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BACKGROUND: Since 2005, International Committee of Medical Journal Editors (ICMJE) member journals have required that clinical trials be registered in publicly available trials registers before they are considered for publication.
OBJECTIVES: The research explores whether it is adequate, when searching to inform systematic reviews, to search for relevant clinical trials using only public trials registers and to identify the optimal search approaches in trials registers.
METHODS: A search was conducted in ClinicalTrials.gov and the International Clinical Trials Registry Platform (ICTRP) for research studies that had been included in eight systematic reviews. Four search approaches (highly sensitive, sensitive, precise, and highly precise) were performed using the basic and advanced interfaces in both resources.
RESULTS: On average, 84% of studies were not listed in either resource. The largest number of included studies was retrieved in ClinicalTrials.gov and ICTRP when a sensitive search approach was used in the basic interface. The use of the advanced interface maintained or improved sensitivity in 16 of 19 strategies for Clinicaltrials.gov and 8 of 18 for ICTRP. No single search approach was sensitive enough to identify all studies included in the 6 reviews.
CONCLUSIONS: Trials registers cannot yet be relied upon as the sole means to locate trials for systematic reviews. Trials registers lag behind the major bibliographic databases in terms of their search interfaces.
IMPLICATIONS: For systematic reviews, trials registers and major bibliographic databases should be searched. Trials registers should be searched using sensitive approaches, and both the registers consulted in this study should be searched.
BACKGROUND: Search filters or hedges are search strategies developed to assist information specialists and librarians to retrieve different types of evidence from bibliographic databases. The objectives of this project were to learn about searchers' filter use, how searchers choose search filters and what information they would like to receive to inform their choices.
METHODS: Interviews with information specialists working in, or for, the National Institute for Health and Care Excellence (NICE) were conducted. An online questionnaire survey was also conducted and advertised via a range of email lists.
RESULTS: Sixteen interviews were undertaken and 90 completed questionnaires were received. The use of search filters tends to be linked to reducing a large amount of literature, introducing focus and assisting with searches that are based on a single study type. Respondents use numerous ways to identify search filters and can find choosing between different filters problematic because of knowledge gaps and lack of time.
CONCLUSIONS: Search filters are used mainly for reducing large result sets (introducing focus) and assisting with searches focused on a single study type. Features that would help with choosing filters include making information about filters less technical, offering ratings and providing more detail about filter validation strategies and filter provenance.
We explored the value of handsearching to identify diagnostic test accuracy (DTA) studies to inform systematic reviews of DTA. Handsearching was conducted alongside a systematic review of the DTA of 18F-fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET-CT) for colorectal cancer. Ten journals, identified by frequency analysis of studies from six imaging reviews, were handsearched for reports of DTA studies. The numbers of studies identified by handsearching and by database searching were compared. A total of 573 journal issues from ten journals were handsearched in 185 h. A total of 936 potential reports of DTA studies were identified: 25 were relevant to the FDG PET-CT review. 7/25 FDG PET-CT papers had not been identified by database searches. No papers met the systematic review inclusion criteria. The FDG-PET systematic review included 30 papers, from 24 different journals. Handsearching two of those journals identified 211 potential reports of DTA studies for all topics and 18 for FDG PET-CT. Handsearching identified previously unseen papers but did not yield unique relevant DTA studies for the specific review. DTA imaging studies are widely distributed, and it may be more efficient to choose journals to handsearch after the identification of some relevant studies.
Regulation (EC) No 178/2002 recommends that risk assessments are undertaken by the European Food Safety Authority (EFSA) in an independent, objective and transparent manner, on the basis of all available scientific information and data. The systematic review (SR) method implemented by EFSA to inform risk assessment models ensures a methodologically rigorous stepwise process, minimising biases and emphasising transparency and reproducibility. To minimise bias, SRs include an extensive literature search. Locating all relevant information sources can be problematic and missing relevant scientific information may influence SR conclusions. The EFSA Scientific Assessment Support Unit contracted YHEC (CFT/EFSA/SAS/2011/03) to produce five deliverables to support literature searching to inform SRs of food and feed safety. This report describes the development of an inventory of information sources of relevance to systematic reviews of food and feed safety. The inventory uses a metadata schema to record information about each information source. 376 candidate information sources were identified from the EFSA SAS inventory of information sources and other catalogues and websites. The selection of information sources to include in the EFSA inventory were determined using selection criteria (1) relevance to EFSA research areas (2) currency of information in the information source (3) provision of searchable bibliographic data records or full text reports of research and (4) be accessible to EFSA staff. Metadata were identified and recorded in an Excel spreadsheet for the 199 information sources meeting these four criteria.
