Children and adults with haemophilia A (9 studies, n= 2,531).
Plasma-derived factor VIII.
Recombinant factor VIII.
Most of the included participants in the studies were children. A higher incidence of inhibitor development was found to be associated with recombinant factor VIII (odds ratio (OR)= 1.57, 95% confidence interval (CI): 0.95-2.59; hazard ratio (HR)= 1.89, 95% CI: 1.15-3.12). The same trend was also found for high-responding inhibitors (OR= 1.38, 95% CI: 0.70-2.70; HR= 1.42, 95% CI: 0.84-2.39). Recombinant factor VIII was associated with a higher risk of overall and high-responding inhibitor development compared to plasma-derived factor VIII.