Novel citation-based search method for scientific literature: application to meta-analyses

A Two-Decade Bibliometric Analysis of Laser in Ophthalmology: From Past to Present

Background

Laser therapy has been proven as an effective technique for managing ophthalmological disorders. To guide future research, we conducted a bibliometric analysis of laser applications in eye diseases from 1990 to 2022, aiming to identify key themes and trends.

Methods

We retrieved 3027 publications from the Web of Science Core Collection (WoSCC). Bibliometrix was used for science mapping of the literature, while VOSviewer and CiteSpace were applied to visualize co-authorship, co-citation, co-occurrence, and bibliographic coupling networks.

Results

From a co-citation reference network, we identified 52 distinct clusters. Our analysis uncovered three main research trends. The first trend revolves around the potential evolution of corneal laser surgery techniques, shifting from the treatment of refractive errors to broader applications in biomedical optics. The second trend illustrates the advancement of laser applications in treating a range of disorders, from retinal and ocular surface diseases to glaucoma. The third trend focuses on the innovative uses of established technologies.

Conclusion

This study offers significant insights into the evolution of laser applications in ophthalmology over the past 30 years, which will undoubtedly assist scientists in directing further research in this promising field.

Archaeological evidence of resource utilisation of the great whales over the past two millennia: A systematic review protocol

Archaeological faunal remains provide key insights into human societies in the past, alongside information on previous resource utilisation and exploitation of wildlife populations. The great whales (Mysticete and sperm whales) were hunted unsustainably throughout the 16th - 20th centuries (herein defined as the modern period) leading to large population declines and variable recovery patterns among species. Humans have utilised whales as a resource through carcass scavenging for millennia; however, increasing local and regional ethnographic and archaeological evidence suggests that, prior to the modern period, hunting of the great whales was more common than previously thought; impacts of earlier hunting pressures on the population ecology of many whale species remains relatively unknown. Hunting guided by traditional ecological knowledge may have been sustainable and likely originated in societies that also incorporated opportunistic use of stranded individuals. The collation of georeferenced zooarchaeological data of the great whales between the 1st - 20th centuries CE worldwide will provide insight into the timescale and distribution of resource utilisation of the great whales and how this varied within and between societies, and may have changed over time. By comparing regions of known resource utilisation and breeding and feeding grounds of current-day whale populations, this information will subsequently be used to infer regions where whale populations were possibly lost or extirpated prior to detailed historical records. This systematic review protocol also provides a template for archaeologists, ecologists, and historians interested in using faunal remains to infer historical ecology and resource use of wild animal populations. The transparency of our data collection approach provides opportunities for reproducibility and comparability with future datasets.

A systematic review and meta-analysis of randomized controlled trials on the effectiveness of immersive virtual reality in cancer patients receiving chemotherapy

PURPOSE

Immersive virtual reality (IVR) shows promise in cancer care, especially for chemotherapy patients. This systematic review and meta-analysis assesses IVR's impact on adult and pediatric cancer patients undergoing chemotherapy.

METHODS

We searched PubMed, Cochrane Library, Embase, Scopus, Web of Science, and Google Scholar for relevant randomized controlled trials (RCTs). We focused on anxiety, depression, fatigue, pain, and anxiety in adults and pain and anxiety in pediatric patients.

RESULTS

Fifteen trials were included, enrolling 607 adult and 257 pediatric cancer patients. IVR significantly reduced anxiety (SMD = -1.89, 95% CI = -2.93 to -0.85), depression (SMD = -1.85, 95% CI = -3.14 to -0.55), fatigue (SMD = -3.40, 95% CI = -5.54 to -1.26), and systolic blood pressure (MD = -3.54, 95% CI = -6.67 to -0.40) in adults. In pediatric patients, IVR significantly lowered pain (SMD = -1.17, 95% CI = -1.84 to -0.50) and anxiety (SMD = -1.18, 95% CI = -1.77 to -0.59) but not heart rate (MD = 0.48, 95% CI = -2.38 to 3.34).

