Iris Lansdorp Vogelaar

Prof. Iris Lansdorp Vogelaar


Research Focus & Metrics

Academic Career Length

21Years (2006-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 June 2011 in Epidemiologic Reviews
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Journal Article
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IVIris Lansdorp Vogelaar
Iris Lansdorp Vogelaar
AKAmy B. Knudsen
Amy B. Knudsen
HBHermann Brenner
Hermann Brenner
Colorectal cancer is an important public health problem. Several screening methods have been shown to be effective in reducing colorectal cancer mortality. The objective of this review was to assess the cost-effectiveness of the different colorectal cancer screening methods and to determine the preferred method from a cost-effectiveness point of view. Five databases (MEDLINE, EMBASE, the Cost-Effectiveness Analysis Registry, the British National Health Service Economic Evaluation Database, and the lists of technology assessments of the Centers for Medicare and Medicaid Services) were searched for cost-effectiveness analyses published in English between January 1993 and December 2009. Fifty-five publications relating to 32 unique cost-effectiveness models were identified. All studies found that colorectal cancer screening was cost-effective or even cost-saving compared with no screening. However, the studies disagreed as to which screening method was most effective or had the best incremental cost-effectiveness ratio for a given willingness to pay per life-year gained. There was agreement among studies that the newly developed screening tests of stool DNA testing, computed tomographic colonography, and capsule endoscopy were not yet cost-effective compared with the established screening options.

1 May 2012 in Cancer Epidemiology, Biomarkers & Prevention
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Journal Article
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IVIris Lansdorp Vogelaar
Iris Lansdorp Vogelaar
KKKaren M. Kuntz
Karen M. Kuntz
AKAmy B. Knudsen
Amy B. Knudsen
MBMarjolein van Ballegooijen
Marjolein van Ballegooijen
AZAnn G. Zauber
Ann G. Zauber
AJAhmedin Jemal
Ahmedin Jemal
Background: Considerable disparities exist in colorectal cancer (CRC) incidence and mortality rates between blacks and whites in the United States. We estimated how much of these disparities could be explained by differences in CRC screening and stage-specific relative CRC survival. Methods: We used the MISCAN-Colon microsimulation model to estimate CRC incidence and mortality rates in blacks, aged 50 years and older, from 1975 to 2007 assuming they had: (i) the same trends in screening rates as whites instead of observed screening rates (incidence and mortality); (ii) the same trends in stage-specific relative CRC survival rates as whites instead of observed (mortality only); and (iii) a combination of both. The racial disparities in CRC incidence and mortality rates attributable to differences in screening and/or stage-specific relative CRC survival were then calculated by comparing rates from these scenarios to the observed black rates. Results: Differences in screening accounted for 42% of disparity in CRC incidence and 19% of disparity in CRC mortality between blacks and whites. Thirty-six percent of the disparity in CRC mortality could be attributed to differences in stage-specific relative CRC survival. Together screening and survival explained a little more than 50% of the disparity in CRC mortality between blacks and whites. Conclusion: Differences in screening and relative CRC survival are responsible for a considerable proportion of the observed disparities in CRC incidence and mortality rates between blacks and whites. Impact: Enabling blacks to achieve equal access to care as whites could substantially reduce the racial disparities in CRC burden. Cancer Epidemiol Biomarkers Prev; 21(5); 728–36. ©2012 AACR.

18 September 2006 in Cancer
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Journal Article
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IVIris Lansdorp Vogelaar
Iris Lansdorp Vogelaar
MBMarjolein van Ballegooijen
Marjolein van Ballegooijen
DSDeborah Schrag
Deborah Schrag
RBRob Boer
Rob Boer
SWSidney J. Winawer
Sidney J. Winawer
AZAnn G. Zauber
Ann G. Zauber
BACKGROUND.: Although colorectal cancer (CRC) is the second leading cause of cancer death in the U.S., available interventions to reduce CRC mortality are disseminated only partially throughout the population. This study assessed the potential reduction in CRC mortality that may be achieved through further dissemination of current interventions for risk‐factor modification, screening, and treatment.METHODS.: The MISCAN‐COLON microsimulation model was used to simulate the 2000 U.S. population with respect to CRC risk‐factor prevalence, screening use, and treatment use. The model was used to project age‐standardized CRC mortality from 2000 to 2020 for 3 intervention scenarios.RESULTS.: Without changes in risk‐factor prevalence, screening use, and treatment use after 2000, CRC mortality would decrease by 17% by the Year 2020. If the 1995 to 2000 trends continue, then the projected reduction in mortality would be 36%. However, if trends in the prevalence of risk‐factors could be improved above continued trends, if screening use increased to 70% of the target population, and if the use of chemotherapy increased among all age groups, then a 49% reduction would be possible. Screening drove most (23%) of the projected mortality reduction with these optimistic trends; however, decreasing risk‐factors (16%) and increasing use of chemotherapy (10%) also contributed substantially. The contribution of risk‐factors may have been overestimated, because effect estimates could not be obtained from randomized controlled trials.CONCLUSIONS.: Currently available interventions for risk‐factor modification, screening, and treatment have the potential to reduce CRC mortality by almost 50% by the Year 2020. However, without action now to further increase the uptake of current effective interventions, the reduction in CRC mortality may be only 17%. Cancer 2006. © American Cancer Society.

