G. Ardine de Wit
Utrecht University
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Featured researches published by G. Ardine de Wit.
PLOS Medicine | 2008
Pieter van Baal; Johan J. Polder; G. Ardine de Wit; Rudolf T. Hoogenveen; Talitha Feenstra; Hendriek C. Boshuizen; Peter M. Engelfriet; Werner Brouwer
Background Obesity is a major cause of morbidity and mortality and is associated with high medical expenditures. It has been suggested that obesity prevention could result in cost savings. The objective of this study was to estimate the annual and lifetime medical costs attributable to obesity, to compare those to similar costs attributable to smoking, and to discuss the implications for prevention. Methods and Findings With a simulation model, lifetime health-care costs were estimated for a cohort of obese people aged 20 y at baseline. To assess the impact of obesity, comparisons were made with similar cohorts of smokers and “healthy-living” persons (defined as nonsmokers with a body mass index between 18.5 and 25). Except for relative risk values, all input parameters of the simulation model were based on data from The Netherlands. In sensitivity analyses the effects of epidemiologic parameters and cost definitions were assessed. Until age 56 y, annual health expenditure was highest for obese people. At older ages, smokers incurred higher costs. Because of differences in life expectancy, however, lifetime health expenditure was highest among healthy-living people and lowest for smokers. Obese individuals held an intermediate position. Alternative values of epidemiologic parameters and cost definitions did not alter these conclusions. Conclusions Although effective obesity prevention leads to a decrease in costs of obesity-related diseases, this decrease is offset by cost increases due to diseases unrelated to obesity in life-years gained. Obesity prevention may be an important and cost-effective way of improving public health, but it is not a cure for increasing health expenditures.
Gastroenterology | 2010
Irene K. Veldhuijzen; Mehlika Toy; Susan J.M. Hahné; G. Ardine de Wit; Solko W. Schalm; Robert A. de Man; Jan Hendrik Richardus
BACKGROUND & AIMS Persons with chronic hepatitis B virus (HBV) infection are at risk of developing cirrhosis and hepatocellular carcinoma. Early detection of chronic HBV infection through screening and treatment of eligible patients has the potential to prevent these sequelae. We assessed the cost-effectiveness in The Netherlands of systematically screening migrants from countries that have high and intermediate HBV infection levels. METHODS Epidemiologic data of the expected numbers of patients with active chronic HBV infection in the target population and information about the costs of a screening program were used in a Markov model and used to determine costs and quality-adjusted life years (QALY) for patients who were and were not treated. RESULTS Compared with the status quo, a 1-time screen for HBV infection can reduce mortality of liver-related diseases by 10%. Using base case estimates, the incremental cost-effectiveness ratio (ICER) of screening, compared with not screening, is euros (euro) 8966 per QALY gained. The ICER ranged from euro7936 to euro11,705 based on univariate sensitivity analysis, varying parameter values of HBV prevalence, participation rate, success in referral, and treatment compliance. Using multivariate sensitivity analysis for treatment effectiveness, the ICER ranged from euro7222 to euro15,694; for disease progression, it ranged from euro5568 to euro60,418. CONCLUSIONS Early detection and treatment of people with HBV infection can have a large impact on liver-related health outcomes. Systematic screening for chronic HBV infection among migrants is likely to be cost-effective, even using low estimates for HBV prevalence, participation, referral, and treatment compliance.
PharmacoEconomics | 2002
Philippe Beutels; W. John Edmunds; Fernando Antoñanzas; G. Ardine de Wit; David B. Evans; Rachel Feilden; A. Mark Fendrick; Gary M. Ginsberg; Henry A. Glick; Eric Mast; Marc Péchevis; Eddy van Doorslaer; Ben van Hout
The methods that have been used to estimate the clinical and economic impact of vaccination programmes are not always uniform, which makes it difficult to compare results between economic analyses. Furthermore, the relative efficiency of vaccination programmes can be sensitive to some of the more controversial aspects covered by general guidelines for the economic evaluation of healthcare programmes, such as discounting of health gains and the treatment of future unrelated costs. In view of this, we interpret some aspects of these guidelines with respect to vaccination and offer recommendations for future analyses.These recommendations include more transparency and validation, more careful choice of models (tailored to the infection and the target groups), more extensive sensitivity analyses, and for all economic evaluations (also nonvaccine related) to be in better accordance with general guidelines.We use these recommendations to interpret the evidence provided by economic evaluation applied to viral hepatitis vaccination. We conclude that universal hepatitis B vaccination (of neonates, infants or adolescents) seems to be the most optimal strategy worldwide, except in the few areas of very low endemicity, where the evidence to enable a choice between selective and universal vaccination remains inconclusive. While targeted hepatitis A vaccination seems economically unattractive, universal hepatitis A vaccination strategies have not yet been sufficiently investigated to draw general conclusions.
