|
Age in years, mean (SD)
|
56.5 (19.4)
|
51.5 (19.6)
|
59.0 (18.8)
|
<0.001
|
|
18-44
|
2066 (28.8%)
|
956 (40.1%)
|
1110 (23.1%)
| |
|
45-54
|
1285 (17.9%)
|
463 (19.4%)
|
822 (17.1%)
| |
|
55-64
|
1275 (17.8%)
|
335 (14%)
|
940 (19.6%)
| |
|
65-74
|
971 (13.5%)
|
229 (9.6%)
|
742 (15.5%)
| |
|
75-84
|
947 (13.2%)
|
258 (10.8%)
|
689 (14.4%)
| |
|
>85
|
639 (8.9%)
|
146 (6.1%)
|
493 (10.3%)
| |
|
Gender
| | | | |
|
Male
|
3966 (55.2%)
|
1364 (57.1%)
|
2602 (54.3%)
|
0.013
|
|
Female
|
3216 (44.8%)
|
1022 (42.8%)
|
2194 (45.7%)
| |
|
Unknown
|
1 (0%)
|
1 (0%)
|
0 (0%)
| |
|
Race
| | | | |
|
Caucasian
|
5314 (74%)
|
1709 (71.6%)
|
3605 (75.2%)
|
<0.001
|
|
African American
|
1507 (21%)
|
572 (24%)
|
935 (19.5%)
| |
|
Other/Unknown
|
362 (5%)
|
106 (4.4%)
|
256 (5.3%)
| |
|
Insurance type
| | | | |
|
Commercial
|
963 (13.4%)
|
331 (13.9%)
|
632 (13.2%)
|
<0.001
|
|
Medicare
|
1741 (24.2%)
|
444 (18.6%)
|
1297 (27.0%)
| |
|
Medicaid
|
456 (6.3%)
|
161 (6.7%)
|
295 (6.2%)
| |
|
Self-paid
|
203 (2.8%)
|
86 (3.6%)
|
117 (2.4%)
| |
|
Other/Unknown
|
3820 (53.2%)
|
1365 (57.2%)
|
2455 (51.2%)
| |
|
Patient type
| | | | |
|
Surgical
|
1983 (27.6%)
|
613 (25.7%)
|
1370 (28.6%)
|
0.010
|
|
Medical
|
5200 (72.4%)
|
1774 (74.3%)
|
3426 (71.4%)
| |
|
Year of discharge
| | | | |
|
2005
|
875 (12.2%)
|
265 (11.1%)
|
610 (12.7%)
|
0.380
|
|
2006
|
1648 (22.9%)
|
552 (23.1%)
|
1096 (22.9%)
| |
|
2007
|
1935 (26.9%)
|
660 (27.6%)
|
1275 (26.6%)
| |
|
2008
|
2250 (31.3%)
|
750 (31.4%)
|
1500 (31.3%)
| |
|
2009
|
475 (6.6%)
|
160 (6.7%)
|
315 (6.6%)
| |
|
Hospital Characteristics
| | | | |
|
Census region
| | | | |
|
Northeast
|
2887 (40.2%)
|
818 (34.3%)
|
2069 (43.1%)
|
<0.001
|
|
Midwest
|
1897 (26.4%)
|
573 (24.0%)
|
1324 (27.6%)
| |
|
South
|
2123 (29.6%)
|
923 (38.7%)
|
1200 (25%)
| |
|
West
|
276 (3.8%)
|
73 (3.1%)
|
203 (4.2%)
| |
|
Urban setting (vs. rural)
|
7171 (99.8%)
|
2385 (99.9%)
|
4786 (99.8%)
|
0.358
|
|
Hospital bed size
| | | | |
|
6-99
|
371 (5.2%)
|
166 (7.0%)
|
205 (4.3%)
|
<0.001
|
|
100-199
|
980 (13.6%)
|
316 (13.2%)
|
664 (13.8%)
| |
|
200-299
|
1751 (24.4%)
|
557 (23.3%)
|
1194 (24.9%)
| |
|
300-499
|
2116 (29.5%)
|
663 (27.8%)
|
1302 (27.1%)
| |
|
≥500
|
1965 (27.4%)
|
685 (28.7%)
|
1431 (29.8%)
| |
|
Teaching (vs. non-teaching)
|
4412 (61.4%)
|
1406 (58.9%)
|
3006 (62.7%)
|
0.002
|
|
Charlson comorbidity index, mean (SD)
|
1.8 (2.1)
|
1.5 (2.0)
|
2.0 (2.1)
|
<0.001
|
|
Risk factors for healthcare-associated infection (any)
|
2543 (35.4%)
|
777 (32.6%)
|
1766 (36.8%)
|
<0.001
|
|
Recent hospital discharge (within 180 days) or recent outpatient surgery
|
2,255 (31.4%)
|
702 (29.4%)
|
1,553 (32.8%)
|
0.011
|
|
Outpatient hemodialysis within 90 days or ESRD patient