24 September 2009 in JNCI: Journal of the National Cancer Institute
Verified
Journal Article
Open access
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IVIris Lansdorp Vogelaar
Iris Lansdorp Vogelaar
MBMarjolein van Ballegooijen
Marjolein van Ballegooijen
AZAnn G. Zauber
Ann G. Zauber
JHJ. Dik F. Habbema
J. Dik F. Habbema
EKErnst J. Kuipers
Ernst J. Kuipers
Although colorectal cancer screening is cost-effective, it requires a considerable net investment by governments or insurance companies. If screening was cost saving, governments and insurance companies might be more inclined to invest in colorectal cancer screening programs. We examined whether colorectal cancer screening would become cost saving with the widespread use of the newer, more expensive chemotherapies. We used the MISCAN-Colon microsimulation model to assess whether widespread use of new chemotherapies would affect the treatment savings of colorectal cancer screening in the general population. We considered three scenarios for chemotherapy use: the past, the present, and the near future. We assumed that survival improved and treatment costs for patients diagnosed with advanced stages of colorectal cancer increased over the scenarios. Screening strategies considered were annual guaiac fecal occult blood testing (FOBT), annual immunochemical FOBT, sigmoidoscopy every 5 years, colonoscopy every 10 years, and the combination of sigmoidoscopy every 5 years and annual guaiac FOBT. Analyses were conducted from the perspective of the health-care system for a cohort of 50-year-old individuals who were at average risk of colorectal cancer and were screened with 100% adherence from age 50 years to age 80 years and followed up until death. Compared with no screening, the treatment savings from preventing advanced colorectal cancer and colorectal cancer deaths by screening more than doubled with the widespread use of new chemotherapies. The lifetime average treatment savings were larger than the lifetime average screening costs for screening with Hemoccult II, immunochemical FOBT, sigmoidoscopy, and the combination of sigmoidoscopy and Hemoccult II (average savings vs costs per individual in the population: Hemoccult II, $1398 vs $859; immunochemical FOBT, $1756 vs $1565; sigmoidoscopy, $1706 vs $1575; sigmoidoscopy and Hemoccult II $1931 vs $1878). Colonoscopy did not become cost saving, but the total net costs of this strategy decreased from $1317 to $296 per individual in the population. With the increase in chemotherapy costs for advanced colorectal cancer, most colorectal cancer screening strategies have become cost saving. As a consequence, screening is a desirable approach not only to reduce colorectal cancer incidence and mortality but also to control the costs of colorectal cancer treatment.

15 July 2014 in Annals of Internal Medicine
Verified
Journal Article
Closed access
IVIris Lansdorp Vogelaar
Iris Lansdorp Vogelaar
RGRoman Gulati
Roman Gulati
AMAngela B. Mariotto
Angela B. Mariotto
CSClyde B. Schechter
Clyde B. Schechter
TCTiago M. de Carvalho
Tiago M. de Carvalho
JMJeanne S. Mandelblatt
Jeanne S. Mandelblatt
The net benefit of cancer screening depends on the patient's age and comorbid conditions, but reliable methods of evaluating when to cease screening are lacking. This modeling study estimated the h... Background: Harms and benefits of cancer screening depend on age and comorbid conditions, but reliable estimates are lacking. Objective: To estimate the harms and benefits of cancer screening by ag...

3 June 2014 in Annals of Internal Medicine
Verified
Journal Article
Closed access
FHFrank van Hees
Frank van Hees
JHJ. Dik F. Habbema
J. Dik F. Habbema
RMReinier G. Meester
Reinier G. Meester
IVIris Lansdorp Vogelaar
Iris Lansdorp Vogelaar
MBMarjolein van Ballegooijen
Marjolein van Ballegooijen
AZAnn G. Zauber
Ann G. Zauber
Some guidelines caution against routine screening for colorectal cancer in persons older than 75 years with an adequate screening history but have not addressed screening in those without a screeni... Background: The U.S. Preventive Services Task Force recommends against routine screening for colorectal cancer (CRC) in adequately screened persons older than 75 years but does not address the appr...