PIAMA In English 


1. The PIAMA research project

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The PIAMA-study is a large ongoing population-based birth cohort study with prenatal inclusion and follow-up until the current age of 23/24 years. The study was designed to investigate the influence of lifestyle and environment on the development of asthma, allergy and lung function. It therefore contains a detailed characterization of lifestyle and environmental exposures in all stages of childhood.

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Study design and population

The study started with 3,963 newborns, who were born in 1996/97 after prenatal recruitment through prenatal clinics in the northern, middle and southwestern part of the Netherlands.

After inclusion, allergic and non-allergic mothers were identified through a validated screening questionnaire. Pregnant women identified as allergic were primarily allocated to an intervention study with a random subset allocated to a "natural history study". The intervention involved the use of mite-impermeable mattress and pillow covers on the children's and parents' beds. Non-allergic pregnant women were invited to participate in a "natural history" study arm.

The intervention part and the natural history part were integrated into one study: the PIAMA birth cohort study with two main aims:

  1. to investigate the effect of mite-allergen avoidance on the incidence of asthma and allergy in childhood (Intervention study); and
  2. to investigate lifestyle and environmental (indoor and outdoor) risk factors for childhood asthma and allergy (Natural History study).

The evaluation of the effectiveness of the mattress covers in terms of reducing allergen exposure preventing asthma and allergies at age 8 years, showed that the covers were successful in reducing exposure to house dust mite Der f1, but not Der p1, and did not succeed in preventing asthma and allergy outcomes.

This is consistent with findings of other prospective birth cohort studies investigating the independent effects of HDM allergen reduction on the development of asthma and allergies, but may partly be attributable to the fact that the PIAMA intervention study by coincidence recruited its participants in years with two consecutive very cold winters, which significantly reduced mite allergens in all arms of the study, so that the effect of the intervention was considerably smaller than it could have been.

Figure 1.
Participants PIAMA - per age for parents and children
Participants PIAMA - per age for children

A. Response per follow up - parental completed questionnaires


B. Response per follow up - participant



At the start of the study, the length of follow-up was planned to be 8 years to allow sufficient time for allergic sensitization and symptoms to develop. The study was highly successful both in terms of follow-up rates and in terms of the wealth of data obtained.

These success factors in combination with new research questions that came up during the course of the study were reason for the investigators to extend the follow-up beyond the age of 8 years and also to broaden the scope of the health outcomes investigated to cardiometabolic health outcomes. Three years after the originally planned 8 years of follow-up had been completed, the remaining participants were invited to participate in 4 more waves of data collection at the age of 11–12, 14-15, 17-18 and 20 years and a 5th wave of data collection at the current age of 23-24 years with questionnaires and medical examinations is currently ongoing.

PIAMA - Data collection
Figure 2. Data collected. This separate PDF document gives an overview of the available data.  

2. Collaboration and Data availability 


Successful (international) research collaboration confers clear benefits to the collaborating parties and to scientific progress in general. Data from the PIAMA study has been used in international collaborations over the years to study asthma and allergy, resulting in many scientific papers, as can be seen in "publicaties".

The PIAMA study group welcomes initiatives from external researchers or research groups who want to make use of the PIAMA data for specific research questions in collaboration with the PIAMA group, or members thereof. An overview of the data available in the PIAMA study can be found at http://www.birthcohorts.net/.

Interested researchers can contact one of the PIAMA Principal Investigators with their questions or proposals.

Dr. Ulrike Gehring Prof. Roel Vermeulen Prof. dr. Gerard Koppelman Dr. Judith Vonk Dr Jolanda Boer

Data availability

In the interest of transparancy and quality control, the data underlying the findings presented in published papers will be made available upon request. Requests can be submitted to the PIAMA Principal Investigators.

The PIAMA data are not freely accessible in the public domain, because this would be in conflict with the agreement between the study team and the PIAMA participants.

If you wish to receive a reprint of one of the listed publications, please contact Eef van Otterloo (E.vanotterloo@uu.nl).