Study of the Impact of Exposure to Outdoor and Indoor Pollutants in Patients With Asthma (EXAP)

April 14, 2026 updated by: Nantes University Hospital
The project is to measure exposure to outdoor and indoor air pollutants in asthma patients in order to show a possible association between variation in pollutant exposure and the occurrence of exacerbations in these patients

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Detailed Description

Asthma is a chronic airway disease affecting between 6% and 7% of the French adult population. Asthma is responsible for nearly 1000 deaths each year in France. Air pollution (indoor and outdoor) is responsible for 7 million deaths each year according to the World Health Organization (WHO) assessment published in 2018, including 65,000 in France. Studies monitoring exposure to indoor air pollutants are few in number in asthmatic patients. Very little research has been devoted to continuous monitoring of indoor air quality in homes. Our hypothesis is that variation in exposure to indoor air pollutants, in relation to outdoor air, would have an impact on the occurrence of exacerbations in asthmatic patients.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
30

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years to 99 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

The study population will consist of adult men and women recruited from the active file of asthma patients followed at the Nantes University Hospital, the Saint Nazaire Hospital, the Châteaubriant Nozay Pouancé Hospital and the Erdre et Loire Hospital. Regardless of the type of asthma, patients will be potentially included if they have a minimum of 4 exacerbations during the year preceding inclusion in the EXAP project>. Participation in other non-interventional research is allowed during the study unless this research increases the number of exacerbations.

Description

Inclusion Criteria:

  • Patient over 18 years of age,
  • Patient with a confirmed diagnosis of asthma for at least 12 months as defined by the investigator,
  • Patient with at least 4 asthma exacerbations in the last year
  • Patient sleeping at least 6 nights per week in the same home

Exclusion Criteria:

  • Patient who is an active smoker or living with an active smoker,
  • Patient with a diagnosis of COPD, ABPA or associated pulmonary fibrosis,
  • Patient with an asthma exacerbation within 15 days prior to the inclusion visit,
  • Patient with known occupational exposure,
  • Patient living in a dwelling that does not allow the installation of sensors (inability to connect the sensor to the power supply, no location for the outdoor sensor...)
  • Patient who plans to move in the next 6 months,
  • Patient with a life expectancy of less than 6 months,
  • Patient who has someone living in their household also included in EXAP,
  • Patient who lives in an apartment and does not have a balcony or space for the outdoor sensor,
  • Pregnant or breastfeeding women,

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Asthma exacerbations
Time Frame: 36 months

The primary criterion is the association between the occurrence of exacerbations and the concentrations of the following pollutants or other environmental factors measured daily in the patients' homes by air pollution sensor inside and outside the home.

  • the concentration of indoor pollutants: PM1 (µg/m3), PM2.5 (µg/m3), PM10 (µg/m3), volatile organic compounds (VOC) (µg/m3) , CO2 (ppm),
  • the concentration of outdoor pollutants (µg/m3): PM1, PM2.5, PM10,
  • The ratios (indoor/outdoor air) of PM1, PM2.5 and PM10 in the home,
  • Temperature(°C) and relative humidity (RH) (%) in indoor and outdoor air,
  • Exceedances of regulatory (provided by the Environmental Code) or recommended (determined by the sensor supplier) pollutant thresholds.
36 months

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Daily Peak flow (l/ min)
Time Frame: 36 months

The secondary criterion is the the temporal association between the daily Peak flow and the concentrations of the same pollutants or other environmental factors listed in the primary criterion.

Subgroup analyses : groups of patients will be created according to the characteristics of their habitat (heating mode, ventilation, rural or urban area...).

Both primary and secondary outcomes will be studied in these subgroups.
36 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Nantes University Hospital

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: François-Xavier Blanc, PU-PH, Nantes university hospital

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
November 15, 2022

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
November 15, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
November 15, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
July 7, 2022

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 30, 2022

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
September 1, 2022

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
April 17, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 14, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • RC22_0115

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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