Christopher Hyde - Academia.edu (original) (raw)

Papers by Christopher Hyde

Pediatric Allergy and Immunology

Blood

Background: Epoetin (EPO), darbepoetin (DARB) and red blood cell transfusions (RBCT) are therapeu... more Background: Epoetin (EPO), darbepoetin (DARB) and red blood cell transfusions (RBCT) are therapeutic alternatives to treat anemia associated with cancer and cancer therapy. Results of randomized controlled trials (RCTs) conflict, and some question the safety of EPO and DARB. Previously, we systematically reviewed this topic (Bohlius et al, JNCI 2005). Since then many new studies became available necessitating an update the prior systematic review. Objectives: To determine the effectiveness and safety of recombinant human erythropoietin and darbepoetin to prevent or alleviate anemia in cancer patients (pts), and to compare current and previous results of systematic review. Methods: Included RCTs compared EPO or DARB plus RBCT if needed with observation plus RBCT for prophylaxis or treatment of anemia in cancer patients receiving or not receiving antineoplastic therapy. Patients had solid tumors or hematological malignancies including MDS. Endpoints were rates of RBCT, hematological r...

Diabetologia, Dec 18, 2018

Treatment change following a genetic diagnosis of MODY is frequently indicated, but little is kno... more Treatment change following a genetic diagnosis of MODY is frequently indicated, but little is known about the factors predicting future treatment success. We therefore conducted the first prospective study to determine the impact of a genetic diagnosis on individuals with GCK-, HNF1A- or HNF4A-MODY in the UK, and to identify clinical characteristics predicting treatment success (i.e. HbA ≤58 mmol/mol [≤7.5%]) with the recommended treatment at 2 years. This was an observational, prospective, non-selective study of individuals referred to the Exeter Molecular Genetic Laboratory for genetic testing from December 2010 to December 2012. Individuals from the UK with GCK- or HNF1A/HNF4A-MODY who were not on recommended treatment at the time of genetic diagnosis, and who were diagnosed below the age of 30 years and were currently aged less than 50 years, were eligible to participate. A total of 44 of 58 individuals (75.9%) changed treatment following their genetic diagnosis. Eight individua...

Value in Health

To suggest alterations to cost-effectiveness models of biologics for moderate to severe psoriasis... more To suggest alterations to cost-effectiveness models of biologics for moderate to severe psoriasis that would account for the utility of partial responders. METHODS: Clinical guidelines dictate that, for the continuation of a biologic in treatment of moderate to severe psoriasis, a 75% improvement from baseline on the Psoriasis Area Severity Index (PASI) must be achieved which serves as a Minimum Clinical Endpoint (MCE). However, patients achieving a PASI 50% improvement may also continue treatment if supplemented by a minimally important difference (MID) in health-related quality of life (5-point improvement on the Dermatology Life Quality Index (DLQI)). Since costeffectiveness models of biologic medications for treatment of psoriasis do not account for the utility of any patients achieving a PASI 50% improvement, a systematic review was conducted to identify whether patients achieving a PASI 50% improvement also achieved a 5-point DLQI improvement in large RCTs. Statistical inference from data obtained therein was used to modify equations used in cost-effectiveness calculations. RESULTS: The systematic review returned 8 studies that reported DLQI improvements in terms of Mean ± SD, stratified by increasing PASI response. Each study returned mean DLQI scores for patients with a PASI 50% improvement that were within one standard deviation of a 5-point DLQI improvement. This finding drove proposed alterations in which patients with a PASI 50% improvement are counted as "partial responders" or "non-responders" based on the probability of whether or not a 5-point DLQI improvement was attained. CONCLUSIONS: The literature confirms that patients with severe psoriasis can achieve a MID in DLQI improvement without achieving an MCE in PASI improvement. This study proposes alterations to the methodology of cost-effectiveness calculations that recognize the meaningful improvement in outcomes achieved by this subset of patients. Nevertheless, future studies should examine how these alterations affect overall costeffectiveness of biologics for psoriasis.

