Table 3.

Risk factors associated with frequent ED use, N = 364

	Risk factors	Unadjusted OR	Adj. OR (95 % CI)	p-value*
Demographic	Age (by 10 years over 18 years)	0.9 (0.8-1.0)	0.8 (0.6-1.0)	<0.05
	Gender (female)	0.7 (0.5-1.0)	0.4 (0.2-0.9)	<0.05
Social	Household income < CHF 3′000	2.7 (1.7-4.3)	4.3 (2.0-9.2)	<0.001
	Distance from home to ED <5 km	2.2 (1.4-3.4)	4.4 (2.1-9.0)	<0.001
Somatic	ED primary diagnosis (ref. = circulatory system)	1.0	1.0
	Injuries	0.4 (0.2-0.9)	0.3 (0.1-0.9)	<0.05
	Other	1.4 (0.7-2.4)	0.9 (0.3-2.6)	ns
	Comorbidity index	1.1 (1.0-1.2)	1.2 (1.1-1.4)	<0.01
	Chronic disease (yes)	0.7 (0.5-1.1)	0.3 (0.1-0.7)	<0.01
Mental	Comorbidities (yes)	3.2 (2.1-4.9)	2.3 (1.2-4.7)	<0.05
Risk behavior	Tobacco consumption (≠ no use)	2.6 (1.6-4.4)	2.6 (1.1-5.9)	<0.05
Health care use	PCP and number of visits (ref. = PCP, no visits)	1.0	1.0
	No PCP	3.3 (1.4-8.0)	8.4 (2.1-32.7)	<0.01
	PCP, 1 or more visits	1.4 (0.7-2.9)	1.0 (0.3-3.0)	ns
	Hospital admissions (ref = 1 or 2)	1.0	1.0
	0 admissions	0.6 (0.4-1.0)	0.3 (0.1-0.5)	<0.001
	3 or more admissions	15.3 (7.2-32.1)	23.2 (9.1-59.2)	<0.001
	Use of other EDs (yes)	1.6 (1.0-2.6)	2.7 (1.2-6.1)	<0.05

^* ns non-significant

Sensitivity = 85.8 %, specificity = 81.3 %, and area under curve (AUC) = 0.921

CHF Swiss Francs (in January 2009, 1 Swiss Franc = USD 0.9), ED emergency department, PCP primary care physician