CONCLUSION

IVR effectively reduces anxiety, depression, fatigue, systolic blood pressure, pain, and anxiety in cancer patients. More robust RCTs are needed for further IVR research.

A 2-decade bibliometric analysis of epigenetics of cardiovascular disease: from past to present

BACKGROUND

Cardiovascular disease (CVD) remains a major health killer worldwide, and the role of epigenetic regulation in CVD has been widely studied in recent decades. Herein, we perform a bibliometric study to decipher how research topics in this field have evolved during the past 2 decades.

RESULTS

Publications on epigenetics in CVD produced during the period 2000-2022 were retrieved from the Web of Science Core Collection (WoSCC). We utilized Bibliometrix to build a science map of the publications and applied VOSviewer and CiteSpace to assess co-authorship, co-citation, co-occurrence, and bibliographic coupling. In total, 27,762 publications were included for bibliometric analysis. The yearly amount of publications experienced exponential growth. The top 3 most influential countries were China, the United States, and Germany, while the most cited institutions were Nanjing Medical University, Harbin Medical University, and Shanghai Jiao Tong University. Four major research trends were identified: (a) epigenetic mechanisms of CVD; (b) epigenetics-based therapies for CVD; (c) epigenetic profiles of specific CVDs; and (d) epigenetic biomarkers for CVD diagnosis/prediction. The latest and most important research topics, including "nlrp3 inflammasome", "myocardial injury", and "reperfusion injury", were determined by detecting citation bursts of co-occurring keywords. The most cited reference was a review of the current knowledge about how miRNAs recognize target genes and modulate their expression and function.

CONCLUSIONS

The number and impact of global publications on epigenetics in CVD have expanded rapidly over time. Our findings may provide insights into the epigenetic basis of CVD pathogenesis, diagnosis, and treatment.

2009 CKD-EPI glomerular filtration rate estimation in Black individuals outside the United States: a systematic review and meta-analysis

Background

The 2009 Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation is the most used equation to estimate glomerular filtration rate (GFR), with race being a factor thereof, increasing GFR by 16% in self-identified Black persons compared with non-Black persons. However, recent publications indicate that it might overestimate GFR for Black adults outside the USA. In this meta-analysis, we assessed the accuracy, evaluated by the percentage of estimated GFR within 30% of measured GFR (P30), of the 2009 CKD-EPI equation in estimating GFR with and without the race coefficient in Black individuals outside the United States of America (USA).

Methods

We searched MEDLINE and Embase from inception to 9 July 2022, with no language restriction, supplemented by manual reference searches. Studies that assessed the CKD-EPI P30 accuracy with or without the race coefficient in Black adults outside the USA with an adequate method of GFR measurement were included. Data were extracted by independent pairs of reviewers and were pooled using a random-effects model.

Results

We included 11 studies, with a total of 1834 Black adults from South America, Africa and Europe. The race coefficient in the 2009 CKD-EPI equation significantly decreased P30 accuracy {61.9% [95% confidence interval (CI) 53-70%] versus 72.9% [95% CI 66.7-78.3%]; P = .03}.

Conclusions

Outside the USA, the 2009 CKD-EPI equation should not be used with the race coefficient, even though the 2009 CKD-EPI equation is not sufficiently accurate either way (<75%). Thus we endorse the Kidney Disease: Improving Global Outcomes guidelines to use exogenous filtration markers when this may impact clinical conduct.

Health disparities in past influenza pandemics: A scoping review of the literature

Objective

The COVID-19 pandemic has exacerbated existing health disparities. To provide a historical perspective on health disparities for pandemic acute respiratory viruses, we conducted a scoping review of the public health literature of health disparities in influenza outcomes during the 1918, 1957, 1968, and 2009 influenza pandemics.