Journal of clinical epidemiology, Jan 28, 2017

Motivated by recent calls to use electronic health records for research, we reviewed the applicat... more Motivated by recent calls to use electronic health records for research, we reviewed the application and development of methods for addressing the bias from unmeasured confounding in longitudinal data. Methodological review of existing literature. We searched MEDLINE and EMBASE for articles addressing the threat to causal inference from unmeasured confounding in nonrandomized longitudinal health data through quasi-experimental analysis. Among the 121 studies included for review, 84 used instrumental variable analysis (IVA), of which 36 used lagged or historical instruments. Difference-in-differences (DiD) and fixed effects (FE) models were found in 29 studies. Five of these combined IVA with DiD or FE to try to mitigate for time-dependent confounding. Other less frequently used methods included prior event rate ratio adjustment, regression discontinuity nested within pre-post studies, propensity score calibration, perturbation analysis, and negative control outcomes. Well-establishe...

European journal of radiology, 2017

To determine the diagnostic accuracy of lung nodule detection in thoracic CT using 2 reduced dose... more To determine the diagnostic accuracy of lung nodule detection in thoracic CT using 2 reduced dose protocols comparing 3 available CT reconstruction algorithms (filtered back projection-FBP, adaptive statistical reconstruction-ASIR and model-based iterative reconstruction-MBIR) in a western population. A prospective single-center study recruited 98 patients with written consent. Standard dose (STD) thoracic CT followed by 2 reduced-dose protocols using automatic tube current modulation (RD1) and fixed tube current (RD2) were performed and reconstructed with FBP, ASIR and MBIR with subsequent diagnostic accuracy analysis for nodule detection. 108 solid nodules, 47 subsolid nodules and 89 purely calcified nodules were analyzed. RD1 was superior to RD2 for assessment of solid nodules ≤4mm, and subsolid nodules ≤5mm (p<0.05). Deterioration of RD2 is correlated to patient's body mass index and least affected by MBIR. For solid nodules ≤4mm, MBIR area under curve (AUC) for RD1 was 0...

BMC anesthesiology, Oct 1, 2016

Peripheral venous cannulation is an everyday practice in hospitals, which many adults find painfu... more Peripheral venous cannulation is an everyday practice in hospitals, which many adults find painful. However, anaesthesia for cannulation is usually only offered to children. Inadequate pain relief is not only unpleasant for patients but may cause anxiety about further treatment and deter patients from seeking medical care in the future. The aim of this study is to discover the most effective local anaesthetic for adult peripheral venous cannulation and to find out how the pain of local anaesthetic application compares with that of unattenuated cannulation. These aims are addressed through a systematic review, network meta-analysis and random-effects meta-analysis. Searching covered 12 databases including MEDLINE and EMBASE from 1990 to August 2015. The main included study design was RCTs. The primary outcome measure is self-reported pain, measured on a 100 mm visual analogue scale. The systematic review found 37 includable studies, 27 of which were suitable for network meta-analysis...

BMC Medical Research Methodology, 2016

Background: When data needed to inform parameters in decision models are lacking, formal elicitat... more Background: When data needed to inform parameters in decision models are lacking, formal elicitation of expert judgement can be used to characterise parameter uncertainty. Although numerous methods for eliciting expert opinion as probability distributions exist, there is little research to suggest whether one method is more useful than any other method. This study had three objectives: (i) to obtain subjective probability distributions characterising parameter uncertainty in the context of a health technology assessment; (ii) to compare two elicitation methods by eliciting the same parameters in different ways; (iii) to collect subjective preferences of the experts for the different elicitation methods used. Methods: Twenty-seven clinical experts were invited to participate in an elicitation exercise to inform a published model-based cost-effectiveness analysis of alternative treatments for prostate cancer. Participants were individually asked to express their judgements as probability distributions using two different methodsthe histogram and hybrid elicitation methodspresented in a random order. Individual distributions were mathematically aggregated across experts with and without weighting. The resulting combined distributions were used in the probabilistic analysis of the decision model and mean incremental cost-effectiveness ratios and the expected values of perfect information (EVPI) were calculated for each method, and compared with the original cost-effectiveness analysis. Scores on the ease of use of the two methods and the extent to which the probability distributions obtained from each method accurately reflected the expert's opinion were also recorded. Results: Six experts completed the task. Mean ICERs from the probabilistic analysis ranged between £162,600-£175,500 per quality-adjusted life year (QALY) depending on the elicitation and weighting methods used. Compared to having no information, use of expert opinion decreased decision uncertainty: the EVPI value at the £30,000 per QALY threshold decreased by 74-86 % from the original cost-effectiveness analysis. Experts indicated that the histogram method was easier to use, but attributed a perception of more accuracy to the hybrid method. Conclusions: Inclusion of expert elicitation can decrease decision uncertainty. Here, choice of method did not affect the overall cost-effectiveness conclusions, but researchers intending to use expert elicitation need to be aware of the impact different methods could have.

