Title: Comparison of different prophylaxis regimens for hemophilia A pediatric patients Principal Investigator: Assistant Professor Darintr Sosothikul, MD Research Question: Does different factor VIII dosage effect outcome of hemophilia treatment in term of breakthrough bleeding, number of hospital stay and day-off from school? Type Research: Clinical research

Study design: Single center clinical trials

Concise methodology:

1. Study Population: Children with hemophilia A who received treatment at KCMH from May 2015 to March 2016 will be enrolled in this study. The consent will be obtained before the study.

2. Observation and measurement:

   1. History, interesting clinical data and laboratory data will be recorded in Clinical record Form (CRF)
   2. Measurement:

   i. Complete blood count (CBC), Factor VIII level, Factor VIII inhibitor level ii. Number of breakthrough bleedings, number of hospital stay and day-off from school iii. Joint score from Hemophilia Joint Health Score 2.1 iv. EQ-5D-5L quality of life assessment score

3. Data analysis: The p-value of less than 0.05 will be considered statistically significant. Mann-Whitney test will be used to test correlation of these variables (CBC, Factor VIII level, Factor VIII inhibitor level, Number of breakthrough bleedings, number of hospital stay, day-off from school, Hemophilia Joint Health Score 2.1, EQ-5D-5L quality of life assessment score) Sample size: 16 patients

Potential impacts:

The outcomes of different factor VIII concentrate dose between 15-20 U/kg/dose 2 times/week and 35-40 U/kg/dose 1 time/week will be revealed. These outcomes include number of breakthrough bleeding, number of hospital stay, day-off from school, joint health and quality of life. The result of this study will guide further study on optimal dose and duration of factor VIII treatment of hemophilia A patients in the future.

Inclusion Criteria:

• Hemophilia patients with moderate (factor level 1-3%) or severe (factor level <1%) severity

Exclusion Criteria:

• Platelet count less than 100,000 /mm3 or other bleeding tendency
• Hemophilia patients who have FVIII inhibitor >0.6 BU (modified Nijmogen method)
• Hemophilia patients who have no bleeding symptoms