CONCLUSIONS: Trials registers cannot yet be relied upon as the sole means to locate trials for systematic reviews. Trials registers lag behind the major bibliographic databases in terms of their search interfaces.
IMPLICATIONS: For systematic reviews, trials registers and major bibliographic databases should be searched. Trials registers should be searched using sensitive approaches, and both the registers consulted in this study should be searched.
BACKGROUND: Search filters or hedges are search strategies developed to assist information specialists and librarians to retrieve different types of evidence from bibliographic databases. The objectives of this project were to learn about searchers' filter use, how searchers choose search filters and what information they would like to receive to inform their choices.
METHODS: Interviews with information specialists working in, or for, the National Institute for Health and Care Excellence (NICE) were conducted. An online questionnaire survey was also conducted and advertised via a range of email lists.
RESULTS: Sixteen interviews were undertaken and 90 completed questionnaires were received. The use of search filters tends to be linked to reducing a large amount of literature, introducing focus and assisting with searches that are based on a single study type. Respondents use numerous ways to identify search filters and can find choosing between different filters problematic because of knowledge gaps and lack of time.
CONCLUSIONS: Search filters are used mainly for reducing large result sets (introducing focus) and assisting with searches focused on a single study type. Features that would help with choosing filters include making information about filters less technical, offering ratings and providing more detail about filter validation strategies and filter provenance.
We explored the value of handsearching to identify diagnostic test accuracy (DTA) studies to inform systematic reviews of DTA. Handsearching was conducted alongside a systematic review of the DTA of 18F-fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET-CT) for colorectal cancer. Ten journals, identified by frequency analysis of studies from six imaging reviews, were handsearched for reports of DTA studies. The numbers of studies identified by handsearching and by database searching were compared. A total of 573 journal issues from ten journals were handsearched in 185 h. A total of 936 potential reports of DTA studies were identified: 25 were relevant to the FDG PET-CT review. 7/25 FDG PET-CT papers had not been identified by database searches. No papers met the systematic review inclusion criteria. The FDG-PET systematic review included 30 papers, from 24 different journals. Handsearching two of those journals identified 211 potential reports of DTA studies for all topics and 18 for FDG PET-CT. Handsearching identified previously unseen papers but did not yield unique relevant DTA studies for the specific review. DTA imaging studies are widely distributed, and it may be more efficient to choose journals to handsearch after the identification of some relevant studies.
Regulation (EC) No 178/2002 recommends that risk assessments are undertaken by the European Food Safety Authority (EFSA) in an independent, objective and transparent manner, on the basis of all available scientific information and data. The systematic review (SR) method implemented by EFSA to inform risk assessment models ensures a methodologically rigorous stepwise process, minimising biases and emphasising transparency and reproducibility. To minimise bias, SRs include an extensive literature search. Locating all relevant information sources can be problematic and missing relevant scientific information may influence SR conclusions. The EFSA Scientific Assessment Support Unit contracted YHEC (CFT/EFSA/SAS/2011/03) to produce five deliverables to support literature searching to inform SRs of food and feed safety. This report describes the development of an inventory of information sources of relevance to systematic reviews of food and feed safety. The inventory uses a metadata schema to record information about each information source. 376 candidate information sources were identified from the EFSA SAS inventory of information sources and other catalogues and websites. The selection of information sources to include in the EFSA inventory were determined using selection criteria (1) relevance to EFSA research areas (2) currency of information in the information source (3) provision of searchable bibliographic data records or full text reports of research and (4) be accessible to EFSA staff. Metadata were identified and recorded in an Excel spreadsheet for the 199 information sources meeting these four criteria.
