Saskia de Groot
Erasmus University Rotterdam
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Publication
Featured researches published by Saskia de Groot.
European Journal of Haematology | 2016
Hedwig M. Blommestein; S. Verelst; Saskia de Groot; Peter C. Huijgens; Pieter Sonneveld; Carin A. Uyl-de Groot
To study the impact of novel treatments for elderly (≥66 yr) patients with multiple myeloma (MM) in daily practice by comparing real‐world effects [overall survival (OS) and quality‐adjusted life years (QALYs)] and costs over time. Also, we calculate cost‐effectiveness of treatment sequences commonly prescribed to predict effects and costs if patients had received a different treatment sequence.
Urology | 2016
Saskia de Groot; William K. Redekop; Stefan Sleijfer; Egbert Oosterwijk; Axel Bex; Lambertus A. Kiemeney; Carin A. Uyl-de Groot
OBJECTIVE To evaluate the effect of cytoreductive nephrectomy (CN) on overall survival (OS) in primary metastatic renal cell carcinoma (mRCC) patients treated with first-line sunitinib. PATIENTS AND METHODS Patients with primary mRCC treated with first-line sunitinib were selected from a Dutch population-based registry. A propensity score was calculated reflecting the probability of a patient undergoing CN prior to sunitinib using a set of known covariates, such as the Memorial Sloan Kettering Cancer Center and International mRCC Database Consortium risk factors. After propensity score matching, differences in OS were analyzed using the Kaplan-Meier method and a multivariable Cox proportional hazards model was used to evaluate the effect of CN on OS. RESULTS A total of 227 patients met the selection criteria; 74 patients (33%) underwent CN prior to sunitinib. In the matched population, the median OS of patients who underwent CN was 17.9 months compared to 8.8 months for patients treated with sunitinib only. Multivariable analysis showed that CN was an independent predictor of OS (hazard ratio 0.61, 95% confidence interval: 0.41-0.92). A subgroup analysis of patients with a time to targeted therapy of <1 year showed a median OS of 12.7 months for patients treated with CN compared to 8.0 months for patients treated with sunitinib only. The corresponding hazard ratio was 0.67 (95% confidence interval: 0.46-0.98). CONCLUSION This study suggests that CN may be effective. However, the benefit was modest when correcting for time from diagnosis to sunitinib. One important limitation is the use of a registry (with retrospectively collected data), which made it impossible to correct for unmeasured characteristics that could be associated with treatment choices or survival.
Expert Review of Pharmacoeconomics & Outcomes Research | 2010
Carin A. Uyl-de Groot; Saskia de Groot; Adri Steenhoek
In 2006, over three million new cases of cancer were diagnosed in Europe. This number will increase in the coming years as a result of an aging population and population growth. Advances in the diagnosis and treatment of cancer have resulted in increased survival rates. Simultaneously, increasing costs of screening, diagnosis and the treatment of cancer could threaten the ability to ensure high-quality care and provide access to care for all patients. New genetic tests and biomarkers may help to identify those subtypes of patients that would be most likely to benefit from new cancer drugs. In our opinion, there is still much to gain in cancer diagnosis and treatment but these gains should be worth the costs.
Leukemia Research | 2016
Hedwig M. Blommestein; Saskia de Groot; Mieke J. Aarts; Pepijn Vemer; Robin de Vries; Annet F.M. van Abeelen; E.F.M. Ward Posthuma; Carin A. Uyl-de Groot
BACKGROUND Obinutuzumab combined with chlorambucil (GClb) has shown to be superior to rituximab combined with chlorambucil (RClb) and chlorambucil (Clb) in newly diagnosed patients with chronic lymphocytic leukaemia (CLL). This study evaluates the cost-effectiveness per life-year and quality-adjusted life-year (QALY) of GClb compared to RClb, Clb, and ofatumumab plus chlorambucil (OClb) in The Netherlands. METHODS A Markov model was developed to assess the cost-effectiveness of GClb, RClb, Clb and other treatments in the United Kingdom. A country adaptation was made to estimate the cost-effectiveness of these therapies in The Netherlands using Dutch unit costs and Dutch data sources for background mortality and post-progression survival. RESULTS An incremental gain of 1.06 and 0.64 QALYs was estimated for GClb compared to Clb and RClb respectively, at additional costs of €23,208 and €7254 per patient. Corresponding incremental cost-effectiveness ratios (ICERs) were €21,823 and €11,344 per QALY. Indirect treatment comparisons showed an incremental gain varying from 0.44 to 0.77 QALYs for GClb compared to OClb and additional costs varying from €7041 to €5028 per patient. The ICER varied from €6556 to €16,180 per QALY. Sensitivity analyses showed the robustness of the results. CONCLUSION GClb appeared to be a cost-effective treatment strategy compared to RClb, OClb and Clb.
