The Impact of Asthma study wants to research daily variation in asthma symptoms and the impact of this variation on daily life of people living with asthma. This knowledge helps to create a new way to measure results in clinical studies, potentially speeding up the development of new therapies for asthma.

What happens in the study?

If you participate in the Impact of Asthma study, we ask you to perform the following activities twice per day for a period of 13 weeks:

  1. Perform a lung function test at home using a portable device that you will receive from us.
  2. Fill in an electronic diary about your symptoms and medication use.

Completing the lung function test and diary will take you approximately 10 minutes. You can perform these activities at a moment that suits you well, between 5 and 12 am for the morning session and 5 and 12 pm for the evening session. We will ask you to perform these activities before you use your daily inhaler. If you have to use your rescue inhaler because you are short of breath, we also ask you to perform the lung test first and then take your medicine if possible. Of course, you only have to do the lung test first if your symptoms allow you to!

The care you receive for your asthma (including the medication you use) will continue as usual.

In addition to the daily sessions, you will receive an email once a week, with the request to fill in two additional questions on your symptoms. At three moments during the study, twice at the start and once at the end, you will be asked to fill in a short questionnaire.

Some of the participants in this study will also be invited for two interviews of 30 minutes each, to talk about how they experience their symptoms. Selection for the interviews is random, we do not know beforehand which participants will be interviewed.

Can anyone participate?

Before the start of the study, we have to ask you to give permission by signing a consent form. We ask for permission to collect screening questions to see whether you meet the inclusion criteria for the study, and for your participation in the study if this is the case.
Optionally, you can give permission to be contacted for other studies in the future. This is not needed to take part in the Impact of Asthma study. In the consent form, you also find more information about the study, the screening, what we do with your information and how we protect your privacy.

As mentioned above, there are a few inclusion criteria that are required to participate in the study. To see whether you can participate in these studies, there is a short screening questionnaire that we would like you to fill in. We will ask you some questions on general information (like age and sex), as well as some specific questions about your asthma (about your diagnosis, symptoms and medication use). Filling in the screening questionnaire will take approximately 10-15 minutes. Afterwards, we are also required to contact your physician to confirm some inclusion criteria. If you are the right fit for Impact of Asthma, you will be invited to take part in the rest of the study. You will be contacted by a member of the study team and will receive the portable device for your daily measurements and questions.

When does the study end? 

Normally, participation in the study takes 13 weeks. The study can also last a bit shorter or longer if you are invited for the interviews. After the second interview the study ends, and you can stop with the daily activities.

If you wish to no longer participate, you can always stop your participation in the study yourself at any moment. You do not have to explain why you want to stop, but it will help the researchers if you do give an explanation.


In the Impact of Asthma study, you get paid for the time you spent on the study. You will receive a compensation for every week in which you complete at least 80% of the lung tests and the diaries. Additionally, you will get compensated per interview if you are invited for the interviews.

Signing up for the study

If you want to participate in the study, click the button below. This will take you to the Castor website. Castor is an online environment where you can sign the consent form and fill in the screening questionnaire. By making an account in Castor your information is fully protected and only accessible for you and the researchers.

When you have questions about the screening questionnaire, one of the studies or about how to enrol for the screening questionnaire, you can reach the researchers via the number below, depending on your location (there are no extra costs for calling this phone number).

  • USA: 001 (231) 289-6787
  • Canada: 001 (437) 292-3388
  • UK: 0044 20 4592 9846
  • Australia: 0061 2 5111 1765

Thank you very much for your interest!