How Did NNCSS Begin?

Congress authorized National Neurological Condition Surveillance System (NNCSS) in 2016 as part of the 21st Century Cures Act to track the epidemiology of neurological conditions. Multiple sclerosis (MS) and Parkinson’s disease (PD) were chosen as the conditions of focus for initial demonstration projects. In later stages, using lessons learned from the demonstration projects, NNCSS will build a standard surveillance approach that can be expanded to include additional neurological conditions (pending funding).

What Is Surveillance?

Public health surveillance is the continuous, systematic collection, analysis, and interpretation of health-related data needed for the planning, implementation, and evaluation of public health practice. It should be linked with the timely distribution of information to those who need to know and act upon that information.

Surveillance data can be collected from a variety of sources, including administrative data (e.g., Medicare, Medicaid), mandated reports (e.g., data on conditions that must be reported to CDC), surveys, and registries.

Why Is NNCSS Important?

Focused surveillance enables CDC to:

  • Calculate estimates of prevalence (number of people with a condition) and mortality for a range of neurological conditions.
  • Explore how prevalence and mortality vary within different demographic categories (e.g., age, sex, and race/ethnicity), and in the presence of co-morbidities (other diseases or conditions).
  • Explore incidence (number of new diagnoses during a specific period).
  • Strengthen partner collaboration and shared resources.

Ultimately, NNCSS will expand scientific and public understanding of the conditions, catalyze research into the causes of neurological conditions and ways to improve their diagnosis and treatment, and help improve health outcomes for millions of people of all ages.

How Does NNCSS Fit in with Data Modernization?

NNCSS is part of a connected data ecosystem to harness the power of multiple data sources for better understanding of prevalence of neurological conditions. For example, consistent with Data Modernization, CDC reviewed existing data sources as well as newly emerging and future data sources and tools that could potentially be useful for surveillance of multiple sclerosis (MS), Parkinson’s disease (PD), and other neurological conditions. Assessing the usefulness and contributions of each of these sources as well as other sources identified over time will help NNCSS surveillance to remain state-of-the-art and interoperable with other surveillance systems.

How did CDC select Multiple Sclerosis (MS) and Parkinson’s Disease (PD) for the initial demonstration project?

MS and PD were chosen for the demonstration projects because of their similarities and differences. Both involve significant morbidity, place a substantial burden on patients and their families, and have engaged patient advocacy groups. Differences between the two conditions allowed us to address different challenges and increased the relevance of the demonstration project to a broad range of neurological conditions. For example, they differ in age of onset (PD impacts people at older ages, generally 60+, while MS is generally diagnosed at younger ages, usually between ages 20-40). Additionally, they differ in diagnosis challenges. PD is complicated by a lack of biomarkers and some symptoms are shared by other neurodegenerative disorders. There are no standard diagnostic criteria for PD, but standard diagnostic criteria do exist for MS.