A program of methodological research to arrive at the new international EQ-5D-5L valuation protocol.

Objectives: To describe the research that has been undertaken by the EuroQol Group to improve current methods for health state valuation, to summarize the results of an extensive international pilot program, and to outline the key elements of the five-level EuroQol five-dimensional (EQ-5D-5L) questionnaire valuation protocol, which is the culmination of that work.

Methods: To improve on methods of health state valuation for the EQ-5D-5L questionnaire, we investigated the performance of different variants of time trade-off and discrete choice tasks in a multinational setting. We also investigated the effect of three modes of administration on health state valuation: group interviews, online self-completion, and face-to-face interviews.

Developing the Chinese version of the new 5-level EQ-5D descriptive system: the response scaling approach.

Purpose: To develop a Chinese version of the new, 5-level EQ-5D descriptive system (EQ-5D-5L) from the existing EQ-5D-3L by identifying Chinese label wording suitable for constructing EQ-5D-5L's 5-point response scales.

Methods: In face-to-face interviews, perceived severity of selected Chinese labels when they were used to describe EQ-5D health problems was measured from 50 native Chinese speakers using a 0 (no problems) to 100 (the worst problems) visual analog scale. Selection of label wording was based on the severity scores and semantic similarity with label wording used in the existing English and Spanish EQ-5D-5L.

Quantifying the benefit of early living-donor renal transplantation with a simulation model of the Dutch renal replacement therapy population.

Background: Early living-donor transplantation improves patient- and graft-survival compared with possible cadaveric renal transplantation (RTx), but the magnitude of the survival gain is unknown. For patients starting renal replacement therapy (RRT), we aimed to quantify the survival benefit of early living-donor transplantation compared with dialysis and possible cadaveric transplantation and to estimate the population benefit from increasing the early transplantation rate.

Methods: We used a decision-analytic computer-simulation model, with a lifetime time horizon, simulating patients starting RRT, using data from the Dutch End-Stage Renal Disease Registry and published data.

Propensity scores in the presence of effect modification: A case study using the comparison of mortality on hemodialysis versus peritoneal dialysis.

Purpose: To control for confounding bias from non-random treatment assignment in observational data, both traditional multivariable models and more recently propensity score approaches have been applied. Our aim was to compare a propensity score-stratified model with a traditional multivariable-adjusted model, specifically in estimating survival of hemodialysis (HD) versus peritoneal dialysis (PD) patients.

Methods: Using the Dutch End-Stage Renal Disease Registry, we constructed a propensity score, predicting PD assignment from age, gender, primary renal disease, center of dialysis, and year of first renal replacement therapy.

Cost-effectiveness of clopidogrel in STEMI patients in the Netherlands: a model based on the CLARITY trial.

Objective: This study assesses the costs and effects of combination treatment with clopidogrel and aspirin in comparison to aspirin alone in patients with an ST-segment elevation myocardial infarction (STEMI) in a Dutch setting.

Methods: A decision tree model is used to combine data from different sources about efficacy, epidemiology and costs. In the short-run, cost-effectiveness is based on efficacy data derived from the CLARITY trial.