Methods

We searched for articles examining socioeconomic or racial/ethnic disparities in any population, examining any influenza-related outcome (e.g., incidence, hospitalizations, mortality), during the 1918, 1957, 1968, and 2009 influenza pandemics. We conducted a structured search of English-written articles in PubMed supplemented by a snowball of articles meeting inclusion criteria.

Results

A total of 29 articles met inclusion criteria, all but one focusing exclusively on the 1918 or 2009 pandemics. Individuals of low socioeconomic status, or living in low socioeconomic status areas, experienced higher incidence, hospitalizations, and mortality in the 1918 and 2009 pandemics. There were conflicting results regarding racial/ethnic disparities during the 1918 pandemic, with differences in magnitude and direction by outcome, potentially due to issues in data quality by race/ethnicity. Racial/ethnic minorities had generally higher incidence, mortality, and hospitalization rates in the 1957 and 2009 pandemics.

Conclusion

Individuals of low socioeconomic status and racial/ethnic minorities have historically experienced worse influenza outcomes during pandemics. These historical patterns can inform current research to understand disparities in the ongoing COVID-19 pandemic and future pandemics.

citationchaser: a tool for transparent and efficient forward and backward citation chasing in systematic searching

Systematic searching aims to find all possibly relevant research from multiple sources, the basis for an unbiased and comprehensive evidence base. Along with bibliographic databases, systematic reviewers use a variety of additional methods to minimise procedural bias. Citation chasing exploits connections between research articles to identify relevant records for a review by making use of explicit mentions of one article within another. Citation chasing is a popular supplementary search method because it helps to build on the work of primary research and review authors. It does so by identifying potentially relevant studies that might otherwise not be retrieved by other search methods; for example, because they did not use the review authors' search terms in the specified combinations in their titles, abstracts, or keywords. Here, we briefly provide an overview of citation chasing as a method for systematic reviews. Furthermore, given the challenges and high resource requirements associated with citation chasing, the limited application of citation chasing in otherwise rigorous systematic reviews, and the potential benefit of identifying terminologically disconnected but semantically linked research studies, we have developed and describe a free and open source tool that allows for rapid forward and backward citation chasing. We introduce citationchaser, an R package and Shiny app for conducting forward and backward citation chasing from a starting set of articles. We describe the sources of data, the backend code functionality, and the user interface provided in the Shiny app. This article is protected by copyright. All rights reserved.

Half a century of research on antipsychotics and schizophrenia: A scientometric study of hotspots, nodes, bursts, and trends

Changes over 50 years of research on antipsychotics in schizophrenia have occurred. A scientometric synthesis of such changes over time and a measure of researchers' networks and scientific productivity is currently lacking. We searched Web of Science Core Collection from inception until November 5, 2021, using the appropriate key. Our primary objective was to conduct systematic mapping with CiteSpace to show how clusters of keywords have evolved over time and obtain clusters' structure and credibility. Our secondary objective was to measure research network performance (countries, institutions, and authors) using CiteSpace, VOSviewer, and Bibliometrix. We included 32,240 studies published between 1955 and 2021. The co-cited reference network identified 25 clusters with a well-structured network (Q=0.8166) and highly credible clustering (S=0.91). The main trends of research were: 1) antipsychotic efficacy; 2) cognition in schizophrenia; 3) side effects of antipsychotics. Last five years research trends were: 'ultra-resistance schizophrenia' (S=0.925), 'efficacy/dose-response' (S=0.775), 'evidence-synthesis' (S=0.737), 'real-world effectiveness' (S=0.794), 'cannabidiol' (S=0.989), and 'gut microbiome' (S=0.842). These results can inform funding agencies and research groups' future directions.

