Loss of patient information can hinder medical care for evacuees and the reconstruction of medical facilities damaged by major incidents. In Japan, health insurance coverage is universal, and information about diagnoses and health care services provided is shared by the medical facilities, Health Insurance Claims Review and Reimbursement Services or the National Health Insurance Organization (NHIO), and the insurers. After the Great East Japan Earthquake on March 11, 2011, we interviewed officers in charge of NHIO in the 3 prefectures that were damaged by the earthquake and elicited how they assisted with medical care for evacuees and reconstruction of the damaged medical facilities.

Comprehensive interviews were conducted with officers in charge of the NHIO in the 3 prefectures to obtain information about the use and provision of health insurance claims data 3 to 4 months after the event. We then analyzed the official data concerning use of the information from the claims in chronological order.

The NHIO headquarters in the 3 prefectures were not physically affected by the disaster, and their information on the health insurance claims was intact. Patient information acquired before the disaster was obtained from the health insurance claims and applied to the medical care of the evacuees. The information also was used to reconstruct patient records lost in the disaster.

The information that was obtained from health insurance claims was used to improve medical care after the large-scale disaster. (Disaster Med Public Health Preparedness. 2013;0:1–5)