Table 1:

Patient Characteristics Across Hospital Mechanical Ventilation Quartiles

Variable	Quartile 1 n=3,620	Quartile 2 n=8,230	Quartile 3 n=13,976	Quartile 4 n=25,863	p-value
MV Episodes - (number of cases)	<94	94–170	171–289	≥290	N/A
Hospitals (n)	68	69	68	69
Mean Age (SD)	63.6 (17.1)	65.2 (16.9)	65.4 (16.9)	63.3 (17.3)	<0.0001
Female (%)	44.0	45.2	45.3	43.6	0.02
Race/Ethnicity (%)					<0.0001
Caucasian	58.1	56.3	49.1	50.9
Black	6.8	8.0	13.6	12.7
Hispanic	23.0	20.5	21.6	22.7
Asian	8.2	11.2	11.3	8.4
Other	3.9	4.1	4.4	5.3
Primary Payer (%)					0.06
Medicare	57.9	61.3	61.3	57.1
Medicaid	25.6	21.4	20.7	26.5
Private Insurance	13.7	14.0	15.3	13.4
Self-Pay	1.0	1.0	1.2	1.2
Other	1.9	2.2	1.5	1.8
Early DNR Order (%)	15.6	14.2	14.2	14.5	0.46
Mean Elixhauser Comorbidity Score (SD)*	10.6 (8.8)	10.8 (8.9)	11.1 (8.8)	10.4 (8.9)	<0.0001
Shock (%)**	29.1	31.1	31.2	31.0	0.17
Renal Failure (%)**	39.0	39.9	40.6	37.4	<0.0001
Neurologic Failure (%)**	4.1	5.1	4.8	4.7	0.74
Hepatic Failure (%)**	7.3	8.0	7.9	7.5	0.55
Hematologic Failure (%)**	16.3	18.1	18.2	16.9	0.17
Acidosis (%)**	27.0	25.2	27.3	27.0	0.09
Pneumonia (%)	37.2	34.8	34.3	33.3	<0.0001
COPD (%)	16.2	13.9	13.1	12.4	<0.0001
Asthma (%)	2.0	2.4	2.2	2.0	0.14
Heart Failure (%)	14.9	16.0	16.0	15.8	0.47
Severe Sepsis (%)	8.0	7.7	8.8	6.7	<0.0001
Septic Shock (%)	28.9	29.2	30.0	29.5	0.43
ARDS (%)	2.6	2.3	2.0	1.8	0.0002

Abbreviations: MV – mechanical ventilation. SD – standard deviation. DNR – do-not-resuscitate. COPD – chronic obstructive pulmonary disease. ARDS – acute respiratory distress syndrome.

^*Individual comorbidities were used in multivariable modeling. The comorbidity score was calculated without the cardiac arrhythmia comorbidity. See reference 29

^**Present on admission