Table 2.
Input parameters for the Knee OSteoarthritis MicrOSimulation (KOSMOS) model
| Parameters* | Data (95% CI) | Source |
|---|---|---|
| Annual TKR incidence | Individualized | OAI |
| Annual background mortality | Individualized | OAI |
| Annual revision probability | Age and time dependent | NJR, 201419 |
| Hazard ratio for re-revision | 1.74 (1.57 to 1.91) | Ong, 201020 |
| Proportion bilateral TKR | 13% (9% to 17%) | OAI |
| Procedural mortality with TKR at age <85 | 0.06% (0.04% to 0.08%) | HCUP5 |
| Procedural mortality with TKR at age ≥85 | 0.39% (0.20% to 0.64%) | HCUP5 |
| Annual probability of taking osteoarthritis pain medication | Individualized | OAI |
| Proportion of each drug type if taking osteoarthritis pain medication: | ||
| Prescription NSAIDs | 0.19 | OAI |
| Non-prescription NSAIDs | 0.55 | OAI |
| Celecoxib | 0.22 | OAI |
| Acetaminophen | 0.31 | OAI |
| Annual probability using non-pharmacological treatment | Individualized | OAI |
| Proportion of each non-pharmacological treatment type if used: | ||
| Acupuncture | 0.05 | OAI |
| Chiropractic | 0.40 | OAI |
| Massage | 0.21 | OAI |
| Other | 0.34 | OAI |
| No of annual visits for each non-pharmacological treatment type if used: | ||
| Acupuncture | 7 (3 to 13) | OAI |
| Chiropractic | 9 (3 to 15) | OAI |
| Massage | 7 (3 to 13) | OAI |
| Other | 8 (3 to 14) | OAI |
| Prescription NSAIDs: | ||
| Diclofenac | 813 | Losina, 201521 |
| Ibuprofen | 69 | Losina, 201521 |
| Meloxicam | 467 | Losina, 201521 |
| Nabumetone | 283 | Losina, 201521 |
| Naproxen | 470 | Losina, 201521 |
| Weighted total | 460 | OAI |
| Non-prescription NSAIDs: | ||
| Ibuprofen | 149 | Losina, 201521 |
| Naproxen | 99 | Losina, 201521 |
| Weighted total | 124 | OAI |
| Celecoxib | 3047 | Losina, 201521 |
| Acetaminophen | 71 | Losina, 201521 |
| Non-pharmacological treatment: | ||
| Acupuncture | 725 | Gore, 2012,22 OAI |
| Chiropractic | 494 | Gore, 2012,22 OAI |
| Massage | 189 | Gore, 2012,22 OAI |
| Other | 473 | Gore, 2012,22 OAI |
| Physician office visits | 66 | Losina, 201521 |
| Radiographic imaging | 29 | Losina, 201521 |
| Procedural costs (in 2013 $) | ||
| Primary TKR costs: | ||
| Hospital costs | 16 051 (15 771 to 16 331) | HCUP |
| Surgeon fees | 1582 (1022 to 2266) | Losina, 201521 |
| Anesthesiologist fees | 427 (276 to 612) | Losina, 201521 |
| Rehabilitation costs including physiotherapy | 7764 (5015 to 11 121) | Losina, 201521 |
| Revision TKR costs: | ||
| Hospital costs | 21 014 (19 369 to 22 696) | HCUP5 |
| Surgeon fees | 1812 (1170 to 2595) | Losina, 201521 |
| Anesthesiologist fees | 494 (319 to 708) | Losina, 201521 |
| Rehabilitation costs including physiotherapy | 7764 (5015 to 11 121) | Losina, 201521 |
| Quality of life utility values: | ||
| SF-6D utility index | Individualized | OAI |
| One off quality of life penalty of primary TKR | −0.008 (−0.014 to −0.005) | HCUP5 |
| One off quality of life penalty of revision TKR | −0.011 (−0.044 to −0.002) | HCUP5 |
TKR=total knee replacement.
*β distributions used for probabilities, γ distributions for costs, Poisson distribution for counts, and lognormal distributions for one off quality of life penalties.