Legislation including the Indian Healthcare Improvement Act and the Snyder Act are the bases on which the IHS was founded. The passing of the Patient Protection and Affordable Care act by President Obama is the cornerstone of the IHS, however no single event seems to shape the agency's way of approaching health.
This group works with American natives and is a Federal agency so its conceptions of disaster and healthcare are politically based. This group's benefits focus on the needs of the native population assessed by information collected through the U.S. Census and other surveys.
The IHS mainly focuses on disaster prevention and preparedness with initiatives such as teaching children about illness prevention, teaching about safe drinking water and food safety, preventing the spread of disease, and preventing injuries. They also have a number of resources available to their members to connect with healthcare professionals. This seems to be a community awareness type approach that prevents the spread of disease by teaching the community. It resembles that of many healthcare systems and does not seem to suggest problems with other approaches.
The organization has the infrastructure of the Federal government, however they operate in areas that are more rural, including Alaska and the Southwest where environmental issues such as clean drinking water can be present, which they address in their community health approach. All members also are allowed access to the internet, which I'm assuming is available at each of their locations.
Representatives of the Indian Health Service have made numerous congressional testimonies and numerous pieces of legislation have been passes to support the IHS, however, it does not appear that any relate to emergency response or disaster.
The organization has done research and generated fact sheets on statistics like injuries, behavior health, and environmental safety.
The membership consists of American natives who would like to receive the benefits of this organization. To be eligible to be a member you must be "an Indian and/or Alaskan Native" evidenced by several factors including being a part of a tribe, living on reservation land, or living in the household of a native. The employees consist of federal healthcare professionals commissioned by the United States Public Health Service and Civil Service federal employees.
I could not find any data or reports on their website that have been collected to support their approach to healthcare other than the legislation previously mentioned.
Quoted from the front page of the website
"Our Mission ... to raise the physical, mental, social, and spiritual health of American Indians and Alaska Natives to the highest level.
Our Goal ... to assure that comprehensive, culturally acceptable personal and public health services are available and accessible to American Indian and Alaska Native people."
The IHS is funded by Congress after being reviewed by The House, Senate, and Congressional committees annually. A budget is formulated by a division within the IHS for approval each year. This means that their way of thinking about disaster and health must be approved by Congress, since they are a Federal agency.