Adherence to Clotting Factor Prophylaxis in Adolescent and Adult Males With Haemophilia

Clotting factor prophylaxis remains the most prescribed standard-of-care treatment for people with haemophilia (PwH). Prophylaxis prevents bleeds, joint damage, and improves quality of life (QoL). Its success depends on treatment adherence, consisting of socioeconomic, behavioural, and disease- or therapy-related factors.

To identify determinants of clotting factor prophylaxis adherence among PwH followed at a Hemophilia Treatment Center (HTC) in Brazil.

A cross-sectional study was conducted at a Brazilian HTC in June-October/2022. Eligible participants were PwH A or B without inhibitors and on clotting factor prophylaxis, aged ≥ 14 years. Demographic, clinical, and therapeutic data were collected from records and interviews. Health-related QoL was assessed by the SF-36 questionnaire. Adherence was assessed using the Brazilian validated Validated Hemophilia Regimen Treatment Adherence Scale-Prophylaxis (VERITAS-Pro) questionnaire.

Among 78 PwH (median age 30 years), 70 (90%) had severe haemophilia, 46 (59%) reported joint impairment, and 67 (86%) infused 3 times/week. Median SF-36 score was 70.3 (interquartile range [IQR] 57.3-83.3). Median VERITAS-Pro score was 44.0 (IQR 35.0-50.0), resulting in 70 (90%) adherent PwH. SF-36 score was not correlated with VERITAS-Pro. Clotting factor prophylaxis adherence was associated with having haemophilia A (p = 0.012) and infusing factor >2 times weekly (p = 0.008), and inversely correlated with prophylaxis duration (r = 0.317 [weak clinical correlation]; p = 0.005), and directly correlated with SF-36 domain "Mental health" (r = -0.304 [weak clinical correlation]; p = 0.007).

The main factors determining adherence to clotting factor prophylaxis were having haemophilia A, receiving factor infusions more than twice weekly, having a shorter duration of prophylaxis, and good mental health.