Value in Health | 2016
Matthijs M. Versteegh; Karin M. Vermeulen; Silvia M. A. A. Evers; G. Ardine de Wit; Rilana Prenger; Elly A. Stolk
BACKGROUND In 2009, a new version of the EuroQol five-dimensional questionnaire (EQ-5D) was introduced with five rather than three answer levels per dimension. This instrument is known as the EQ-5D-5L. To make the EQ-5D-5L suitable for use in economic evaluations, societal values need to be attached to all 3125 health states. OBJECTIVES To derive a Dutch tariff for the EQ-5D-5L. METHODS Health state values were elicited during face-to-face interviews in a general population sample stratified for age, sex, and education, using composite time trade-off (cTTO) and a discrete choice experiment (DCE). Data were modeled using ordinary least squares and tobit regression (for cTTO) and a multinomial conditional logit model (for DCE). Model performance was evaluated on the basis of internal consistency, parsimony, goodness of fit, handling of left-censored values, and theoretical considerations. RESULTS A representative sample (N = 1003) of the Dutch population participated in the valuation study. Data of 979 and 992 respondents were included in the analysis of the cTTO and the DCE, respectively. The cTTO data were left-censored at -1. The tobit model was considered the preferred model for the tariff on the basis of its handling of the censored nature of the data, which was confirmed through comparison with the DCE data. The predicted values for the EQ-5D-5L ranged from -0.446 to 1. CONCLUSIONS This study established a Dutch tariff for the EQ-5D-5L on the basis of cTTO. The values represent the preferences of the Dutch population. The tariff can be used to estimate the impact of health care interventions on quality of life, for example, in context of economic evaluations.
BMJ | 2012
Ingrid V. F. van den Broek; Jan E. A. M. van Bergen; Elfi E. H. G. Brouwers; Johannes S A Fennema; Hannelore M. Götz; Christian J. P. A. Hoebe; Rik H. Koekenbier; Mirjam Kretzschmar; Eelco A B Over; Boris V. Schmid; Lydia L. Pars; Sander M. van Ravesteijn; Marianne A. B. van der Sande; G. Ardine de Wit; Nicola Low; Eline L. M. Op de Coul
Objective To evaluate the effectiveness of register based, yearly chlamydia screening. Design Controlled trial with randomised stepped wedge implementation in three blocks. Setting Three regions of the Netherlands: Amsterdam, Rotterdam, and South Limburg. Participants 317 304 women and men aged 16-29 years listed on municipal registers at start of trial. Intervention From March 2008 to February 2011, the Chlamydia Screening Implementation programme offered yearly chlamydia screening tests. Postal invitations asked people to use an internet site to request a kit for self collection of samples, which would then be sent to regional laboratories for testing. Treatment and partner notification were done by the general practitioner or at a sexually transmitted infection clinic. Main outcome measures Primary outcomes were the percentage of chlamydia tests positive (positivity), percentage of invitees returning a specimen (uptake), and estimated chlamydia prevalence. Secondary outcomes were positivity according to sex, age, region, and sociodemographic factors; adherence to screening invitations; and incidence of self reported pelvic inflammatory disease. Results The participation rate was 16.1% (43 358/269 273) after the first invitation, 10.8% after the second, and 9.5% after the third, compared with 13.0% (6223/48 031) in the control block invited at the end of round two of the intervention. Chlamydia positivity in the intervention blocks at the first invitation was the same as in the control block (4.3%) and 0.2% lower at the third invitation (odds ratio 0.96 (95% confidence interval 0.83 to 1.10)). No substantial decreases in positivity were seen after three screening rounds in any region or sociodemographic group. Among the people who participated three times (2.8% of all invitees), positivity fell from 5.9% to 2.9% (odds ratio 0.49 (0.47 to 0.50)). Conclusions There was no statistical evidence of an impact on chlamydia positivity rates or estimated population prevalence from the Chlamydia Screening Implementation programme after three years at the participation levels obtained. The current evidence does not support a national roll out of this register based chlamydia screening programme. Trial registration NTR 3071 (Netherlands Trial Register, www.trialregister.nl).
