bolt-ons.info supports ongoing research to develop ‘bolt-on’ items for the EQ-5D. We’re conducting research in the context of cognition, vision, and hearing.

If you are a participant in our research, please visit the Participate section of our website.

If you are a researcher, you can find out more about our team’s publications and presentations on the Output page. If you would like to use the EQ-5D (with or without a bolt-on), please register on the EuroQol website.

What is the EQ-5D?

The EQ-5D is a questionnaire that is used in health research. It includes five questions that together describe a person’s health state. Data collected using the EQ-5D are used to identify differences and changes in people’s health. This information can then be informative to decision-makers, who must determine whether or not different types of health care represent good value. You can find out more about the EQ-5D at euroqol.org

What is a bolt-on?

The EQ-5D consists of five dimensions, each one corresponding to an item on the questionnaire. The five dimensions are mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. Together, these five dimensions do a good job of describing people’s health in many contexts. However, there are some circumstances where it may be worthwhile adding an additional dimension. For example, cognition, vision, and hearing are three dimensions that some researchers have suggested could be added to the EQ-5D where relevant. When we add an item to the EQ-5D to include one of these dimensions, we call it a ‘bolt-on’.

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    About us

    We are a collaborative group of researchers based at different institutions around the world. Our research is funded by the EuroQol Research Foundation, but anything that you read on this website represents the view of the researchers and does not necessarily reflect the views of the EuroQol Group.