Assessing the impact of age, race, ethnicity and inhibitor status on functional limitations of patients with severe and moderately severe haemophilia A

Few data exist on the impact of age and inhibitor status on activity levels among patients with severe and moderately severe haemophilia A. The aim of this analysis was to assess the impact of age, race/ethnicity and inhibitor status on functional limitations through retrospective analysis of data from the Hemophilia and Thrombosis Research Society (HTRS) Registry. Functional status data from patients with haemophilia A with or without inhibitors who were enrolled in the HTRS Registry between October 1999 and July 2008 were analysed by age, race and ethnicity. Of the 2497 registrants, 1340 had congenital haemophilia A (333 with inhibitors). Functional status was available for 274 subjects with haemophilia A with current inhibitors and 247 subjects without inhibitors who had moderately severe (FVIII levels ≤ 2%). Functional impairment increased with age across five levels of functional status (P < 0.01). Inhibitors were associated with greater functional impairment in two age groups (13-21 years and older than 21 years) [unrestricted activity in 57.8% vs. 63.6% (P = 0.06) and 18.3% vs. 28.6% (P = 0.04), respectively]. Blacks had worse functional status than caucasians across all ages regardless of inhibitor status. Functional status decreases with age, and impairment is greater among patients with inhibitors beginning in adolescence. These results reaffirm the need for early eradication of inhibitors and early treatment of bleeds in inhibitor and non-inhibitor patients. This analysis highlights the benefit of ongoing study of these patients through data collected for the HTRS Registry.