Gareth Ambler
A5062898952- Intracerebral and Subarachnoid Hemorrhage Research
- Acute Ischemic Stroke Management
- Neurosurgical Procedures and Complications
- Health Systems, Economic Evaluations, Quality of Life
- Atrial Fibrillation Management and Outcomes
- Mental Health Treatment and Access
- Statistical Methods in Clinical Trials
- Glaucoma and retinal disorders
- Statistical Methods and Bayesian Inference
- Bladder and Urothelial Cancer Treatments
- Statistical Methods and Inference
- Mental Health Research Topics
- Corneal surgery and disorders
- Psychiatric care and mental health services
- Long-Term Effects of COVID-19
- Traumatic Brain Injury and Neurovascular Disturbances
- Retinal Diseases and Treatments
- Ovarian cancer diagnosis and treatment
- Cerebrovascular and genetic disorders
- Stroke Rehabilitation and Recovery
- Cerebrospinal fluid and hydrocephalus
- Cerebrovascular and Carotid Artery Diseases
- Schizophrenia research and treatment
- Meta-analysis and systematic reviews
- Urinary and Genital Oncology Studies
University College London
2016-2025
Royal Statistical Society
2011-2025
National Hospital for Neurology and Neurosurgery
2015-2024
Biomedical Research Institute
2022-2024
Hospital de Sant Pau
2022-2024
Medical University of Graz
2023-2024
MRC Prion Unit
2024
University Hospital of Bern
2021-2024
University of Bern
2024
Fujian Medical University
2020-2023
BACKGROUND: The traditional method of analysing continuous or ordinal risk factors by categorization linear models may be improved. METHODS: We propose an approach based on transformation and fractional polynomials which yields simple regression with interpretable curves. suggest a way presenting the results from such involves tabulating risks estimated model at convenient values factor. discuss how to incorporate several confounding variables within single model. is exemplified data...
When the number of events is low relative to predictors, standard regression could produce overfitted risk models that make inaccurate predictions. Use penalised may improve accuracy prediction
Primary open angle glaucoma and ocular hypertension are habitually treated with eye drops that lower intraocular pressure. Selective laser trabeculoplasty is a safe alternative but rarely used as first-line treatment. We compared the two.In this observer-masked, randomised controlled trial treatment-naive patients or no comorbidities were recruited between 2012 2014 at six UK hospitals. They randomly allocated (web-based randomisation) to initial selective drops. An objective target pressure...
Cerebral microbleeds are a potential neuroimaging biomarker of cerebral small vessel diseases that prone to intracranial bleeding. We aimed determine whether presence can identify patients at high risk symptomatic haemorrhage when anticoagulated for atrial fibrillation after recent ischaemic stroke or transient attack.
Robot-assisted radical cystectomy is being performed with increasing frequency, but it unclear whether total intracorporeal surgery improves recovery compared open for bladder cancer.
It is not known whether patients with atrial fibrillation (AF) ischemic stroke despite oral anticoagulant therapy are at increased risk for further recurrent strokes or how ongoing secondary prevention should be managed.
Multiple primary outcomes may be specified in randomised controlled trials (RCTs). When analysing multiple it's important to control the family wise error rate (FWER). A popular approach do this is adjust p-values corresponding each statistical test used investigate intervention effects by using Bonferroni correction. It's also consider power of trial detect true effects. In context outcomes, depending on clinical objective, can defined as: 'disjunctive power', probability detecting at least...
The Global Registry of Acute Coronary Events (GRACE) 2.0 score was developed and validated in predominantly male patient populations. We aimed to assess its sex-specific performance non-ST-segment elevation acute coronary syndromes (NSTE-ACS) develop an improved (GRACE 3.0) that accounts for sex differences disease characteristics.We evaluated the GRACE 420 781 consecutive patients with NSTE-ACS contemporary nationwide cohorts from UK Switzerland. Machine learning models predict in-hospital...