Can social support be improved in people with a severe mental illness? A systematic review and meta-analysis

People with a severe mental illness often have less social support than other people, yet these people need social support to face the challenges in their lives. Increasing social support could benefit the person's recovery, but it is not clear whether interventions that aim to improve social support in people with a severe mental illness are effective. A systematic literature search and review in MEDLINE (PubMed), PsycINFO, CINAHL, Cochrane, JSTOR, IBSS, and Embase was performed. Studies were included if they had a control group and they were aimed at improving social support in people with a severe mental illness who were receiving outpatient treatment. Summary data were extracted from the research papers and compared in a meta-analysis by converting outcomes to effect sizes (Hedges's g). Eight studies (total n = 1538) that evaluated ten different interventions met the inclusion criteria. All but one of these studies was of sufficient quality to be included in the review. The studies that were included in the meta-analysis had a combined effect size of 0.17 (confidence interval: 0.02 to 0.32), indicating a small or no effect for the interventions that were evaluated. A subgroup analysis of more personalized studies showed a combined effect size of 0.35 (CI = 0.27 to 0.44), indicating a noteworthy effect for these more personalized studies. This evaluation of interventions aimed at improving social support in people with a severe mental illness suggests that these interventions in general have little or no clinical benefit. However, in a subgroup analysis the more personalized interventions have a larger effect on improving social support and merit further research.

Semi-automated Tools for Systematic Searches

Traditionally, literature identification for systematic reviews has relied on a two-step process: first, searching databases to identify potentially relevant citations, and then manually screening those citations. A number of tools have been developed to streamline and semi-automate this process, including tools to generate terms; to visualize and evaluate search queries; to trace citation linkages; to deduplicate, limit, or translate searches across databases; and to prioritize relevant abstracts for screening. Research is ongoing into tools that can unify searching and screening into a single step, and several protype tools have been developed. As this field grows, it is becoming increasingly important to develop and codify methods for evaluating the extent to which these tools fulfill their purpose.

Using citation tracking for systematic literature searching - study protocol for a scoping review of methodological studies and an expert survey

Background: Up-to-date guidance on comprehensive study identification for systematic reviews is crucial. According to current recommendations, systematic searching should combine electronic database searching with supplementary search methods. One such supplementary search method is citation tracking. It aims at collecting directly and/or indirectly cited and citing references from "seed references". Tailored and evidence-guided recommendations concerning the use of citation tracking are strongly needed. Objective: We intend to develop recommendations for the use of citation tracking in health-related systematic literature searching. Our study will be guided by the following research questions: What are the benefits of citation tracking for health-related systematic literature searching? Which perspectives and experiences do experts in the field of literature retrieval methods have with regard to citation tracking in health-related systematic literature searching? Methods: Our study will have two parts: a scoping review and an expert survey. The scoping review aims at identifying methodological studies on benefits or problems of citation tracking in health-related systematic literature searching with no restrictions on study design, language, and publication date. We will perform database searching in MEDLINE, The Cumulative Index to Nursing and Allied Health Literature (CINAHL), Web of Science Core Collection, two information science databases, and free web searching. Two reviewers will independently assess full texts of selected abstracts. We will conduct direct backward and forward citation tracking on included articles. The results of the scoping review will inform our expert survey through which we aim to learn about experts΄ perspectives and experiences. We will narratively synthesize the results and derive recommendations for performing health-related systematic reviews.

Using citation tracking for systematic literature searching - study protocol for a scoping review of methodological studies and a Delphi study

Background: Up-to-date guidance on comprehensive study identification for systematic reviews is crucial. According to current recommendations, systematic searching should combine electronic database searching with supplementary search methods. One such supplementary search method is citation tracking. It aims at collecting directly and/or indirectly cited and citing references from "seed references". Tailored and evidence-guided recommendations concerning the use of citation tracking are strongly needed. Objective: We intend to develop recommendations for the use of citation tracking in systematic literature searching for health-related topics. Our study will be guided by the following research questions: What is the benefit of citation tracking for systematic literature searching for health-related topics? Which methods, citation indexes, and other tools are used for citation tracking? What terminology is used for citation tracking methods? Methods: Our study will have two parts: a scoping review and a Delphi study. The scoping review aims at identifying methodological studies on the benefit and use of citation tracking in systematic literature searching for health-related topics with no restrictions on study design, language, and publication date. We will perform database searching in MEDLINE (Ovid), CINAHL (EBSCOhost), Web of Science Core Collection, two information science databases, web searching, and contact experts in the field. Two reviewers will independently perform study selection. We will conduct direct backward and forward citation tracking on included articles. Data from included studies will be extracted using a prespecified extraction sheet and presented in both tabular and narrative form. The results of the scoping review will inform the subsequent Delphi study through which we aim to derive consensus recommendations for the future practice and research of citation tracking.

