Table 1.
Parameters included in the economic model
| Variables | Mean | Distribution | Lower limit/alpha | Upper limit/beta/lambda | Source |
|---|---|---|---|---|---|
| Clinical effectiveness parameters | |||||
| Failure rate per 6 months (control arm) | 7.46% | Multivariate normal | NA | NA | VENUS clinical trial [27] |
| Failure rate per 6 months (MM replacement using NUsurface prosthesis) | 2.45% | Multivariate normal | NA | NA | VENUS clinical trial [27] |
| Percentage of patients who need knee arthroplasty per year (control arm) | 2.62% | Beta | 32.4 (alpha) | 1205.0 (beta) | Winter et al., 2017 [30] |
| Percentage of patients who need knee arthroplasty per year (MM replacement using NUsurface prosthesis) | 1.60% | Multivariate normal | NA | NA | VENUS clinical trial [27] |
| Failure rate of knee arthroplasty per year (years 1–4) | 1.9% | Beta | 15.1 (alpha) | 778.3 (beta) | Feeley et al., 2016 [32]; Chatain et al., 2003 [31] |
| Failure rate of knee arthroplasty per year (years 5–9) | 1.0% | Beta | 15.2 (alpha) | 1506.1 (beta) | Feeley et al., 2016 [32]; Chatain et al., 2003 [31] |
| Failure rate of knee arthroplasty per year (year 10) | 0.9% | Beta | 15.2 (alpha) | 1676.8 (beta) | Feeley et al., 2016 [32]; Chatain et al., 2003 [31] |
| Failure rate of knee arthroplasty per year (years 11+) | 0.6% | Beta | 15.3 (alpha) | 2530.4 (beta) | Feeley et al., 2016 [32]; Chatain et al., 2003 [31] |
| Failure rate of revised knee arthroplasty per year | 3.0% | Beta | 9.8 (alpha) | 316.8 (beta) | Feeley et al., 2016 [32]; Chatain et al., 2003 [31] |
| Implant-related adverse events (clinical events post MM replacement using NUsurface prosthesis) | |||||
| Deep vein thrombosis rate per 6 months | 1.50% | Multivariate normal | NA | NA | VENUS clinical trial [27] |
| Prosthesis repositioning rate per 6 months | 2.43% | Multivariate normal | NA | NA | VENUS clinical trial [27] |
| Prosthesis replacement rate per 6 months | 12.42% | Multivariate normal | NA | NA | VENUS clinical trial [27] |
| Unplanned arthroscopy rate per 6 months | 1.73% | Multivariate normal | NA | NA | VENUS clinical trial [27] |
| Adverse event (clinical events post arthroscopy) | |||||
| Deep vein thrombosis rate per 6 months | 0.41% | Beta | 4.3 (alpha) | 1029.2 (beta) | Thorlund et al., 2015 [39] |
| Pulmonary embolism rate per 6 months | 0.08% | Beta | 552.8 (alpha) | 708,112.5 (beta) | Abram et al., 2018 [40] |
| Infection rate per 6 months | 0.14% | Beta | 863.2 (alpha) | 638,539.1 (beta) | Abram et al., 2018 [40] |
| Adverse event (clinical events post arthroplasty) | |||||
| Deep vein thrombosis rate per 6 months | 1.20% | Beta | 6.1 (alpha) | 498.6 (beta) | Bannister et al., 2010 [41] |
| Pulmonary embolism rate per 6 months | 0.80% | Beta | 3.4 (alpha) | 418.6 (beta) | Bannister et al., 2010 [41] |
| Infection rate per 6 months | 2.90% | Beta | 0.4 (alpha) | 11.8 (beta) | Bannister et al., 2010 [41] |
| Adverse event (clinical events post high tibial osteotomy) | |||||
| Deep vein thrombosis rate per 6 months | 3.50% | Beta | 20.2 (alpha) | 556.5 (beta) | Atrey et al., 2012 [42] |
| Pulmonary embolism rate per 6 months | 0.08% | Beta | 552.8 (alpha) | 708,112.5 (beta) | Abram et al., 2018 [40] |
| Infection rate per 6 months | 3.50% | Beta | 24.9 (alpha) | 687.0 (beta) | Woodacre et al., 2016 [43]; Atrey et al., 2012 [42] |
| Non-union requiring revision rate per 6 months | 4.30% | Beta | 9.3 (alpha) | 207.5 (beta) | Woodacre et al., 2016 [43] |
| Health utility | |||||
| Post index procedure [1.5 months] (control arm) | 0.69 | Beta | 271.10 (alpha) | 120.30 (beta) | VENUS clinical trial [27] |
| Post index procedure [1.5 months] (MM replacement using NUsurface prosthesis) | 0.61 | Beta | 200.50 (alpha) | 129.40 (beta) | VENUS clinical trial [27] |
