When an unruptured aneurysm of 3 mm or more is detected in a patient of 20 years or more, the participating hospital registers each patient by using the procedure described below. When data is available, it is acquired through the electronic data capture method.
When an unruptured aneurysm is found, the patients and their families are informed about the disease and the UCAS study. When patients agree to participate in the study, their private information is recorded and the initial information is sent to the UCAS office on Form I.
Periodic data entry
New data are collected at 3 months, 1 year (12 months), and 3 years (36 months) after the initial registration. And if any data are available beyond 36months, additional data are collected.
- Three months after registration, the 3-month form (Form II) is sent.
- One year after registration, the 12-month form (Form III) is sent
- Three years after registration, the 36-month form (Form IV) is sent.
- Final form (Form F) is registered if any data available beyond 36months.
At each time point, any changes in the patient’s condition are also reported. Changes in physical or neurological findings are recorded on Form C. Information about any treatment is recorded on Form T. Form D is used to transfer data when an imaging study is done.
When an aneurysm ruptures or a patient dies, follow-up of the case ends and an emergency report is sent using Form E.