Using citation tracking for systematic literature searching - study protocol for a scoping review of methodological studies and a Delphi study

Background: Up-to-date guidance on comprehensive study identification for systematic reviews is crucial. According to current recommendations, systematic searching should combine electronic database searching with supplementary search methods. One such supplementary search method is citation tracking. It aims at collecting directly and/or indirectly cited and citing references from "seed references". Tailored and evidence-guided recommendations concerning the use of citation tracking are strongly needed. Objective: We intend to develop recommendations for the use of citation tracking in systematic literature searching for health-related topics. Our study will be guided by the following research questions: What is the benefit of citation tracking for systematic literature searching for health-related topics? Which methods, citation indexes, and other tools are used for citation tracking? What terminology is used for citation tracking methods? Methods: Our study will have two parts: a scoping review and a Delphi study. The scoping review aims at identifying methodological studies on the benefit and use of citation tracking in systematic literature searching for health-related topics with no restrictions on study design, language, and publication date. We will perform database searching in MEDLINE (Ovid), CINAHL (EBSCOhost), Web of Science Core Collection, two information science databases, web searching, and contact experts in the field. Two reviewers will independently perform study selection. We will conduct direct backward and forward citation tracking on included articles. Data from included studies will be extracted using a prespecified extraction sheet and presented in both tabular and narrative form. The results of the scoping review will inform the subsequent Delphi study through which we aim to derive consensus recommendations for the future practice and research of citation tracking.

Novel citation-based search method for scientific literature: a validation study

Background

We recently developed CoCites, a citation-based search method that is designed to be more efficient than traditional keyword-based methods. The method begins with identification of one or more highly relevant publications (query articles) and consists of two searches: the co-citation search, which ranks publications on their co-citation frequency with the query articles, and the citation search, which ranks publications on frequency of all citations that cite or are cited by the query articles.

Methods

We aimed to reproduce the literature searches of published systematic reviews and meta-analyses and assess whether CoCites retrieves all eligible articles while screening fewer titles.

Results

A total of 250 reviews were included. CoCites retrieved a median of 75% of the articles that were included in the original reviews. The percentage of retrieved articles was higher (88%) when the query articles were cited more frequently and when they had more overlap in their citations. Applying CoCites to only the highest-cited article yielded similar results. The co-citation and citation searches combined were more efficient when the review authors had screened more than 500 titles, but not when they had screened less.

Conclusions

CoCites is an efficient and accurate method for finding relevant related articles. The method uses the expert knowledge of authors to rank related articles, does not depend on keyword selection and requires no special expertise to build search queries. The method is transparent and reproducible.

Evidence-based practice educational intervention studies: a systematic review of what is taught and how it is measured

BACKGROUND

Despite the established interest in evidence-based practice (EBP) as a core competence for clinicians, evidence for how best to teach and evaluate EBP remains weak. We sought to systematically assess coverage of the five EBP steps, review the outcome domains measured, and assess the properties of the instruments used in studies evaluating EBP educational interventions.

METHODS

We conducted a systematic review of controlled studies (i.e. studies with a separate control group) which had investigated the effect of EBP educational interventions. We used citation analysis technique and tracked the forward and backward citations of the index articles (i.e. the systematic reviews and primary studies included in an overview of the effect of EBP teaching) using Web of Science until May 2017. We extracted information on intervention content (grouped into the five EBP steps), and the outcome domains assessed. We also searched the literature for published reliability and validity data of the EBP instruments used.

