Search

Background: In the development of search strategies for systematic reviews, "conceptual approaches" are generally recommended to identify appropriate search terms for those parts of the strategies for which no validated search filters exist. However, "objective approaches" based on search terms identified by text analysis are increasingly being applied., Objectives: To prospectively compare an objective with a conceptual approach for the development of search strategies., Methods: Two different MEDLINE search strategies were developed in parallel for five systematic reviews covering a range of topics and study designs. The Institute for Quality and Efficiency in Health Care (IQWiG) applied an objective approach, and external experts applied a conceptual approach for the same research questions. For each systematic review, the citations retrieved were combined and the overall pool of citations screened to determine sensitivity and precision., Results: The objective approach yielded a weighted mean sensitivity and precision of 97% and 5%. The corresponding values for the conceptual approach were 75% and 4%., Conclusion: Our findings indicate that the objective approach applied by IQWiG for search strategy development yields higher sensitivity than and similar precision to a conceptual approach. The main advantage of the objective approach is that it produces consistent results across searches., (Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.)

A retrospective analysis published by the German Institute for Quality and Efficiency in Health Care (IQWiG) in 2018 concluded that no filter for non‐randomized studies (NRS) achieved sufficient sensitivity (≥92%), a precondition for comprehensive information retrieval. New NRS filters are therefore required, taking into account the challenges related to this study type. Our evaluation focused on the development of study filters for NRS with a control group ("controlled NRS"), as this study type allows the calculation of an effect size. In addition, we assumed that due to the more explicit search syntax, controlled NRS are easier to identify than non‐controlled ones, potentially resulting in better performance measures of study filters for controlled NRS. Our aim was to develop study filters for identifying controlled NRS in PubMed and Ovid MEDLINE. We developed two new search filters that can assist clinicians and researchers in identifying controlled NRS in PubMed and Ovid MEDLINE. The reference set was based on 2110 publications in Medline extracted from 271 Cochrane reviews and on 4333 irrelevant references. The first filter maximizes sensitivity (92.42%; specificity 79.67%, precision 68.49%) and should be used when a comprehensive search is needed. The second filter maximizes specificity (92.06%; precision 82.98%, sensitivity 80.94%) and should be used when a more focused search is sufficient. [ABSTRACT FROM AUTHOR]

Background It is unclear which terms should be included in bibliographic searches for randomized controlled trials (RCTs) of drugs, and identifying relevant drug terms can be extremely laborious. The aim of our analysis was to determine whether a bibliographic search using only the generic drug name produces sufficient results for the generation of informative systematic reviews (SRs). Methods We conducted a retrospective analysis of relevant references included in SRs of drugs. We determined the proportion of references identified by a simplified technique consisting of a systematic search for RCTs in MEDLINE and EMBASE via the search interface Ovid and using only the truncated generic drug name in all search fields. We calculated aggregated sensitivity and also evaluated the unidentified references. Results Forty-eight SRs contained 873 primary publications, of which we found 829 in MEDLINE and 757 in EMBASE ('gold standard'). The simplified search identified 823 of the 829 MEDLINE references (sensitivity 99.3%) and 754 of the 757 EMBASE references (99.6%). Ultimately, only three references could not be found by additional searches. Conclusion Our findings indicate that when searching for RCTs of drugs in MEDLINE and EMBASE, a search using the truncated generic drug name in all fields produces sufficient results. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Background: Low physical activity has been identified as a major risk factor for cardiovascular disease. Medical societies therefore recommend increased physical activity be part of any antihypertensive therapy. Objective: Focusing on patient-relevant outcomes such as mortality and cardiovascular events, this review was conducted to assess the long-term effects of interventions aiming at increasing physical activity in comparison with no such interventions on adult patients with essential hypertension. Data sources: We searched for high-quality systematic reviews in MEDLINE, EMBASE, Cochrane Database of Systematic Reviews (Cochrane Reviews), Database of Abstracts of Reviews of Effects (Other Reviews) and Health Technology Assessment Database (Technology Assessments) published between 1997 and February 2009 and for randomized controlled trials (RCTs) in MEDLINE, EMBASE and Cochrane Central Register of Controlled Trials (Clinical Trials) published before September 2012. Additional studies were identified by hand searching reference lists of reviews. Study selection: RCTs with at least 24 weeks' follow-up that evaluated the effect of increased physical activity on the blood pressure of adults with essential hypertension were included in our review. Primary outcomes were all-cause mortality, cardiovascular morbidity and mortality, end-stage renal disease, quality of life and adverse events. Study appraisal and synthesis methods: When appropriate, we used random effects meta-analyses to determine mean difference with 95 % confidence intervals for each endpoint. All data were analysed using the Review Manager software version 5.0.24 from the Cochrane Collaboration. Results: None of the included nine trials, covering 891 patients with hypertension, provided sufficient data on patient-relevant outcomes such as mortality, cardiovascular events or injuries related to physical activity. Information on changes in systolic and diastolic blood pressure was provided for all included trials. The majority of the included RCTs reported that increased physical activity led to a decrease in systolic and diastolic blood pressure of 5-10 and 1-6 mmHg, respectively, but due to marked heterogeneity in the meta-analyses both for systolic and diastolic blood pressure (I = 70.0 and 73.0 %), no effect estimates were provided. Limitations: About 50 % of the included trials were small, evaluating at most 20 participants per study group, and more than twothirds were deemed to have a high risk of bias. Conclusions: Although a decrease in blood pressure is shown to be a consequence of increased physical activity, RCTs of appropriate study size and quality that examine potential patient-relevant benefits or harms still need to be conducted to evaluate whether physical activity really improves the health of patients with essential hypertension. [ABSTRACT FROM AUTHOR]

Background: Different approaches can be adopted for the development of search strategies of systematic reviews. The objective approach draws on already established text analysis methods for developing search filters. Our aim was to determine whether the objective approach for the development of search strategies was noninferior to the conceptual approach commonly used in Cochrane reviews (CRs). Methods: We conducted a search for CRs published in the Cochrane Library. The studies included in the CRs were searched for in MEDLINE and represented the total set. We then tested whether references previously removed could be identified via the objective approach. We also reconstructed the original search strategies from the CRs to determine why references could not be identified by the objective approach. As we performed the validation of the search strategies without study filters, we used only sensitivity as a quality measure and did not calculate precision. Results: The objective approach yielded a mean sensitivity of 96% based on 13 searches. The noninferiority test showed that this approach was noninferior to the conceptual approach used in the CRs (P < 0.002). An additional descriptive analysis showed that the original MEDLINE strategies could identify only 86% of all references; however, this lower sensitivity was largely due to one CR. Conclusion: To the best of our knowledge, our findings indicate for the first time that the objective approach for the development of search strategies is noninferior to the conceptual approach. [ABSTRACT FROM AUTHOR]