Table 2.

Risk factors for all-cause 30-d readmission in multivariable model^a

Predictor	Odds Ratio (95% CI)	P value
New Variables
Outpatient visit (vs. Yes)
No	5.74 (5.35-6.15)	<0.001
Not documented	0.28 (0.25-0.31)	<0.001
Discharge status of index admission (vs. Home)
Against medical advice	1.60 (1.32-1.94)	<0.001
Home with nursing care	1.03 (0.95-1.11)	0.46
Sub-acute facility	0.99 (0.91-1.08)	0.90
Other	0.72 (0.51-1.01)	0.054
Charlson comorbidity index (vs. 0)
>6	1.38 (1.17-1.64)	<0.001
5 – 6	1.17 (0.98-1.39)	0.083
3 – 4	1.17 (1.00-1.38)	0.053
1 – 2	1.07 (0.91-1.26)	0.39
Length-of-stay (days)(log)	1.14 (1.09-1.19)	<0.001
Previously studied variables
Sociodemographic/Administrative
Employment status (vs. Employed)
Disabled	1.55 (1.35-1.78)	<0.001
Retired	1.46 (1.28-1.67)	<0.001
Unemployed	1.26 (1.10-1.44)	<0.001
Other or unknown	1.09 (0.85-1.40)	0.51
Insurance status (vs. Private)
Medicaid	1.17 (1.06-1.29)	0.0015
Medicare	0.95 (0.88-1.0 $3$)	0.25
None	0.77 (0.65-0.91)	0.0029
Home zip code <8 km from hospital	1.11 (1.0 $3$-1.20)	0.0086
Race/ethnicity (vs. White)
Black	0.90 (0.83-0.98)	0.014
Hispanic	0.86 (0.77-0.9 $5$)	0.0049
Other	0.72 (0.62-0.83)	<0.001
Female (vs. Male)	0.90 (0.84-0.96)	0.002 $8$
Pre-admission clinical
Discharged within 90 days before admission	1.76 (1.64-1.89)	<0.001
Discharge status 1 year prior to index admission
Against medical advice	1.27 (1.03-1.58)	0.025
Home with nursing care	1.04 (0.95-1.13)	0.37
Sub-acute facility	1.01 (0.93-1.11)	0.77
No discharge recorded	0.91 (0.83-0.99)	0.022
Pre-admission glucocorticoid use	1.16 (1.05-1.28)	0.0048
Pre-admission insulin use	1.14 (1.06-1.22)	<0.001
Pre-admission thiazolidinedione use	0.84 (0.75-0.95)	0.0034
Hospital
Gastroparesis ever	1.38 (1.18-1.63)	<0.001
White blood cell count (vs. Normal)
Low <4.0 × 109 L	1.27 (1.12-1.45)	<0.001
High >11.0 × 109 L	1.19 (1.11-1.28)	<0.001
Serum sodium (vs. Normal)
Low <135 mmol/L	$1.19$ (1.10-1.3 $0$)	<0.001
High >145 mmol/L	1.06 (0.82-1.38)	0.66
Most extreme blood glucose level (vs. 3.9 – 10.0 mmol/L)
<2.2 or >16.6 mmol/L	1.20 (1.10-1.31)	<0.001
2.2 – 3.8 or 10.1 – 16.6 mmol/L	1.07 (1.00-1.1 $5$)	0.038
Urgent or emergent admission	1.18 (1.08-1.29)	<0.001
Serum albumin (vs. ≥40 g/L)
<40 g/L	1.14 (1.07-1.22)	<0.001
Unknown	0.94 (0.85-1.04)	0.2 $6$
Anemia ever	1.15(1.07-1.24)	<0.001
Schizophrenia or mood disorder ever	1.12 (1.04-1.2 $1$)	0.0022
Current fluid or electrolyte disorder	1.10 (1.03-1.18)	0.0048
Cardiac dysrhythmias ever	1.15 (1.06-1.24)	<0.001
Serum creatinine (mg/dL)(log)	1.08 (1.03-1.14)	0.0025
Blood transfusion given	0. $90$ (0.82-0.97)	0.010
Hematocrit (per 5% increase)	0.89 (0.86-0.92)	<0.001

^aAdjusted for year of discharge