Table 3.

Mixed access site: differences in frequency of occurrence of characteristics (n=10 779)^*

Characteristic	Adjusted OR	p Value	95% CI	Marginal PHIE†	Marginal Pnon-HIE‡	Difference§
Hospitalized	0.478	<0.001	0.402 to 0.568	0.217	0.238	−221
Head CT	0.913	0.029	0.842 to 0.991	0.124	0.134	−103
Body CT	0.886	<0.001	0.828 to 0.948	0.203	0.221	−196
Echocardiogram	1.239	0.407	0.747 to 2.056	0.003	0.003	NS
Outpatient Surgery	0.905	0.107	0.802 to 1.022	0.049	0.053	NS
Chest x-ray	0.973	0.370	0.917 to 1.033	0.403	0.408	NS
Laboratory tests	0.880	<0.001	0.828 to 0.935	0.311	0.335	−258
24-h Admission	1.084	0.213	0.955 to 1.230	0.045	0.042	NS
Ankle x-ray	0.939	0.669	0.705 to 1.252	0.008	0.008	NS

^*Logistic regression analysis using generalized estimating equations (logit link function and binomial distribution); controlled for admission type, age, health plan status, logarithmic transformation of Charlson comorbidity index and length of stay.

^†Marginal P_HIE = the mean probability of different healthcare procedures among HIE exposure patients.

^‡Marginal P_non-HIE = the mean probability of these procedures patients with HIE exposure were not accessed by HIE.

^§Difference = (number of encounters from HIE exposure patients) × (Marginal P_HIE–Marginal P_non-HIE).

HIE, health information exchange; NS, non-significant.