Factors associated with adherence to the action plan:* univariable and multivariable analyses on 217 exacerbations
| Categories or units | OR | 95% CI | |
| Univariable analysis | |||
| Influenza vaccination | Yes vs no | 4.83 | 1.74 to 13.37 |
| Cardiac disease† | Yes vs no | 2.44 | 1.08 to 5.52 |
| Exacerbation intervention plan prior to study | Yes vs no | 1.63 | 0.75 to 3.54 |
| Post-BD FEV1 | Each % predicted | 0.98 | 0.96 to 1.00 |
| Age | Each year | 0.98 | 0.94 to 1.02 |
| Sex | Female vs male | 1.28 | 0.65 to 2.52 |
| Exacerbation sequence | Each exacerbation | 1.11 | 0.84 to 1.46 |
| Number of exacerbation symptoms | 3 vs 2 symptoms | 1.45 | 0.73 to 2.87 |
| ER COPD visit prior to study | Each visit | 1.11 | 0.85 to 1.44 |
| Contacting the case manager | Yes vs no | 1.19 | 0.6 to 2.38 |
| Depressive symptoms‡ | Yes vs no | 0.95 | 0.85 to 1.07 |
| Pulmonary rehabilitation in RCT§ | Home vs hospital | 1.25 | 0.63 to 2.48 |
| Multivariable analyses¶ | |||
| Influenza vaccination | Yes vs no | 4.82 | 1.71 to 13.54 |
| Cardiac disease | Yes vs no | 3.05 | 1.26 to 7.39 |
| Age | Each year | 0.96 | 0.92 to 1.00 |
| Post-BD FEV1 | Each % predicted | 0.98 | 0.95 to 1.00 |
| Random effects | Estimate | 95% CI | |
| Subject | 0.47 | −0.32 to 1.26 | |
| Study centre | 0.51 | −0.33 to 1.35 |
↵* Adherence to the action plan was defined as the initiation of both prednisone and antibiotics within 3 days of exacerbation onset. All other actions were defined as non-adherence.
↵† Cardiac disease includes chronic heart failure, angina pectoris, myocardial infarction and arrhythmia.
↵‡ Depressive symptoms were measured with the 15-item Geriatric Depression Scale (GDS). Sum scores (range 0–15) ≥6 points are suggestive for depression.
↵§ Canadian pulmonary rehabilitation trial (http://ClinicalTrials.gov identifier: NCT00169897).
↵¶ After backward elimination with removal of variables with p>0.05.
Post-BD FEV1, post-bronchodilator forced expiratory volume in 1 s.