Level 1 data
Project Tycho® level 1 data include data counts that have been standardized for specific analyses. This involves standardization of various types of data counts into a common format and exclusion of data counts that are not required for a specific purpose. In addition, external data such as population data may have been integrated with diseases data to derive rates or for other applications. Click here to read more about different types of counts and data standardization methods. Data availability is also dependent on historical reporting priorities and not all diseases were reported by all locations every year.
The current version (1.0.0) of level 1 data includes counts at the state level for smallpox, polio, measles, mumps, rubella, hepatitis A, and whooping cough and at the city level for diphtheria. The time period of data varies per disease somewhere between 1916 and 2010. This version includes cases as well as incidence rates per 100,000 population based on historical population estimates. These data have been used by investigators at the University of Pittsburgh to estimate the impact of vaccination programs in the United States, recently published in the New England Journal of Medicine.
Data availability for case reports