Searching ClinicalTrials.gov and the International Clinical Trials Registry Platform to inform systematic reviews: what are the optimal search approaches?

Three levels of discrepancies in the records of trial sites in India, registered with the European Union Clinical Trials Register

Introduction

Clinical trial registries serve a key role in tracking the trial enterprise. We are interested in the record of trials sites in India. In this study, we focused on the European Union Clinical Trial Registry (EUCTR). This registry is complex because a given study may have records from multiple countries in the EU, and therefore a given study ID may be represented by multiple records. We wished to determine what steps are required to identify the studies that list sites in India that are registered with EUCTR.

Methods

We used two methodologies. Methodology A involved downloading the EUCTR database and querying it. Methodology B used the search function on the registry website.

Results

Discrepant information, on whether or not a given study listed a site in India, was identified at three levels: (i) the methodology of examining the database; (ii) the multiple records of a given study ID; and (iii) the multiple fields within a given record. In each of these situations, there was no basis to resolve the discrepancy, one way or another.

Discussion

This work contributes to methodologies for more accurate searches of trial registries. It also adds to the efforts of those seeking transparency in trial data.

Both clinical trial register and electronic bibliographic database searches were needed to identify randomized clinical trials for systematic reviews: an evaluation study

OBJECTIVES

To determine whether clinical trial register (CTR) searches can accurately identify a greater number of completed randomized clinical trials (RCTs) than electronic bibliographic database (EBD) searches for systematic reviews of interventions, and to quantify the number of eligible ongoing trials.

STUDY DESIGN AND SETTING

We performed an evaluation study and based our search for RCTs on the eligibility criteria of a systematic review that focused on the underrepresentation of people with chronic kidney disease in cardiovascular RCTs. We conducted a combined search of ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform through the Cochrane Central Register of Controlled Trials to identify eligible RCTs registered up to June 1, 2023. We searched Cochrane Central Register of Controlled Trials, EMBASE, and MEDLINE for publications of eligible RCTs published up to June 5, 2023. Finally, we compared the search results to determine the extent to which the two sources identified the same RCTs.

RESULTS

We included 92 completed RCTs. Of these, 81 had results available. Sixty-six completed RCTs with available results were identified by both sources (81% agreement [95% CI: 71-88]). We identified seven completed RCTs with results exclusively by CTR search (9% [95% CI: 4-17]) and eight exclusively by EBD search (10% [95% CI: 5-18]). Eleven RCTs were completed but lacked results (four identified by both sources (36% [95% CI: 15-65]), one exclusively by EBD search (9% [95% CI: 1-38]), and six exclusively by CTR search (55% [95% CI: 28-79])). Also, we identified 42 eligible ongoing RCTs: 16 by both sources (38% [95% CI: 25-53]) and 26 exclusively by CTR search (62% [95% CI: 47-75]). Lastly, we identified four RCTs of unknown status by both sources.

CONCLUSION

CTR searches identify a greater number of completed RCTs than EBD searches. Both searches missed some included RCTs. Based on our case study, researchers (eg, information specialists, systematic reviewers) aiming to identify all available RCTs should continue to search both sources. Once the barriers to performing CTR searches alone are targeted, CTR searches may be a suitable alternative.

Development and evaluation of objective trial performance metrics for multisite clinical studies: Experience from the AlcHep Network

BACKGROUND

Recruitment and retention are critical in clinical studies but there are limited objective metrics of trial performance. We tested if development of trial performance metrics will allow for objective evaluation of study quality. Performance metrics were developed using data from the observational cohort (OBS) and randomized clinical trial (RCT) arms of the prospective Alcoholic Hepatitis Network.

METHODS

Yield-rate (%YR; eligible/screened), recruitment index (RI; mean recruitment time/patient), completion index (CI; average number of days to complete the follow-up/patient), and protocol adherence index (AI; average number of deviations/subject recruited) were determined.

RESULTS

2250 patients (1168 for OBS; 1082 for RCT) were screened across 8 sites. Recruitment in the RCT (57% target) was similar to that in the OBS (59% target). Of those screened, 743 (63.6%) subjects in the OBS and 147 (13.6%) subjects in the RCT were enrolled in the study. In OBS study, 253 (34.1%) subjects, and in the RCT, 68 (46.3%) subjects, completed the study or reached a censoring event. Across all sites (range), YR for OBS was 63.6% (41.3-98.3%) and for RCT was 13.6% (5.5-92.6%); RI for OBS was 1.66 (8.79-19.85) and for RCT was 4.05 (19.76-36.43); CI for OBS was 4.87 (22.6-118.3) and for RCT was 8.75 (27.27-161.5); and AR for OBS was 0.56 (0.08-1.04) and for RCT was 1.55 (0.39-3.21. Factors related to participants, research design, study team, and research sponsors contributed to lower performance metrics.

CONCLUSIONS

Objective measures of clinical trial performance allow for strategies to enhance study quality and development of site-specific improvement plans.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov NCT4072822 NCT03850899.

A systematic analysis of the landscape of synthetic lethality-driven precision oncology

BACKGROUND

Synthetic lethality (SL) denotes a genetic interaction between two genes whose co-inactivation is detrimental to cells. Because more than 25 years have passed since SL was proposed as a promising way to selectively target cancer vulnerabilities, it is timely to comprehensively assess its impact so far and discuss its future.

METHODS

We systematically analyzed the literature and clinical trial data from the PubMed and Trialtrove databases to portray the preclinical and clinical landscape of SL oncology.

FINDINGS

We identified 235 preclinically validated SL pairs and found 1,207 pertinent clinical trials, and the number keeps increasing over time. About one-third of these SL clinical trials go beyond the typically studied DNA damage response (DDR) pathway, testifying to the recently broadening scope of SL applications in clinical oncology. We find that SL oncology trials have a greater success rate than non-SL-based trials. However, about 75% of the preclinically validated SL interactions have not yet been tested in clinical trials.

CONCLUSIONS

Dissecting the recent efforts harnessing SL to identify predictive biomarkers, novel therapeutic targets, and effective combination therapy, our systematic analysis reinforces the hope that SL may serve as a key driver of precision oncology going forward.

FUNDING

Funded by the Samsung Research Funding & Incubation Center of Samsung Electronics, the Institute of Information & Communications Technology Planning & Evaluation (IITP) grant funded by the Republic of Korea government (MSIT), the Kwanjeong Educational Foundation, the Intramural Research Program of the National Institutes of Health (NIH), National Cancer Institute (NCI), and Center for Cancer Research (CCR).

Perspective: Systematic review and meta-analysis in obstructive sleep apnea - What is lacking?

Obstructive sleep apnea (OSA) affects nearly one billion of the global adult population. It is associated with substantial burden in terms of quality of life, cognitive function, and cardiovascular health. Positive airway pressure (PAP) therapy, commonly considered the first-line treatment, is limited by low compliance and lacking efficacy on long-term cardiovascular outcomes. A substantial body of research has been produced investigating (novel) non-PAP treatments. With increased understanding of OSA pathogenesis, promising therapeutic approaches are emerging. There is an imperative need of high-quality synthesis of evidence; however, current systematic reviews and meta-analyses (SR/MA) on the topic demonstrate important methodological limitations and are seldom based on research questions that fully reflect the complex intricacies of OSA management. Here, we discuss the current challenges in management of OSA, the need of treatable traits based OSA treatment, the methodological limitations of existing SR/MA in the field, potential remedies, as well as future perspectives.

