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Dive into the research topics where Mirthe E. van der Valk is active.

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Featured researches published by Mirthe E. van der Valk.


Gut | 2014

Healthcare costs of inflammatory bowel disease have shifted from hospitalisation and surgery towards anti-TNFα therapy: results from the COIN study.

Mirthe E. van der Valk; Marie-Josée J. Mangen; Max Leenders; Gerard Dijkstra; Ad A. van Bodegraven; Herma H. Fidder; Dirk J. de Jong; Marieke Pierik; C. Janneke van der Woude; Mariëlle Romberg-Camps; Cees H. Clemens; Jeroen M. Jansen; Nofel Mahmmod; Paul C. van de Meeberg; Andrea E. van der Meulen-de Jong; Cyriel Y. Ponsioen; Clemens J. M. Bolwerk; J. Reinoud Vermeijden; Peter D. Siersema; Martijn G. van Oijen; Bas Oldenburg

Objective The introduction of anti tumour necrosis factor-α (anti-TNFα) therapy might impact healthcare expenditures, but there are limited data regarding the costs of inflammatory bowel diseases (IBD) following the introduction of these drugs. We aimed to assess the healthcare costs and productivity losses in a large cohort of IBD patients. Design Crohns disease (CD) and ulcerative colitis (UC) patients from seven university hospitals and seven general hospitals were invited to fill-out a web-based questionnaire. Cost items were derived from a 3 month follow-up questionnaire and categorised in outpatient clinic, diagnostics, medication, surgery and hospitalisation. Productivity losses included sick leave of paid and unpaid work. Costs were expressed as mean 3-month costs per patients with a 95% CI obtained using non-parametric bootstrapping. Results A total of 1315 CD patients and 937 UC patients were included. Healthcare costs were almost three times higher in CD as compared with UC, €1625 (95% CI €1476 to €1775) versus €595 (95% CI €505 to €685), respectively (p<0.01). Anti-TNFα use was the main costs driver, accounting for 64% and 31% of the total cost in CD and UC. Hospitalisation and surgery together accounted for 19% and <1% of the healthcare costs in CD and 23% and 1% in UC, respectively. Productivity losses accounted for 16% and 39% of the total costs in CD and UC. Conclusions We showed that healthcare costs are mainly driven by medication costs, most importantly by anti-TNFα therapy. Hospitalisation and surgery accounted only for a minor part of the healthcare costs.


PLOS ONE | 2016

Evolution of costs of inflammatory bowel disease over two years of follow-up

Mirthe E. van der Valk; Marie-Josée J. Mangen; Mirjam Severs; Mike van der Have; Gerard Dijkstra; Ad A. van Bodegraven; Herma H. Fidder; Dirk J. de Jong; C. Janneke van der Woude; Mariëlle Romberg-Camps; Cees H. Clemens; Jeroen M. Jansen; Paul C. van de Meeberg; Nofel Mahmmod; Andrea E. van der Meulen-de Jong; Cyriel Y. Ponsioen; Clemens J. M. Bolwerk; J. Reinoud Vermeijden; Peter D. Siersema; Max Leenders; Bas Oldenburg; Colitis (Icc)

Background With the increasing use of anti-TNF therapy in inflammatory bowel disease (IBD), a shift of costs has been observed with medication costs replacing hospitalization and surgery as major cost driver. We aimed to explore the evolution of IBD-related costs over two years of follow-up. Methods and Findings In total 1,307 Crohns disease (CD) patients and 915 ulcerative colitis (UC) patients were prospectively followed for two years by three-monthly web-based questionnaires. Changes of healthcare costs, productivity costs and out-of-pocket costs over time were assessed using mixed model analysis. Multivariable logistic regression analysis was used to identify costs drivers. In total 737 CD patients and 566 UC were included. Total costs were stable over two years of follow-up, with annual total costs of €7,835 in CD and €3,600 in UC. However, within healthcare costs, the proportion of anti-TNF therapy-related costs increased from 64% to 72% in CD (p<0.01) and from 31% to 39% in UC (p < 0.01). In contrast, the proportion of hospitalization costs decreased from 19% to 13% in CD (p<0.01), and 22% to 15% in UC (p < 0.01). Penetrating disease course predicted an increase of healthcare costs (adjusted odds ratio (adj. OR) 1.95 (95% CI 1.02–3.37) in CD and age <40 years in UC (adj. OR 4.72 (95% CI 1.61–13.86)). Conclusions BD-related costs remained stable over two years. However, the proportion of anti-TNF-related healthcare costs increased, while hospitalization costs decreased. Factors associated with increased costs were penetrating disease course in CD and age <40 in UC.


