Changes to the Design of the National Health Interview Survey to Support Enhanced Monitoring of Health Reform Impacts at the State Level.

Pursuant to passage of the Patient Protection and Affordable Care Act, the National Center for Health Statistics has enhanced the content of the National Health Interview Survey (NHIS)-the primary source of information for monitoring health and health care use of the US population at the national level-in several key areas and has positioned the NHIS as a source of population health information at the national and state levels. We review recent changes to the NHIS that support enhanced health reform monitoring, including new questions and response categories, sampling design changes to improve state-level analysis, and enhanced dissemination activities. We discuss the importance of the NHIS, the continued need for state-level analysis, and suggestions for future consideration.