Exploring Clinical Trials to Manage Firefighters' Sleep Quality: A PRISMA Compliant Systematic Review

Sleep research has grown over the past decades and investigators are deeply involved in studying sleep and its impact on human health and body regulation. Despite the understanding that insufficient sleep is strongly linked to the development of several disorders, unsatisfactory sleep exposes health and safety to innumerous risks. The present study aims to review and analyze the main results of clinical trials, registered at ClinicalTrials.gov and ICTRT databases, and developed construct strategies to improve sleep quality on firefighters and enhance professionals' sleep and health conditions. The protocol was registered in PROSPERO under number CRD42022334719. Trials registered between first registry and 2022 were included. We retrieved 11 registered clinical trials; seven met eligibility criteria and were included in the review. A relation between sleep disorders, shift work, and occupational health problems was found, and retrieved trials showed that sleep education programs can improve sleep quality and sleep hygiene. Science has already recognized sleep's importance for metabolic functioning and survivorship. Nevertheless, it continues to play a major role in discovering methods to diminish the problems faced. Strategies contemplating sleep education, or intervention, should be presented to fire services to tackle this problem and promote healthier and safer environments.

Current Characteristics of Herbal Medicine Interventions for Cancer on Clinical Databases: A Cross-Sectional Study

BACKGROUND

The utilization of herbal medicine has been noteworthy for treating cancer; however, there is not enough information regarding the characteristics of clinical trials of herbal medicine interventions. This study aimed to evaluate the characteristic of registered trials using herbal medicine interventions for cancer.

METHODS

A cross-sectional study was performed via the website ClinicalTrials.gov, ISRCTN registry, Chinese clinical trial registry, and international clinical trials registry platform to gather associated registered clinical trials using an advanced search with the developed keyword strategy as of March 26, 2023. All obtainable information from the trials was collected without any restrictions to conduct a comprehensive review.

RESULTS

A total of 169 registered trials were included for evaluation. Of all trials, 102 trials were eligible for this study. Countries from Asia registered the most trials (62.75%), and hospitals sponsored most of the trials (42.16%). Randomized, Phase 2, interventional trials were dominant, and approximately 64.71% of the trials anticipated recruiting less than 100 participants. More than half of the trials were from 2016 to 2023 (53.92%). While 45 trials were completed, only 16 trials had results for further analysis. According to the completed results, the types of herbal medicines from the trials mainly focused on lung, breast, and colorectal cancer.

CONCLUSION

This study is the first to explore the characteristics of clinical trials of herbal medicine for cancer registered in large clinical databases. The acquired trials had relatively informative data; however, better-designed trials may be needed for health professionals to consider herbal medicine as an option when treating cancer patients.

Home-built environment interventions and inflammation biomarkers: a systematic review and meta-analysis protocol

BACKGROUND

Inflammation control is a fundamental part of chronic care in patients with a history of cancer and comorbidity. As the risk-benefit profile of anti-inflammatory drugs is unclear in survivors of cancer, GPs and patients could benefit from alternative non-pharmacological treatment options for dysregulated inflammation. There is a potential for home-built environment (H-BE) interventions to modulate inflammation; however, discrepancies exist between studies.

AIM

To evaluate the effectiveness of H-BE interventions on cancer-associated inflammation biomarkers.

DESIGN & SETTING

A systematic review and meta-analysis of randomised and non-randomised trials in community-dwelling adults.

METHOD

PubMed and MEDLINE, Embase, Web of Science, and Google Scholar will be searched for clinical trials published in January 2000 onwards. The study will include H-BE interventions modifying air quality, thermal comfort, non-ionising radiation, noise, nature, and water. No restrictions to study population will be applied to allow deriving expectations for effects of the interventions in cancer survivors from available source populations. Outcome measures will be inflammatory biomarkers clinically and physiologically relevant to cancer. The first reviewer will independently screen articles together with GPs and extract data that will be verified by a second reviewer. The quality of studies will be assessed using the Cochrane risk-of-bias tools. Depending on the clinical and methodological homogeneity of populations, interventions, and outcomes, a meta-analysis will be conducted using random-effects models.

CONCLUSION

Findings will determine the effectiveness of H-BE interventions on inflammatory parameters, guide future directions for its provision in community-dwelling survivors of cancer and support GPs with safer anti-inflammatory treatment options in high-risk patients for clinical complications.

Effectiveness of Continuous Cuff Pressure Control in Preventing Ventilator-Associated Pneumonia: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

OBJECTIVES

Microaspiration of subglottic secretions is the main pathogenic mechanism for ventilator-associated pneumonia (VAP). Adequate inflation of the endotracheal cuff is pivotal to providing an optimal seal of the extraluminal airway. However, cuff pressure substantially fluctuates due to patient or tube movements, which can induce microaspiration. Therefore, devices for continuous cuff pressure control (CCPC) have been developed in recent years. The purpose of this systematic review and meta-analysis is to assess the effectiveness of CCPC in VAP prevention.

DATA SOURCES

A systematic search of Embase, the Cochrane Central Register of Controlled Trials, and the International Clinical Trials Registry Platform was conducted up to February 2022.

STUDY SELECTION

Eligible studies were randomized controlled trials (RCTs) and quasi-RCTs comparing the impact of CCPC versus intermittent cuff pressure control on the occurrence of VAP.

DATA EXTRACTION

Random-effects meta-analysis was used to calculate odds ratio (OR) and 95% CI for VAP incidence between groups. Secondary outcome measures included mortality and duration of mechanical ventilation (MV) and ICU stay. The certainty of the evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation approach.

DATA SYNTHESIS

Eleven RCTs with 2,092 adult intubated patients were included. The use of CCPC was associated with a reduced risk of VAP (OR, 0.51). Meta-analyses of secondary endpoints showed no significant difference in mortality but significant differences in durations of MV (mean difference, -1.07 d) and ICU stay (mean difference, -3.41 d) in favor of CCPC. However, the risk of both reporting and individual study bias was considered important. The main issues were the lack of blinding, potential commercial conflicts of interest of study authors and high heterogeneity due to methodological differences between studies, differences in devices used for CCPC and in applied baseline preventive measures. Certainty of the evidence was considered "very low."

CONCLUSIONS

The use of CCPC was associated with a reduction in VAP incidence; however, this was based on very low certainty of evidence due to concerns related to risk of bias and inconsistency.