Gut | 2012

Crohn's disease patients treated with adalimumab benefit from co-treatment with immunomodulators

Mirthe E. van der Valk; Martijn G. van Oijen; Marije J. Ammerlaan; Peter D. Siersema; Bas Oldenburg

We read with interest the study by Sokol et al in Gut , emphasising the need for co-treatment with immunomodulators in patients receiving infliximab maintenance therapy. Concomitant use of immunosuppressives was associated with reduced disease activity and infliximab dose escalation, presumably through a lowered frequency of antibody formation.1 Although adalimumab is a 100% human anti-tumour necrosis factor monoclonal antibody, it is not devoid of immunogenicity. Antibodies against adalimumab have been reported in 2.6–38% of patients treated for Crohns disease or rheumatoid arthritis.2 However, the long-term efficacy of the combination of adalimumab plus immunosuppressives in this setting is not known. One observational study from Karmiris et al performed at …


Gastrointestinal Endoscopy | 2014

A risk-profiling approach for surveillance of inflammatory bowel disease-colorectal carcinoma is more cost-effective: a comparative cost-effectiveness analysis between international guidelines

Maurice W. Lutgens; Martijn G. van Oijen; Erik Mooiweer; Mirthe E. van der Valk; Frank P. Vleggaar; Peter D. Siersema; Bas Oldenburg

BACKGROUND Colonoscopic surveillance for neoplasia is recommended for patients with inflammatory bowel disease (IBD)-related colitis. However, data on cost-effectiveness predate current international guidelines. OBJECTIVE To compare cost-effectiveness based on contemporary data between the surveillance strategies of the American Gastroenterological Association (AGA) and British Society of Gastroenterology (BSG). DESIGN We constructed a Markov decision model to simulate the clinical course of IBD patients. SETTING We compared the 2 surveillance strategies for a base case of a 40-year-old colitis patient who was followed for 40 years. PATIENTS AGA surveillance distinguishes 2 groups: a high-risk group with annual surveillance and an average-risk group with biannual surveillance. BSG surveillance distinguishes 3 risk groups with yearly, 3-year, or 5-year surveillance. INTERVENTIONS Patients could move from a no-dysplasia state with colonoscopic surveillance to 1 of 3 states for which proctocolectomy was indicated: (1) dysplasia/local cancer, (2) regional/metastasized cancer, or (3) refractory disease. After proctocolectomy, a patient moved to a no-colon state without surveillance. MAIN OUTCOME MEASUREMENTS Direct costs of medical care, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios. RESULTS BSG surveillance dominated AGA surveillance with


Inflammatory Bowel Diseases | 2016

Assessing Self-reported Medication Adherence in Inflammatory Bowel Disease: A Comparison of Tools.

Mirjam Severs; Peter Zuithoff; Marie-Josée J. Mangen; Mirthe E. van der Valk; Peter D. Siersema; Herma H. Fidder; Bas Oldenburg

9846 per QALY. Both strategies were equally effective with 24.16 QALYs, but BSG surveillance was associated with lower costs because of fewer colonoscopies performed. Costs related to IBD, surgery, or cancer did not affect cost-effectiveness. LIMITATIONS The model depends on the accuracy of derived data, and the assumptions that were made to reflect real-life situations. Study conclusions may only apply to the U.S. health care system. CONCLUSION The updated risk-profiling approach for surveillance of IBD colorectal carcinoma by the BSG guideline appears to be more cost-effective.


