Classification accuracy (positive and negative predictive value (PV)) according to expected prevalence rates of rheumatoid arthritis and spondyloarthropathy in the community
| Positive PV | Negative PV | |||
|---|---|---|---|---|
| Prevalence | 0.5% | 1% | 2% | 0.5, 1, and 2% |
| Rheumatoid arthritis | ||||
| Self report of diagnosis | 0.04 | 0.07 | 0.13 | 0.99 |
| Self report of diagnosis + hand and wrist x rays performed | 0.06 | 0.11 | 0.19 | 0.99 |
| Self report of diagnosis + morning joint stiffness | 0.04 | 0.08 | 0.15 | 0.99 |
| Self report of diagnosis + rheumatoid factor test performed | 0.02 | 0.04 | 0.07 | 0.99 |
| Spondyloarthropathy | ||||
| Self report of diagnosis | 0.09 | 0.16 | 0.30 | 0.99 |
| Self report of diagnosis + family history of reactive arthritis | 0.05 | 0.10 | 0.18 | 0.99 |
| Self report of diagnosis + family history of spondylitis | 0.04 | 0.08 | 0.15 | 0.99 |
| Self report of diagnosis + rheumatoid factor test performed | 0.04 | 0.07 | 0.14 | 0.99 |