Risk of inhibitor development according to type of factor VIII product
| . | NED . | All clinically relevant inhibitor development . | High-titer inhibitor development* . | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Crude . | Adjusted . | Crude . | Adjusted . | ||||||
| RR (CI) . | P . | RR (CI) . | P . | RR (CI) . | P . | RR (CI) . | P . | ||
| Recombinant | 8493 | 1.0 | 1.0 | 1.0 | 1.0 | ||||
| Plasma-derived | 4425 | 0.8 (0.5-1.3) | .34 | 0.7 (0.4-1.1) | .14 | 0.9 (0.5-1.5) | .72 | 0.8 (0.4-1.3) | .33 |
| Recombinant | 8493 | 1.0 | 1.0 | 1.0 | 1.0 | ||||
| Plasma-derived | |||||||||
| Low VWF content† | 1272 | 0.3 (0.1-1.1) | .07 | 0.4 (0.1-1.1) | .08 | 0.3 (0.1-1.2) | .09 | 0.3 (0.1-1.3) | .11 |
| High VWF content† | 3153 | 1.0 (0.6-1.6) | .91 | 0.8 (0.5-1.4) | .45 | 1.1 (0.7-2.0) | .61 | 0.9 (0.5-1.6) | .79 |
| Kogenate | 4267 | 1.0 | 1.0 | 1.0 | 1.0 | ||||
| Kogenate Bayer | 378 | 1.1 (0.2-4.5) | .94 | 1.2 (0.3-5.4) | .79 | 1.5 (0.3-6.5) | .60 | 1.6 (0.3-7.3) | .55 |
| Recombinate | 1639 | 1.1 (0.5-2.3) | .75 | 1.0 (0.5-2.1) | .99 | 1.4 (0.6-3.1) | .39 | 1.2 (0.5-2.7) | .70 |
| Refacto | 2209 | 1.4 (0.8-2.6) | .24 | 1.6 (0.9-3.2) | .14 | 1.5 (0.7-3.0) | .30 | 1.4 (0.6-3.1) | .38 |
| . | NED . | All clinically relevant inhibitor development . | High-titer inhibitor development* . | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Crude . | Adjusted . | Crude . | Adjusted . | ||||||
| RR (CI) . | P . | RR (CI) . | P . | RR (CI) . | P . | RR (CI) . | P . | ||
| Recombinant | 8493 | 1.0 | 1.0 | 1.0 | 1.0 | ||||
| Plasma-derived | 4425 | 0.8 (0.5-1.3) | .34 | 0.7 (0.4-1.1) | .14 | 0.9 (0.5-1.5) | .72 | 0.8 (0.4-1.3) | .33 |
| Recombinant | 8493 | 1.0 | 1.0 | 1.0 | 1.0 | ||||
| Plasma-derived | |||||||||
| Low VWF content† | 1272 | 0.3 (0.1-1.1) | .07 | 0.4 (0.1-1.1) | .08 | 0.3 (0.1-1.2) | .09 | 0.3 (0.1-1.3) | .11 |
| High VWF content† | 3153 | 1.0 (0.6-1.6) | .91 | 0.8 (0.5-1.4) | .45 | 1.1 (0.7-2.0) | .61 | 0.9 (0.5-1.6) | .79 |
| Kogenate | 4267 | 1.0 | 1.0 | 1.0 | 1.0 | ||||
| Kogenate Bayer | 378 | 1.1 (0.2-4.5) | .94 | 1.2 (0.3-5.4) | .79 | 1.5 (0.3-6.5) | .60 | 1.6 (0.3-7.3) | .55 |
| Recombinate | 1639 | 1.1 (0.5-2.3) | .75 | 1.0 (0.5-2.1) | .99 | 1.4 (0.6-3.1) | .39 | 1.2 (0.5-2.7) | .70 |
| Refacto | 2209 | 1.4 (0.8-2.6) | .24 | 1.6 (0.9-3.2) | .14 | 1.5 (0.7-3.0) | .30 | 1.4 (0.6-3.1) | .38 |
Adjusted for baseline factor VIII activity level, ethnicity, factor VIII gene mutation type, age at first exposure, duration between exposure days, dose of factor VIII, and regular prophylaxis.
NED indicates number of exposure days on the concerning product type; CI, 95% confidence interval; and RR, relative risk.
High-titer inhibitor was defined as a clinically relevant inhibitor with inhibitor titers of at least 5 Bethesda units/mL at any time.
Low VWF content was defined as less than 0.01 IU VWF antigen per IU factor VIII antigen; high VWF content was defined as more than 0.01 IU VWF antigen per IU factor VIII antigen.