A single European currency for EQ-5D health states. Results from a six-country study

The EQ-5D questionnaire is a widely used generic instrument for describing and valuing health that was developed by the EuroQol Group. A primary objective of the EuroQol Group is the investigation of values for health states in the general population in different countries. As part of the EuroQol enterprise 11 population surveys were carried out in six Western European countries (Finland, Germany, The Netherlands, Spain, Sweden and the UK) to value health states as defined by the EQ-5D using a standardised visual analogue scale (EQ-5D VAS). This contribution reports how a European set of general population preference weights was derived from the data collected in the 11 valuation studies. The scores from this set of preference weights can be applied to generate a VAS-based weighted health status index for all the potential 243 EQ-5D health states for use in multi-national studies. To estimate the preference weights a multi-level regression analysis was performed on 82,910 valuations of 44 EQ-5D health states elicited from 6,870 respondents. Stable and plausible solutions were found for the model parameters. The R(2) value was 75%. The analysis showed that the major source of variance, apart from 'random error', was variance between individuals (28.3% of the total residual variance). These results suggest that VAS values for EQ-5D health states in six Western European countries can be described by a common model.

The effect of medical care by a helicopter trauma team on the probability of survival and the quality of life of hospitalised victims

In 1995, an experiment was started to give extra medical help by helicopter to patients who needed emergency treatment. The aim of the experiment was not to reduce the transportation time to the hospital, but to bring specialised medical care directly to patients as soon as possible. An evaluation study was carried out to assess the effect of the treatment given by the Helicopter Trauma Team (HTT) on survival and quality of life. The study focused on hospitalised patients suffering from polytrauma. A direct comparison between an experimental and control group was not possible, because the HTT group consisted of more severely injured patients. A refined severity index was constructed on the basis of the Revised Trauma Scale (RTS) and the Injury Severity Scale (ISS) and their sub-scores. Using this index, it was possible to make a clear distinction between three groups of patients, i.e. those with a high probability of survival (with or without special medical treatment), those with a very low probability of survival and the patients in between. It was shown that the HTT-treatment was effective. The survival rate increased for patients in the 'in between' group, but not for patients with a low probability of survival. There was no difference in the quality of life of patients from the HTT and non-HTT groups 15 months after the accident. These findings refute the hypothesis that only the most severely injured patients with a low quality of life profit from HTT-treatment.

Macroscopic models for traffic and traffic safety

This paper describes models for traffic volumes and traffic safety. These models have a very simple mathematical form and consist of time parameters only. The first model assumes that fatality rates follow a negative exponential function. The second model assumes a logistic type of saturation model for traffic volumes. The models are applied to traffic volumes and fatality rates in the Netherlands, the United States, West Germany, and Great Britain. These applications show fairly good results. The agreement between the models and the data shows that linearity of the log-fatality rates and the log-volume rates turn out to be reasonable assumptions. Furthermore, a relation between the two models is suggested from the data that links safety outcomes to developments in traffic volume. From the models, predictions are made for traffic volume, fatality rates, and fatalities in the future on the basis of time parameters only.