Journal of Vascular Surgery | 2010
Ralf W. Sprengers; Martin Teraa; Frans L. Moll; G. Ardine de Wit; Yolanda van der Graaf; Marianne C. Verhaar
OBJECTIVE To provide a solid baseline reference for quality of life (QoL) in patients with no-option critical limb ischemia (CLI). CLI is associated with surgery, endovascular interventions, hospitalization, and a poor prognosis. An increasing number of clinical trials are, therefore, investigating new treatment strategies (eg, therapeutic neovascularization) in patients with CLI. QoL serves as an important secondary endpoint in many of these trials, but solid reference QoL data for patients with no-option CLI are lacking. METHODS The Medical Outcomes Study Short Form 36 (SF-36) and the EuroQol-5D (EQ-5D) questionnaires were used to obtain baseline QoL scores from 47 patients with no-option CLI participating in a therapeutic neovascularization trial. To allow for easy comparability, a norm-based scoring (NBS) method was used to report the results of the SF-36. Scores of patients with CLI were furthermore compared with scores of patients with milder forms of peripheral arterial disease (PAD) and with patients with cardiovascular risk factors only. Determinants of QoL in patients with PAD were identified using multiple linear regression methods. RESULTS Patients with no-option CLI reported QoL scores below the general population mean on every health dimension of the SF-36. Physical functioning, role physical functioning, and bodily pain were affected most intensively. These poor physical QoL scores were further underlined when compared with other patients with milder forms of PAD or patients with cardiovascular risk factors only. Patients with CLI scored poorly on the pain/discomfort and the usual activities domain of the EQ-5D. Diabetes, female gender, body mass index, and the ankle-brachial index at rest were significant determinants of the QoL in PAD on multivariate analysis. CONCLUSION The QoL data of patients with no-option CLI using NBS methods for the SF-36 provide a baseline reference for ongoing clinical trials on new treatment strategies. Our data stress the need for new revascularization therapies in patients with no-option CLI.
PharmacoEconomics | 2006
S.M.C. Vijgen; M Hoogendoorn; Caroline A. Baan; G. Ardine de Wit; Wien Limburg; Talitha Feenstra
A systematic review of the literature was conducted to give an overview of economic evaluations of preventive interventions in type 2 diabetes mellitus. The interventions were sorted by type of preventive intervention (primary, secondary or tertiary) and by category (e.g. education, medication for hypertension). Several databases were searched for studies published between January 1990 and May 2004 on the three types of preventive intervention. For each study selected, inclusion of specific components from a standardised list of items, including quality, was recorded in a database. Summary tables were generated based on the database.A number of conclusions were drawn from this review. The most important was that strict blood pressure control was a more cost-effective intervention than less strict control, as shown by six studies reporting cost savings to very low costs per life-year gained. Primary and secondary prevention of type 2 diabetes were also highly cost effective, but these results were based on very few studies. Medications to reduce weight and hyperglycaemia together were cost effective compared with conventional interventions. Finally, the separate results regarding medications to reduce weight, hyperglycaemia and hypercholesterolaemia varied enormously, thus no conclusion could be drawn and further economic analysis is required.
