Table 2.
Model parameters Further detail is provided in the supplementary information (Table S1-7; Appendix 3)
| Parameter | Value | Source |
|---|---|---|
| Clinical effectiveness | ||
| Proportion with marked improvement post-procedure | 88.9% | 18 |
| Proportion with mild to moderate improvement post-procedure | 10.0% | 18 |
| Proportion with no improvement post-procedure | 1.1% | 18 |
| Annual proportion moving from marked to mild due to waning in surgical effectiveness (MRgFUS) | 9.2% | 18 |
| Annual proportion moving from marked to mild due to waning in surgical effectiveness (DBS) | 7.7% | 36 |
| Annual probability of recurrence in (MRgFUS) | 1% | 18 |
| Annual probability of recurrence in (DBS) | 3.9% | 36 |
| Annual probability of re-operation after recurrence | 5% | Assumption (based on expert opinion) |
| Costs | ||
| DBS procedure (all resource use for 1 year) | £47,627 | Table S3 |
| MRgFUS procedure (all resource use for 5 years) | £16,500 | Assumption (based on expert opinion) |
| Medication cost per year | £744 | Table S3 |
| Ongoing monitoring costs | ||
| No procedure | £169 | Table S6 |
| DBS 2 + years | £3,172 | Table S6 |
| MRgFUS 5 + years | £169 | Table S6 |
| Adverse events costs | ||
| Infection | £657 | Table S7 |
| Intracranial haemorrhage | £20,545 | Table S7 |
| Lead fracture or migration | £14,777 | Table S7 |
| Gait disturbance | £0 | Table S7 |
| Speech problem | £42 | Table S7 |
| Utilities | ||
| Alive with disabling tremor (baseline) | 0.69 | 34 |
| Improved tremor post-procedure (marked improvement – no adverse events) | 0.91 | 34 |
| Improved tremor post-procedure (mild to moderate improvement – no adverse events) | 0.80 | Assumed to be between baseline and marked improvement post-procedure |
| Improved tremor post-procedure with adverse events (marked improvement) (MRgFUS) Short term (year 1) Long term (year 2+) |
0.91 0.90 |
A weighted average utility including the disutility of common adverse events using the adverse event proportion found in Table S2 and corresponding utilities in Table S8. |
| Improved tremor post-procedure with adverse events (marked improvement) (DBS) Short term (year 1) Long term (year 2+) |
0.91 0.91 |
A weighted average utility including the disutility of common adverse events using the adverse event proportion found in Table S7 and corresponding utilities in Table S8. |
| Improved tremor post-procedure with adverse events (mild/moderate improvement) (MRgFUS) Short term (year 1) Long term (year 2+) |
0.80 0.79 |
A weighted average utility including of the disutility of common adverse events using the adverse event proportion found in Table S7 and corresponding utilities in Table S8. |
| Improved tremor post-procedure with adverse events (mild/moderate improvement) (DBS) Short term (year 1) Long term (year 2+) |
0.80 0.76 |
A weighted average utility including of the disutility of common adverse events using the adverse event proportion found in Table S2 and corresponding utilities in Table S8. |
| Others | ||
| Population | 1,415 | Calculated using assumptions found in Table S1 |
| DBS onset of benefit (months) | 3 months | Assumption (based on expert opinion) |
DBS, deep brain stimulation;MRgFUS, magnetic resonance-guided focused ultrasound.
a
recurrence refers to diminished tremor control back to baseline