... for reading disability: A systematic review Esther Albon, Yaser Adi & Chris Hyde Depa... more ... for reading disability: A systematic review Esther Albon, Yaser Adi & Chris Hyde Department of Public Health and Epidemiology ... Authors: Esther Albon, Systematic Reviewer Yaser Adi, Systematic Reviewer Chris Hyde, Director of WMHTAC ...

Diabetes care, Nov 6, 2016

Monogenic diabetes is rare but is an important diagnosis in pediatric diabetes clinics. These pat... more Monogenic diabetes is rare but is an important diagnosis in pediatric diabetes clinics. These patients are often not identified as this relies on the recognition of key clinical features by an alert clinician. Biomarkers (islet autoantibodies and C-peptide) can assist in the exclusion of patients with type 1 diabetes and allow systematic testing that does not rely on clinical recognition. Our study aimed to establish the prevalence of monogenic diabetes in U.K. pediatric clinics using a systematic approach of biomarker screening and targeted genetic testing. We studied 808 patients (79.5% of the eligible population) <20 years of age with diabetes who were attending six pediatric clinics in South West England and Tayside, Scotland. Endogenous insulin production was measured using the urinary C-peptide creatinine ratio (UCPCR). C-peptide-positive patients (UCPCR ≥0.2 nmol/mmol) underwent islet autoantibody (GAD and IA2) testing, with patients who were autoantibody negative undergoi...

... evaluation. Zulian Liu, Esther Albon and Chris Hyde Department of Public Health and Epidemiol... more ... evaluation. Zulian Liu, Esther Albon and Chris Hyde Department of Public Health and Epidemiology West Midlands Health Technology Assessment Group ... Authors: Zulian Liu Systematic reviewer Esther Albon Systematic Reviewer Chris Hyde Senior Lecturer ...

Evidence Based Healthcare, 2000

BMJ open, Jun 3, 2016

To evaluate the effectiveness of behaviour changing interventions targeting ordering of thyroid f... more To evaluate the effectiveness of behaviour changing interventions targeting ordering of thyroid function tests. Systematic review. MEDLINE, EMBASE and the Cochrane Database up to May 2015. We included studies evaluating the effectiveness of behaviour change interventions aiming to reduce ordering of thyroid function tests. Randomised controlled trials (RCTs), non-randomised controlled studies and before and after studies were included. There were no language restrictions. 2 reviewers independently screened all records identified by the electronic searches and reviewed the full text of any deemed potentially relevant. Study details were extracted from the included papers and their methodological quality assessed independently using a validated tool. Disagreements were resolved through discussion and arbitration by a third reviewer. Meta-analysis was not used. 27 studies (28 papers) were included. They evaluated a range of interventions including guidelines/protocols, changes to fundi...

British Journal of Clinical Governance, 1996

Abstract: The need to make better use of research evidence in delivering health care is undeniabl... more Abstract: The need to make better use of research evidence in delivering health care is undeniable. Primary and secondary research of greater quality and relevance will help. However, without improvements in the understanding and skills of using research ...

BMJ Open, 2015

Objective: Clinicians predominantly use clinical features to differentiate type 1 from type 2 dia... more Objective: Clinicians predominantly use clinical features to differentiate type 1 from type 2 diabetes yet there are no evidence-based clinical criteria to aid classification of patients. Misclassification of diabetes is widespread (7-15% of cases), resulting in patients receiving inappropriate treatment. We sought to identify which clinical criteria could be used to discriminate type 1 and type 2 diabetes. Design: Systematic review of all diagnostic accuracy studies published since 1979 using clinical criteria to predict insulin deficiency (measured by C-peptide). Data sources: 14 databases including: MEDLINE, MEDLINE in Process and EMBASE. The search strategy took the form of: (terms for diabetes) AND (terms for C-Peptide). Eligibility criteria: Diagnostic accuracy studies of any routinely available clinical predictors against a reference standard of insulin deficiency defined by cutoffs of C-peptide concentrations. No restrictions on race, age, language or country of origin.

