Table 3
Analysis of sensitivity of economic model to assumptions of frequency of giant cell arteritis (GCA) in cases with periarterial lymphocyte infiltration (PALI) and relative costs of diagnostic strategies
| Assumption (other variables held constant) | Marginal cost* of strategy B compared with strategy A | Marginal cost* of strategy C compared with strategy A | Marginal cost* of strategy B compared with strategy C |
|---|---|---|---|
| *In Welcan units. | |||
| CL, confidence limit. | |||
| GCA at upper 95% CL of frequency in cases with PALI | 21.84 | 7.01 | 38.06 |
| GCA at observed frequency in cases with PALI | 83.5 | 21 | 208.5 |
| GCA at lower 95% CL of frequency in cases with PALI | No extra cases detected | No extra cases detected | No extra cases detected |
| Strategy B costs 4 Welcan units/case (rather than 4.5) | 55.67 | 21 | 125 |