Background— Heart valve surgery has an associated in-hospital mortality rate of 4% to 8%. This study aims develop a simple risk model predict the for patients undergoing heart provide information and clinicians facilitate institutional comparisons. Methods Results— Data on 32 839 were obtained from Society Cardiothoracic Surgeons Great Britain Ireland who underwent between April 1995 March 2003. first 5 years (n=16 679) used model; its performance was evaluated remaining data 160). The...
Risk models that aim to predict the future course and outcome of disease processes are increasingly used in health research, it is important they accurate reliable. Most these risk fitted using routinely collected data hospitals or general practices. Clinical outcomes such as short-term mortality will be near-complete, but many predictors may have missing values. A common approach dealing with this perform a complete-case analysis. However, lead overfitted biased estimates if entire patient...
Background: Treatment of long-standing complex regional pain syndrome (CRPS) is empirical and often limited efficacy. Preliminary data suggest that the immune system involved in sustaining this condition treatment with low-dose intravenous immunoglobulin (IVIG) may substantially reduce some patients. Objective: To evaluate efficacy IVIG patients longstanding CRPS under randomized, controlled conditions. Design: A double-blind, placebo-controlled crossover trial. (National Research Registry...
<h3>Objective:</h3> In an international collaborative multicenter pooled analysis, we compared mortality, functional outcome, intracerebral hemorrhage (ICH) volume, and hematoma expansion (HE) between non–vitamin K antagonist oral anticoagulation–related ICH (NOAC-ICH) vitamin antagonist–associated (VKA-ICH). <h3>Methods:</h3> We all-cause mortality within 90 days for NOAC-ICH VKA-ICH using a Cox proportional hazards model adjusted age; sex; baseline Glasgow Coma Scale score, location, log...
BackgroundHigh resource expenditure on acute care is a challenge for mental health services aiming to focus supporting recovery, and relapse after an crisis episode common. Some evidence supports self-management interventions prevent such relapses, but their effect readmissions following untested. We tested whether intervention facilitated by peer support workers could reduce rates of readmission people discharged from resolution teams, which provide intensive home treatment crisis.MethodsWe...
To compare intracerebral hemorrhage (ICH) volume and clinical outcome of non-vitamin K oral anticoagulants (NOAC)-associated ICH to warfarin-associated ICH.In this multicenter cross-sectional observational study patients with anticoagulant-associated ICH, consecutive NOAC-ICH were compared those warfarin-ICH selected from a population 344 ICH. was measured by an observer blinded details. Outcome measures adjusted for confounding factors.We 11 52 warfarin-ICH. The median 2.4 mL (interquartile...
ABSTRACT Background Diagnosis of Parkinson's disease (PD) is typically preceded by nonspecific presentations in primary care. Objectives The objective this study was to develop and validate a prediction model for diagnosis PD based on Setting settings were general practices providing data Health Improvement Network UK care database. Methods Data from 8,166 patients aged older than age 50 years with incident 46,755 controls analyzed. Likelihood ratios, sensitivity, specificity, positive...
We compared outcomes after treatment with direct oral anticoagulants (DOACs) and vitamin K antagonists (VKAs) in patients atrial fibrillation (AF) a recent cerebral ischemia.We conducted an individual patient data analysis of seven prospective cohort studies. included AF ischemia (<3 months before starting anticoagulation) minimum follow-up 3 months. analyzed the association between type anticoagulation (DOAC versus VKA) composite primary endpoint (recurrent ischemic stroke [AIS],...
PurposeTo report clinical efficacy, predictors of success, and safety primary selective laser trabeculoplasty (SLT) used in treatment-naive patients with open-angle glaucoma (OAG) or ocular hypertension (OHT).DesignPost hoc analysis a multicenter, prospective, randomized, controlled trial.ParticipantsTreatment-naive OAG OHT.MethodsPatients randomized to SLT topical medication treated predefined target intraocular pressures (IOPs) requiring ≥20% IOP reduction from baseline for all disease...