Sandra van Dijk
Leiden University Medical Center
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Publication
Featured researches published by Sandra van Dijk.
Journal of Clinical Oncology | 2006
Sandra van Dijk; Danielle R.M. Timmermans; Hanne Meijers-Heijboer; Aad Tibben; Christi J. van Asperen; Wilma Otten
PURPOSE DNA mutation testing for breast cancer usually yields an uninformative result, which is a negative result in the absence of a known BRCA mutation within the family. However, few data are available on the psychological impact of this result. Moreover, the clinical heterogeneity within this group has not yet been considered. This study provides prospective data about the course of cancer-specific worry and distress for different groups of test applicants. PATIENTS AND METHODS All DNA test applicants (n = 238) completed three questionnaires: before and 1 and 7 months after disclosure of a DNA mutation test. With repeated-measures analysis of variance, differences were assessed between BRCA1/2-positive women (n = 42), BRCA1/2-true-negative women (n = 43), and women with an uninformative test result (n = 153). RESULTS On the group level, women with an uninformative result seemed to be reassured after disclosure (P < .001), but to a lesser extent than those women who received a true-negative result. However, not all women with an uninformative result reacted similarly: higher levels of worry and distress could be explained by relatively straightforward clinical variables, namely a personal history of cancer (P < or = .001) and a higher pedigree-based risk (P < or = .005). Furthermore, these clinical variables determined whether these women were either comparable to women who received a true-negative result or to BRCA mutation carriers. CONCLUSION Women with an uninformative result form a heterogeneous group of test applicants. The subpopulation of those with both a personal history of cancer and a relatively high pedigree-based risk expressed the highest levels of worry 7 months after DNA testing.
Nephrology Dialysis Transplantation | 2011
Gurbey Ocak; Nynke Halbesma; Saskia le Cessie; Ellen K. Hoogeveen; Sandra van Dijk; Jeroen P. Kooman; Friedo W. Dekker; Raymond T. Krediet; Elisabeth W. Boeschoten; Marion Verduijn
BACKGROUND Catheter use has been associated with an increased mortality risk in haemodialysis patients. However, differences in the all-cause and cause-specific mortality risk between catheter use and arteriovenous access use in young and elderly haemodialysis patients have not yet been investigated. METHODS In this prospective cohort study of 1109 incident haemodialysis patients from 38 centres in the Netherlands, hazard ratios (HRs) with 95% confidence intervals (95% CIs) were calculated for 2-year all-cause, infection-related and cardiovascular mortality in patients with a catheter as compared to patients with an arteriovenous access stratified for age (< 65 years and ≥ 65 years). RESULTS Of the 1109 patients, 919 had an arteriovenous access and 190 had a catheter. The mortality rate was 76 per 1000 person-years in young patients with an arteriovenous access, 129 per 1000 person-years in young patients with a catheter, 222 per 1000 person-years in elderly patients with an arteriovenous access and 427 per 1000 person-years in elderly patients with a catheter. The adjusted HR was 3.15 (95% CI: 2.09-4.75) for elderly patients with a catheter as compared to young patients with an arteriovenous access. The adjusted HRs in elderly patients with a catheter as compared to elderly patients with an arteriovenous access were 1.54 (95% CI: 1.13-2.12) for all-cause mortality, 1.60 (95%: CI 0.62-4.19) for infection-related mortality and 1.67 (95% CI: 1.04-2.68) for cardiovascular mortality. CONCLUSIONS Especially, elderly haemodialysis patients with a catheter have an increased all-cause, infection-related and cardiovascular mortality risk as compared to patients with an arteriovenous access.