BMJ Open | 2015
Saskia de Groot; A.J. Rijnsburger; Matthijs M. Versteegh; Juanita M Heymans; Sarah Kleijnen; W. Ken Redekop; Ilse M Verstijnen
Objectives Reimbursement decisions require evidence of effectiveness and, in general, a blinded randomised controlled trial (RCT) is the preferred study design to provide it. However, there are situations where a cohort study, or even patient series, can be deemed acceptable. The aim of this study was to develop an instrument that first examines which study characteristics of a blinded RCT are necessary, and then, if particular characteristics are considered necessary, examines whether these characteristics are feasible. Design We retrospectively studied 22 interventions from 20 reimbursement reports concerning medical specialist care made by the Dutch National Health Care Institute (ZIN) to identify any factors that influenced the necessity and feasibility of blinded RCTs, and their constituent study characteristics, that is, blinding, randomisation and a control group. A literature review was performed to identify additional factors. Additional expertise was included by interviewing eight experts in epidemiology, medicine and ethics. The resulting instrument was called the FIT instrument (Feasible Information Trajectory), and was prospectively validated using three consecutive reimbursement reports. Results (Blinded) RCT evidence was lacking in 5 of 11 positive reimbursement decisions and 3 of 11 negative decisions. In the reimbursement reports, we found no empirical evidence supporting situations where a blinded RCT is unnecessary. The literature also revealed few arguments against the necessity of a blinded RCT. In contrast, many factors influencing the feasibility of randomisation, a control group and blinding, were found in the reimbursement reports and the literature; for example, when a patient population is too small or when an intervention is common practice, randomisation will be hindered. Conclusions Policy regarding the necessity and feasibility of different types of evidence of effectiveness would benefit from systematic guidance. The FIT instrument has the potential to support transparent, reproducible and well-founded decisions on appropriate evidence of effectiveness in medical specialist care.
PharmacoEconomics | 2018
Nasuh Büyükkaramikli; Saskia de Groot; Debra Fayter; Robert Wolff; Nigel Armstrong; Gill Worthy; Fernando Albuquerque de Almeida; Jos Kleijnen; Maiwenn Al
The National Institute for Health and Care Excellence (NICE), as part of the institute’s single technology appraisal (STA) process, invited the manufacturer of pomalidomide (POM; Imnovid®, Celgene) to submit evidence regarding the clinical and cost effectiveness of the drug in combination with dexamethasone (POM + LoDEX) for the treatment of relapsed and refractory multiple myeloma (RRMM) after at least two regimens including lenalidomide (LEN) and bortezomib (BOR). Kleijnen Systematic Reviews Ltd (KSR) and Erasmus University Rotterdam were commissioned as the Evidence Review Group (ERG) for this submission. The ERG reviewed the evidence submitted by the manufacturer, validated the manufacturer’s decision analytic model, and conducted exploratory analyses in order to assess the robustness and validity of the presented clinical and cost-effectiveness results. This paper describes the company submission, the ERG assessment, and NICE’s subsequent decisions. The company conducted a systematic review to identify studies comparing POM with comparators outlined in the NICE scope: panobinostat with bortezomib and dexamethasone (PANO + BOR + DEX), bendamustine with thalidomide and dexamethasone (BTD) and conventional chemotherapy (CC). The main clinical effectiveness evidence was obtained from MM-003, a randomized controlled trial (RCT) comparing POM + LoDEX with high-dose dexamethasone (HiDEX; used as a proxy for CC). Additional data from other studies were also used as nonrandomized observational data sources for the indirect treatment comparison of POM + LoDEX with BTD and PANO + BOR + DEX. Covariate or treatment switching adjustment methods were used for each comparison. The model developed in Microsoft® Excel 2010 using a semi-Markov partitioned survival structure, submitted in the original submission to NICE for TA338, was adapted for the present assessment of the cost effectiveness of POM + LoDEX. Updated evidence from the clinical-effectiveness part was used for the survival modelling of progression-free survival and overall survival. For POM + LoDEX, the patient access scheme (PAS) discount was applied to the POM price. Three separate comparisons were conducted for each comparator, each comparison using a different dataset and adjustment methods. The ERG identified and corrected some errors, and the corrected incremental cost-effectiveness ratios (ICERs) for POM + LoDEX versus each comparator were presented: approximately £45,000 per quality-adjusted life-year (QALY) gained versus BTD, savings of approximately £143,000 per QALY lost versus PANO + BOR + DEX, and approximately £49,000 per QALY gained versus CC. The ERG also conducted full incremental analyses, which revealed that CC, POM + LoDEX and PANO + BOR + DEX were on the cost-effectiveness frontier. The committee’s decision on the technology under analysis deemed that POM + LoDEX should be recommended as an option for treating multiple myeloma in adults at third or subsequent relapse of treatments including both LEN and BOR, contingent on the company providing POM with the discount agreed in the PAS.