Mapping ongoing nutrition intervention trials in muscle, sarcopenia, and cachexia: a scoping review of future research

Muscle loss alone, or in the context of sarcopenia or cachexia, is a prevalent condition and a predictor of negative outcomes in aging and disease. As adequate nutrition is essential for muscle maintenance, a growing number of studies has been conducted to explore the role of specific nutrients on muscle mass or function. Nonetheless, more research is needed to guide evidence-based recommendations. This scoping review aimed to compile and document ongoing clinical trials investigating nutrition interventions as a strategy to prevent or treat low muscle mass or function (strength and physical performance), sarcopenia, or cachexia. ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform were searched up to 21 April 2021 for planned and ongoing trials. Randomized controlled trials with ≥20 participants per arm were included based on intent to explore the effects of nutrition interventions on muscle-related outcomes (i.e. muscle mass or strength, physical performance, or muscle synthesis rate) in both clinical and non-clinical conditions (i.e. aging). Two reviewers independently screened records for eligibility, and a descriptive synthesis of trials characteristics was conducted. A total of 113 trials were included in the review. Most trials (69.0%) enroll adults with clinical conditions, such as cancer (19.5%), obesity and metabolic diseases (16.8%), and musculoskeletal diseases (10.7%). The effects of nutrition interventions on age-related muscle loss are explored in 31% of trials. Although nutrition interventions of varied types were identified, food supplements alone (48.7%) or combined with dietary advice (11.5%) are most frequently reported. Protein (17.7%), amino acids (10.6%), and β-hydroxy-β-methylbutyrate (HMB, 6.2%) are the top three food supplements' nutrients under investigation. Primary outcome of most trials (54.9%) consists of measures of muscle mass alone or in combination with muscle strength and/or performance (as either primary or secondary outcomes). Muscle strength and physical performance are primary outcomes of 38% and 31.9% of the trials, respectively. These measurements were obtained using a variety of techniques. Only a few trials evaluate muscle synthesis rate either as a primary or secondary outcome (5.3%). Several nutrition studies focusing on muscle, sarcopenia, and cachexia are underway and can inform future research in this area. Although many trials have similar type of interventions, methodological heterogeneity may challenge study comparisons, and future meta-analyses aiming to provide evidence-based recommendations. Upcoming research in this area may benefit from guidelines for the assessment of therapeutic effects of nutrition interventions.

Global trends in chronic thromboembolic pulmonary hypertension clinical trials and dissemination of results

Treatment options for chronic thromboembolic pulmonary hypertension (CTEPH) are rapidly expanding. The purpose of this study is to identify trends in CTEPH clinical trials and the publication of results. We performed a worldwide review of completed and ongoing clinical trials through searching the ClinicalTrials.gov database and the World Health Organization International Clinical Trials Registry Platform for "CTEPH" and related terms. Entries were classified as pharmaceutical/procedural interventions (Group 1), all other clinical trials (Group 2) and patient registries (Group 3). Trial characteristics and national affiliation were recorded. PubMed was searched for related publications. There were 117 clinical trials registry entries after removing duplicates and non-target records. Group 1 comprised 29 pharmaceutical, 15 procedural, and four combined interventions starting in 2005, 2010, and 2016, respectively. Riociguat and balloon pulmonary angioplasty were the most frequent pharmaceutical and procedural interventions, respectively. The proportion of procedural trials increased over time from 0% of those in 2005-2009 to 29% in 2010-2014 and 54% in 2015-2020. There were 56 entries in Group 2 and 13 in Group 3. Japan was the most frequent national affiliation and the most frequent participating country, present in 28% of all trials. The proportion of entries with published results was highest with Group 3 (62%) and lowest with Group 1 (27%). Thirty percent of all publications occurred in 2020. In conclusion, CTEPH clinical trials are increasingly procedural based, with growth largely attributable to Japan and balloon pulmonary angioplasty. Most trials have not published, but results from balloon pulmonary angioplasty clinical trials are anticipated soon.

Secondary electronic sources demonstrated very good sensitivity for identifying studies evaluating interventions for COVID-19

Objectives

To assess the sensitivity of two secondary electronic sources of COVID-19 studies: 1) the Cochrane COVID-19 Study Register (https://covid-19.cochrane.org/); and, 2) the Living Overview of the Evidence (L•OVE) COVID-19 platform (https://iloveevidence.com/).

Study design and setting

We identified reports of randomized controlled trials (RCTs) and observational studies (OS) assessing preventive interventions or treatment for COVID-19.

The reference standard comprised all reports included in the COVID-NMA platform (covid-nma.com), in two major living systematic reviews of RCTs assessing pharmacologic treatment of COVID-19, or identified in either of the two secondary sources evaluated. The search for all sources was conducted through September 7, 2020.

Our primary outcome was the proportion of the reports included in the reference standard that were identified by each secondary source.

Results

We identified 680 reports, 91 RCT reports, 97 RCT protocols, and 492 OS reports. The Cochrane COVID-19 Study Register identified 88% [95% confidence interval, 79–94] of the RCT reports, 90% [82–95] of the RCT protocols, and 82% [78–85] of the OS reports. The L•OVE platform identified 100% [97–100] of the RCT reports and RCT protocols and 100% [99–100] of the OS reports.

Conclusion

These platforms proved to be a viable screening alternative to searching every individual source.

Searching for medical devices - practical guidance

Systematic reviews of medical devices have generally adopted the same methodology for the conduct of their reviews as reviews of other clinical interventions, in particular, medicines. It has been suggested that these methods may need to be developed to account for the challenges of reviewing the evidence for medical devices when compared to reviews of medicines. The purpose of this research note is to focus on the methods of searching for medical devices. Our aim is to set out guidance on 'how to search' for medical devices. This includes: Defining what you are searching for; How to design a search strategy; Searching bibliographic databases; Searching beyond bibliographic databases; and Search reporting. The research note is written by three experienced searchers/researchers with experience of critically appraising Medical Technologies Evaluation Programme (MTEP) submissions, undertaking systematic searches and/or reviews of medical devices, or developing guidance for searching for studies for systematic reviews of the effectiveness of interventions, including medical devices. The research note includes a worked example of a search for a fictitious medical device. This article is protected by copyright. All rights reserved.

Neuromodulatory treatments for psychiatric disease: A comprehensive survey of the clinical trial landscape

BACKGROUND

Numerous neuromodulatory therapies are currently under investigation or in clinical use for the treatment of psychiatric conditions.

OBJECTIVE/HYPOTHESIS

We sought to catalogue past and present human research studies on psychiatric neuromodulation and identify relevant trends in this field.

METHODS

ClinicalTrials.gov (https://www.clinicaltrials.gov/) and the International Clinical Trials Registry Platform (https://www.who.int/ictrp/en/) were queried in March 2020 for trials assessing the outcome of neuromodulation for psychiatric disorders. Relevant trials were categorized by variables such as neuromodulation modality, country, brain target, publication status, design, and funding source.

RESULTS

From 72,086 initial search results, 1252 unique trials were identified. The number of trials registered annually has consistently increased. Half of all trials were active and a quarter have translated to publications. The largest proportion of trials involved depression (45%), schizophrenia (18%), and substance use disorders (14%). Trials spanned 37 countries; China, the second largest contributor (13%) after the United States (28%), has increased its output substantially in recent years. Over 75% of trials involved non-convulsive non-invasive modalities (e.g., transcranial magnetic stimulation), while convulsive (e.g., electroconvulsive therapy) and invasive modalities (e.g., deep brain stimulation) were less represented. 72% of trials featured approved or cleared interventions. Characteristic inter-modality differences were observed with respect to enrollment size, trial design/phase, and funding. Dorsolateral prefrontal cortex accounted for over half of focal neuromodulation trial targets. The proportion of trials examining biological correlates of neuromodulation has increased.