Clinical Journal of The American Society of Nephrology | 2012
Ellen K. Hoogeveen; Nynke Halbesma; Kenneth J. Rothman; Theo Stijnen; Sandra van Dijk; Friedo W. Dekker; Elisabeth W. Boeschoten; Renée de Mutsert
BACKGROUND AND OBJECTIVES Many studies show that obesity in dialysis patients is not strongly associated with mortality but not whether this modest association is constant over age. This study investigated the extent to which the relation of body mass index (BMI) and mortality differs between younger and older dialysis patients. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Adult dialysis patients were prospectively followed from their first dialysis treatment for 7 years or until death or transplantation. Patients were stratified by age (<65 or ≥65 years) and baseline BMI (<20, 20-24 [reference], 25-29, and ≥30 kg/m(2)). RESULTS The study sample included 984 patients younger than 65 years and 765 patients 65 years or older; cumulative survival proportions at end of follow-up were 50% and 16%. Age-standardized mortality rate was 1.7 times higher in obese younger patients than those with normal BMI, corresponding to an excess rate of 5.2 deaths/100 patient-years. Mortality rates were almost equal between obese older patients and those with normal BMI. Excess rates of younger and older patients with low compared with normal BMI were 8.7 and 1.1 deaths/100 patient-years. After adjustment for age, sex, smoking, comorbidity, and treatment modality, hazard ratios by increasing BMI were 2.00, 1, 0.95, and 1.57 for younger patients and 1.07, 1, 0.88, and 0.91 for older patients, implying that obesity is a 1.7-fold (95% confidence interval, 1.1- to 2.9-fold) stronger risk factor in younger than older patients. CONCLUSIONS In contrast to older dialysis patients, younger patients with low or very high BMI had a substantially elevated risk for death.
Journal of Clinical Oncology | 2008
Sandra van Dijk; Mariëlle S. van Roosmalen; Wilma Otten; Peep F. M. Stalmeier
PURPOSE Women who test positive for a BRCA1/2 mutation face difficult choices to manage their breast cancer risk; one of these choices is whether to opt for prophylactic mastectomy. Few data are available about this decision-making process. The current study provides data regarding the stability of risk-management preferences over time and the factors that are associated with these preferences. PATIENTS AND METHODS We analyzed data from 338 women who opted for breast cancer antigen (BRCA) testing. First, we prospectively assessed preferences of 80 BRCA mutation carriers at five different points in time ranging from 1 week after blood sampling up to 9 months after BRCA-test disclosure. Second, we applied univariate and multivariate regression analyses to examine which medical, sociodemographic, and psychological factors are related to a preference for prophylactic mastectomy. RESULTS Ninety percent of the women already indicated a preference regarding risk management at baseline. Moreover, most women had stable preferences over time. Furthermore, anticipated feelings of regret in case of a hypothetical breast cancer diagnosis in the near future were strongly related to risk-management preference (odds ratio = 8.93; P < .0001). CONCLUSION Women seem to decide at a relatively early stage about their risk-management preferences. Many of them may be sensitive to the possibility of regret in case of a bad outcome. We discuss whether possible regret in the future is a rational reason for opting for prophylactic mastectomy, or whether it signifies an emotional coping process or strategy in which the future costs are no longer fully considered.
Genetics in Medicine | 2005
Sandra van Dijk; Wilma Otten; Danielle R.M. Timmermans; Christi J. van Asperen; Hanne Meijers-Heijboer; Aad Tibben; Martijn H. Breuning; Job Kievit
Purpose: To test the “false-reassurance hypothesis,” which suggests that women who receive an uninformative BRCA1/2 test result may incorrectly conclude that they no longer have an elevated risk, with possible harmful consequences for adherence to breast surveillance guidelines.Methods: A prospective questionnaire design was used to compare 183 women with an uninformative BRCA test result (94 affected and 89 unaffected) with 41 proven BRCA mutation-carriers and 49 true negatives before and after BRCA1/2 test disclosure.Results: After DNA-test disclosure, test applicants differed from each other with regard to their perception of the likelihood of carrying a deleterious gene (P < 0.0001). The BRCA mutation carriers reported the highest perceived likelihood and the true negatives reported the lowest. Compared to the predisclosure measures, women who received an uninformative DNA test result reported a lower perceived risk after disclosure (P < 0.0001), suggesting a relatively high level of reassurance because of the test result. However, after DNA-test disclosure, only 12 women concluded that the risk of carrying a mutation was nonexistent, and perceived likelihood was significantly associated with the pedigree-based risk assessment (P = 0.0001). Moreover, despite the significant decrease in perceived likelihood for uninformative women, intention to obtain mammograms did not change (P = 0.71); it remained at the same almost optimal level as for BRCA mutation carriers.Conclusion: No support was found for the suggestion that the nature of uninformative test results is often misunderstood. Moreover, an uninformative test result did not affect the positive mammography intentions of both affected and unaffected women.
