Characterization of Asthma–Chronic Obstructive Pulmonary Disease Overlap Syndrome: A Qualitative Analysis

Figures & data

Table 1. Questions for focus groups.

1. ACOS definition and diagnosis a. Based on your knowledge and experience, can you define the asthma–COPD overlap syndrome for me? b. Can you give me a concrete example of a typical patient with ACOS? c. What clinical criteria do pulmonologists used to diagnose a patient with ACOS? d. Are the GINA and GOLD 2014 strategy document for ACOS diagnosis clear enough? Can you elaborate on what is or isn't clear? e. Where the GINA and GOLD 2014 strategy document are not clear, can you describe what you think is the best pathway to follow to diagnose a patient with ACOS? f. The diagnostic method that you use is based on what tool? g. Does the entire department use the same tool?

2. ACOS treatment a. Based on your experience, which respiratory drug classes are currently used in the treatment of ACOS? b. Within each drug class mentioned earlier, can you give me a list of the medications used? c. What do you know about the ACOS treatment GINA and GOLD 2014 strategy document? d. What is your opinion of this strategy document? e. What do you think is the optimal maintenance therapy for a typical patient diagnosed with ACOS?

3. Assessment of ACOS control a. How do you assess ACOS control in clinical practice? b. Can you give me a concrete example of a questionnaire or a protocol used to assess ACOS control? c. Which criteria do you use to determine whether a patient diagnosed with ACOS is under control or not?

Figure 1. Coding scheme used to analyze the content from both focus groups.

Table 2. Characteristics of the participating pulmonologists.

				Length of practice as a
				pulmonologist at the affiliated			Percentage of patients
				hospital			seen per month with:
	Number of
	pulmonologists	Gender,	Mean duration of	<5	5–10	> 10
Institution	(N = 12)	male (%)	practice (years)	years	years	years	Asthma	COPD	ACOS
1	7	57.1	19.3	0.0	28.6	71.4	25.7	54.3	14.3
2	5	80.0	25.2	0.0	20.0	80.0	29.2	46.6	34.0

Figure 2. Percentage of pulmonologists who agreed with the opinions regarding the definitions of ACOS reported in the focus groups. ACOS, asthma–chronic obstructive pulmonary disease overlap syndrome; COPD, chronic obstructive pulmonary disease.

Figure 3. Percentage of pulmonologists who agreed with the opinions regarding the diagnosis of ACOS reported in the focus groups. ACOS, asthma–chronic obstructive pulmonary disease overlap syndrome; RAMQ, Régie de l'Assurance Maladie du Québec.

Figure 4. Percentage of pulmonologists who agreed with the opinions regarding the treatment of ACOS reported in the focus groups. ACOS, asthma–chronic obstructive pulmonary disease overlap syndrome; BD, bronchodilator; ICS, inhaled corticosteroid; LAAC, long-acting anticholinergic; LABA, long-acting beta₂-agonist.

Figure 5. Percentage of pulmonologists who agreed with the opinions regarding the assessment of ACOS control reported in the focus groups. ACOS, asthma–chronic obstructive pulmonary disease overlap syndrome.

Figure 6. Characteristics of the two phenotypes of ACOS proposed by pulmonologists in the focus groups. ^*The patients share characteristics of asthma and COPD. The bottom boxes include features found in each phenotype of ACOS. Predominant features of each phenotype are indicated in bold font. ACOS, asthma–chronic obstructive pulmonary disease overlap syndrome; COPD, chronic obstructive pulmonary disease.

Table 3. Examples of clinical cases reported by the pulmonologists to illustrate typical patients with ACOS.

Clinical case description	Suggested diagnosis
Case 1:	ACOS
The patient has atopy, rhinitis or eczema, asthma during childhood, and a history of smoking. Pulmonary function tests revealed a 350–400 ml improvement in post-BD FEV^1, and fixed airflow obstruction.
Case 2:	ACOS
The patient presents with clear features of COPD with an FEV^1 of 0.9 L, and is a heavy smoker. When the patient was removed from his workplace, the pulmonologist saw an improvement in FEV^1 and better control of the disease, but exacerbations continued. This patient had clear COPD and asthma components.

BD, bronchodilator; FEV¹, forced expiratory volume in 1 second; COPD, chronic obstructive pulmonary disease.