Identifying Patients With the COPD-Asthma Overlap Phenotype: Therapeutic Implications

Study Overview
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Brief Summary
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Background: Asthma and COPD are considered different diseases but many patients share characteristics of both entities. This has been termed COPD-asthma overlap syndrome. Study objective: To examine: (a) the frequency of the overlap phenotype among patients referred for pulmonary function testing and, (b) the impact of this phenotype on the therapeutic management and the quality of life of these patients as compared with patients with COPD only and asthma only. Methods: Type of study: Observational, cross-sectional. Study subjects: Patients referred for pulmonary function test diagnosed with airway obstruction (FEV1/FVC < 0.7) willing to sign an informed consent. Study procedures: Spirometry will be performed before and after the administration of a bronchodilator. Respiratory questionnaire: Questionnaires about smoking habits, past history of asthma and wheezing, current medications and history of exacerbations will be administered at inclusion. Questionnaire on medication utilization will be administered by telephone one month after inclusion. Quality of life: Will be assessed using the Saint George Respiratory Questionnaire (SGRQ). Working definitions: The following definitions will be adopted: a) COPD only: smoking history > 10 pack/years and post-bronchodilator (BD) FEV1/FVC ratio of < 0.70; b) Asthma only: (1) presence of wheezing in the last year plus a minimum post-BD increase in FEV1 or FVC of 12% and 200 ml; (2) prior physician diagnosis (before age 40); and c) both COPD-Asthma (the overlap group) - the combination of the two. Outcome measures: The clinical outcome is the prevalence rate of the phenotypes. Patient-reported outcomes will include the utilization of medication, the number of exacerbations, and quality of life.

Detailed Description
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Background: Asthma and COPD are considered different diseases but many patients share characteristics of both entities. This has been termed COPD-asthma overlap syndrome. Study objective: To examine: (a) the frequency of the overlap phenotype among patients referred for pulmonary function testing and, (b) the impact of this phenotype on the therapeutic management and the quality of life of these patients as compared with patients with COPD only and asthma only. Methods: Type of study: Observational, cross-sectional. Study subjects: Patients referred for pulmonary function test diagnosed with airway obstruction (FEV1/FVC < 0.7) willing to sign an informed consent. Study procedures: Spirometry will be performed before and after the administration of a bronchodilator. Respiratory questionnaire: Questionnaires about smoking habits, past history of asthma and wheezing, current medications and history of exacerbations will be administered at inclusion. Questionnaire on medication utilization will be administered by telephone one month after inclusion. Quality of life: Will be assessed using the Saint George Respiratory Questionnaire (SGRQ). Working definitions: The following definitions will be adopted: a) COPD only: smoking history > 10 pack/years and post-bronchodilator (BD) FEV1/FVC ratio of < 0.70; b) Asthma only: (1) presence of wheezing in the last year plus a minimum post-BD increase in FEV1 or FVC of 12% and 200 ml; (2) prior physician diagnosis (before age 40); and c) both COPD-Asthma (the overlap group) - the combination of the two. Outcome measures: The clinical outcome is the prevalence rate of the phenotypes. Patient-reported outcomes will include the utilization of medication, the number of exacerbations, and quality of life. Statistical plan: Sample size: For an estimated prevalence rate of 20%, 246 patients should be recruited with 5% imprecision and 95% degree of confidence. To round up, 250 patients will be included. Statistical methods: Multiple comparisons will be carried out using the one-way ANOVA for continuous variables and chi-squared test (or Fisher Exact Test) for qualitative variables. Multiple logistic regression models will be tested to examine the relation between the COPD-asthma overlap phenotype and various independent or predictor variables. Expected benefits: Data collected could serve to advance the medical community's knowledge pertaining to the COPD-asthma overlap syndrome. Most importantly, however, they will encourage reflection on the best therapeutic options for the patients with the overlap syndrome. Indeed, recommendations on this matter are noticeably absent from the current guidelines proposed to treat and monitor obstructive lung diseases.

Official Title
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Identifying Patients With the COPD-Asthma Overlap Phenotype: Therapeutic Implications

Conditions
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COPD Asthma

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: men or women aged > 18 years , with spirometric evidence of airway obstruction defined as an FEV1/FVC ratio < 0.7 Exclusion Criteria: Subjects with normal spirometry or presenting a pattern of restrictive lung disease will be listed for the purpose of characterising the source population but will not enter the study

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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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| patients with airway obstruction<br>Patients referred for pulmonary function test diagnosed with airway obstruction (FEV1/FVC < 0.7) willing to sign an informed consent. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| utilization of medication | completion of RS questionnaires | enrollment to 2 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| number of exacerbations | completion of RS questionnaires | enrollment to 2 months | 
| quality of life | completion of Saint George Respiratory Questionnaire | enrollment | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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COPD Asthma Overlap