Comparison of patient attributes in PORT study, Zimmer total, Zimmer subset with complete data, and single site registry
| Pre-TKR Patient attributes | Zimmer subset (Research Cohort)* | Zimmer total | PORT study† | Central NY: Single site |
|---|---|---|---|---|
| Years of enrollment | 2000–2004 | 2000–2004 | 1992–1993 | 1998–2000 |
| # Surgeons | 135 | 171 | 48 | 2 |
| # Patients eligible for inclusion | unknown | unknown | 563 | 172 |
| # Patients included | 8050 | 17,270 | 291 | 172 |
| % Patients included | unknown | unknown | 52 | 100 |
| % Patients with followup data* | 100 (1 year) | 51 (1 year) | 92 (2 years) | 100 (1 year) |
| Patients Included | ||||
| Osteoarthritis diagnosis (%) | 95 | 94 | 100 | 100 |
| Knee pain past 6 M (%) | 100 | 100 | 100 | 100 |
| Primary TKR (%) | 100 | 100 | 100 | 100 |
| Potential Prognostic Variables | ||||
| Age (mean years) | 67.8 | 67.6 | 70.2 | 67.3 |
| Male % | 34 | 35 | 37 | 34 |
| Female % | 66 | 65 | 63 | 66 |
| Region of US (# states) | 31 | 36 | Indiana | Central NY |
| BMI (mean) | 32 | 32 | 30 | — |
| SF12 PCS preoperative | 30.3 | 30.2 | 27.4 | 30.4 |
| SF12 MCS preoperative | 52.6 | 53.6 | 52.5 | 52.5 |
| KSS- Pain preoperative | 37.0 | 35.6 | 34.7 | — |
| KSS- Function preoperative | 47.0 | 47.7 | 41.2 | — |
| Outcome Variables | ||||
| SF12 PCS 12 month | 43.8 | 42.6 | 38.1 | 40.8 |
| Mean PCS change (pre to 12 mo) | 13.6 | 14.1 | 10.5 | 10.4 |
| KSS- Pain 6 month | 80.0 | 76.8 | 62.8 | — |
| KSS- Function 6 month | 67.3 | 66.1 | 62.5 | — |
| Surgeon and hospital factors | ||||
| % patients treated by surgeons with annual volume > 20/year | 78% | 73% | 77% | 100% |
| Surgeon volume > 20/year in database (%) | 30.4% | 22.5% | — | 100% |
| % patients treated in hospitals with annual volume < 50 | 40% | 39% | — | 0 |
| Hospital < 50 TKR/year (%) | 41% (n = 92) | 45% (n = 144) | 20% (n = 5) | 0 |