| Post index procedure [6 months] (control arm) | 0.72 | Beta | 155.90 (alpha) | 60.70 (beta) | VENUS clinical trial [27] |
| Post index procedure [6 months] (MM replacement using NUsurface prosthesis) | 0.76 | Beta | 277.80 (alpha) | 87.40 (beta) | VENUS clinical trial [27] |
| Post index procedure [12 months] (control arm) | 0.78 | Beta | 387.40 (alpha) | 110.10 (beta) | VENUS clinical trial [27] |
| Post index procedure [12 months] (MM replacement using NUsurface prosthesis) | 0.79 | Beta | 170.00 (alpha) | 45.40 (beta) | VENUS clinical trial [27] |
| Post index procedure [24 months] (control arm) | 0.77 | Beta | 245.10 (alpha) | 75.80 (beta) | VENUS clinical trial [27] |
| Post index procedure [24 months] (MM replacement using NUsurface prosthesis) | 0.79 | Beta | 134.10 (alpha) | 35.80 (beta) | VENUS clinical trial [27] |
| Post index procedure [>24 months] (control arm) | 0.79 | Beta | 67.80 (alpha) | 19.40 (beta) | VENUS clinical trial [27] |
| Post index procedure [>24 months] (MM replacement using NUsurface prosthesis) | 0.87 | Beta | 125.50 (alpha) | 18.70 (beta) | VENUS clinical trial [27] |
| Post total knee replacement (control arm) | 0.77 | Beta | 11,635.10 (alpha) | 3475.40 (beta) | NHS Digital [33] |
| Post total knee replacement (MM replacement using NUsurface prosthesis) | 0.77 | Beta | 11,635.10 (alpha) | 3475.40 (beta) | NHS Digital [33] |
| Post revision of total knee replacement (control arm) | 0.63 | Beta | 3700.00 (alpha) | 2173.00 (beta) | NHS Digital [33] |
| Post revision of total knee replacement (MM replacement using NUsurface prosthesis) | 0.63 | Beta | 3700.00 (alpha) | 2173.00 (beta) | NHS Digital [33] |
| Costs | |||||
| Prosthetic implant costs | |||||
| Cost of procedure | £1715 | Normal | NHS Reference Costs [35] | ||
| Device price | £4000 | Normal | Active Implants [21] | ||
| Number of knees treated | 1 | Fixed | NA | NA | Assumption |
| Health care professional visits | |||||
| GP visits, including prescription costs (primary care) | £73 | Fixed | NA | NA | PSSRU [34] |
| Practice nurse visits (primary care) | £14 | Fixed | NA | NA | PSSRU [34] |
| Physiotherapist visits | £67 | Fixed | NA | NA | PSSRU [34] |
| NHS consultant visits | £123 | Fixed | NA | NA | NHS reference costs [35] |
| Knee-related investigations and treatment | £341 | Fixed | NA | NA | PSSRU [34] |
| Non-pharmacological treatments | |||||
| Supervised physical therapy | £804 | Fixed | NA | NA | PSSRU [34] |
| Electrotherapy (TENS) | £35 | Fixed | NA | NA | NHS reference costs [35] |
| Bracing | £263 | Fixed | NA | NA | NHS reference costs [35] |
| Pharmacological treatments | |||||
| Simple analgesics | £68 | Fixed | NA | NA | British National Formulary [37] |
| Weak combination opioids | £92 | Gamma | 75.00 (alpha) | 450.00 (lambda) | British National Formulary [37] |
| Moderate combination opioids | £68 | Fixed | NA | NA | British National Formulary [37] |
| Strong combination opioids | £110 | Fixed | NA | NA | British National Formulary [37] |
| NSAIDs and COX-2 inhibitors | £132 | Fixed | NA | NA | British National Formulary [37] |
| Intra-articular injections | |||||
| Intra-articular corticosteroid injections | £43 | Fixed | NA | NA | British National Formulary [37] |
| Intra-articular hyaluronic acid injections | £57 | Fixed | NA | NA | British National Formulary [37] |
| Cost of surgical interventions and other treatments for complications | |||||
| Arthroscopy | £3158 | Normal | NHS reference costs [35] | ||
| Prosthesis repositioning | £572 | Normal | NHS reference costs [35] | ||
| Prosthesis replacement | £4572 | Normal | NHS reference costs [35] | ||
| Permanent prosthetic implant removal | £572 | Normal | NHS reference costs [35] | ||
| Knee arthroplasty | £6352 | Normal | NHS reference costs [35] | ||
