Publications by authors named "Talitha Verhoef"
The cytochrome P450 (CYP)4F2 gene is known to influence mean coumarin dose. The aim of the present study was to undertake a meta-analysis at the individual patients level to capture the possible effect of ethnicity, gene-gene interaction, or other drugs on the association and to verify if inclusion of CYP4F2*3 variant into dosing algorithms improves the prediction of mean coumarin dose. We asked the authors of our previous meta-analysis (30 articles) and of 38 new articles retrieved by a systematic review to send us individual patients' data.
View Article and Find Full Text PDFObjectives: To evaluate the cost-effectiveness of the implementation of the Identification and Referral to Improve Safety (IRIS) programme using up-to-date real-world information on costs and effectiveness from routine clinical practice. A Markov model was constructed to estimate mean costs and quality-adjusted life-years (QALYs) of IRIS versus usual care per woman registered at a general practice from a societal and health service perspective with a 10-year time horizon.
Design And Setting: Cost-utility analysis in UK general practices, including data from six sites which have been running IRIS for at least 2 years across England.
Objective: To determine if use of point of care testing (POCT) is less costly than laboratory testing to the National Health Service (NHS) in delivering the NHS Health Check (NHSHC) programme in the primary care setting.
Design: Observational study and theoretical mathematical model with microcosting approach.
Setting: We collected data on NHSHC delivered at nine general practices (seven using POCT; two not using POCT).
Objective: to estimate the costs to women, their friends and family for different antenatal tests in the Down's syndrome (DS) screening pathway.
Design: questionnaire-based costing study.
Setting: eight maternity clinics across the UK.
Background: We evaluated the cost-effectiveness of the Give-it-a-Go programme, which offers free leisure centre memberships to physically inactive members of the public in a single London Borough receiving state benefits.
Methods: A decision analytic Markov model was developed to analyse lifetime costs and quality-adjusted life-years (QALYs) of 1025 people recruited to the intervention versus no intervention. In the intervention group, people were offered 4 months of free membership at a leisure centre.
Objective: To investigate the benefits and costs of implementing non-invasive prenatal testing (NIPT) for Down's syndrome into the NHS maternity care pathway.
Design: Prospective cohort study.
Setting: Eight maternity units across the United Kingdom between 1 November 2013 and 28 February 2015.
Objective: Evaluate the costs of offering non-invasive prenatal diagnosis (NIPD) for single gene disorders compared to traditional invasive testing to inform NIPD implementation into clinical practice.
Method: Total costs of diagnosis using NIPD or invasive testing pathways were compared for a representative set of single gene disorders.
Results: For autosomal dominant conditions, where NIPD molecular techniques are straightforward, NIPD cost £314 less than invasive testing.
Background: Oomph! Wellness organises interactive exercise and activity classes (Oomph! classes) for older people in care homes. We investigated the cost-effectiveness of Oomph! classes.
Methods: Health-related quality of life was measured using the EQ-5D-5 L questionnaire at three time points; 3 months and 1 week prior to the start of the classes and after 3 months of Oomph! classes.
Objective: To investigate the cost-effectiveness of a hypothetical cardioprotective agent used to reduce infarct size in patients undergoing percutaneous coronary intervention (PCI) after anterior ST-elevation myocardial infarction.
Design: A cost-utility analysis using a Markov model.
Setting: The National Health Service in the UK.
Article Synopsis
- A study was conducted to investigate the impact of clinical dosing algorithms for acenocoumarol and phenprocoumon on the percentage of time patients spent within the therapeutic range (TTR) compared to standard care in the Netherlands.
- The results showed that acenocoumarol users with the clinical algorithm had a significantly higher TTR and spent less time outside the therapeutic range, while phenprocoumon users did not see significant improvements in TTR.
- The findings suggest that using a clinical dosing algorithm for acenocoumarol can enhance anticoagulation therapy quality in the first 2-12 weeks, but phenprocoumon did not show similar benefits.
Introduction: Little is known about the overall quality of life (QOL) in patients newly diagnosed with venous thromboembolism (VTE) and atrial fibrillation (AF). We studied QOL in patients with VTE and AF immediately after the start of anticoagulant therapy, and after three months of treatment. Furthermore we identified whether QOL was affected by age, gender and nationality.
View Article and Find Full Text PDFObjectives: We aim to develop non-invasive prenatal diagnosis (NIPD) for cystic fibrosis (CF) and determine costs and implications for implementation.
Methods: A next-generation sequencing assay was developed to detect ten common CF mutations for exclusion of the paternal mutation in maternal plasma. Using uptake data from a study exploring views on NIPD for CF, total test-related costs were estimated for the current care pathway and compared with those incorporating NIPD.
Aim: To investigate the cost-effectiveness of a pharmacogenetic dosing algorithm versus a clinical dosing algorithm for coumarin anticoagulants in The Netherlands.
Materials & Methods: A decision-analytic Markov model was used to analyze the cost-effectiveness of pharmacogenetic dosing of phenprocoumon and acenocoumarol versus clinical dosing.