RESULTS

Of 1831 records identified, 302 full-text articles were screened, and 85 included. Of these, 46 (54%) studies were randomised trials, 51 (60%) included postgraduate level participants, and 63 (75%) taught medical professionals. EBP Step 3 (critical appraisal) was the most frequently taught step (63 studies; 74%). Only 10 (12%) of the studies taught content which addressed all five EBP steps. Of the 85 studies, 52 (61%) evaluated EBP skills, 39 (46%) knowledge, 35 (41%) attitudes, 19 (22%) behaviours, 15 (18%) self-efficacy, and 7 (8%) measured reactions to EBP teaching delivery. Of the 24 instruments used in the included studies, 6 were high-quality (achieved ≥3 types of established validity evidence) and these were used in 14 (29%) of the 52 studies that measured EBP skills; 14 (41%) of the 39 studies that measured EBP knowledge; and 8 (26%) of the 35 studies that measured EBP attitude.

CONCLUSIONS

Most EBP educational interventions which have been evaluated in controlled studies focus on teaching only some of the EBP steps (predominantly critically appraisal of evidence) and did not use high-quality instruments to measure outcomes. Educational packages and instruments which address all EBP steps are needed to improve EBP teaching.

Completeness of the reporting of evidence-based practice educational interventions: a review

CONTEXT

Complete reporting of intervention details in trials of evidence-based practice (EBP) educational interventions is essential to enable clinical educators to translate research evidence about interventions that have been shown to be effective into practice. In turn, this will improve the quality of EBP education.

OBJECTIVES

This study was designed to examine the completeness of reporting of EBP educational interventions in published studies and to assess whether missing details of educational interventions could be retrieved by searching additional sources and contacting study authors.

METHODS

A systematic review of controlled trials that had evaluated EBP educational interventions was conducted using a citation analysis technique. Forward and backward citations of the index articles were tracked until March 2016. The TIDieR (template for intervention description and replication) checklist was used to assess the completeness of intervention reporting. Missing details were sought from: (i) the original publication; (ii) additional publicly available sources, and (iii) the study authors.

RESULTS

Eighty-three articles were included; 45 (54%) were randomised controlled trials (RCTs) and 38 (46%) were non-RCTs. The majority of trials (n = 62, 75%) involved medical professionals. None of the studies completely reported all of the main items of the educational intervention within the original publication or in additional sources. However, details became complete for 17 (20%) interventions after contact with the respective authors. The item most frequently missing was 'intervention materials', which was missing in 80 (96%) of the original publications, in additional sources for 77 (93%) interventions, and in 59 (71%) studies after contact with the authors. Authors of 69 studies were contacted; 33 provided the details requested.

CONCLUSIONS

The reporting of EBP educational interventions is incomplete and remained so for the majority of studies, even after study authors had been contacted for missing information. Collaborative efforts involving authors and editors are required to improve the completeness of reporting of EBP educational interventions.

A comparison of results of empirical studies of supplementary search techniques and recommendations in review methodology handbooks: a methodological review

BACKGROUND

The purpose and contribution of supplementary search methods in systematic reviews is increasingly acknowledged. Numerous studies have demonstrated their potential in identifying studies or study data that would have been missed by bibliographic database searching alone. What is less certain is how supplementary search methods actually work, how they are applied, and the consequent advantages, disadvantages and resource implications of each search method. The aim of this study is to compare current practice in using supplementary search methods with methodological guidance.

METHODS

Four methodological handbooks in informing systematic review practice in the UK were read and audited to establish current methodological guidance. Studies evaluating the use of supplementary search methods were identified by searching five bibliographic databases. Studies were included if they (1) reported practical application of a supplementary search method (descriptive) or (2) examined the utility of a supplementary search method (analytical) or (3) identified/explored factors that impact on the utility of a supplementary method, when applied in practice.

