Barriers to and Opportunities for Cross-Temporal Analysis with U.S. Health Survey Data: The Integrated Health Interview Series (IHIS) as a Case Study

Miriam King, University of Minnesota
Pamela Johnson, University of Minnesota
William Block, University of Minnesota

Since 1957, the U.S. National Health Interview Survey (NHIS) has been a principal source of information on health status and disability, health behaviors, acute and chronic conditions, healthcare access and utilization, and insurance coverage. The full potential of NHIS data for analyzing long-term change has rarely been exploited due to large nuber of data files and voluminous documentation; complexity of file structures; and changes in sample designs, questionnaires, and variable coding schemes. We report on the Integrated Health Interview Series (IHIS), a harmonized set of data and documentation covering the NHIS from 1969 to the present. This integrated data series facilitates cross-sectional and cross-time comparisons via composite coding schemes for recoding variables across time, integrated documentation, and free internet access. We describe the motivation for integrating NHIS data, the components of this data integration project, and the methods used to create this four-decade, cross-sectional time-series of population health data.