European Respiratory Journal | 2015
Marie-Josée J. Mangen; Mark H. Rozenbaum; Susanne M. Huijts; Cornelis H. van Werkhoven; Douwe F. Postma; Mark Atwood; Anna M.M. Van Deursen; Arie van der Ende; Diederick E. Grobbee; Elisabeth A. M. Sanders; Reiko Sato; Theo Verheij; Conrad E Vissink; Marc J.M. Bonten; G. Ardine de Wit
The Community-Acquired Pneumonia Immunization Trial in Adults (CAPiTA) demonstrated the efficacy of 13-valent pneumococcal conjugate vaccine (PCV13) in preventing vaccine-type community-acquired pneumonia and vaccine-type invasive pneumococcal disease in elderly subjects. We examined the cost-effectiveness of PCV13 vaccination in the Netherlands. Using a Markov-type model, incremental cost-effectiveness ratios (ICER) of PCV13 vaccination in different age- and risk-groups for pneumococcal disease were evaluated using a societal perspective. Estimates of quality-adjusted life-years (QALYs), costs, vaccine efficacy and epidemiological data were based on the CAPiTA study and other prospective studies. The base-case was PCV13 vaccination of adults aged 65–74 years compared to no vaccination, assuming no net indirect effects in base-case due to paediatric 10-valent pneumococcal conjugate vaccine use. Analyses for age- and risk-group specific vaccination strategies and for different levels of hypothetical herd effects from a paediatric PCV programme were also conducted. The ICER for base-case was €8650 per QALY (95% CI 5750–17 100). Vaccination of high-risk individuals aged 65–74 years was cost-saving and extension to medium-risk individuals aged 65–74 years yielded an ICER of €2900. Further extension to include medium- and high-risk individuals aged ≥18 years yielded an ICER of €3100. PCV13 vaccination is highly cost-effective in the Netherlands. The transferability of our results to other countries depends upon vaccination strategies already implemented in those countries. Vaccinating the elderly with 13-valent pneumococcal conjugate vaccine is highly cost-effective http://ow.ly/NVeui
PharmacoEconomics | 2011
Pieter van Baal; Albert Wong; Laurentius C.J. Slobbe; Johan J. Polder; Werner Brouwer; G. Ardine de Wit
A shortcoming of many economic evaluations is that they do not include all medical costs in life-years gained (also termed indirect medical costs). One of the reasons for this is the practical difficulties in the estimation of these costs. While some methods have been proposed to estimate indirect medical costs in a standardized manner, these methods fail to take into account that not all costs in life-years gained can be estimated in such a way. Costs in lifeyears gained caused by diseases related to the intervention are difficult to estimate in a standardized manner and should always be explicitly modelled. However, costs of all other (unrelated) diseases in life-years gained can be estimated in such a way.We propose a conceptual model of how to estimate costs of unrelated diseases in life-years gained in a standardized manner. Furthermore, we describe how we estimated the parameters of this conceptual model using various data sources and studies conducted in the Netherlands. Results of the estimates are embedded in a software package called ‘Practical Application to Include future Disease costs’ (PAID 1.0). PAID 1.0 is available as a Microsoft® Excel tool (available as Supplemental Digital Content via a link in this article) and enables researchers to ‘switch off’ those disease categories that were already included in their own analysis and to estimate future healthcare costs of all other diseases for incorporation in their economic evaluations.We assumed that total healthcare expenditure can be explained by age, sex and time to death, while the relationship between costs and these three variables differs per disease. To estimate values for age- and sex-specific per capita health expenditure per disease and healthcare provider stratified by time to death we used Dutch cost-of-illness (COI) data for the year 2005 as a backbone. The COI data consisted of age- and sex-specific per capita health expenditure uniquely attributed to 107 disease categories and eight healthcare provider categories. Since the Dutch COI figures do not distinguish between costs of those who die at a certain age (decedents) and those who survive that age (survivors), we decomposed average per capita expenditure into parts that are attributable to decedents and survivors, respectively, using other data sources.
Clinical Journal of The American Society of Nephrology | 2013
Albert H.A. Mazairac; G. Ardine de Wit; Muriel P.C. Grooteman; E. Lars Penne; Neelke C. van der Weerd; Claire H. den Hoedt; Renée Lévesque; Marinus A. van den Dorpel; Menso J. Nubé; Piet M. ter Wee; Michiel L. Bots; Peter J. Blankestijn
BACKGROUND AND OBJECTIVES It is unclear if hemodiafiltration leads to a better quality of life compared with hemodialysis. It was, therefore, the aim of this study to assess the effect of hemodiafiltration on quality of life compared with hemodialysis in patients with ESRD. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS This study analyzed the data of 714 patients with a median follow-up of 2 years from the Convective Transport Study. The patients were enrolled between June of 2004 and December of 2009. The Convective Transport Study is a randomized controlled trial on the effect of online hemodiafiltration versus low-flux hemodialysis on all-cause mortality. Quality of life was assessed with the Kidney Disease Quality of Life-Short Form. This questionnaire provides data for a physical and mental composite score and describes kidney disease-specific quality of life in 12 domains. The domains have scales from 0 to 100. RESULTS There were no significant differences in changes in health-related quality of life over time between patients treated with hemodialysis (n=358) or hemodiafiltration (n=356). The quality of life domain patient satisfaction declined over time in both dialysis modalities (hemodialysis: -2.5/yr, -3.4 to -1.5, P<0.001; hemodiafiltration: -1.4/yr, -2.4 to -0.5, P=0.004). CONCLUSIONS Compared with hemodialysis, hemodiafiltration had no significant effect on quality of life over time.