RESULTS

Thirty-five studies were included in this review in addition to the four methodological handbooks. Studies were published between 1989 and 2016, and dates of publication of the handbooks ranged from 1994 to 2014. Five supplementary search methods were reviewed: contacting study authors, citation chasing, handsearching, searching trial registers and web searching.

CONCLUSIONS

There is reasonable consistency between recommended best practice (handbooks) and current practice (methodological studies) as it relates to the application of supplementary search methods. The methodological studies provide useful information on the effectiveness of the supplementary search methods, often seeking to evaluate aspects of the method to improve effectiveness or efficiency. In this way, the studies advance the understanding of the supplementary search methods. Further research is required, however, so that a rational choice can be made about which supplementary search strategies should be used, and when.

Can Dexmedetomidine Influence Recovery Profiles from General Anesthesia in Nasal Surgery?

Objectives Dexmedetomidine has sympatholytic, sedative, anesthetic, and analgesic effects, as well as vasoconstrictive effects, which may help prevent hypotension under general anesthesia. This meta-analysis aimed to perform a systematic review of the literature and investigate the effect of dexmedetomidine on perioperative morbidity following nasal surgery and its adverse effects. Data Sources MEDLINE, SCOPUS, and the Cochrane database. Review Methods Two authors independently searched the databases from their inception to March 2017. Studies were selected that compared perioperative dexmedetomidine administration (dexmedetomidine groups) with a placebo or remifentanil (control groups) with regard to intraoperative morbidity, including surgical time, bleeding amount, hypotension, and bradycardia during operation, and postoperative morbidity, such as emergence agitation, nausea and vomiting, and sedation after operation. Results Surgical time, intraoperative blood loss, dose of inhaled anesthetic gas, dose of fentanyl, postoperative pain, and incidence of emergence agitation were significantly lower in the dexmedetomidine group versus the placebo group. In contrast, there were no significant differences in intraoperative hemodynamic stability and postoperative residual sedation and nausea and vomiting between groups. Additionally, compared with remifentanil (a currently widely used agent), dexmedetomidine was superior in view of postoperative pain and intraoperative blood pressure control. Conclusion This meta-analysis shows that the systemic administration of dexmedetomidine can decrease surgical time, intraoperative blood loss, and doses of intraoperative inhaled anesthetic gas and fentanyl as compared with placebo. It can also decrease postoperative pain and incidence of the emergence agitation. Due to the small number of studies, further clinical trials are needed to confirm these results.

Patient preferences for cardiovascular preventive medication: a systematic review

OBJECTIVE

To systematically review current evidence regarding the minimum acceptable risk reduction of a cardiovascular event that patients feel would justify daily intake of a preventive medication.

METHODS

We used the Web of Science to track the forward and backward citations of a set of five key articles until 15 November 2016. Studies were eligible if they quantitatively assessed the minimum acceptable benefit-in absolute values-of a cardiovascular disease preventive medication among a sample of the general population and required participants to choose if they would consider taking the medication.

RESULTS

Of 341 studies screened, we included 22, involving a total of 17 751 participants: 6 studied prolongation of life (POL), 12 studied absolute risk reduction (ARR) and 14 studied number needed to treat (NNT) as measures of risk reduction communicated to the patients. In studies framed using POL, 39%-54% (average: 48%) of participants would consider taking a medication if it prolonged life by <8 months and 56%-73% (average: 64%) if it prolonged life by ≥8 months. In studies framed using ARR, 42%-72% (average: 54%) of participants would consider taking a medication that reduces their 5-year cardiovascular disease (CVD) risk by <3% and 50%-89% (average: 77%) would consider taking a medication that reduces their 5-year CVD risk by ≥3%. In studies framed using 5-year NNT, 31%-81% (average: 60%) of participants would consider taking a medication with an NNT of >30 and 46%-87% (average: 71%) with an NNT of ≤30.

CONCLUSIONS

Many patients require a substantial risk reduction before they consider taking a daily medication worthwhile, even when the medication is described as being side effect free and costless.