Table 1.
Probability and cost assumptions
| Description | Base case | Low | High | Source |
|---|---|---|---|---|
| Probabilities | ||||
| Positive SIJ block | 0.15 | 0.05 | 0.25 | Sembrano and Polly8 |
| Successful response after SIJF | 0.82 | 0.7 | 0.85 | INSITE21 and SIFI22 |
| Successful response after LF | 0.6 | 0.4 | 0.7 | Infuse summary of safety and effectiveness data23 |
| Revision surgery in 4 years after SIJF | 0.035 | 0.03 | 0.08 | Cher et al43 |
| Successful response to LF after negative SIJ block | 0.7 | 0.6 | 0.8 | Expert opinion: If SIJ dysfunction ruled out as cause of LBP, LF success rate might be higher |
| Probability of revision surgery after LF in 2 years | 0.08 | 0.05 | 0.10 | Martin et al44 |
| Costs in $US | ||||
| Physician/facility payment for SIJ block | 444 | 355 | 533 | G0260 and CPT 27096, 53% office-based, 47% outpatient facility-based |
| SIJF | 13,636 | 10,000 | 18,000 | 30% inpatient, 70% outpatient MS-DRG 460 and CPT 27279 Ambulatory payment classification for SIJF |
| Surgeon payment for SIJF | 574 | 459 | 689* | CPT 27279 |
| Anesthesia for SIJF | 180 | 144 | 216* | CPT 01160, 4 base units and 4 time units |
| Workup and treatment of poor response to SIJF | 1,000 | 500 | 3,000 | Expert opinion. Costs include additional physician visit, SIJ block, and MRI |
| LF | 22,339 | 20,000 | 30,000 | 99% inpatient, 1% outpatient Facility payment: inpatient: MS-DRG 460 (US$21,596×94%) + MS-DRG 459 (US$36,006×6%) = US$22,461; outpatient: US$10,224 |
| Surgeon payment for LF | 2,621 | 2,200 | 2,800 | CPT 22612, arthrodesis, posterior or posterolateral technique, single level; lumbar (with lateral transverse technique when performed) CPT 22614, each additional vertebral segment |
| Anesthesia for LF | 337 | 300 | 500 | 1-hour anesthesia: 7 base units and 8 time units |
| Failed back surgery syndrome over 2 years | 50,000 | 40,000 | 82,000 | Hollingworth et al5, Lad et al6 |
| Revision surgery relative to index surgery | 1.3 | 1.1 | 1.5 | Expert opinion: multiplier comparing cost of revision surgery vs index surgery |
| Cost multiplier Medicare | 1.3 | 1 | 1.6 | Private health care insurance reimbursements exceed Medicare payments by 30% |
Note:
*
Range equal to ±20%.
Abbreviations: SIJ, sacroiliac joint; SIJF, SIJ fusion; INSITE, Investigation of Sacroiliac Fusion Treatment; SIFI, Sacroiliac Joint Fusion With iFuse Implant System®; LBP, low back pain; LF, lumbar fusion; CPT, Current Procedural Terminology; MS-DRG, Medicare Severity-Diagnosis Related Group; MRI, magnetic resonance imaging.