Results: Pharmacogenetic dosing increased costs by €33 and quality-adjusted life-years (QALYs) by 0.
Introduction: A large proportion of the coumarin dose variability is explained by environmental factors and by common genetic variants in the VKORC1 and CYP2C9 genes. Genotype-guided coumarin dosing has been proposed for a more accurate prediction of the coumarin dose in order to reduce the incidence of coumarin-related complications.
Areas Covered: This review discusses the current state of coumarin pharmacogenetics, the evidence from recent randomized controlled trials and economic evaluations regarding the possible clinical implementation of genotype-guided coumarin dosing.
Growing resistance to antibacterial agents has increased the need for the development of new drugs to treat bacterial infections. Given increasing pressure on limited health budgets, it is important to study the cost-effectiveness of these drugs, as well as their safety and efficacy, to find out whether or not they provide value for money and should be reimbursed. In this article, we systematically reviewed 38 cost-effectiveness analyses of new antibacterial agents.
View Article and Find Full Text PDFObjectives: Our objectives were to investigate the cost effectiveness of apixaban, rivaroxaban, and dabigatran compared with coumarin derivatives for stroke prevention in patients with atrial fibrillation in a country with specialized anticoagulation clinics (the Netherlands) and in a country without these clinics (the UK).
Methods: A decision-analytic Markov model was used to analyse the cost effectiveness of apixaban, rivaroxaban, and dabigatran compared with coumarin derivatives in the Netherlands and the UK over a lifetime horizon.
Results: In the Netherlands, the use of rivaroxaban, apixaban, or dabigatran increased health by 0.
Beliefs about medicines in Dutch acenocoumarol and phenprocoumon users.
Br J Clin Pharmacol
August 2014
Aims: Adherence to the generally complex regimen of coumarin derivatives is vital in order to keep patients in the adequate International Normalized Ratio range. Patients' beliefs about medicines are associated with the level of therapy adherence. Our first aim was to assess beliefs about coumarins.
View Article and Find Full Text PDFBackground: Observational evidence suggests that the use of a genotype-guided dosing algorithm may increase the effectiveness and safety of acenocoumarol and phenprocoumon therapy.
Methods: We conducted two single-blind, randomized trials comparing a genotype-guided dosing algorithm that included clinical variables and genotyping for CYP2C9 and VKORC1 with a dosing algorithm that included only clinical variables, for the initiation of acenocoumarol or phenprocoumon treatment in patients with atrial fibrillation or venous thromboembolism. The primary outcome was the percentage of time in the target range for the international normalized ratio (INR; target range, 2.
Coumarin derivatives, such as warfarin, acenocoumarol and phenprocoumon are frequently prescribed oral anticoagulants to treat and prevent thromboembolism. Because there is a large inter-individual and intra-individual variability in dose-response and a small therapeutic window, treatment with coumarin derivatives is challenging. Certain polymorphisms in CYP2C9 and VKORC1 are associated with lower dose requirements and a higher risk of bleeding.
View Article and Find Full Text PDFAim: To investigate the cost-effectiveness of pharmacogenetic-guided phenprocoumon dosing versus standard anticoagulation care in Dutch patients with atrial fibrillation.
Materials & Methods: Using a decision-analytic Markov model, cost-effectiveness of pharmacogenetic-guided therapy versus standard care was estimated.
Results: Compared with standard care, the pharmacogenetic-guided dosing strategy increased quality-adjusted life-years (QALYs) only very slightly and increased costs by €15.
Aim: To investigate whether the phenprocoumon and acenocoumarol maintenance doses are influenced by genetic variations in GATA-4, a transcription factor of CYP2C9.
Patients & Methods: The influence of seven GATA-4 SNPs on the coumarin maintenance dose was investigated by performing an analysis of variance trend analysis, stratified for CYP2C9 genotypes. Results of the best-explaining SNP were validated in the Rotterdam Study cohort.
Background: Statins and coumarins are prescribed in combination on a regular basis. Some case reports suggested that statins might affect the dose requirements of coumarins. The aim of the study was to investigate whether acenocoumarol and phenprocoumon maintenance doses are influenced by statin use.
View Article and Find Full Text PDFGenotyping patients for CYP2C9 and VKORC1 polymorphisms can improve the accuracy of dosing during the initiation of anticoagulation with vitamin K antagonists (coumarin derivatives). The anticipated degree of improvement in the safety of anticoagulation with coumarins through genotyping may vary depending on the quality of patient care, which varies both with and among countries. The management and the cost of anticoagulant care can therefore influence the cost-effectiveness of genotyping within any given country.
View Article and Find Full Text PDFAim: To evaluate the performance of the European Pharmacogenetics of Anticoagulant Therapy (EU-PACT) acenocoumarol dose algorithms in an independent data set. The EU-PACT trial investigates the added value of pretreatment genotyping for use of warfarin, phenprocoumon and acenocoumarol.
Patients & Methods: External validation was performed in the Rotterdam Study cohort using information about 707 acenocoumarol users.