|
591 (8.2%)
|
176 (7.4%)
|
415 (8.7%)
|
0.063
|
|
Admission from a chronic care facility
|
369 (5.1%)
|
105 (4.4%)
|
264 (5.5%)
|
0.046
|
|
Mechanical ventilation/Dependence on respirator
|
48 (0.7%)
|
12 (0.5%)
|
36 (0.8%)
|
0.224
|
|
Immunosuppression Factors (any below), N (%)
|
1931 (26.9%)
|
546 (22.9%)
|
1385 (28.9%)
|
<0.001
|
|
ESRD (current or prior)
|
868 (12.1%)
|
247 (10.3%)
|
621 (12.9%)
|
0.001
|
|
Received systemic corticosteroid/immunosuppressive/chemotherapy
|
590 (8.2%)
|
177 (7.4%)
|
413 (8.6%)
|
0.082
|
|
Leukemia, lymphoma, metastasis
|
388 (5.4%)
|
80 (3.4%)
|
308 (6.4%)
|
<0.001
|
|
Autoimmune diseases*
|
266 (3.7%)
|
75 (3.1%)
|
191 (4%)
|
0.076
|
|
Aplastic anemia and pancytopenia
|
144 (2.0%)
|
22 (0.9%)
|
122 (2.5%)
|
<0.001
|
|
Organ transplantation
|
116 (1.6%)
|
32 (1.3%)
|
84 (1.8%)
|
0.193
|
|
HIV/AIDS
|
55 (0.8%)
|
31 (1.3%)
|
24 (0.5%)
|
<0.001
|
|
Neutropenia
|
46 (0.6%)
|
6 (0.3%)
|
40 (0.8%)
|
0.004
|
|
Other immunosuppression factors**
|
17 (0.2%)
|
4 (0.2%)
|
13 (0.3%)
|
0.395
|
|
Comorbidity (current or 12 months prior to admission unless noted), N (%)
| | | | |
|
Hypertension
|
3585 (49.9%)
|
1071 (44.9%)
|
2514 (52.4%)
|
<0.001
|
|
Diabetes mellitus by diagnosis code or medications
|
3440 (47.9%)
|
936 (39.2%)
|
2504 (52.2%)
|
<0.001
|
|
Diabetic lower extremity infection (current encounter)
|
1746 (24.3%)
|
458 (19.2%)
|
1288 (26.9%)
|
<0.001
|
|
Renal dysfunction at baseline
|
1348 (18.8%)
|
332 (13.9%)
|
1016 (21.2%)
|
<0.001
|
|
Heart failure
|
1221 (17.0%)
|
330 (13.8%)
|
891 (18.6%)
|
<0.001
|
|
Coronary artery disease
|
1139 (15.9%)
|
328 (13.7%)
|
811 (16.9%)
|
0.001
|
|
Complication of electronic internal device (ICD-9 Code = 996.6, current encounter)
|
1087 (15.1%)
|
259 (10.9%)
|
828 (17.3%)
|
<0.001
|
|
Chronic obstructive pulmonary disease
|
815 (11.3%)
|
250 (10.5%)
|
565 (11.8%)
|
0.100
|
|
Cardiac dysrhythmias (prior to index encounter)
|
569 (7.9%)
|
166 (7%)
|
403 (8.4%)
|
0.032
|
|
Acute coronary syndrome/angina
|
534 (7.4%)
|
144 (6%)
|
390 (8.1%)
|
0.001
|
|
Cancer
|
521 (7.3)
|
110 (4.6%)
|
411 (8.6%)
|
<0.001
|
|
Cerebrovascular disease
|
283 (3.9%)
|
81 (3.4%)
|
202 (4.2%)
|
0.093
|
|
Hematologic dysfunction at baseline
|
265 (3.7%)
|
87 (3.6%)
|
215 (4.5%)
|
0.096
|
|
Cirrhosis/chronic liver disease
|
198 (2.8%)
|
45 (1.9%)
|
153 (3.2%)
|
0.001
|
|
Laboratory values, mean (SD)
| | | | |
|
Hematocrit (%)
|
36.7 (6.0)
|
37.4 (5.7)
|
36.4 (6.1)
|
<0.001
|
|
White blood cell count (k/mm3)
|
12.8 (8.4)
|
12.5 (8.3)
|
12.9 (8.4)
|
0.048
|
|
Serum creatinine (mg/dL)
|
2.0 (2.3)
|
1.7 (2.1)
|
2.1 (2.4)
|
<0.001
|
|
Platelet count (k/mm3)
|
266.8 (119.2)
|
272.2 (109.3)
|
264.1 (123.7)
|
0.015
|
