Age in years, mean (std. dev.) [1]
|
60.86 (13.13)
|
60.74 (13.46)
|
0.5604
|
60.09 (13.31)
|
60.05 (13.62)
|
0.8749
|
Female sex, n (%) [2]
|
3653 (55.45)
|
5302 (55.32)
|
0.8850
|
2963 (55.08)
|
4492 (55.20)
|
0.4381
|
Race, n (%) [3]
|
White
|
5586 (84.79)
|
8415 (87.80)
|
< 0.0001*
|
4568 (84.92)
|
7121 (87.50)
|
< 0.0001^
|
Black
|
500 (7.59)
|
521 (5.44)
|
393 (7.31)
|
457 (5.62)
|
Other/unknown
|
502 (7.62)
|
648 (6.76)
|
418 (7.77)
|
560 (6.88)
|
Ethnicity, n (%) [3]
|
Hispanic
|
143 (2.17)
|
342 (3.57)
|
< 0.0001*
|
126 (2.34)
|
298 (3.66)
|
< 0.0001^
|
Non-Hispanic
|
5588 (84.82)
|
8712 (90.90)
|
4574 (85.03)
|
7383 (90.72)
|
Unknown
|
857 (13.01)
|
530 (5.53)
|
679 (12.62)
|
457 (5.62)
|
Charlson comorbidities, n (%) [2]
|
Any malignancy
|
83 (1.26)
|
63 (0.66)
|
0.0001*
|
77 (1.34)
|
58 (0.68)
|
< 0.0001^
|
Cerebrovascular disease
|
105 (1.60)
|
109 (1.14)
|
0.0141*
|
99 (1.74)
|
98 (1.15)
|
0.0041^
|
Congestive heart failure
|
380 (5.77)
|
499 (5.21)
|
0.129
|
364 (6.41)
|
472 (5.55)
|
0.0372^
|
Chronic obstructive pulmonary disorder
|
1403 (21.30)
|
1878 (19.60)
|
0.0086*
|
1310 (23.05)
|
1694 (19.92)
|
< 0.0001^
|
Dementia
|
113 (1.72)
|
149 (1.60)
|
0.447
|
107 (1.88)
|
138 (1.62)
|
0.2712
|
Diabetes with chronic complications
|
494 (7.50)
|
601 (6.27)
|
0.0025*
|
480 (8.45)
|
505 (5.94)
|
< 0.0001^
|
Diabetes without chronic complications
|
1030 (15.63)
|
1304 (13.60)
|
0.0003*
|
912 (16.05)
|
1114 (13.10)
|
< 0.0001^
|
Hemiplegia or paraplegia
|
149 (2.26)
|
94 (0.98)
|
< 0.0001*
|
139 (2.45)
|
86 (1.01)
|
< 0.0001^
|
HIV/AIDS
|
4 (0.06)
|
4 (0.04)
|
0.7232
|
0 (0.00)
|
2 (0.02)
|
0.6639
|
Metastatic solid tumor
|
54 (0.82)
|
9 (0.09)
|
< 0.0001*
|
51 (0.90)
|
9 (0.11)
|
< 0.0001^
|
Myocardial infarction
|
351 (5.33)
|
389 (4.06)
|
0.0002*
|
336 (5.91)
|
355 (4.17)
|
< 0.0001^
|
Mild liver disease
|
35 (0.53)
|
41 (0.43)
|
0.3513
|
28 (0.49)
|
28 (0.33)
|
0.1660
|
Moderate or severe liver disease
|
9 (0.14)
|
7 (0.07)
|
0.2144
|
9 (0.16)
|
7 (0.08)
|
0.2857
|
Peptic ulcer disease
|
39 (0.59)
|
33 (0.34)
|
0.0233*
|
36 (0.63)
|
30 (0.35)
|
0.0225^
|
Peripheral vascular disease
|
266 (4.04)
|
319 (3.33)
|
0.0184*
|
247 (4.35)
|
284 (3.34)
|
0.0023^
|
Renal disease
|
458 (6.92)
|
699 (7.29)
|
0.4196
|
425 (7.48)
|
642 (7.54)
|
0.9025
|
Rheumatic disease
|
376 (5.71)
|
531 (5.54)
|
0.6513
|
359 (6.32)
|
494 (5.81)
|
0.2251
|
Charlson comorbidity index, mean (Std. Dev.) [4]
|
0.92 (1.39)
|
0.78 (1.20)
|
< 0.0001*
|
0.90 (1.38)
|
0.78 (1.20)
|
< 0.0001^
|
Health insurance status, n (%) [3]
|
Medicare
|
3276 (49.73)
|
4669 (48.72)
|
< 0.0001*
|
2570 (49.78)
|
3856 (47.38)
|
< 0.0001^
|
Medicaid
|
617 (9.37)
|
522 (5.45)
|
526 (9.78)
|
470 (5.78)
|