CONCLUSION(S)

These results provide a comprehensive overview of the state of psychiatric neuromodulation research, revealing the growing scope and internationalism of this field.

Using clinical trial registries to inform Copas selection model for publication bias in meta-analysis

Prospective registration of study protocols in clinical trial registries is a useful way to minimize the risk of publication bias in meta-analysis, and several clinical trial registries are available nowadays. However, they are mainly used as a tool for searching studies and information submitted to the registries has not been utilized as efficiently as it could. In addressing publication bias in meta-analyses, sensitivity analysis with the Copas selection model is a more objective alternative to widely-used graphical methods such as the funnel-plot and the trim-and-fill method. Despite its ability to quantify the potential impact of publication bias, the Copas selection model relies on sensitivity analyses, in which some parameters are varied across a certain range. This may result in some difficulty in interpreting the results. In this paper, we propose an alternative inference procedure for the Copas selection model by utilizing information from clinical trial registries. Our method provides a simple and accurate way to estimate all unknown parameters of the Copas selection model. A simulation study revealed that our proposed method resulted in smaller biases and more accurate confidence intervals than existing methods. Furthermore, three published meta-analyses were re-analyzed to demonstrate how to implement the proposed method in practice.

Smoking cessation in individuals who use vaping as compared with traditional nicotine replacement therapies: a systematic review and meta-analysis

OBJECTIVES

Despite the aggressive marketing of electronic nicotine device systems (ENDS) as smoking cessation tools, the evidence of their effectiveness is mixed. We conducted a systematic review of randomised controlled trials to determine the effect of ENDS on cigarette smoking cessation, as compared with other types of nicotine replacement therapies (NRT).

DESIGN

Systematic review and meta-analysis using the Grading of Recommendations Assessment, Development and Evaluation approach.

DATA SOURCES

MEDLINE, Embase, the CENTRAL Trials Registry of the Cochrane Collaboration using the Ovid interface, ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform trials registries were searched through 17 June 2020.

ELIGIBILITY CRITERIA FOR STUDIES

Randomised controlled trials in which any type of ENDS was compared with any type of NRT, in traditional cigarette users.

DATA EXTRACTION AND SYNTHESIS

The primary outcome was smoking cessation, defined as abstinence from traditional cigarette smoking for any time period, as reported in each included study, regardless of whether abstinence is self-reported or biochemically validated. Secondary outcomes included smoking reduction, harms, withdrawal and acceptance of therapy. A random-effect model was used, and data were pooled in meta-analyses where appropriate.

RESULTS

Six studies were retained from 270. Most outcomes were judged to be at high risk of bias. The overall quality of evidence was graded as 'low' or 'very low'. Pooled results showed no difference in smoking cessation (rate ratio (RR) 1.42, 95% CI 0.97 to 2.09), proportion of participants reducing smoking consumption (RR 1.25, 95% CI 0.79 to 1.98), mean reduction in cigarettes smoked per day (mean difference 1.11, 95% CI -0.41 to 2.63), or harms (RR 0.96, 95% CI 0.76 to 1.20), between groups.

CONCLUSION

We found no difference in smoking cessation, harms and smoking reduction between e-cigarette and NRT users. However, the quality of the evidence was low. Further research is needed before widespread recommendations are made with regard to the use of ENDS.

PROSPERO REGISTRATION NUMBER

Systematic review registration number: protocol registered with the International Prospective Register of Systematic Reviews (PROSPERO) on February 27th, 2020; CRD42020169416.

A technical review of three clinical trials register resources indicates where improvements to the search interfaces are needed

Clinical trials registers form an important part of the search for studies in systematic reviews of intervention effectiveness but the search interfaces and functionality of registers can be challenging to search systematically and resource intensive to search well. We report a technical review of the search interfaces of three leading trials register resources: ClinicalTrials.gov, the EU Clinical Trials Register and the WHO International Clinical Trials Registers Platform. The technical review used a validated checklist to identify areas where the search interfaces of these trials register resources performed well, where performance was adequate, where performance was poor, and to identify differences between search interfaces. The review found low overall scores for each of the interfaces (ClinicalTrials.gov 55/165, the EU Clinical Trials Register 25/165, the WHO International Clinical Trials Registers Platform 32/165). This finding suggests a need for joined-up dialogue between the producers of the registers and researchers who search them via these interfaces. We also set out a series of four proposed changes which might improve the search interfaces. Trials registers are an invaluable resource in systematic reviews of intervention effectiveness. With the continued growth in systematic reviews, and initiatives such as 'AllTrials', there is an anticipated need for these resources. We conclude that small changes to the search interfaces, and improved dialogue with providers, might improve the future search functionality of these valuable resources.

Using the Cochrane Central Register of Controlled Trials to identify clinical trial registration is insufficient: a cross-sectional study

BACKGROUND

While conducting systemic reviews, searching for ongoing or unpublished trials is critical to address publication bias. As of April 2019, records of ongoing or unpublished randomized and/or quasi-randomized controlled trials registered in the International Clinical Trials Registry Platform (ICTRP) and ClinicalTrials.gov are available in the Cochrane Central Register of Controlled Trials (CENTRAL). These records registered in CENTRAL include studies published since the inception of ICTRP and ClinicalTrials.gov . Whether systematic reviewers can search CENTRAL to identify ongoing or unpublished trials instead of ICTRP and ClinicalTrials.gov is unknown.

METHODS

This was a cross-sectional study. A consecutive sample of ongoing or unpublished studies published from June 1, 2019 to December 27, 2019 was selected from the Cochrane Reviews. The sensitivity and the number needed to read (NNR) were assessed from among the studies selected from CENTRAL instead of ICTRP and ClinicalTrials.gov and also assessed the characteristics of studies not identified by searching CENTRAL.

RESULTS

In total, 247 records from 50 Cochrane reviews were included; of these, 200 were identified by searching CENTRAL, whereas the remaining 47 records were not. The sensitivity of searching CENTRAL was 0.81 (95% confidence interval [CI]: 0.76, 0.85). The NNR was 115 (95% CI: 101, 133). The 47 unidentified studies were registered through ClinicalTrials.gov or ICTRP. Sixteen unidentified studies were not indexed in CENTRAL.

CONCLUSIONS

For systematic reviewers, searching CENTRAL could not substitute for searching ClinicalTrials.gov and/or ICTRP. Systematic reviewers should not only search CENTRAL but also ICTRP and ClinicalTrials.gov to identify unpublished trials.

TRIAL REGISTRATION

A pre-specified protocol was applied to conduct this study. The study was registered in the University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR).

TRIAL REGISTRATION NUMBER

UMIN000038981 .

Evaluation of selective outcome reporting and trial registration practices among addiction clinical trials

BACKGROUND AND AIMS

Selective outcome reporting occurs when trialists pre-specify primary and secondary outcomes during trial planning but alter the definitions in the published report. Here, we investigate selective outcome reporting in published addiction randomized controlled trials (RCTs) and evaluate whether particular funding sources are associated with an increased likelihood of selective outcome reporting.