Journal of Crohns & Colitis | 2015

Comparison of Costs and Quality of Life in Ulcerative Colitis Patients with an Ileal Pouch-Anal Anastomosis, Ileostomy and Anti-TNFα Therapy

Mirthe E. van der Valk; Marie-Josée J. Mangen; Mirjam Severs; Mike van der Have; Gerard Dijkstra; Ad A. van Bodegraven; Herma H. Fidder; Dirk J. de Jong; Marieke Pierik; C. Janneke van der Woude; Mariëlle Romberg-Camps; Cees H. Clemens; Jeroen M. Jansen; Paul C. van de Meeberg; Nofel Mahmmod; Andrea E. van der Meulen-de Jong; Cyriel Y. Ponsioen; Clemens J. M. Bolwerk; J. Reinoud Vermeijden; Peter D. Siersema; Max Leenders; Bas Oldenburg

Background:Capturing (non)-adherence to medical prescriptions in patients with inflammatory bowel disease (IBD) is challenging. We aimed to compare 3 different tools to measure self-assessed medication adherence of patients with IBD. Methods:Adult patients with Crohns disease and ulcerative colitis were prospectively followed. IBD-specific medication use was collected by 3-monthly questionnaires. At 2.5 years of follow-up, medication adherence was assessed using 3 tools: (1) the 8-item Morisky Medication Adherence Scale (MMAS-8), (2) the single question how well patients take their daily medication using a Visual Analogue Scale (VAS), and (3) the Forget Medicine scale (FM), assessing how often patients forget their medication. Cross-sectional agreement among measures was visualized with scatterplots and quantified with Spearmans rank correlations. Results:In total, 913 patients with IBD were analyzed, 697 of whom received IBD-specific medication. High adherence on the MMAS-8 was consistent with high scores on the VAS and low scores on the FM. Disagreement between tools increased when patients were less adherent. A correlation of 0.44 was found between the MMAS-8 and VAS; −0.59 between the MMAS-8 and FM, and −0.55 between the VAS and FM (all P < 0.01). The VAS most optimally represented the quantitative variability of adherence, whereas the MMAS-8 and the FM might have resulted in overestimation or underestimation of adherence due to unequal differences in outcome possibilities. Conclusions:In patients with IBD, a VAS seems the most appropriate tool for quantifying medication adherence in clinical practice. The MMAS-8 may be used additionally to provide insight in specific reasons for non-adherence.


Inflammatory Bowel Diseases | 2014

Effect of Aging on Healthcare Costs of Inflammatory Bowel Disease: A Glimpse into the Future

Mike van der Have; Marie-Josée J. Mangen; Mirthe E. van der Valk; Hugo M. Smeets; Ad A. van Bodegraven; Gerard Dijkstra; Herma H. Fidder; Dirk J. de Jong; Marieke Pierik; Cyriel Y. Ponsioen; Andrea E. van der Meulen-de Jong; C. Janneke van der Woude; Paul C. van de Meeberg; Mariëlle Romberg-Camps; Cees H. Clemens; Jeroen M. Jansen; Nofel Mahmmod; Clemens J. M. Bolwerk; J. Reinoud Vermeijden; Peter D. Siersema; Max Leenders; Bas Oldenburg

BACKGROUND AND AIMS More data are warranted on the economic impact of different treatment strategies in ulcerative colitis (UC) patients. We compared the costs and quality of life of UC patients with a pouch reconstruction, an ileostomy or anti-tumour necrosis factor α (TNFα) therapy. METHODS UC patients filled out 3-monthly questionnaires for 2 years. Differences in 3-monthly healthcare costs, productivity costs and patient costs were tested using mixed model analysis. Quality of life was assessed employing the ) and the inflammatory bowel disease questionnaire (IBDQ). RESULTS Out of 915 UC patients, 81 (9%) had a pouch and 48 (5%) an ileostomy, and 34 (4%) were on anti-TNFα therapy. Anti-TNFα-treated patients reported high UC related-healthcare costs per 3 months (€5350). Medication use accounted for 92% of healthcare costs. UC-attributable healthcare costs were 3-fold higher in ileostomy patients compared with pouch patients (€1581 versus €407; p < 0.01). Main cost drivers in ileostomy patients were healthcare costs and ileostomy supplies (2 and 23% of healthcare costs, respectively). In pouch patients, the main cost driver was hospitalization, accounting for 50% of healthcare costs. Productivity loss did not differ between pouch and ileostomy patients (€483 versus €377; p < 0.23), but was significantly higher in anti-TNFα-treated patients (€1085). No difference was found in IBDQ scores, but pouch patients were found to have higher quality-adjusted life years than ileostomy patients and anti-TNFα-treated patients (0.90 [interquartile range 0.78-1.00] versus 0.84 [0.78-1.00] and 0.84 [0.69-1.00], respectively; p < 0.01). CONCLUSION Patients receiving anti-TNFα therapy reported the highest healthcare cost, in which medication use was the major cost driver. Ileostomy patients were three times more expensive than pouch patients due to frequent hospitalization and ileostomy supplies.


