Terapi profilaksis sekunder dosis rendah dibandingkan terapi on-demand untuk mencegah progresivitas artropati pada anak penyandang hemofilia a berat: kajian pada luaran klinis, skor muskuloskeletal, ultrasonografi sendi, kadar c-terminal telopeptide o = Secondary low dose prophylaxis versus on demand treatment to prevent progressivity of arthropathy in children with severe hemophilia a clinical outcome musculoskeletal scores joint ultrasonography urinary c terminal telopeptide of collagen type II A