Background: In the post Affordable Care Act (ACA) era marked by inter-organization collaborations and availability of large amounts of electronic data from other community partners (referred to as “Big Data”), it is imperative to assess the interoperability of the information systems used by the local health departments (LHDs).

Data and Sampling Design: This research is based on mixed methods with two sources of recent data from our informatics studies. We used the 2015 Informatics Capacity and Needs Assessment Survey, with a target population of all LHDs in the United States. A representative sample of 650 LHDs was drawn using a stratified random sampling design. A total of 324 completed responses were received with a 50 percent response rate. We also used qualitative data from a 2015 qualitative study of LHD informatics staff consisting of 50 key informant interviews.

Analytic Methods: We used NVivo for the thematic coding of qualitative data and Stata 14 for conducting the multivariable logistic regression analysis of factors associated with interoperability.

Results: For 30.2% of LHDs, none of the systems, and for 38.5% some of the systems were interoperable. Significant determinants of interoperability included LHDs having: the leadership support (AOR, 3.54), control of IT budget allocation (AOR, 2.48), and data systems (AOR, 2.31), a strategic plan for information systems (AOR, 1.92), and business process analysis and redesign (AOR, 1.49).

Conclusions: Interoperability of all systems may be an informatics goal, but only small proportion of LHDs reported having interoperable systems, pointing to a public health intervention need.