Table 2.
Results of the univariate analysis
| Type* | Item | Question | Odds ratio (asthma to ACO) | p-value | Odds ratio (COPD to ACO) | p-value |
|---|---|---|---|---|---|---|
| 1 | 2 | How often does the subject need to keep a rescue inhaler with him/her? | 0.33 | 0.004 | 0.19 | <0.001 |
| 1 | 18 | If the subject stops taking his/her regular (maintenance/controller) respiratory medications, how do his/her respiratory symptoms change? | 0.31 | 0.002 | 0.31 | 0.002 |
| 1 | 21 | On average how frequently does the subject use his/her rescue medication? | 0.70 | 0.050 | 0.61 | 0.002 |
| 2 | 4 | In the past two (2) years has the subject had periods of several weeks or longer where he/she had no respiratory symptoms? | 2.18 | <0.001 | 0.58 | <0.001 |
| 2 | 5 | On the days the subject does not have daytime respiratory symptoms, how often does the subject wake at night due to respiratory symptoms? | 1.47 | 0.019 | 0.60 | <0.001 |
| 2 | 7 | Does the subject tend to have both “good” and “bad” days with regard to breathing, or are most days about the same? | 1.55 | 0.005 | 0.69 | 0.006 |
| 2 | 8 | On average, how much do the subject’s good and bad days differ? | 1.66 | 0.004 | 0.62 | <0.001 |
| 2 | 11 | Has the subject ever had nasal allergies or eczema? | 3.31 | <0.001 | 0.62 | <0.001 |
| 3a | 1 | How well does the subject’s quick relief inhaler (rescue inhaler) provide symptom relief? | 1.40 | 0.689 | 0.25 | 0.008 |
| 3a | 3 | How does the subject describe his/her respiratory disease over the past two (2) years? | 1.36 | 0.110 | 0.71 | 0.028 |
| 3a | 6 | Typically, how are the subject’s respiratory symptoms during the night and upon awakening compared to respiratory symptoms during the day? | 0.90 | 0.724 | 0.58 | 0.035 |
| 3a | 14 | Do the subject’s respiratory symptoms get worse after exposure to cold air or weather changes? | 1.35 | 0.127 | 0.71 | 0.036 |
| 3a | 15 | Do the subject’s respiratory symptoms get worse with exposure to air pollution or noxious fumes? | 1.12 | 0.573 | 0.69 | 0.025 |
| 3a | 20 | How often does the subject typically have respiratory symptoms at night? | 1.20 | 0.241 | 0.75 | 0.033 |
| 3a | 22 | How often do the subject’s respiratory symptoms disturb his/her sleep? | 1.39 | 0.081 | 0.59 | <0.001 |
| 3a | 31 | In the past 12 months, how frequently has the subject experienced chest tightness? | 1.20 | 0.212 | 0.77 | 0.046 |
| 3a | 33c | Cough is the most bothersome symptom | 1.03 | 0.878 | 1.65 | 0.001 |
| 3a | 33w | Wheezing is the most bothersome symptom | 1.20 | 0.396 | 0.58 | 0.021 |
| 3c | 10 | When the subject’s respiratory symptoms are bad, how long until they return to normal? | 1.34 | 0.039 | 1.18 | 0.219 |
| 3c | 12 | How many members of the subject’s immediate biological family have had asthma, nasal allergies or eczema? | 3.24 | <0.001 | 0.96 | 0.729 |
| 3c | 13 | Does the subject’s respiratory symptom get worse after exposure to pollen or pets? | 2.95 | <0.001 | 0.79 | 0.077 |
| 3c | 16 | Does the subject react emotionally to distress (eg, cry easily during a sad film)? | 1.36 | 0.033 | 0.94 | 0.619 |
| 3c | 19 | How many days in a week does the subject typically have respiratory symptoms during the day? | 0.59 | 0.006 | 0.82 | 0.309 |
| 3c | 24 | How often would the subject describe themselves as feeling anxious? | 1.60 | 0.030 | 1.04 | 0.818 |
| 3c | 26 | Do colds often go to the subject’s chest? | 5.01 | 0.003 | 0.80 | 0.380 |
| 3c | 27 | Over the past two years, how often has the subject had periods of frequent cough that lasted for several days or more? | 2.91 | 0.003 | 0.84 | 0.449 |
| 3c | 29 | In the past 12 months, how frequently has the subject experienced breathlessness? | 0.56 | <0.001 | 0.88 | 0.447 |
| 3c | 30 | In the past 12 months, how frequently has the subject coughed up sputum (phlegm or mucus)? | 0.61 | <0.001 | 1.28 | 0.097 |
| 3c | 34 | When the subject is at his/her best, how much exercise can he/she do before the subject gets breathless? | 0.40 | <0.001 | 1.14 | 0.485 |
| 3c | 33b | Breathlessness is the most bothersome symptom | 0.66 | 0.004 | 0.84 | 0.197 |
| 3c | 33t | Chest tightness is the most bothersome symptom | 2.68 | <0.001 | 1.01 | 0.960 |
| 4 | 9 | Describe how quickly a good day may change to a bad day due to respiratory symptoms. | 0.89 | 0.408 | 1.18 | 0.220 |
| 4 | 17 | How much of an impact does emotional distress have on the subject’s respiratory symptoms? | 1.20 | 0.221 | 0.92 | 0.528 |
| 4 | 23 | How much impact do the subject’s respiratory symptoms have on his/her energy level? | 0.64 | 0.141 | 0.84 | 0.556 |
| 4 | 25 | When the subject coughs, how often does he/she bring up phlegm or mucus? | 0.62 | 0.112 | 0.70 | 0.227 |
| 4 | 28 | In the past 12 months, how frequently has the subject experienced cough? | 0.81 | 0.186 | 1.35 | 0.063 |
| 4 | 32 | In the past 12 months, how frequently has the subject experienced wheezing? | 1.17 | 0.319 | 0.98 | 0.887 |
| 4 | 33s | Sputum is the most bothersome symptom | 0.86 | 0.624 | 0.92 | 0.781 |
| 4 | 35 | How often would the subject describe themselves as feeling depressed? | 1.25 | 0.138 | 1.15 | 0.316 |
| 4 | 36 | How scared or worried was the subject about his/her lung function? | 0.87 | 0.470 | 0.77 | 0.135 |
Notes:
*
Type 1: ORs of the COPD and asthma cohorts to the ACO cohort both significantly different from 1 in the same direction; Type 2: ORs both significantly different from 1 in different directions; Type 3: ORs significantly different from 1 for one comparison only (Type 3a: ACO was similar to asthma but different from COPD; Type 3c: ACO was similar to COPD but different from asthma); Type 4: ORs showed no significant difference between either asthma and ACO or COPD and ACO. The reference group for the univariate analysis was represented by the first answer for each question.
Abbreviations: ACO, asthma–COPD overlap; COPD, chronic obstructive pulmonary disease; OR, odds ratio.