Publications by authors named "Paul C van Dijk"
Background: A health insurance-initiated programme to improve cost-effectiveness of acid-suppressing drugs (ASDs).
Aim: To evaluate the effect of two different interventions of general practitioner support in reducing drug prescription.
Materials And Methods: A sequential cluster randomized controlled trial with 90 participating general practitioners in a telephone support (TS) group or practice visit (PV) group.
Objective: To evaluate the effectiveness of a health insurance company-initiated intervention strategy aimed at optimizing acid-suppressing drug (ASD) prescriptions in primary care.
Methods: In a cluster randomized controlled trial design, 112 primary care physician (PCP) peer review groups (993 PCPs) in the central region of the Netherlands were randomized. The PCPs in the intervention group received an ASD prescription optimization protocol, a list of their patients taking ASDs frequently on a long-term basis, and financial compensation for additional consultations with these patients.
Context: Cardiovascular mortality is considered the main cause of death in patients receiving dialysis and is 10 to 20 times higher in such patients than in the general population.
Objective: To evaluate if high overall mortality in patients starting dialysis is a consequence of increased cardiovascular mortality risk only or whether noncardiovascular mortality is equally increased.
Design, Setting, And Patients: Using data from between January 1, 1994, and January 1, 2007, age-stratified mortality in a European cohort of adults starting dialysis and receiving follow-up for a mean of 1.
In traditional Kaplan-Meier or Cox regression analysis, usually a risk factor measured at baseline is related to mortality thereafter. During follow-up, however, things may change: either the effect of a fixed baseline risk factor may vary over time, resulting in a weakening or strengthening of associations over time, or the risk factor itself may vary over time. In this paper, short-term versus long-term effects (so-called time-dependent effects) of a fixed baseline risk factor are addressed.
View Article and Find Full Text PDFWhat is this patient's prognosis regarding graft rejection? Do patients using a particular drug live longer than those not using it? How does this co-morbidity affect access to transplantation? To answer this type of questions one needs to perform survival analysis. This paper focuses on the Kaplan-Meier method, the most popular method used for survival analysis. It makes it possible to calculate the incidence rate of events like recovery of renal function, myocardial infarction or death by using information from all subjects at risk for these events.
View Article and Find Full Text PDFHow much does the survival of one group differ from the survival of another group? How do differences in age in these two groups affect such a comparison? To obtain a quantity to compare the survival of different patient groups and to account for confounding effects, a multiple regression technique for survival data is needed. Cox regression is perhaps the most popular regression technique for survival analysis. This paper explains how Cox regression works, what the proportionality assumption means and how to interpret the results of univariate and multiple Cox regression models.
View Article and Find Full Text PDFBackground: After taking other confounding factors into account, the impact of comorbidity on mortality was investigated when comparing mortality between five European countries, dialysis modalities and renal disease groups.
Methods: The study included 15 571 incident patients on renal replacement therapy (RRT) from five national or regional registries participating in the European Renal Association-European Dialysis and Transplant Association Registry that collect comorbidity data. The presence of diabetes mellitus, ischaemic heart disease, peripheral vascular disease, cerebrovascular disease and malignancy was recorded at the start of RRT.
Background: Despite improved treatment of hypertension and decreasing rates of stroke and coronary heart disease, the reported incidence of hypertensive end-stage renal disease (ESRD) increased during the 1990s. However, bias, particularly from variations in acceptance into ESRD treatment (ascertainment) and diagnosis (classification), has been a major source of error when comparing ESRD incidences or estimating trends.
Methods: Age-standardized rates were calculated in persons aged 30 to 44, 45 to 64, and 65 to 74 years for 15 countries or regions (separately for the Europid and non-Europid populations of Canada, Australia, and New Zealand), and temporal trends were estimated by means of Poisson regression.
Background: Accurate prediction of patient survival from the time of starting renal replacement therapy (RRT) is desirable, but previously published predictive models have low accuracy. We have attempted to overcome limitations of previous studies by conducting an ambidirectional inception cohort study in patients on RRT from centres throughout Europe. A conventional multivariate regression (MVR) model, a self-learning rule-based model (RBM) and a simple co-morbidity score [the Charlson score modified for renal disease (MCS)] were compared.
View Article and Find Full Text PDFBackground: This study compared the prevalence of co-morbidity in patients starting renal replacement therapy (RRT) between European countries and further examined how co-morbidity affects access to transplantation.
Methods: In this ERA-EDTA registry special study, 17907 patients from Austria, Catalonia (Spain), Lombardy (Italy), Norway, and the UK (England/Wales) were included (1994-2001). Co-morbidity was recorded at the start of RRT.
Background: There is concern about the rising prevalence of type 2 diabetes mellitus and of the resultant nephropathy. This study uses data from the European Renal Association-European Dialysis and Transplant Association (ERA-EDTA) Registry to provide information on the epidemiology and outcome of renal replacement therapy (RRT) for end-stage renal disease (ESRD) due to diabetic nephropathy (DN).
Methods: Data from the following 10 registries: Austria, French-speaking Belgium, Denmark, Finland, Greece, Norway, Scotland (UK), Catalonia (Spain), Sweden, and The Netherlands were combined.
In June 2000 the ERA-EDTA Registry office moved to Amsterdam and started collecting core data on renal replacement therapy (RRT) entirely through national and regional registries. This paper reports the pediatric data from 12 registries. The analysis comprised 3,184 patients aged less than 20 years and starting RRT between 1980 and the end of 2000.
View Article and Find Full Text PDFBackground: The epidemiology of renal replacement therapy (RRT) for end-stage renal disease (ESRD) varies considerably worldwide, but we have lacked reliable quantitative estimates of trends in the incidence by age, sex and cause in Europe over the last decade.
Methods: We analysed data from nine countries participating in the ERA-EDTA registry: Austria, Belgium, Denmark, Finland, Greece, The Netherlands, Norway, Spain and UK (Scotland). Adjusted incidence rates for age and sex were studied for 2 year periods between 1990 and 1999.
Background: Nonadherence among hemodialysis patients compromises dialysis delivery, which could influence patient morbidity and mortality. The Dialysis Outcomes and Practice Patterns Study (DOPPS) provides a unique opportunity to review this problem and its determinants on a global level.
Methods: Nonadherence was studied using data from the DOPPS, an international, observational, prospective hemodialysis study.