ESP combines two open source software systems developed by the Harvard Medical School’s Department of Population Medicine at the Harvard Pilgrim Health Care Institute. The system, EHR Support for Public Health (ESP), is a disease surveillance software application that can extract and analyze data from electronic health record systems for events of public health importance.

The second, PopMedNet, is a software application that enables controlled, secure, distributed analyses of health data owned by different organizations and stored in different locations.
Combining these two technologies allows hospitals and clinics to give health departments controlled access to their EHR data monitor health indicators in their patient populations and makes it possible for health departments to easily query the EHR systems of multiple providers at once to get a population level view of health indicators.
ESP also supports an intelligent presentation system, the RiskScape, which graphically displays population level surveillance data to inform public health.

Hospitals and clinics retain full control over their data at all times. ESP runs behind the host practice’s firewall and only permits external users to run analyses and/or retrieve data that have been approved by the hospital or clinic.