Inflammatory Bowel Diseases | 2017

Clinical Predictors of Future Nonadherence in Inflammatory Bowel Disease

Mirjam Severs; Marie-Josée J. Mangen; Herma H. Fidder; Mirthe E. van der Valk; Mike van der Have; Ad A. van Bodegraven; Cees H. Clemens; Gerard Dijkstra; Jeroen M. Jansen; Dirk J. de Jong; Nofel Mahmmod; Paul C. van de Meeberg; Andrea E. van der Meulen-de Jong; Marieke Pierik; Cyriel Y. Ponsioen; Mariëlle Romberg-Camps; Peter D. Siersema; Bindia Jharap; C. Janneke van der Woude; Nicolaas P.A. Zuithoff; Bas Oldenburg

Background:Population aging is expected to result in a substantial additional burden on healthcare resources in the near future. We aimed to assess the current and future impact of aging on direct healthcare costs (DHC) attributed to inflammatory bowel disease (IBD). Methods:Patients with IBD from a Dutch multicenter cohort filled out 3-monthly questionnaires for 2 years. Elderly (≥60 yr) and younger patients (18–60 yr) IBD were analyzed for differences in 3-monthly DHC, productivity losses, and out-of-pocket costs. Prevalence rates were obtained from a health insurance database. Estimates of annual DHC and prevalence rates were applied to the total Dutch adult population in 2011 and then projected to 2040, using predicted changes in population demography, prices, and volume. Results:IBD-attributable DHC were lower in elderly than in younger patients with IBD with respect to 3-monthly DHC (&OV0556;359 versus &OV0556;978, P < 0.01), productivity losses (&OV0556;108 versus &OV0556;456, P < 0.01), and out-of-pocket costs (&OV0556;40 versus &OV0556;57, P < 0.01). Between 2011 and 2040, the percentage of elderly IBD patients in the Netherlands has been projected to rise from 24% to 35%. Between 2011 and 2040, DHC of the total IBD population in the Netherlands are projected to increase from &OV0556;161 to &OV0556;661 million. Population aging accounted for 1% of this increase, next to rising prices (29%), and volume growth (70%). Conclusions:Population aging has a negligible effect on IBD-attributable DHC of the IBD population in the near future, because the average costs incurred by elderly patients with IBD are considerably lower than those incurred by younger patients with IBD.


Inflammatory Bowel Diseases | 2018

Sex-Related Differences in Patients With Inflammatory Bowel Disease: Results of 2 Prospective Cohort Studies

Mirjam Severs; Lieke M. Spekhorst; Marie-Josée J. Mangen; Gerard Dijkstra; M. Lowenberg; Frank Hoentjen; Andrea E. van der Meulen-de Jong; Marieke Pierik; Cyriel Y. Ponsioen; Gerd Bouma; Janneke van der Woude; Mirthe E. van der Valk; Mariëlle Romberg-Camps; Cees H. Clemens; Paul C. van de Meeberg; Nofel Mahmmod; Jeroen M. Jansen; Bindia Jharap; Rinse K. Weersma; Bas Oldenburg; Eleonora A. Festen; Herma H. Fidder