| Revision knee arthroplasty | £14,371 | Normal | Mistry et al., 2019 [44] | ||
| Tibial osteotomy | £3880 | Normal | NHS reference costs [35] | ||
| Chondral allograft | £16,502 | Normal | Mistry et al., 2019 [44] | ||
| Meniscal allograft transplant | £8738 | Normal | NHS reference costs [35] | ||
| Unicompartmental knee replacement | £6352 | Normal | NHS reference costs [35] | ||
| Medial meniscectomy and autologous chondrocyte implantation | £21,497 | Normal | NICE TA477 [45] | ||
| Meniscectomy medial and lateral | £3158 | Normal | NHS reference costs [35] | ||
| Treatment following total knee replacement | £263 | Normal | Dakin et al., 2012 [46] | ||
| Deep vein thrombosis treatment | £2438 | Normal | Bamber et al., 2015 [47] | ||
| Venous thromboembolism prophylaxis following knee replacement and other surgeries | £1 | Fixed | NA | NA | British National Formulary [37] |
| Pulmonary embolism treatment | £5306 | Normal | Bamber et al., 2015 [47] | ||
| Infection treatment with further surgery and admission | £3880 | Normal | NHS reference costs [35] | ||
| Non-union requiring revision | £3880 | Normal | NHS reference costs [35] | ||
| Probabilities and relative risks related to resource use (annual) | |||||
| Number of patients undergoing GP visits (primary care) | 0.95 | Gamma | 0.20 (alpha) | 5.60 (beta) | Kigozi et al., 2016 [38] |
| Number of patients undergoing practice nurse visits (primary care) | 0.13 | Gamma | 0.00 (alpha) | 3.90 (beta) | Kigozi et al., 2016 [38] |
| Number of patients undergoing physiotherapist visits | 0.21 | Gamma | 0.00 (alpha) | 7.90 (beta) | Kigozi et al., 2016 [38] |
| Number of patients undergoing NHS consultant visits | 0.70 | Gamma | 0.10 (alpha) | 7.60 (beta) | Kigozi et al., 2016 [38] |
| Number of patients undergoing knee-related investigations and treatment | 0.14 | Beta | 86.00 (alpha) | 528.30 (beta) | Kigozi et al., 2016 [38] |
| Percentage of patients undergoing supervised physical therapy | 50.00 | Beta | 50.00 (alpha) | 50.00 (beta) | Assumption based on expert clinical input |
| Percentage of patients undergoing electrotherapy (TENS) | 50.00 | Beta | 50.00 (alpha) | 50.00 (beta) | Assumption based on expert clinical input |
| Percentage of patients undergoing bracing | 50.00 | Beta | 50.00 (alpha) | 50.00 (beta) | Assumption based on expert clinical input |
| Percentage of patients undergoing simple analgesics | 17.00 | Beta | 82.70 (alpha) | 394.30 (beta) | Kigozi et al., 2016 [38] |
| Percentage of patients undergoing weak combination opioids | 7.00 | Beta | 92.70 (alpha) | 1171.00 (beta) | Kigozi et al., 2016 [38] |
| Percentage of patients undergoing moderate combination opioids | 1.00 | Beta | 99.30 (alpha) | 14,800.70 (beta) | Kigozi et al., 2016 [38] |
| Percentage of patients undergoing strong combination opioids | 8.00 | Beta | 92.00 (alpha) | 1058.00 (beta) | Kigozi et al., 2016 [38] |
| Percentage of patients undergoing NSAIDs and COX-2 inhibitors | 11.00 | Beta | 89.30 (alpha) | 748.20 (beta) | Kigozi et al., 2016 [38] |
| Percentage of patients undergoing intra-articular corticosteroid injections | 20.00 | Beta | 80.00 (alpha) | 320.00 (beta) | Assumption based on expert clinical input |
| Percentage of patients undergoing intra-articular hyaluronic acid injections | 0.00 | Fixed | NA | NA | Assumption based on expert clinical input |
| Relative risk of non-surgical resource use for pain management in the intervention arm | 0.50 | Beta | 0.50 (alpha) | 0.50 (beta) | Bedson et al., 2007 [36] |
NA not available, MM medial meniscus, GP general practitioner, NHS National Health Service, TENS transcutaneous electrical nerve stimulation, NSAIDs non-steroidal anti-inflammatory drugs, COX-2 cyclooxygenase 2, PSSRU Personal Social Services Research Unit, NICE National Institute for Health and Care Excellence