Table 3.
Patient characteristics, diagnosis and operative features of workers compensation patient undergoing inpatient lumbar fusion.
| California (n = 4,082) | Washington (n = 546) | Overall (n = 4628) | P-value for difference between states | ||
|---|---|---|---|---|---|
| Rate per 100,000 (95%CI) employed adults aged 20–65 [1] | 19.0 (18.6 – 19.5) | 12.9 (12.0 – 13.8) | 18.0 (17.6 – 18.4) | <0.001 | |
| Age, mean (sd) | 47.1 (9.5) | 46.6 (9.4) | 47.0 (9.5) | 0.253 | |
| Age group | 20–24 | 29 (1%) | 6 (1%) | 35 (1%) | 0.691 |
| 25–29 | 149 (4%) | 18 (3%) | 167 (4%) | ||
| 30–34 | 288 (7%) | 44 (8%) | 332 (7%) | ||
| 35–39 | 443 (11%) | 64 (12%) | 507 (11%) | ||
| 40–44 | 619 (15%) | 70 (13%) | 689 (15%) | ||
| 45–49 | 789 (19%) | 111 (20%) | 900 (19%) | ||
| 50–54 | 755 (18%) | 108 (20%) | 863 (19%) | ||
| 55–59 | 618 (15%) | 80 (15%) | 698 (15%) | ||
| 60–64 | 392 (10%) | 45 (8%) | 437 (9%) | ||
| Sex, % | Male | 2614 (65%) | 390 (71%) | 3004 (66%) | 0.003 |
| Female | 1405 (35%) | 156 (29%) | 1561 (34%) | ||
| Charlson comorbidity [2], % | None | 3157 (77%) | 434 (79%) | 3591 (78%) | 0.384 |
| 1 | 795 (19%) | 93 (17%) | 888 (19%) | ||
| 2+ | 130 (3%) | 19 (3%) | 149 (3%) | ||
| Length of stay, days (SD) | 4.39 (2.8) | 3.06 (1.8) | 4.2 (2.8) | <0.001 | |
| Diagnosis | Disc Degeneration | 1161 (28%) | 115 (21%) | 1276 (28%) | <0.001 |
| Herniated | 1390 (34%) | 102 (19%) | 1492 (32%) | ||
| Herniated + myelopathy | 111 (3%) | 10 (2%) | 121 (3%) | ||
| Stenosis | 257 (6%) | 79 (15%) | 336 (7%) | ||
| Spondylolisthesis | 999 (25%) | 220 (41%) | 1219 (26%) | ||
| Scoliosis | 159 (4%) | 17 (3%) | 176 (4%) | ||
| Codes that imply previous surgery | No | 3203 (79%) | 407 (75%) | 3610 (78%) | 0.056 |
| Yes | 874 (21%) | 136 (25%) | 1010 (22%) | ||
| Procedure | Fusion only | 1183 (29%) | 154 (28%) | 1337(29%) | 0.707 |
| Fusion + decompression | 2899 (71%) | 392 (72%) | 3291(71%) | ||
| Instrumentation | No | 896 (22%) | 112 (21%) | 1008 (22%) | 0.445 |
| Yes | 3186 (78%) | 434 (79%) | 3620 (78%) | ||
| 3+ disc levels fused | No | 3654 (90%) | 521 (95%) | 4175 (90%) | <0.001 |
| Yes | 428 (10%) | 25 (5%) | 453 (10%) | ||
| BMP [3] | No | 2,037 (50%) | 378 (69%) | 2415 (52%) | <0.001 |
| Yes | 2,045 (50%) | 168 (31%) | 2213 (48%) | ||
| Approach | Posterior | 2428 (60%) | 475 (87%) | 2903 (63%) | <0.001 |
| Anterior | 586 (14%) | 41 (8%) | 627 (14%) | ||
| Circum. | 1054 (26%) | 28 (5%) | 1082 (23%) | ||
[1]
Age- and sex-adjusted rate of fusion for degenerative disease reimbursed through WC systems per 100,000 employed adults aged 20–65 based on U.S. Census denominator.
[2]
Charlson index modified to remove acute myocardial infarction and stroke
[3]
BMP, Bone Morphogenetic Proteins