Centrum, Netherlands
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Adjuvant treatments can be added to primary curative cancer treatments to increase the probability of survival. However, these treatments have side effects. Research into what additional probability of survival cancer patients require from an adjuvant treatment before they consider it worthwhile, has been carried out in hypothetical situations. The published literature on this subject shows that the additional benefit which patients expect is small. Yet, variation in patient preferences within studies is large. Preferences regarding additional benefit are not consistently associated with patient socio-demographic or disease characteristics. It is very likely that new patients who face the choice of adjuvant treatment will greatly differ from each other in the benefit that they require from it. In order to give individualized recommendations, specialists need to ask the patient which benefits and disadvantages he or she considers to be important.


The case-crossover study is a relatively unknown way of identifying short-term transient risk factors for acute-onset diseases. In patients with the disease of interest, the frequency of exposure to a certain risk factor is compared between two time periods. If the exposure is more common in the period directly preceding disease onset than in an earlier period, the control period, it is likely that the exposure contributes to the development of the disease. The problem of confounding is minimized in case-crossover studies since the patient serves as his or her own control. A potential disadvantage is that sufficient biological knowledge of the clinical picture is needed to provide a good estimate of the risk period. As administrative databases are now commonly used for research purposes, future use of case-crossover methods is likely to increase. We illustrate the case-crossover study with the question of whether antibiotic use increases the risk of unwanted pregnancy in women who use the contraceptive pill.


OBJECTIVE: To describe the epidemiological characteristics of Clostridium difficile infection (CDI) in the Netherlands. DESIGN: Descriptive. METHOD: After the first outbreaks in 2005 of Clostridium difficile infection (CDI) due to the hypervirulent PCR ribotype 027, a national reference laboratory was started in the Leiden University Medical Centre for typing and characterisation of C. difficile. Data were obtained from this national reference laboratory and from a continuous surveillance in 14 Dutch hospitals. The study period was January 2008-June 2009. RESULTS: In 2008, the incidence of CDI was 18 per 10.000 admissions (range: 14-23) in the 14 participating hospitals in the national surveillance study. In the study period, a total of 1867 cases of CDI were reported from 63 centres. The number of CDI outbreaks caused by type 027 decreased in the period January 2008 to June 2009, compared to the preceding years: type 027 was the cause of outbreaks in 4 Dutch hospitals in 2008-2009, whereas all 14 hospitals experienced an outbreak due to this type in the period 2005-2007. Although no systemic surveillance has been carried out in nursing homes, 24 Dutch nursing homes reported outbreaks of C. difficile in the period 2005-2009, in 12 of which type 027 was isolated. There was an increase of CDI detected in patients with diarrhoea outside health care facilities which appeared to coincide with the emergence of other types. In particular, type 078 increased since the end of 2006 and became the third most frequent type in the Netherlands. This type has also been recognised since 2007 as an important cause of CDI infection in animals, especially pigs. Recently there have also been reports that at least a third of the patients with CDI outside health care institutions do not have known risk factors for CDI such as an underlying disease, recent hospitalization or antibiotic use. CONCLUSION: CDI can also develop in the community The general practitioner should consider C. difficile in the differential diagnosis of elderly patients with diarrhoea.


The aim of non-inferiority trials is to show that a new treatment is not less effective than standard treatment, in other words 'non-inferior'. The non-inferiority margin should be determined before a study commences. This margin determines the maximal magnitude of difference in effectiveness permissible if it is to be concluded that a new treatment is not less effective than the standard treatment. There is usually a good reason for a non-inferiority design. For example, because the new treatment is easier to use, provides better cost-effectiveness or has fewer side effects. The reader of a non-inferiority trial should consider a number of aspects critically: (a) the reason for use of this study design, (b) the assumed benefit of the new treatment, (c) the rationale for the choice of non-inferiority margin and (d) the choice of the standard therapy with which the new treatment is compared.


la Chapelle C.F.,Leids Universitair Medisch Centrum
Nederlands tijdschrift voor geneeskunde | Year: 2013

More than 10 years after its first introduction, robot-assisted surgery is now performed in 17 Dutch hospitals. Robotic-assisted radical prostatectomy (RARP) is the most frequently performed, though its clinical superiority compared to open (RRP) and laparoscopic prostatectomy (LRP) has not been demonstrated. One randomized controlled trial showed better outcome in erectile function after RARP compared to LRP. The quality of the other studies into RARP is too limited to draw reliable conclusions on clinically relevant outcome measures such as survival, disease-free survival and quality of life. Given the high costs and small scientific evidence, the introduction of robotic surgery has been irresponsibly quick. Better scientific research of robotic surgery is needed before this technology can be broadly applied in clinical practice.


