Haemophilia is an inherited bleeding disorder affecting predominantly males, where the ability for ones blood to clot is absent or reduced. There are 3 main types of haemophilia; A, B and C. In this study we will describe patients with haemophilia A and B with respect to age, sex and year of diagnosis. We will also describe treatments for the disease and other diseases present in people with haemophilia.
We will identify all patients with a Read code for haemophilia A or B and will conduct a validation study of the diagnoses. We will request clinical records for a random sample of all haemophilia A and B patients from GPs, where available, to validate the diagnosis and to collect information on treatments and details of the disease course not available in the computer record. Haemophilia is an unambiguous disease with clear diagnostic criteria based on simple lab tests, thus we will accept the opinion of the consultant if it states in the record that the patient has the disease. We will also review the complete computer record of each patient to identify disease codes, symptoms, and treatments as additional validation. This will be the only validation for patients for whom we do not receive clinical records. We will provide the results of the validation study as a proportion of validated cases/total cases reviewed. We will also provide descriptive statistics for these haemophilia patients which will include distribution of disease by age, sex, year of diagnosis, comorbidities and treatments both before and after disease diagnosis. We will also calculate annual prevalence of haemophilia A and B as the number of cases of haemophilia alive in each year divided by the number of people alive in the CPRD population in each year.
Susan Jick - Chief Investigator - BCDSP - Boston Collaborative Drug Surveillance Program
Susan Jick - Corresponding Applicant - BCDSP - Boston Collaborative Drug Surveillance Program
Judith Kempf - Collaborator - Genzyme Corporation (USA)
Marianne Ulcickas Yood - Collaborator - Episource