Characteristic, unit | Full cohort† | Single-level only cohort‡ | ||||
---|---|---|---|---|---|---|
Group | P value | Group | P value | |||
V-CBA (n = 6588) | rhBMP-2 (n = 9584) | V-CBA (n = 5683) | rhBMP-2 (n = 8505) | |||
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) |