American Journal of Medical Genetics Part A | 2004
Sandra van Dijk; Wilma Otten; Christi J. van Asperen; Danielle R.M. Timmermans; Aad Tibben; Moniek W. Zoeteweij; Sylvia Silberg; Martijn H. Breuning; Job Kievit
Womens inaccuracy in recalling their breast cancer risk, even immediately after genetic counseling, has received much attention. However, scarce data are available about how women describe their risk in their own words and about what the risk information actually means to them. The present study aims to address interpretations questions and to assess whether these are congruent with the objective risk. Face‐to‐face interviews were conducted with 123 women immediately after their (initial) counseling session. N‐Vivo software was used to describe the data. The level of accuracy of recall depended strongly on the leniency of the criterion applied. For example, the level of verbal accuracy ranged from 25.8% (an exact match with the verbal label) to 98.4% (a more global awareness of having a high versus a low risk). In assessing the significance of personal risk information, we identified a wide variety of risk beliefs, and stress and coping responses. In general, women associated their risk with the medical options, for example, breast screening, that were available for them given their risk status. The results indicate that the accuracy of recall might be a limited outcome measure for the effectiveness of genetic counseling. First, this is because the level of accuracy of recall depends on how rigorously accuracy is defined. Secondly, because the probability of occurrence is just one of the elements comprising perceived risk, accuracy might rather apply to the distress, and to risk management behaviors that are elicited by the risk information. These beliefs that women hold about their risk status, and concomitant levels of stress should play a prominent role in genetic counseling.
BMC Nephrology | 2012
Ingrid B. de Groot; Karen Schipper; Sandra van Dijk; Paul J.M. van der Boog; Anne M. Stiggelbout; Andrzej G. Baranski; Perla J. Marang-van de Mheen
BackgroundLimited data exist on the impact of living kidney donation on the donor-recipient relationship. Purpose of this study was to explore motivations to donate or accept a (living donor) kidney, whether expected relationship changes influence decision making and whether relationship changes are actually experienced.MethodsWe conducted 6 focus groups in 47 of 114 invited individuals (41%), asking retrospectively about motivations and decision making around transplantation. We used qualitative and quantitative methods to analyze the focus group transcripts.ResultsMost deceased donor kidney recipients had a potential living donor available which they refused or did not want. They mostly waited for a deceased donor because of concern for the donor’s health (75%). They more often expected negative relationship changes than living donor kidney recipients (75% vs. 27%, p = 0.01) who also expected positive changes. Living donor kidney recipients mostly accepted the kidney to improve their own quality of life (47%). Donors mostly donated a kidney because transplantation would make the recipient less dependent (25%). After transplantation both positive and negative relationship changes are experienced.ConclusionExpected relationship changes and concerns about the donor’s health lead some kidney patients to wait for a deceased donor, despite having a potential living donor available. Further research is needed to assess whether this concerns a selected group.
Nephrology Dialysis Transplantation | 2012
Tessa O. van den Beukel; Carl E.H. Siegert; Sandra van Dijk; Pieter M. Ter Wee; Friedo W. Dekker; Adriaan Honig
BACKGROUND The Beck Depression Inventory (BDI) is a standard and validated questionnaire to screen for depressive symptoms in chronic dialysis patients, but is relatively extensive to use repeatedly in clinical practice. We investigated whether the five-item Mental Health Inventory (MHI-5) of the 36-item Short-Form Health Survey Questionnaire (SF-36) could be applied to screen for depressive symptoms in dialysis patients. Moreover, we determined the optimal MHI-5 cut-off score to assess depressive symptoms. METHODS Chronic dialysis patients from three centres filled out the SF-36 and the BDI. A receiver operating characteristic (ROC) curve was constructed for the MHI-5 score with BDI ≥ 16 as reference standard to (i) calculate the area under the curve to determine whether the MHI-5 could be considered as a useful screening instrument for depressive symptoms and (ii) proxy the optimal cut-off score of the MHI-5 to assess depressive symptoms. The optimal cut-off score was determined by the value for which the sum of sensitivity and specificity had an optimum. RESULTS Of 133 included patients, 23% had depressive symptoms as determined with BDI ≥ 16. The correlation of the BDI with MHI-5 was -0.64. The area under the ROC curve was 0.82 (95% confidence interval 0.74-0.90). The optimal cut-off point of the MHI-5 was 70. MHI-5 ≤ 70 had 77 sensitivity, 72 specificity, 44 positive predicting value and 91% negative predicting value with the presence of depressive symptoms determined with BDI ≥ 16. CONCLUSIONS The MHI-5 may help clinicians to screen for depressive symptoms in dialysis patients without using an additional depression screening questionnaire once the SF-36 is completed. A cut-off value of 70 can be used safely for the purposes of screening applications.
