Properties of the Vernier caliper method according to the OMERACT filter.
| Findings | Data source | Study | |
|---|---|---|---|
| Feasibility | Low cost, short acquisition time, high patient acceptability | Observational cross-sectional study | Dalbeth16 |
| Construct validity | High correlation between computed tomography and Vernier caliper measurement (r = 0.91, p < 0.001) | Observational cross-sectional study | Dalbeth16 |
| Reliability | Intraobserver intraclass correlation coefficient 1.0 (95% CI 0.99, 1.0); interobserver intraclass correlation coefficient 0.99 (95% CI 0.97, 0.99) | Observational cross-sectional study | Dalbeth16 |
| Change sensitivity | All index tophi completely resolved with urate-lowering therapy after mean 21 months; effect size 1.83 | Non-randomized parallel treatment study | Perez-Ruiz12 |
| Between-group discrimination | Faster resolution in benzbromarone treatment group vs allopurinol treatment group (velocity of regression 1.21 mm/month vs 0.57 mm/month, p < 0.01) | Non-randomized parallel treatment study | Perez-Ruiz12 |