DESIGN

We conducted a cross-sectional study of published addiction clinical trials. A PubMed search was performed to identify RCTs in addiction journals from 2013 to 2017. Included studies used a randomized design to address one of the following topics: (1) drug, alcohol and tobacco addiction prevention, (2) stabilization following excessive use of a substance, (3) relapse prevention or (4) recovery maintenance.

SETTING

Single-center, medical research institution.

PARTICIPANTS

Our sample included 162 RCTs that were prospectively registered with a clearly defined primary outcome.

MEASUREMENT

We extracted the following items from addiction RCTs: journal, funding source, trial registry number (if included), sample size, dates of subject enrollment, whether primary and secondary outcomes were denoted, all published outcomes, P-value for all outcomes and whether authors mentioned any deviations from the trial protocol as it related to RCT outcomes.

FINDINGS

In total, 47 of 162 RCTs (29.0%) had at least one major discrepancy between the trial registry and published RCT. Overall, these 47 RCTs included 54 major discrepancies. The most common major discrepancy was demotion of a primary registered outcome (19/54, 35.2%). The majority of RCTs (132/162, 81.5%) were funded from public sources. Additionally, 166 RCTs were excluded from our sample because registration could not be confirmed.

CONCLUSIONS

There is evidence suggestive of selective outcome reporting in addiction randomized controlled trials (RCTs). The most common major discrepancies pertained to the primary outcome.

The association between registration status and reported outcomes in physiotherapy randomised controlled trials

Background/Aims

Clinical trial registration has been proposed as a method of mitigating selective reporting in scientific research. It remains unknown whether trial registration is associated with reported outcomes in physiotherapy trials. This study aimed to analyse the association between registration status and outcome (the rejection or acceptance of a primary null hypothesis) for physiotherapy randomised controlled trials.

Methods

All randomised controlled trials reporting a physiotherapy intervention in publications listed in PubMed between 1 January 2017 and 30 June 2017 were included. Trial registration was determined based on the reporting of a registration number in the primary article or by identifying trials through trial registries.

Results

Of the 291 trials analysed, 176 (60.5%) were registered; 115 (39.5%) were not. There was no significant association between trial registration and outcome on multivariate analyses (Odds Ratio 1.65; 95% Confidence Interval (0.92–2.96); P=0.09). Only 22% of trials were prospectively registered.

Conclusions

Registration status and trial outcome are not associated in randomised controlled trials of physiotherapy interventions. The rate of physiotherapy trial registration remains low.

Toolkit of methodological resources to conduct systematic reviews

Background: Systematic reviews (SR) can be classified by type depending on the research question they are based on. This work identifies and describes the most relevant methodological resources to conduct high-quality reviews that answer clinical questions regarding prevalence, prognosis, diagnostic accuracy and efficacy of interventions. Methods: Methodological resources have been identified from literature searches and consulting guidelines from institutions that develop SRs. The selected resources are organized by type of SR, and stage of development of the review (formulation of the research question, development of the protocol, literature search, risk of bias assessment, synthesis of findings, assessment of the quality of evidence, and report of SR results and conclusions). Results: Although the different types of SRs are developed following the same steps, each SR type requires specific methods, differing in characteristics and complexity. The extent of methodological development varies by type of SR, with more solid guidelines available for diagnostic accuracy and efficacy of interventions SRs. This methodological toolkit describes the most up-to-date risk of bias instruments: Quality in Prognostic Studies (QUIPS) tool and Prediction model study Risk Of Bias Assessment Tool (PROBAST) for prognostic SRs, Quality assessment of diagnostic accuracy studies tool (QUADAS-2) for diagnostic accuracy SRs, Cochrane risk of bias tool (ROB-2) and Risk of bias in non-randomised studies of interventions studies tool (ROBINS-I) for efficacy of interventions SRs, as well as the latest developments on the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. Conclusions: This structured compilation of the best methodological resources for each type of SR may prove to be a very useful tool for those researchers that wish to develop SRs or conduct methodological research works on SRs.

Toolkit of methodological resources to conduct systematic reviews

Background: Systematic reviews (SR) can be classified by type depending on the research question they are based on. This work identifies and describes the most relevant methodological resources to conduct high-quality reviews that answer health care questions regarding prevalence, prognosis, diagnostic accuracy and effects of interventions. Methods: Methodological resources have been identified from literature searches and consulting guidelines from institutions that develop SRs. The selected resources are organized by type of SR, and stage of development of the review (formulation of the research question, development of the protocol, literature search, risk of bias assessment, synthesis of findings, assessment of the quality of evidence, and report of SR results and conclusions). Results: Although the different types of SRs are developed following the same steps, each SR type requires specific methods, differing in characteristics and complexity. The extent of methodological development varies by type of SR, with more solid guidelines available for diagnostic accuracy and effects of interventions SRs. This methodological toolkit describes the most up-to-date risk of bias instruments: Quality in Prognostic Studies (QUIPS) tool and Prediction model study Risk Of Bias Assessment Tool (PROBAST) for prognostic SRs, Quality assessment of diagnostic accuracy studies tool (QUADAS-2) for diagnostic accuracy SRs, Cochrane risk of bias tool (ROB-2) and Risk of bias in non-randomised studies of interventions studies tool (ROBINS-I) for effects of interventions SRs, as well as the latest developments on the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. Conclusions: This structured compilation of the best methodological resources for each type of SR may prove to be a very useful tool for those researchers that wish to develop SRs or conduct methodological research works on SRs.

Toolkit of methodological resources to conduct systematic reviews

Background: Systematic reviews (SR) can be classified by type depending on the research question they are based on. This work identifies and describes the most relevant methodological resources to conduct high-quality reviews that answer health care questions regarding prevalence, prognosis, diagnostic accuracy and effects of interventions. Methods: Methodological resources have been identified from literature searches and consulting guidelines from institutions that develop SRs. The selected resources are organized by type of SR, and stage of development of the review (formulation of the research question, development of the protocol, literature search, risk of bias assessment, synthesis of findings, assessment of the quality of evidence, and report of SR results and conclusions). Results: Although the different types of SRs are developed following the same steps, each SR type requires specific methods, differing in characteristics and complexity. The extent of methodological development varies by type of SR, with more solid guidelines available for diagnostic accuracy and effects of interventions SRs. This methodological toolkit describes the most up-to-date risk of bias instruments: Quality in Prognostic Studies (QUIPS) tool and Prediction model study Risk Of Bias Assessment Tool (PROBAST) for prognostic SRs, Quality assessment of diagnostic accuracy studies tool (QUADAS-2) for diagnostic accuracy SRs, Cochrane risk of bias tool (ROB-2) and Risk of bias in non-randomised studies of interventions studies tool (ROBINS-I) for effects of interventions SRs, as well as the latest developments on the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. Conclusions: This structured compilation of the best methodological resources for each type of SR may prove to be a very useful tool for those researchers that wish to develop SRs or conduct methodological research works on SRs.

StudyPortal - Geovisualization of Study Research Networks

StudyPortal was implemented as the first multilingual search platform for geographic visualization of clinical trials and scientific articles. The platform queries information from ClinicalTrials.gov, PubMed, a geodatabase and geographic maps to enable geospatial study search and real-time rendering of study locations or research networks on a map. Thus, disease-specific clinical studies or whole research networks can be shown in a geographic proximity. Moreover, a semantic layer enables multilingual disease input and autosuggestion of medical terms based on the Unified Medical Language System. The portal is accessible on https://studyportal.uni-muenster.de. This paper presents details on implementation of the novel search platform, its search evaluation and future work.