Braun J.,Leids Universitair Medisch Centrum | Klautz R.J.M.,Leids Universitair Medisch Centrum
Current Opinion in Cardiology | Year: 2012

PURPOSE OF REVIEW: The optimal surgical treatment of chronic ischemic mitral regurgitation still is the subject of much debate in the surgical and cardiological communities. Although combined restrictive mitral annuloplasty and revascularization has demonstrated good results with regard to improvement of clinical status, low rates of recurrent mitral regurgitation and sustained left ventricular reverse remodeling, a survival benefit still has not been demonstrated. In addition, not all patients improve. Remaining issues in this field relate to identification of patients who will benefit from treatment, and to further improve and individualize treatment modalities. RECENT FINDINGS: More data support the use of restrictive mitral annuloplasty and revascularization. New surgical techniques to improve mitral competence (posterior leaflet augmentation) and to promote left ventricular reverse remodeling in severely dilated hearts (addressing the subvalvular apparatus) are promising. Disease-specific annuloplasty rings have not (yet) proven additional value. New imaging modalities are available to assess the many components that constitute the complex pathophysiology of remodeling. SUMMARY: The remaining challenge for cardiologists and surgeons is how to integrate data from different imaging techniques that assess mitral valve geometry and left ventricular size, geometry, function and potential functional recovery in order to individualize and optimize the surgical approach to patients with chronic ischemic mitral regurgitation. © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins.


De Weger A.,Leids Universitair Medisch Centrum | Ewe S.H.,Leids Universitair Medisch Centrum | Delgado V.,Leids Universitair Medisch Centrum | Bax J.J.,Leids Universitair Medisch Centrum
European Journal of Cardio-thoracic Surgery | Year: 2011

The trans-catheter valve-in-valve concept has become a feasible therapeutic option for patients with failing degenerated bioprosthesis, who are deemed inoperable. However, little is known about the feasibility of this technique in failed valve annuloplasty. We report the first-in-man implantation of a trans-catheter aortic valve within a mitral annuloplasty ring. Through a trans-apical trans-catheter approach, a 26-mm Sapien-Edwards valve was successfully implanted in a 72-year-old man with ischemic heart failure and failed mitral-valve annuloplasty. The present case report provides a critical appraisal of the procedural technique. © 2010 European Association for Cardio-Thoracic Surgery.


OBJECTIVE: To investigate the incidence of scalp metastases in high-risk breast cancer patients in order to assess whether caution is warranted with scalp cooling during adjuvant therapy. DESIGN: Observational study. METHODS: The incidence of scalp metastases and the disease course were studied in 885 very well evaluated high-risk breast cancer patients. These patients, who had at least four positive axillary lymph nodes, were treated in a randomised study with either classical chemotherapy, or the same chemotherapy followed by high-dose chemotherapy and autologous stem cell transplantation (the so-called N4+ study). RESULTS: After a median follow up of 110 months, 403 of the 885 patients (46%) had relapsed or developed metastases. 25 patients (3%) had developed skin metastasis; 4 of these patients (0.5%) had developed hairy scalp metastasis. The scalp metastases always occurred at the same time as or later than metastases elsewhere. CONCLUSION: Scalp metastases occur with a very low frequency and not as the first sign of metastatic disease. It is therefore unlikely that scalp cooling (to prevent baldness) decreases the local working of chemotherapy to such an extent that the risk of scalp metastases increases.


OBJECTIVE: To determine whether the quality indicator 'tumour positive surgical margin following breast-conserving surgery, consistently measured the quality of breast-cancer surgery independently of the different definitions used and differences in case mix, taking statistical random variation into account. DESIGN: Descriptive study. METHODS: Data was collected from 762 patients who underwent breast-conserving surgery for invasive or in situ carcinoma of the breast, in the period 1 July 2007 - 30 June 2008 in 1 of the 9 hospitals in the region of the Comprehensive Cancer Centre West in the Netherlands. We compared 3 definitions for 'tumour positive surgical margin': the one used by the Health Care Inspectorate, the one used by the organisation 'Zichtbare Zorg' ('transparent care') and the percentage of re-resection. For case mix correction we identified risk factors for tumour margin positivity with logistic regression. The results were presented in a funnel plot, using 95% confidence interval (CI) around the national standard of 20%. RESULTS: Depending on the definition used, the tumour positive surgical margin rate of the total group varied from 11 to 21%. Individual hospital rates varied by up to 19%. In situ carcinoma was associated with higher tumour positive surgical margin rates. Results differed significantly between hospitals for all 3 definitions. However, the funnel plot showed that results for most hospitals fell within the 95% CI of the standard. Whether a hospital fell within the 95% CI of the standard depended upon on the definition used and case mix correction. CONCLUSION: The lack of a single definition for the quality indicator 'tumour positive surgical margin following breast-conserving surgery' and the lack of case-mix correction undermine the validity of the indicator. Standardisation of definitions, uniform registration and the use of funnel plots can provide a more transparent insight into the quality of care.


Patent
Tno and Leids Universitair Medisch Centrum | Date: 2011-01-19

The present invention relates to a method for determining whether a urine sample has been obtained from a subject suffering from a kidney disorder involving kidney damage. The method is based on determining the level of a proteolytic enzyme in urine from the subject.sample and optionally comparing this level with a reference value. The proteolytic enzyme preferably is a matrix metalloproteases, in particular MMP-2 or MMP-9. The method is particularly suitable for subjects with a condition or disorder that is associated with an increased risk of kidney disorders, such as diabetes. The method may adavnatagcously be applied for early detection of kidney damage, in particular when the subject does not yet show any sign of microalbuminuria. The method may also be applied to a subject undergoing dialysis for determining whether the subject is suffering from remodelling of the peritoneal membrane. Thus, the method is particularly suited for patients undergoing continuous ambulatory peritoneal dialysis.

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