The surveilliance and collection of public health data and information is essential to the overall goals and aims of public health, in general. Information obtained through various methods is used to determine the magnitude of a problem, or whether one exists at all, who is primarily affected, who is at risk, and how to best develop policy and interventions to deal with the problem. This information is then further used to determine whether these particular given interventions are effective, themselves. The value of public health surveillance can be measured in terms of the timely dissemination of data and information about health events to those responsible for their control and prevention. The more complete a picture that public health experts can draw, the better they can understand and anticipate the many nuances that go into planning and preparation.
Much of the public health information that is collected is anonymized so as to protect people, but the collection and analysis of otherwise private health information is still a very contentious issue. There is a natural dichotomy inherent in the idea of surveilling and collecting the information of the private citizen for the purposes of the public's health, and this has been a source of consternation for public health officials and academics, and a source of apprehension for the general public. Recognizing this, Federal laws such as the Health Insurance Portability and Accountability Act (HIPAA) have a public health exception written in to their language to allow for the disclosure of otherwise private information for specific public health purposes.
There are, still, however, many public health databases that are open and accessible to the general public. These include birth records, disease surveillance systems, death records, and Medicaid, to name a few. Ultimately, the collection and dissemination of specific public health information is one of the strongest tools that experts and researchers have to combat public health issues.