Variable	Hazard ratio	SE	P > z	Lower 95% CI	Upper 95% CI
ICS low dose (reference no ICS)	1.38	0.06	0.000	1.27	1.49
ICS moderate dose (reference no ICS)	1.69	0.09	0.000	1.52	1.88
ICS high dose (reference no ICS)	2.57	0.34	0.000	1.98	3.33
Charlson comorbidity score	1.07	0.00	0.000	1.06	1.08
Hospitalization (yes vs no)	1.16	0.02	0.000	1.12	1.20
ER (yes vs no)	1.25	0.02	0.000	1.21	1.28
Age	1.03	0.00	0.000	1.03	1.03
Female sex	0.97	0.01	0.010	0.95	0.99
Non-FFS health plan (vs FFS)	0.94	0.02	0.008	0.90	0.99
Region North Central (vs Northeast)	1.05	0.02	0.018	1.01	1.09
Region South (vs Northeast)	1.07	0.02	0.003	1.02	1.11
Region West (vs Northeast)	0.96	0.02	0.061	0.91	1.00
Year 2007 (vs 2006)	1.02	0.02	0.120	0.99	1.06
Year 2008 (vs 2006)	1.01	0.02	0.466	0.98	1.05
Year 2009 (vs 2006)	1.02	0.02	0.265	0.98	1.06
Year 2010 (vs 2006)	1.09	0.03	0.001	1.03	1.14
Liver disease	1.05	0.05	0.318	0.95	1.15
Peripheral vascular disorder	1.01	0.02	0.520	0.98	1.05
Valvular disease	0.97	0.02	0.090	0.93	1.01
Congestive heart failure	1.25	0.02	0.000	1.21	1.30
Drug abuse	1.55	0.13	0.000	1.32	1.82
Alcohol abuse	1.27	0.08	0.000	1.12	1.43
Hypertension	0.94	0.01	0.000	0.91	0.96
Pulmonary circulation disorder	0.92	0.04	0.046	0.86	1.00
Diabetes	1.07	0.02	0.000	1.04	1.10
Short-acting β2-agonists	1.16	0.03	0.000	1.10	1.21
Long-acting β2-agonists	1.05	0.10	0.646	0.86	1.26
Short-acting anticholinergics	1.14	0.05	0.005	1.04	1.26
Long-acting anticholinergics	0.81	0.04	0.000	0.74	0.88
Methylxanthines	0.94	0.09	0.549	0.78	1.14
Systemic glucocorticoids	1.30	0.03	0.000	1.26	1.36
Mast-cell stabilizers	0.83	0.31	0.612	0.39	1.73
Leukotriene modifiers	0.96	0.05	0.395	0.88	1.05
Antibiotics	1.09	0.01	0.000	1.07	1.12

Abbreviations: CI, confidence interval; ER, emergency room; ICS, inhaled corticosteroids; FFS, fee for service; HR, hazard ratio.