Private insurance
|
1416 (21.49)
|
2509 (26.18)
|
1172 (21.79)
|
2202 (27.06)
|
Commercial indemnity
|
727 (11.04)
|
1107 (11.55)
|
627 (11.66)
|
931 (11.44)
|
Other/unknown
|
552 (8.38)
|
777 (8.11)
|
484 (9.00)
|
679 (8.34)
|
Initial visit admission type, n (%) [3]
|
Elective
|
6035 (91.61)
|
8742 (91.21)
|
< 0.0001*
|
4938 (91.80)
|
7425 (91.24)
|
< 0.0001^
|
Emergency
|
309 (4.69)
|
231 (2.41)
|
249 (4.63)
|
201 (2.47)
|
Urgent
|
124 (1.88)
|
574 (5.99)
|
104 (1.93)
|
480 (5.90)
|
Trauma
|
86 (1.31)
|
18 (0.19)
|
67 (1.25)
|
16 (0.20)
|
Other/unknown
|
34 (0.52)
|
19 (0.20)
|
21 (0.39)
|
16 (0.20)
|
Initial visit admission source, n (%) [3]
|
Transfer from non-healthcare facility
|
3528 (53.55)
|
6939 (72.40)
|
< 0.0001*
|
2902 (54.11)
|
5849 (71.93)
|
< 0.0001^
|
Clinic
|
2895 (43.94)
|
2411 (25.16)
|
2354 (43.87)
|
2090 (25.70)
|
Transfer from different hospital facility
|
103 (1.56)
|
168 (1.75)
|
81 (1.51)
|
146 (1.80)
|
Other/unknown
|
62 (0.94)
|
66 (0.69)
|
27 (0.50)
|
47 (0.58)
|
Initial discharge status, n (%) [3]
|
Home/home care service/self-care
|
4056 (61.57)
|
5623 (58.67)
|
< 0.0001*
|
3390 (63.02)
|
4880 (59.97)
|
< 0.0001^
|
Home health organization
|
1158 (17.58)
|
1919 (20.02)
|
942 (17.51)
|
1594 (19.59)
|
Transferred to skilled nursing facility
|
792 (12.02)
|
1078 (11.25)
|
598 (11.12)
|
876 (10.76)
|
Nursing, rehabilitation, or hospice facility
|
477 (7.24)
|
889 (9.28)
|
383 (7.12)
|
732 (8.99)
|
Other/unknown
|
105 (1.59)
|
75 (0.78)
|
67 (1.25)
|
56 (0.69)
|
Cage insertion, n (%) [2]
|
4115 (62.46)
|
5667 (59.13)
|
0.0010*
|
3210 (56.48)
|
4588 (53.94)
|
0.0007*
|
Multiple levels treated, n (%) [2]
|
905 (13.74)
|
1079 (11.26)
|
< 0.0001*
|
–
|
–
|
–
|
Hospital size, n (%) [3]
|
1 to 299 beds
|
696 (10.56)
|
4062 (42.38)
|
< 0.0001*
|
596 (11.08)
|
3304 (40.60)
|
< 0.0001^
|
300 to 499 beds
|
2735 (41.51)
|
2987 (31.17)
|
2223 (41.33)
|
2632 (32.34)
|
500+ beds
|
3157 (47.92)
|
2535 (26.45)
|
2560 (47.59)
|
2202 (27.06)
|
Hospital teaching status, n (%) [3]
|
Teaching hospital
|
4580 (69.52)
|
5087 (53.08)
|
< 0.0001*
|
3754 (69.79)
|
4249 (52.21)
|
< 0.0001^
|
Non-teaching hospital
|
2008 (30.48)
|
4497 (46.92)
|
1625 (30.21)
|
3889 (47.79)
|
Hospital population served, n (%) [3]
|
Rural
|
563 (8.55)
|
6 (0.06)
|
< 0.0001*
|
560 (8.55)
|
6 (0.07)
|
< 0.0001^
|
Urban
|
6025 (91.45)
|
9578 (99.94)
|
4919 (91.45)
|
8132 (99.93)
|
Hospital region, n (%) [3]
|
Midwest
|
1031 (15.65)
|
2639 (27.54)
|
< 0.0001*
|
872 (16.21)
|
2280 (28.02)
|
< 0.0001^
|
Northeast
|
967 (14.68)
|
2413 (25.18)
|
767 (14.26)
|
1968 (24.18)
|
South
|
3688 (55.98)
|
4234 (44.18)
|
2959 (55.01)
|
3626 (44.56)
|
West
|
902 (13.69)
|
298 (3.11)
|
781 (14.52)
|
264 (3.24)
|