Table 2.

Factors associated with ED visits and hospital admissions for COPD or asthma among ACO patients aged 65+ using Cox models (N=1141).

	ED visits				Hospital admissions
	Crude model		Adjusted model		Crude model		Adjusted model
	HR	95% CI	HR	95% CI	HR	95% CI	HR	95% CI
COCI
1 (Reference)	1.00		1.00		1.00		1.00
0.3-0.99	3.11	1.70-5.66	2.69	1.47-4.93	1.85	1.13-3.03	1.72	1.04-2.83
<0.3	3.22	1.68-6.15	2.80	1.45-5.38	2.04	1.18-3.53	1.80	1.03-3.13
Patient characteristics at baseline
Gender
Female (Reference)	1.00		1.00		1.00		1.00
Male	1.33	0.94-1.88	1.21	0.84-1.74	1.49	1.05-2.11	1.49	1.03-2.13
Age (years)	1.04	1.01-1.06	1.04	1.01-1.07	1.03	1.00-1.05	1.02	0.99-1.05
Insurance premium (USD)
<667 (Reference)	1.00		1.00		1.00		1.00
667-1333	1.14	0.80-1.61	1.24	0.86-1.77	0.91	0.65-1.29	0.98	0.69-1.40
≥1333	0.54	0.30-0.96	0.73	0.40-1.33	0.61	0.36-1.02	0.75	0.44-1.28
Medical conditions
In a previous year
History of hypertension
No (Reference)	1.00		1.00		1.00		1.00
Yes	0.70	0.48-1.00	0.81	0.55-1.18	0.94	0.67-1.33	0.99	0.70-1.41
History of diabetes
No (Reference)	1.00		1.00		1.00		1.00
Yes	0.70	0.38-1.30	1.05	0.55-1.99	0.98	0.57-1.67	1.12	0.64-1.96
ED visits for asthma/COPD
No (Reference)	1.00		1.00		1.00		1.00
Yes	4.25	2.99-6.04	2.87	1.93-4.26	2.81	1.93-4.10	1.83	1.21-2.77
Admissions for asthma/COPD
No (Reference)	1.00		1.00		1.00		1.00
Yes	2.56	1.75-3.75	1.63	1.09-2.46	3.01	2.09-4.32	2.39	1.62-3.51
In the COC period
CCI	0.93	0.83-1.05	0.96	0.85-1.08	1.03	0.93-1.14	1.04	0.93-1.16
No. of ambulatory visits
3-12 (Reference)	1.00		1.00		1.00		1.00
13-24	2.56	1.79-3.65	2.00	1.39-2.88	1.65	1.17-2.31	1.39	0.98-1.97
≥25	4.96	2.93-8.39	2.91	1.67-5.08	2.69	1.54-4.71	1.85	1.03-3.31

COCI, continuity of care index; CCI, Charlsons' Comorbidity Index; COPD, Chronic Obstructive Pulmonary Disease; ED, emergency department.