International Journal of Behavioral Medicine | 2015
Yvette Meuleman; Lucia ten Brinke; Arjan J. Kwakernaak; Liffert Vogt; Joris I. Rotmans; Willem Jan W. Bos; Paul J.M. van der Boog; Gerjan Navis; Gert A. van Montfrans; Tiny Hoekstra; Friedo W. Dekker; Sandra van Dijk
BackgroundReducing sodium intake can prevent cardiovascular complications and further decline of kidney function in patients with chronic kidney disease. However, the vast majority of patients fail to reach an adequate sodium intake, and little is known about why they do not succeed.PurposeThis study aims to identify perceived barriers and support strategies for reducing sodium intake among both patients with chronic kidney disease and health-care professionals.MethodA purposive sample of 25 patients and 23 health-care professionals from 4 Dutch medical centers attended 8 focus groups. Transcripts were analyzed thematically and afterwards organized according to the phases of behavior change of self-regulation theory.ResultsMultiple themes emerged across different phases of behavior change, including the patients’ lack of practical knowledge and intrinsic motivation, the maladaptive illness perceptions and refusal skills, the lack of social support and feedback regarding disease progression and sodium intake, and the availability of low-sodium foods.ConclusionsThe results indicate the need for the implementation of support strategies that target specific needs of patients across the whole process of changing and maintaining a low-sodium diet. Special attention should be paid to supporting patients to set sodium-related goals, strengthening intrinsic motivation, providing comprehensive and practical information (e.g., about hidden salt in products), increasing social support, stimulating the self-monitoring of sodium intake and disease progression, and building a supportive patient–professional relationship that encompasses shared decision making and coaching. Moreover, global programs should be implemented to reduce sodium levels in processed foods, introduce sodium-related product labels, and increase consumer awareness.
Peritoneal Dialysis International | 2011
Wieneke M. Michels; Sandra van Dijk; Marion Verduijn; Saskia le Cessie; Elisabeth W. Boeschoten; Friedo W. Dekker; Raymond T. Krediet
♦ Objective: Despite a lack of strong evidence, automated peritoneal dialysis (APD) is often prescribed on account of an expected better quality of life (QoL) than that expected with continuous ambulatory peritoneal dialysis (CAPD). Our aim was to analyze differences in QoL in patients starting dialysis on APD or on CAPD with a follow-up of 3 years. ♦ Methods: Adult patients in the prospective NECOSAD cohort who started dialysis on APD or CAPD were included 3 months after the start of dialysis. The Medical Outcomes Survey Short Form 36 [SF-36 (Medical Outcomes Trust and QualityMetric, Lincoln, RI, USA)] and Kidney Disease and Quality of Life Short Form [KDQOL-SF (KDQOL Working Group, Santa Monica, CA, USA)] questionnaires were used to measure QoL. Differences in QoL over time were calculated using linear mixed models. Patients were followed until transplantation, death, or a first switch to any other dialysis modality. ♦ Results: The clinical and social characteristics of the 64 APD and 486 CAPD patients were slightly different at baseline. In the crude analysis, the pattern of the mental summary score differed between the modalities (p = 0.03, adjusted p = 0.06), because of a different pattern for role function emotional (p = 0.03, adjusted p = 0.05). The pattern of the physical summary score was not different between the groups. Scores on dialysis staff encouragement had a different pattern over time (p = 0.01), because of an inequality in scores 3 months after the start of dialysis, which disappeared after 18 months on dialysis. Over time, patients on APD scored higher on sexual function. After adjustment for age, sex, glomerular filtration rate, comorbidity, and primary kidney disease, that difference disappeared. This study showed no major differences in QoL on the KDQOL-SF and the SF-36 between the two modalities.