Caffeic acid phenethyl ester (CAPE): pharmacodynamics and potential for therapeutic application

Caffeic acid phenethyl ester (CAPE) is the major pharmacologically-active component of some propolis types, rich in polyphenols, such as poplar propolis types. CAPE has the potential to be applied as a pharmaceutical as it possesses most of the pharmacological activities of propolis, such as anti-proliferative, antioxidant, immunomodulatory, antidiabetic, anti-inflammatory and antimicrobial. Its advantage is that it lacks some of the downsides of total propolis extracts, such as inability for unified standardization, which is cornerstone for implementing its therapeutic potential as a drug. The current paper provides an overview on the pharmacodynamic principles of CAPE. We present literature search outcomes form ClinicalTrials.gov database and from scientific publications, available on Scopus and Crossref databases. We take a round view of CAPE’s potential therapeutic implications in light of approved drugs with related modes of action.

Prevention of Ventilator-Associated and Early Postoperative Pneumonia Through Tapered Endotracheal Tube Cuffs: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

OBJECTIVE

Microaspiration of subglottic secretions is considered a major pathogenic mechanism of hospital-acquired pneumonia, either early postoperative or ventilator-associated pneumonia. Tapered endotracheal tube cuffs have been proposed to provide a better seal of the extraluminal airway, thereby preventing microaspiration and possibly hospital-acquired pneumonia. We performed a systematic review and meta-analysis to assess the value of endotracheal tubes with tapered cuffs in the prevention of hospital-acquired pneumonia.

DATA SOURCES

A systematic search of MEDLINE, EMBASE, CENTRAL/CCTR, ClinicalTrials.gov, and ICTRP was conducted up to March 2017.

STUDY SELECTION

Eligible trials were randomized controlled clinical trials comparing the impact of tapered cuffs versus standard cuffs on hospital-acquired pneumonia.

DATA EXTRACTION

Random-effects meta-analysis calculated odds ratio and 95% CI for hospital-acquired pneumonia occurrence rate between groups. Secondary outcome measures included mortality, duration of mechanical ventilation, length of hospital and ICU stay, and cuff underinflation.

DATA SYNTHESIS

Six randomized controlled clinical trials with 1,324 patients from intensive care and postoperative wards were included. Only two studies concomitantly applied subglottic secretion drainage, and no trial performed continuous cuff pressure monitoring. No significant difference in hospital-acquired pneumonia incidence per patient was found when tapered cuffs were compared with standard cuffs (odds ratio, 0.97; 95% CI, [0.73-1.28]; p = 0.81). There were likewise no differences in secondary outcomes.

CONCLUSIONS

Application of tapered endotracheal tube cuffs did not reduce hospital-acquired pneumonia incidence among ICU and postoperative patients. Further research should examine the impact of concomitant use of tapered cuffs with continuous cuff pressure monitoring and subglottic secretion drainage.

From clinical practice guideline development to trial registration: A systematic investigation of research pipeline for inflammatory bowel disease

BACKGROUND

Clinical practice guidelines help practitioners manage patients in an effective and systematic way, and they assist in making evidence-based decisions related to diagnosis and treatment. Each recommendation is ranked based on evidence. The goal of this study is to determine gaps in research for inflammatory bowel diseases (IBD) by using the low-level evidence recommendations.

METHODS

We extracted low-level evidence recommendations set forth by the American College of Gastroenterology in IBD, ulcerative colitis (UC), and Crohn's disease. ClinicalTrials.gov , the World Health Organization's International Clinical Trials Registry Platform and PubMed were then used to locate studies relevant to the recommendations.

RESULTS

There were 30 low-level evidence recommendations, and 23 had recent or ongoing studies addressing them. We screened 2938 trials and 4321 published articles, 221 of which addressed low-quality recommendations. There were five recommendations that received the majority of research attention (143/221, 65%).

CONCLUSION

This study used clinical practice guidelines to help determine areas of needed research in IBD, UC, and Crohn's disease. By searching trial registries and articles indexed on PubMed, we identified the extent to which studies were being conducted to address research gaps. Of the gaps identified, five recommendations received most of the attention. While most of the significant gaps had some recent or ongoing research, our study found several areas where investigation is still needed. Clinical practice guidelines are an effective method to prioritize future research.

An Evaluation of the Rotator Cuff Repair Research Pipeline

BACKGROUND

We conducted a study of recommendations from the American Academy of Orthopaedic Surgeons (AAOS) guideline, "Optimizing the Management of Rotator Cuff Problems." Using these recommendations, we conducted searches of clinical trial registries and bibliographic databases to note the extent to which new research has been undertaken to address areas of deficiency.

HYPOTHESIS

Newly conducted research regarding rotator cuff repair and injury is available that will fill knowledge gaps identified by the AAOS guideline.

STUDY DESIGN

Cross-sectional study.

METHODS

For each recommendation in the AAOS guideline, we created PICO (participants, intervention, comparator, outcome) questions and search strings. Searches were conducted of ClinicalTrials.gov, the World Health Organization's International Clinical Trials Registry Platform, MEDLINE via PubMed, and EMBASE to locate studies undertaken after the final literature search performed by the AAOS work group.

RESULTS

We located 210 newly registered trials and 448 published studies that are relevant to the recommendations made in the rotator cuff guideline. The majority of the recommendations have been addressed by relevant registered trials or published studies. Of the 448 published studies, 185 directly addressed the guideline recommendations. Additionally, 71% of the 185 published studies directly addressing the recommendations were randomized trials or systematic reviews/meta-analyses. The most important finding of our study was that the recommendations in the AAOS rotator cuff guideline have been adequately addressed.

CONCLUSION

Orthopaedic researchers have adequately addressed knowledge gaps regarding rotator cuff repair treatment and management options. As such, the AAOS may consider a guideline update to ensure that recommendations reflect current findings in orthopaedic literature.

Registration of published randomized trials: a systematic review and meta-analysis

BACKGROUND

Prospective trial registration is a powerful tool to prevent reporting bias. We aimed to determine the extent to which published randomized controlled trials (RCTs) were registered and registered prospectively.

METHODS

We searched MEDLINE and EMBASE from January 2005 to October 2017; we also screened all articles cited by or citing included and excluded studies, and the reference lists of related reviews. We included studies that examined published RCTs and evaluated their registration status, regardless of medical specialty or language. We excluded studies that assessed RCT registration status only through mention of registration in the published RCT, without searching registries or contacting the trial investigators. Two independent reviewers blinded to the other's work performed the selection. Following PRISMA guidelines, two investigators independently extracted data, with discrepancies resolved by consensus. We calculated pooled proportions and 95% confidence intervals using random-effects models.

RESULTS

We analyzed 40 studies examining 8773 RCTs across a wide range of clinical specialties. The pooled proportion of registered RCTs was 53% (95% confidence interval 44% to 58%), with considerable between-study heterogeneity. A subset of 24 studies reported data on prospective registration across 5529 RCTs. The pooled proportion of prospectively registered RCTs was 20% (95% confidence interval 15% to 25%). Subgroup analyses showed that registration was higher for industry-supported and larger RCTs. A meta-regression analysis across 19 studies (5144 RCTs) showed that the proportion of registered trials significantly increased over time, with a mean proportion increase of 27%, from 25 to 52%, between 2005 and 2015.