PharmacoEconomics | 2018
Nasuh Büyükkaramikli; Saskia de Groot; R.P. Riemsma; Debra Fayter; Nigel Armstrong; Piet Portegijs; Steven Duffy; Jos Kleijnen; Maiwenn Al
The National Institute for Health and Care Excellence, as part of the institute’s single technology appraisal process, invited the manufacturer of ribociclib (Kisqali®, Novartis) to submit evidence regarding the clinical and cost effectiveness of the drug in combination with an aromatase inhibitor for the treatment of previously untreated, hormone receptor-positive, human epidermal growth factor receptor 2-negative, locally advanced or metastatic breast cancer. Kleijnen Systematic Reviews Ltd and Erasmus University Rotterdam were commissioned as the Evidence Review Group for this submission. The Evidence Review Group reviewed the evidence submitted by the manufacturer, corrected and validated the manufacturer’s decision analytic model, and conducted exploratory analyses to assess the robustness and validity of the presented clinical and cost-effectiveness results. This article describes the company submission, the Evidence Review Group assessment and National Institute for Health and Care Excellence subsequent decisions. The main clinical effectiveness evidence was obtained from the MONALEESA-2 trial, a randomised controlled trial comparing ribociclib plus letrozole with placebo plus letrozole. Progression-free survival was significantly longer in the ribociclib group (95% confidence interval, 19.3–not reached) vs. 14.7 months (95% confidence interval 13.0–16.5) in the placebo group. To assess the cost effectiveness of ribociclib in combination with an aromatase inhibitor, the company developed an individual patient-level model using a discrete-event simulation approach in Microsoft® Excel. In the model, simulated patients move through a series of three health states until death, i.e. first-line progression-free survival, second-line progression-free survival and progressive disease. The length of progression-free survival during the first line was informed by the MONALEESA-2 trial. The benefit in progression-free survival in the first line was transferred to a benefit in overall survival assuming full progression-free survival to overall survival surrogacy (because of the immaturity of overall survival data from the MONALEESA-2 trial). Patient-level data from the BOLERO-2 trial, evaluating the addition of everolimus to exemestane in the second-line treatment of postmenopausal HR-positive advanced breast cancer, were used to inform the length of progression-free survival during the second line. Costs included in the model were treatment costs (e.g. technology acquisition costs of first, second, third and/or later line treatments), drug administration costs, monitoring costs and health state costs (including terminal care). Additionally, the costs of adverse events associated with the first-line treatment were incorporated. The Evidence Review Group recalculated the incremental cost-effectiveness ratio using data from a different data cut-off date from the MONALEESA-2 trial and by changing some assumptions (e.g. progression-free survival to overall survival surrogacy approach and post-progression third and/or later line treatment-related costs). After two appraisal committee meetings and a revised base case submitted by the company (including a second enhanced patient access scheme discount), the committee concluded that taking into account the uncertainties in the calculation of the cost effectiveness, there were plausible cost-effectiveness estimates broadly in the range that could be considered as a cost-effective use of National Health Service resources. Therefore, ribociclib was recommended as a treatment option for the first-line treatment of hormone receptor-positive, human epidermal growth factor receptor 2-negative breast cancer, contingent on the company providing ribociclib with the discount agreed in the second enhanced patient access scheme.
BMJ Open | 2018
Saskia de Groot; C. Enters-Weijnen; P. Geelhoed-Duijvestijn; Tim A. Kanters
Objectives Patients with diabetes mellitus are at a risk for hypoglycaemia. Besides the burden of hypoglycaemia for patients, hypoglycaemia poses an economic burden to society. The aim of this study was to calculate the per patient societal costs of hypoglycaemia among patients with type1 diabetes (T1DM) and type 2 diabetes (T2DM) on insulin therapy in the Netherlands. Methods To calculate the costs of hypoglycaemia, data from the Global Hypoglycaemia Assessment Tool (HAT) study were used. Dutch patients were selected from the HAT study database and data regarding healthcare resource use, informal care use and productivity losses were combined with Dutch unit costs to calculate the per patient 4-week costs of patients experiencing hypoglycaemia. Besides these 4-week costs, costs per hypoglycaemic event were calculated by dividing the study population total 4-week costs by the total number of events in this period. Results Mean 4-week total costs of hypoglycaemia amounted to €163 (SD, €870) in T1DM and €134 (SD, €364) in T2DM. While productivity costs were the most important cost driver of hypoglycaemia in patients with T1DM (accounting for 72% of the total costs), costs of hypoglycaemia in patients with T2DM were almost entirely driven by costs within the healthcare sector (accounting for 98% of the total costs). Mean costs of a severe hypoglycaemic event were €828 and €508 in T1DM and T2DM, respectively, whereas mean costs of a non-severe event were almost zero. Conclusions This study showed that the economic burden of severe hypoglycaemia is substantial. The prevention of hypoglycaemia could therefore not only reduce the burden for patients, but also the economic burden to society.
PharmacoEconomics | 2013
Chantal W. M. van Gils; Saskia de Groot; William K. Redekop; Miriam Koopman; Cornelis J. A. Punt; Carin A. Uyl-de Groot
Value in Health | 2017
Saskia de Groot; Naomi van der Linden; Margreet Franken; Hedwig M. Blommestein; B Leeneman; Ellen van Rooijen; J.J.M. van der Hoeven; Michel W.J.M. Wouters; Hans M. Westgeest; Carin A. Uyl-de Groot