National Medical Expenditure Survey, 1987: Survey of American Indians and Alaska Natives, Preliminary Health Status Questionnaires and Access to Care Supplement [Public Use Tape 21P]

The sample is a stratified area probability design with three stages of sample selection: (1) selection of primary sampling units (PSUs), which are counties or groups of contiguous counties (in Alaska, the county equivalents developed by the state of Alaska and the Census Bureau for statistical purposes were employed), (2) selection of segments within PSUs, (3) selection and screening of dwelling units within segments. Based on the results of the screening, all dwelling units including persons eligible for IHS services were selected in the SAIAN. The sample frame included all counties in the United States including or adjacent to reservations of federally-recognized tribes or Alaska Native villages. For cost considerations, the sample frame was truncated to remove counties with the lowest concentrations of eligible persons, and disproportionate sampling was applied to remaining counties with low concentrations of American Indians.