Incremental cost-utility ratios by group
| Measure | All patients | Patients with DLS who underwent decompression alone, and the matched patients with hip or knee OA | Patients with DLS who underwent decompression with fusion, and the matched patients with hip or knee OA | ||||||
|---|---|---|---|---|---|---|---|---|---|
| MIS decompression with or without fusion for DLS n = 66 | Primary THA for hip OA n = 66 | Primary TKA for knee OA n = 66 | MIS decompression for DLS n = 35 | Primary THA for hip OA n = 35 | Primary TKA for knee OA n = 35 | MIS decompression and fusion for DLS n = 31 | Primary THA for hip OA n = 31 | Primary TKA for knee OA n = 31 | |
| Average cohort lifetime ICUR, point estimate, $/QALY | 7946 | 5098 | 7104 | 5045 | 5824 | 8206 | 9870 | 4338 | 5886 |
| Lifetime ICUR, $/QALY (95 CI%)* | 8177 (8077–8277) | 5196 (5136–5256) | 7242 (7144–7340) | 5371 (5280–5463) | 6216 (6115–6318) | 8838 (8664–9013) | 10472 (10 304–10 641) | 4477 (4417–4537) | 6223 (6118–6329) |
| Worst-case scenario lifetime ICUR, $/QALY† | 17062 | 10396 | 15850 | 12666 | 14260 | 23297 | 25258 | 9692 | 15464 |
| Best-case scenario lifetime ICUR, $/QALY‡ | 3204 | 2056 | 2724 | 1959 | 2183 | 2874 | 3563 | 1619 | 2068 |
Note: CI = confidence interval; DLS = degenerative lumbar spondylolisthesis; ICUR = incremental cost–ulity ratios; MIS = minimally invasive surgery; OA = osteoarthritis; QALY = quality-adjusted life year; THA = total hip arthroplasty; TKA = total knee arthroplasty.
↵* Based on a probabilistic sensitivity analysis, cost and QALYs discounted at an annual rate of 3%.
↵† Worst-case scenario ICUR was determined using the mean primary surgery cost plus 25%, the mean revision surgery cost plus 25%, the upper limit of the proportion of patients undergoing revision surgery, 40% inpatient rehabilitation for THA and TKA, and the lower limit of the 95% CI for QALYs gained and a 5% discount rate.
↵‡ Best-case scenario ICUR was determined using the mean primary surgery cost minus 25%, the mean revision surgery cost minus 25%, the lower limit of the proportion of patients undergoing revision surgery, 0% inpatient rehabilitation for THA and TKA, and the upper limit of the 95% CI for QALYs gained and a 0% discount rate.