Table 4:

Subgroup analysis of Patients with and without Severe Illness^{^^} at Telepsychiatry and Control EDs (n=134 ED pairs)

Severe mental illness	Total No. of ED Visits in Pre and Post Periods	Change from Pre- to Post-Period at Telepsychiatry EDs (n=134)	Change from Pre- to Post-Period at Control EDs (n=134)	Difference-in-Differences***	95% Confidence Interval	p-value for difference
ED Visits that Result in Admission/Transfer to a Psychiatric Specialty Bed (%)
No	133,859	3.10%	−0.80%	3.80%	(3.1, 4.6)	<0.001
Yes	38,849	2.70%	−2.60%	5.30%	(3.8, 6.8)	<0.001
ED Visits that Result in Admission/Transfer to a Medical Bed (%)
No	133,859	−0.50%	1.50%	−1.90%	(−2.7, −1.2)	<0.001
Yes	38,849	−2.60%	−0.20%	−2.40%	(−4.2, −0.5)	<0.001
Prolonged ED length of stay*^ (%)
No	26,569	2.70%	0.20%	2.50%	(1.3, 3.8)	<0.001
Yes	7,424	4.40%	−1.00%	5.40%	(2.3, 8.4)	<0.001
Institutional Spending on Mental Illness 90 Days (mean $)
No	133,859	$817	$601	$216	(9, 423)	0.04
Yes	38,849	$776	$76	$700	(109, 1292)	0.02
Mortality in 90 Days following ED Presentation (%)
No	133,859	−0.10%	−0.30%	0.20%	(−0.1, 0.5)	0.23
Yes	38,849	0.00%	0.00%	0.00%	(−0.4, 0.4)	0.96
Mental Illness Outpatient Follow-up Care in 2 Weeks following ED Discharge* (%)
No	15,338	3.20%	3.80%	−0.60%	(−3.3, 2.0)	0.6
Yes	2,401	0.20%	−1.30%	1.50%	(−6.3, 9.3)	0.7

^*Smaller sample, because only available in 20% random sample of Medicare beneficiaries

^{^}Excessive length of stay defined as a stay in ED that exceeds two midnights

^**Institutional spending encompassed payments to hospitals for inpatient and ED care incurred during the 90 days from ED presentation

^{^^}As noted in text, more severe mental illness was captured by having one or more inpatient stays in 90 days prior to ED visit.

^***Difference-in-difference estimates adjust for changes in patient characteristics.