CONCLUSIONS

The prevalence of trial registration has increased over time, but only one in five published RCTs is prospectively registered, undermining the validity and integrity of biomedical research.

Outcome of kinematic alignment using patient-specific instrumentation versus mechanical alignment in TKA: a meta-analysis and subgroup analysis of randomised trials

INTRODUCTION

Kinematic alignment (KA) in total knee arthroplasty (TKA) matches component position to the pre-arthritic anatomy of an individual patient, with the aim of improving functional outcomes. Recent randomised controlled trials (RCTs) comparing KA to traditional neutral mechanical alignment (MA) have been mixed. This collaborative study combined raw data from RCTs, aiming to compare functional outcomes between KA using patient-specific instrumentation (PSI) and MA, and whether any patient subgroups may benefit more from KA technique.

MATERIALS AND METHODS

A literature search in PubMed, EMBASE and Cochrane databases identified four randomised controlled trials comparing patients undergoing TKA using PSI-KA and MA. Unpublished data including Western Ontario McMaster Universities Arthritis Index (WOMAC) and Knee Society Score (KSS) were obtained from study authors. Meta-analysis compared MA to KA change (post-op minus pre-op) scores. Subgroup-analysis on KA patients looked for subgroups more likely to benefit from KA and the impact of PSI accuracy.

RESULTS

Meta-analyses of change scores in 229 KA patients versus 229 MA patients were no different from WOMAC (mean difference 3.4; 95% confidence interval - 0.5 to 7.3), KSS function (1.3, - 3.9 to 6.4) or KSS combined (7.2, - 0.8 to 15.2). A small advantage was seen for KSS pain in the KA group (3.6, 95% CI 0.2-7.1). Subgroup-analysis showed no difference between varus, valgus and neutral pre-operative alignment groups, and those who did and did not achieve KA plans. Pain-free patients at 1-year were more likely to achieve KA plans.

CONCLUSION

Patient-reported outcome scores following TKA using PSI-KA are similar to MA. No identifiable subgroups benefited more from KA, and long-term results remain unknown. Inaccuracy of the PSI system used in KA patients could potentially affect outcome.

Is the Right Research Being Conducted to Advance Knowledge about Breast Reconstruction? An Analysis of the Research Pipeline

BACKGROUND

It has been estimated that up to 85 percent of research is of limited value or wasted, in part because of the wrong research questions being addressed. In this study, the authors identified research gaps for breast reconstruction using guideline recommendations based on low-quality or no evidence. The authors then evaluated whether research was currently being conducted to fill these gaps.

METHODS

The authors extracted grade C and D options, which are based on limited evidence, from the American Society of Plastic Surgeon's clinical practice guideline for breast reconstruction. For each option, the authors created Participants, Intervention, Comparator, Outcome questions and search strings using a systematic process. Searches were conducted of ClinicalTrials.gov and the World Health Organization's International Clinical Trials Registry Platform to locate new and ongoing studies. The authors also catalogued studies on breast reconstruction funded by the Plastic Surgery Foundation.

RESULTS

Of the 10 research gaps, only six were being addressed by new and ongoing research. Timing of reconstruction (immediate or delayed) and use of acellular dermal matrix were most frequently studied. Preoperative referral of a plastic surgeon before mastectomy, complications associated with preoperative breast size, effects of hormone therapy on postoperative outcomes, and methods for detecting local recurrence after mastectomy were not being addressed by new research. Studies funded by the Plastic Surgery Foundation showed a similar pattern.

CONCLUSIONS

Of the areas identified, some have received more attention than others. Gaps remain. The authors' results should spark interest in conducting research on these topics and, by so doing, strengthen the clinical practice guideline recommendations.

Research Gaps in Wilderness Medicine

INTRODUCTION

Wilderness medicine involves the treatment of individuals in remote, austere environments. Given the high potential for injuries as well as the unique treatment modalities required in wilderness medicine, evidence-based clinical practice guidelines are necessary to provide optimal care. In this study, we identify evidence gaps from low-quality recommendations in wilderness medicine clinical practice guidelines and identify new/ongoing research addressing them.

METHODS

We included relevant clinical practice guidelines from the Wilderness Medical Society and obtained all 1C or 2C level recommendations. Patient/Problem/Population, intervention, comparison, outcome (PICO) questions were created to address each recommendation. Using 24 search strings, we extracted titles, clinical trial registry number, and recruitment status for 8899 articles. We categorized the articles by trial design to infer the effect they may have on future recommendations.

RESULTS

Twelve clinical practice guidelines met inclusion criteria. From these we located 275 low-quality recommendations and used them to create 275 PICO questions. Thirty-three articles were relevant to the PICO questions. Heat-related illness had the highest number of relevant articles (n=9), but acute pain and altitude sickness had the most randomized clinical trials (n=6).

CONCLUSION

Overall, few studies were being conducted to address research gaps in wilderness medicine. Heat-related illness had the most new or ongoing research, whereas no studies were being conducted to address gaps in eye injuries, basic wound management, or spine immobilization. Animals, cadavers, and mannequin research are useful in cases in which human evidence is difficult to obtain. Establishing research priorities is recommended for addressing research gaps identified by guideline panels.

A review of research efforts to address the 2008 ACEP guideline for mild traumatic brain injury

BACKGROUND

The objective of this study was to evaluate the temporal relationship between clinical practice guideline development and subsequent research performed, with the goal of providing more data on areas of sparse evidence that serve to underlie guideline recommendations. We aimed to assess the quality of current research efforts to address the American College of Emergency Physicians guideline and to provide suggestions for future research of mild traumatic brain injury.

METHODS

We identified clinical practice guideline recommendations with low levels of underlying evidence and searched ClinicalTrials.gov and the World Health Organization's International Clinical Trial Registry Portal to determine whether subsequent research has reflected an effort to address guideline recommendations.

RESULTS

Few currently registered clinical trials attempt to focus on clinical practice guideline recommendations where the basis of evidence is weak, and even fewer might benefit future iterations of the guideline due to multiple problems in study design and reporting.

CONCLUSIONS

The amount of research dedicated to investigation of mild traumatic brain injury continues to be sparse and of poor quality. Study results should always be posted, even if the null hypothesis is confirmed. Efforts to improve the evidence base of a guideline should be realized by designing studies that directly assess and speak to the questions posed by guideline authors.

Roles for librarians in systematic reviews: a scoping review

Objective

What roles do librarians and information professionals play in conducting systematic reviews? Librarians are increasingly called upon to be involved in systematic reviews, but no study has considered all the roles librarians can perform. This inventory of existing and emerging roles aids in defining librarians’ systematic reviews services.

Methods

For this scoping review, the authors conducted controlled vocabulary and text-word searches in the PubMed; Library, Information Science & Technology Abstracts; and CINAHL databases. We separately searched for articles published in the Journal of the European Association for Health Information and Libraries, Evidence Based Library and Information Practice, the Journal of the Canadian Heath Libraries Association, and Hypothesis. We also text-word searched Medical Library Association annual meeting poster and paper abstracts.

