[On-line outcome study of unruptured cerebral aneurysm in Japan (UCAS Japan)]

Information technology has been introduced in the medical field recently, and has become an essential tool for medical research in many aspects. Japanese Neurosurgical Society has been conducting a national study on the outcome of unruptured cerebral aneurysms (UCA) using on-line registration system. In this report, the author reports preliminary outcome of this study and discuss the usefulness and limits of studies using such technology. This study is a prospective cohort study and enrolled patients are cases with newly diagnosed UCA after Jan. 1,2001. So far, we have collected data of 2979 new patients (3667 aneurysms) with UCA registered from 385 institutions. Seventy five percent of the institutions sent data through the online registration. On-line registration system made data collection from all over the country very quick and easy. Analyzing such data could be achieved with minimal cost and time. Such study design can eliminate the handicap of geographic distance and can be applied for international studies. On the other hand, such system does not suit complicated study or rare disease. And On-line study design requires special consideration on various scenario and uniformity in assessing inclusion, procedure and outcome.