Background: Nonadherence to medical therapy is frequently encountered in patients with inflammatory bowel disease (IBD). We aimed to identify predictors for future (non)adherence in IBD. Methods: We conducted a multicenter prospective cohort study with adult patients with Crohns disease (CD) and ulcerative colitis (UC). Data were collected by means of 3-monthly questionnaires on the course of disease and healthcare utilization. Medication adherence was assessed using a visual analogue scale, ranging from 0% to 100%. Levels <80% were considered to indicate nonadherence. The Brief Illness Perception Questionnaire was used to identify illness perceptions. We used a logistic regression analysis to identify patient- and disease-related factors predictive of nonadherence 3 months after the assessment of predictors. Results: In total, 1558 patients with CD and 1054 patients with UC were included and followed for 2.5 years. On average, 12.1% of patients with CD and 13.3% of patients with UC using IBD-specific medication were nonadherent. Nonadherence was most frequently observed in patients using mesalazine (CD), budesonide (UC) and rectally administrated therapy (both CD and UC). A higher perceived treatment control and understanding of the disease were associated with adherence to medical therapy. Independent predictors of future nonadherence were age at diagnosis (odds ratio [OR]: 0.99 per year), nonadherence (OR: 26.91), a current flare (OR: 1.30) and feelings of anxiety/depression (OR: 1.17), together with an area under the receiver-operating-characteristics curve of 0.74. Conclusions: Lower age at diagnosis, flares, feelings of anxiety or depression, and nonadherence are associated with future nonadherence in patients with IBD. Altering illness perceptions could be an approach to improve adherence behavior.


Journal of Crohns & Colitis | 2014

Risk factors of work disability in patients with inflammatory bowel disease — A Dutch nationwide web-based survey

Mirthe E. van der Valk; Marie-Josée J. Mangen; Max Leenders; Gerard Dijkstra; Ad A. van Bodegraven; Herma H. Fidder; Dirk J. de Jong; Marieke Pierik; C. Janneke van der Woude; Mariëlle Romberg-Camps; Cees H. Clemens; Jeroen M. Jansen; Nofel Mahmmod; Paul C. van de Meeberg; Andrea E. van der Meulen-de Jong; Cyriel Y. Ponsioen; Clemens J. M. Bolwerk; J. Reinoud Vermeijden; Peter D. Siersema; Martijn G. van Oijen; Bas Oldenburg

Background The understanding of gender differences in inflammatory bowel disease (IBD) patients is an important step towards tailored treatment for the individual patient. The aim of this study was to compare disease phenotype, clinical manifestations, disease activity, and healthcare utilization between men and women with Crohns disease (CD) and ulcerative colitis (UC). Methods Two multicenter observational cohort studies with a prospective design were used to explore the differences between men and women regarding demographic and phenotypic characteristics and healthcare utilization. Detailed data on IBD-phenotype was mainly available from the Dutch IBD Biobank, while the COIN cohort provided healthcare utilization data. Results In the Dutch IBD Biobank study, 2118 CD patients and 1269 UC patients were analyzed. Female CD patients were more often current smokers, and male UC patients were more often previous smokers. Early onset CD (<16 years) was more frequently encountered in males than in females (20% versus 12%, P < 0.01). Male CD patients were more often diagnosed with ileal disease (28% versus 20%, P < 0.01) and underwent more often small bowel and ileocecal resection. Extraintestinal manifestations (EIMs) were more often encountered in female IBD patients. In the COIN study, 1139 CD patients and 1213 UC patients were analyzed. Male CD patients used prednisone more often and suffered more often from osteopenia. IBD-specific healthcare costs did not differ between male and female IBD patients. Conclusions Sex differences in patients with IBD include age of onset, disease location, and EIM prevalence. No large differences in therapeutic management of IBD were observed between men and women with IBD. 10.1093/ibd/izy004_video1izy004_Video_15786481854001.

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Peter D. Siersema

Radboud University Nijmegen

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Gerard Dijkstra

University Medical Center Groningen

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Nofel Mahmmod

University Medical Center Groningen

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Dirk J. de Jong

Radboud University Nijmegen

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