Results

We identified 18 different roles filled by librarians and other information professionals in conducting systematic reviews from 310 different articles, book chapters, and presented papers and posters. Some roles were well known such as searching, source selection, and teaching. Other less documented roles included planning, question formulation, and peer review. We summarize these different roles and provide an accompanying bibliography of references for in-depth descriptions of these roles.

Conclusion

Librarians play central roles in systematic review teams, including roles that go beyond searching. This scoping review should encourage librarians who are fulfilling roles that are not captured here to document their roles in journal articles and poster and paper presentations.

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.

Trial registry searches for randomized controlled trials of new drugs required registry-specific adaptation to achieve adequate sensitivity

OBJECTIVES

To analyze the availability of randomized controlled trials (RCTs) of new drugs in trial registries and to develop and test different search strategies in ClinicalTrials.gov (CT.gov), the EU Clinical Trials Register (EU-CTR), and the International Clinical Trials Registry Platform (ICTRP).

STUDY DESIGN AND SETTING

Information from dossiers submitted by pharmaceutical companies was analyzed regarding the registration of the included RCTs in CT.gov, EU-CTR and ICTRP; different search strategies were developed and tested to determine performance.

RESULTS

A total of 192 (95%) of 203 RCTs on newly approved drugs were registered in CT.gov; the 11 nonregistered trials were completed before 2005 or represented non-RCTs. Simple searches for RCTs on 18 new drugs using the generic drug name yielded a sensitivity of 94% in CT.gov (EU-CTR: 71%; ICTRP: 60%). The main reason for study nondetection was the sole use of the drug code in the registry entries. Simple searches for RCTs on 13 conditions using reasonably inferred search terms yielded a sensitivity of 100% in CT.gov.

CONCLUSION

Almost all relevant RCTs on newly approved drugs will probably be identified in CT.gov alone. A sensitive search in CT.gov can be conducted using single search terms. The searches in ICTRP and EU-CTR should include several search terms (e.g., derived via text analysis).

Selective outcome reporting in obesity clinical trials: a cross-sectional review

Selective outcome reporting is a form of bias resulting from discrepancies between outcomes presented in a trial's registration and the published report. We investigate this selective bias in obesity clinical trials. A PubMed search was conducted to identify randomized controlled trials (RCTs) published in four obesity journals from 2013 to 2015. Primary, secondary and tertiary outcomes were recorded for each trial and compared to pre-specified outcomes in each trial's registration. Of the 392 identified articles, 142 were included in the final analysis; 22 (15%) RCTs demonstrated major outcome discrepancies between registration and publication: No primary outcomes were demoted to a secondary or tertiary outcome; 14 (36.84%) primary outcomes were omitted; 14 (36.84%) primary outcomes were added: 5 (13.16%) secondary outcomes were upgraded to primary outcomes; and timing of assessment for a primary outcome changed 5 (13.16%) times. Out of the 63 prospectively registered studies, 53 had no discrepancies. A total of 76 of the studies (29.80%) were unregistered or did not have an associated registration number. Our results suggest that selective outcome reporting may be a concern in obesity clinical trials. As selective outcome reporting may distort clinical findings and limit outcomes in systematic reviews, we encourage trialists and journal editors to work towards solutions to mitigate this issue.

Evidence of selective reporting bias in hematology journals: A systematic review

Introduction

Selective reporting bias occurs when chance or selective outcome reporting rather than the intervention contributes to group differences. The prevailing concern about selective reporting bias is the possibility of results being modified towards specific conclusions. In this study, we evaluate randomized controlled trials (RCTs) published in hematology journals, a group in which selective outcome reporting has not yet been explored.

Methods

Our primary goal was to examine discrepancies between the reported primary and secondary outcomes in registered and published RCTs concerning hematological malignancies reported in hematology journals with a high impact factor. The secondary goals were to address whether outcome reporting discrepancies favored statistically significant outcomes, whether a pattern existed between the funding source and likelihood of outcome reporting bias, and whether temporal trends were present in outcome reporting bias. For trials with major outcome discrepancies, we contacted trialists to determine reasons for these discrepancies. Trials published between January 1, 2010 and December 31, 2015 in Blood; British Journal of Haematology; American Journal of Hematology; Leukemia; and Haematologica were included.

Results

Of 499 RCTs screened, 109 RCTs were included. Our analysis revealed 118 major discrepancies and 629 total discrepancies. Among the 118 discrepancies, 30 (25.4%) primary outcomes were demoted, 47 (39.8%) primary outcomes were omitted, and 30 (25.4%) primary outcomes were added. Three (2.5%) secondary outcomes were upgraded to a primary outcome. The timing of assessment for a primary outcome changed eight (6.8%) times. Thirty-one major discrepancies were published with a P-value and twenty-five (80.6%) favored statistical significance. A majority of authors whom we contacted cited a pre-planned subgroup analysis as a reason for outcome changes.

Conclusion

Our results suggest that outcome changes occur frequently in hematology trials. Because RCTs ultimately underpin clinical judgment and guide policy implementation, selective reporting could pose a threat to medical decision making.

Improving the adaptability of WHO evidence-informed guidelines for nutrition actions: results of a mixed methods evaluation

BACKGROUND

Over the past decade, the World Health Organization (WHO) has implemented a standardized, evidence-informed guideline development process to assure technically sound and policy-relevant guidelines. This study is an independent evaluation of the adaptability of the guidelines produced by the Evidence and Programme Guidance unit, at the Department of Nutrition for Health and Development (NHD). The study systematizes the lessons learned by the NHD group at WHO.

METHODS

We used a mixed methods approach to determine the adaptability of the nutrition guidelines. Adaptability was defined as having two components; methodological quality and implementability of guidelines. Additionally, we gathered recommendations to improve future guideline development in nutrition actions for health and development. Data sources for this evaluation were official documentation and feedback (both qualitative and quantitative) from key stakeholders involved in the development of nutrition guidelines. The qualitative data was collected through a desk review and two waves of semi-structured interviews (n = 12) and was analyzed through axial coding. Guideline adaptability was assessed quantitatively using two standardized instruments completed by key stakeholders. The Appraisal Guideline for Research and Evaluation questionnaire, version II was used to assess guideline quality (n = 6), while implementability was assessed with the electronic version of the GuideLine Implementability Appraisal (n = 7).

RESULTS

The nutrition evidence-informed guideline development process has several strengths, among them are the appropriate management of conflicts of interest of guideline developers and the systematic use of high-quality evidence to inform the recommendations. These features contribute to increase the methodological quality of the guidelines. The key areas for improvement are the limited implementability of the recommendations, the lack of explicit and precise implementation advice in the guidelines and challenges related to collaborative work within interdisciplinary groups.

CONCLUSIONS

Overall, our study found that the nutrition evidence-informed guidelines are of good methodological quality but that the implementability requires improvement. The recommendations to improve guideline adaptability address the guideline content, the dynamics shaping interdisciplinary work, and actions for implementation feasibility. As WHO relies heavily on a standardized procedure to develop guidelines, the lessons learned may be applicable to guideline development across the organization and to other groups developing guidelines.