Huge amounts of digital data have been accumulated in the medical field by the recent acceleration of medical informatization. Several nationwide projects with medical big data are already running in Japan, and are expected to improve social issues. Medical big data are often complicated and diversified as there are so many sources of individual data items which can be connected to privacy data. Thus, it is necessary to introduce mining technology such as machine learning and also to develop innovative methods of analysis by collaboration between information science and medical professionals. After the “My Number” law will be enforced in 2016, with the adoption of a unique medical ID in Japan, and privacy laws will be revised in the medical field, the era of medical big data will truly begin in Japan.
Ever since the Cancer Control Act was enacted, ensuring the quality of cancer care has been a central theme in cancer control policies. Medical record review was initially considered to be the best available method for quality measurement, and it was attempted in several hospitals. However, the resulting labor burden was enormous. Seeking a viable alternative, we started using existing electronic and widely standardized data ; namely, data from health insurance claims and hospital-based cancer registries. The registry data are useful for defining the target population, and the claims data let us examine the care that the patients received. If we can link these data, they can become a powerful information source. In collecting linkable data, we found that the greatest challenge was deleting personal identifiers while maintaining the links between paired data belonging to the same patients. To overcome this challenge, we developed specialized software to enable hospitals to replace patient identifiers in files with common anonymous IDs and then safely submit these data to the National Cancer Center. The process was challenging because collected data often did not conform to the data format standards, but we finally succeeded in collecting data from 232 hospitals. The primary purpose of the current project was to calculate the performance of 13 quality indicators and provide the results to participating hospitals. As a secondary outcome, the data will be used to provide necessary information in the discussion of cancer control.
Recently, big data analyses have became popular worldwide as AHA/ACC Get With The Guideline program stroke, which registered over 2 million patients. We conducted a study of the effectiveness of comprehensive stroke care capacities on stroke mortality in a nationwide study, J-ASPECT based on the electric claim data from drug prescription group, DPC system, which is the similar to American DRG system. We made a nationwide electrical database for neurosurgeons in Japan, based on the claim data from DPC system taken from Japan Neurosurgical Society registered hospitals. The registration process was automatic with no additional workload for busy physicians. The database included diagnosis, all prescribed drugs and procedures during hospitalization, short-term outcomes, complications and medical costs. We successfully registered the “real world” practices of Japanese neurosurgeons nationwide. We report our analyses for acute stroke care and future directions for this database.
In recent years, the utilization of big data to visualize the real-world status of medical care has received greater attention. Since 2011, the authors have studied a nationwide cohort study named the J-ASPECT Study based on the Japanese Diagnosis Procedure Combination (DPC) and claim database. Here we first describe the overall profile of the joint project conducted by this study group and the Japan Neurosurgical Society as the special project of the 34th Annual Meeting of the Japanese Congress of Neurological Surgeons. Briefly, we built a large scale database of the patients who were admitted for the treatment of neurosurgical diseases, and other cerebrovascular disorders from hospitalization until discharge. Next, we focused on the current status of surgical and endovascular management for patients with subarachnoid hemorrhage, unruptured aneurysms, and carotid stenosis treated during the period of April 2012 to March 2013 in the hospitals participating in this study.
To investigate patient background and current trends in the treatment of brain tumor patients, we analyzed a patient dataset using the Diagnosis Procedure Combination (DPC) database. The DPC data of all inpatients treated between April 2013 and March 2014 in the 327 core and branch hospitals enrolled in the Japan Neurosurgical Society training program were collected. Using ICD-10 code, we could extract 6,142 primary malignant brain tumor patients, 2,538 secondary malignant brain tumor patients, 2,043 pituitary tumor patients, 3,854 meningioma patients, and 5,666 other benign brain tumor patients from amongst a total of 501,609 patients. In this study, we focused on the primary and secondary malignant brain tumor patients. Using a K-code, we could extract 1,564 primary malignant brain tumor patients and 1,072 secondary malignant brain tumor patients who underwent surgery. Treatment modalities were analyzed for these patients. This study provides a general picture of the current trend of treatment for malignant brain tumors in Japan. But further study is needed to validate this patient dataset.
We conducted the survey of brain tumor registry of Japan (BTRJ), which has started in 1973, and performed analyses of the incidence, therapeutic methods, and treatment outcomes of primary and metastatic brain tumors based on WHO 2007 classification with the cooperation of the Japan Neurosurgical Society members. These data reveal the diagnostic and therapeutic problems associated with each type of brain tumor and will lead to clinical trials and prospective surveys to establish evidence of brain tumors as go forward.
A precise understanding of the anatomy is essential to perform vagus nerve stimulation (VNS) therapy for refractory epilepsy. We evaluated the anatomical relationships of the cervical vagus nerve with the carotid artery and jugular vein on the basis of findings during VNS surgery. We investigated the anatomical relationships among the vagus nerve (VN), common carotid artery (CCA), and internal jugular vein (IJV) in 73 patients who underwent VNS surgery at our hospital from December 2010 to January 2015, classified the position of the VN into 5 categories, and studied the frequency of each category. The position of the VN was medial to the IJV and ventral to the CCA (type 1) in 8 patients (10.9%), medial to the IJV and lateral to the CCA (type 2) in 4 (5.5%), dorsomedial to the IJV and ventral to the CCA (type 3) in 51 (70%), dorsomedial to the IJV and lateral to the CCA (type 4) in 7 (9.5%), and dorsal to the CCA (type 5) in 3 (4.1%). This report is the first to propose a classification of the anatomical relationships of the VN with the CCA and IJV based on intraoperative findings. According to this classification, the difficulty of VNS surgery increases with advances of the type. Type 3 was the most frequent, and types 2 and 5 were rare. Understanding the variation in the position of the cervical vagus nerve is considered to contribute to safer surgical manipulations in VNS surgery.
A 12-year-old boy with a thalamic anaplastic astrocytoma underwent surgical excision of the tumor and subsequent chemoradiotherapy. Five months later, a growing mass was detected on the scalp. The mass was excised, and the histological examination revealed an astrocytoma identical to the original thalamic tumor. Subcutaneous metastasis of a brain tumor to the scalp is relatively rare. To our knowledge, this is only the second case report of subcutaneous metastasis of anaplastic astrocytoma to the scalp.