British Journal of Health Psychology, 2015

To understand the meaning of having a false-positive screening mammogram. Qualitative interview s... more To understand the meaning of having a false-positive screening mammogram. Qualitative interview study. Twenty-one women, who had experienced false-positive screening mammograms, took part in semi-structured interviews that were analysed with Interpretive Phenomenological Analysis. This research took place in the United Kingdom. The analysis revealed a wide range of response to having a false-positive mammogram, from nonchalance to extreme fear. These reactions come from the potential for the belief that one is healthy to be challenged by being recalled, as the worst is frequently assumed. For most, the image of the lesion on the X-ray brought the reality of this challenge into sharp focus, as they might soon discover they had breast cancer. Waiting, whether for the appointment, at the clinic or for biopsy results was considered the worst aspect of being recalled. Generally, the uncertainty was quickly resolved with the pronouncement of the &amp;amp;amp;#39;all-clear&amp;amp;amp;#39;, which brought considerable relief and the restoration of belief in the healthy self. However, for some, lack of information, contradictory information, or poor interpersonal communication meant that uncertainty about their health status lingered at least until their next normal screening mammogram. Mammography screening related anxiety lasted for up to 12 years. Breast cancer screening produces a &amp;amp;amp;#39;crisis of visibility&amp;amp;amp;#39;. Accepting the screening invitation is taking a risk that you may experience unnecessary stress, uncertainty, fear, anxiety, and physical pain. Not accepting the invitation is taking a risk that malignant disease will remain invisible. Statement of contribution What is already known on this subject? More than 50,000 women a year in England have a false-positive mammogram (FPM). Having an FPM can cause anxiety compared with a normal mammogram. The anxiety can last up to 35 months. What does this study add? Refocuses attention from the average response found in quantitative studies to the wide range of individual response. Gives insight into the nature of the anxiety of having FPMs. Highlights the role of uncertainty in provoking distress from an FPM.

Diabetes care, Jan 4, 2015

To assess whether clinical characteristics and simple biomarkers of β-cell failure are associated... more To assess whether clinical characteristics and simple biomarkers of β-cell failure are associated with individual variation in glycemic response to GLP-1 receptor agonist (GLP-1RA) therapy in patients with type 2 diabetes. We prospectively studied 620 participants with type 2 diabetes and HbA1c ≥58 mmol/mol (7.5%) commencing GLP-1RA therapy as part of their usual diabetes care and assessed response to therapy over 6 months. We assessed the association between baseline clinical measurements associated with β-cell failure and glycemic response (primary outcome HbA1c change 0-6 months) with change in weight (0-6 months) as a secondary outcome using linear regression and ANOVA with adjustment for baseline HbA1c and cotreatment change. Reduced glycemic response to GLP-1RAs was associated with longer duration diabetes, insulin cotreatment, lower fasting C-peptide, lower postmeal urine C-peptide-to-creatinine ratio, and positive GAD or IA2 islet autoantibodies (P ≤ 0.01 for all). Participa...

Evidence-Based Medicine, 2005

BMJ open, 2015

To gain an understanding of the views of women with false-positive screening mammograms of screen... more To gain an understanding of the views of women with false-positive screening mammograms of screening recall services, their ideas for service improvements and how these compare with current UK guidelines. Inductive qualitative content analysis of semistructured interviews of 21 women who had false-positive screening mammograms. These were then compared with UK National Health Service (NHS) guidelines. Participants' concerns about mammography screening recall services focused on issues of communication and choice. Many of the issues raised indicated that the 1998 NHS Breast Screening Programme guidelines on improving the quality of written information sent to women who are recalled, had not been fully implemented. This included being told a clear reason for recall, who may attend with them, the length of appointment, who they will see and what tests will be carried out. Additionally women voiced a need for: reassurance that a swift appointment did not imply they had cancer; choic...