Cough in Eastern and Central Finland

Study Overview
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Brief Summary
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Comparison of citric acid and mannitol cough provocation tests among subjects with chronic cough and healthy volunteers.

Detailed Description
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35 subjects with chronic cough plus 25 subjects without any cough will be asked to participate. The study consists of two visits in the outpatient clinic of Kuopio University Hospital, department of respiratory medicine, 2 - 7 days apart. They will fill in the Leicester Cough Questionnaire and undergo two different cough provocation tests, in random order: Mannitol test and citric acid test. If a chest x-ray has not been taken within 6 months, it will be taken.

Official Title
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Cough in Eastern and Central Finland

Conditions
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Chronic Cough

Intervention / Treatment
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* Diagnostic Test: Citric acid aerosol bronchial challenge
* Diagnostic Test: Mannitol aerosol bronchial challenge


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria, Chronic cough patients: (both criteria must be fulfilled) presence of current chronic cough (> 8 weeks) Leicester Cough Questionnaire total score < 17 Inclusion criteria, healthy volunteers absence of any form of cough Exclusion Criteria: age < 18 years any disability which would challenge the subject's ability to understand the purpose and methods of the study pregnancy breastfeeding current smoking or ex smoking more than 10 pack years any thoracic x-ray finding indicating urgent mediacal interventions

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: This study compares citric acid and mannitol bronchial challenges in their ability to separate chronic cough subjects from healthy subjects. There are no therapeutic interventions.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Citric acid aerosol bronchial challenge<br>Inhaled citric acid aerosol. This study investigates the diagnostic accuracy of two cough provocation tests, one of which is citric acid aerosol challenge. | Diagnostic Test: Citric acid aerosol bronchial challenge<br>* Inhalation challenge by citric acid aerosol to investigate the subject's cough sensitivity<br>|
| Active Comparator: Mannitol aerosol bronchial challenge<br>Inhaled mannitol aerosol. This study investigates the diagnostic accuracy of two cough provocation tests, one of which is mannitol aerosol challenge. | Diagnostic Test: Mannitol aerosol bronchial challenge<br>* Inhalation challenge by mannitol aerosol to investigate the subject's cough sensitivity<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Receiver operator characteristic curves of the citric acid and the mannitol aerosol bronchial challenges | Receiver operator characteristic curve describes the ability of the bronchial challenge to separate the cough patients from healthy volunteers | Within one week from the start of the study in each individual | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Leicester Cough Questionnaire total score | Measures cough-spesific quality of life. Range is 3 - 21 with low total score indicating poor cough-spesific quality of life. The three Leicester Cough Questionnaire subscales are added together to form the total score. | The first study day | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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cough, cough provocation test, mannitol, citric acid