BACKGROUND: Intervention and treatment in Alzheimer's disease dementia (AD-dementia) can be cost effective but the majority of patients are not diagnosed in a timely manner. Technology is now available that can enable the earlier detection of cognitive loss associated with incipient dementia, offering the potential for earlier intervention in the UK health care system. This study aimed to determine to what extent the timing of an intervention affects its cost-effectiveness.
METHODS: Using published data describing cognitive decline in the years prior to an AD diagnosis, we modelled the effects on healthcare costs and quality-adjusted life years of hypothetical symptomatic and disease-modifying interventions. Early and standard interventions were assumed to have equal clinical effects, but the early intervention could be applied up to eight years prior to standard diagnosis.
RESULTS: A symptomatic treatment which immediately improved cognition by one MMSE point and reduced in efficacy over three years, would produce a maximum net benefit when applied at the earliest timepoint considered, i.e. eight years prior to standard diagnosis. In this scenario, the net benefit was reduced by around 17% for every year that intervention was delayed. In contrast, for a disease-modifying intervention which halted cognitive decline for one year, economic benefits would peak when treatment effects were applied two years prior to standard diagnosis. In these models, the maximum net benefit of the disease modifying intervention was fifteen times larger than that of the symptomatic treatment.
CONCLUSION: Timeliness of intervention is likely to have an important impact on the cost-effectiveness of both current and future treatments. Healthcare policy should aim to optimise the timing of AD-dementia diagnosis, which is likely to necessitate detecting and treating patients several years prior to current clinical practice.
OBJECTIVE: This study compares the cost-effectiveness of intravitreal ranibizumab vs observation and/or laser photocoagulation for treatment of macular edema secondary to retinal vein occlusion in a UK-based model.
METHODS: A Markov model was constructed using transition probabilities and frequency of adverse events derived using data from the BRAVO, CRUISE, and HORIZON trials. Outcomes associated with treatments and health states were combined to predict overall health costs and outcomes for cohorts treated with each option.
RESULTS: In branch retinal vein occlusion, ranibizumab produced a gain of 0.518 quality-adjusted life years at an incremental cost of £8141, compared with laser photocoagulation. The incremental cost-effectiveness ratio was £15,710 per quality-adjusted life year, and the incremental cost per month free from blindness was £658. In central retinal vein occlusion, ranibizumab produced a gain of 0.539 quality-adjusted life years at an incremental cost of £9216, compared with observation only. The incremental cost-effectiveness ratio was £17,103, and the incremental cost per month free from blindness was £423.
CONCLUSIONS: These incremental cost-effectiveness ratios are below the £20,000-30,000 range typically accepted as a threshold for cost-effectiveness. This suggests that ranibizumab may be regarded as a cost-effective therapy for patients with macular edema secondary to retinal vein occlusion, relative to grid laser photocoagulation (for BRVO) and observation (for CRVO). Limitations include sparse data for utilities associated with the severity of visual impairment in the WSE in patients with RVO. A lack of direct comparative evidence between ranibizumab and the dexamethasone intravitreal implant for the treatment of BRVO and CRVO and the infeasibility of an indirect comparison due to significant heterogeneity in trial designs prevented the inclusion of this treatment as a comparator in the Markov model.
BACKGROUND: Grass pollen-induced rhinoconjunctivitis is a common allergic respiratory disorder affecting over 20% of the UK population in terms of quality of life and sleep, work, and school patterns. The SQ-standardized grass allergy immunotherapy tablet (AIT) has been demonstrated as a disease-modifying treatment which gives a sustained effect even after completion of a treatment course. The objective of this study was to provide an economic assessment of whether treatment with the SQ-standardized grass AIT, Grazax® (Phleum pratense) in combination with symptomatic medications is preferable to the standard of care using symptomatic medications only. The analysis was performed for children with grass pollen-induced rhinoconjunctivitis, with or without concomitant asthma, in the UK.
METHODS: The model evaluated the two treatment regimens in a cohort of 1,000 children from a payer's perspective. Treatment was modeled in terms of management of symptoms, impact on resource use, and development of allergic asthma. The analysis modeled the use of SQ-standardized grass AIT and the sustained effects of treatment over a 9-year time horizon (ie, 3 years of treatment, with modeled long-term benefits). Data inputs were drawn from a recent clinical trial, published studies, and databases.
RESULTS: SQ-standardized grass AIT improves patient outcomes, generating an incremental cost per quality-adjusted life year gained of £12,168. This is below commonly accepted thresholds in the UK.
CONCLUSION: The resulting incremental cost per QALY falls below commonly accepted willingness to pay thresholds. Therefore, the SQ-standardized grass AIT is a cost-effective option for the treatment of grass pollen-induced rhinoconjunctivitis in the UK pediatric population.
