The World Trade Center (WTC) Health Program is a limited federal health care program that provides medical monitoring and treatment for WTC-related health conditions to responders and survivors impacted by the terrorist attacks on September 11, 2001.This study described the characteristics of the Program survivor members (who lived, worked, went to school, daycare or adult daycare or present in the New York City Disaster Area of 9/11/2001) to stimulate innovative ideas for improving healthcare services, generate new research interest, and serve as a reference for future research on this population. Administrative and medical claims data collected from the Program start date (07/01/2011) through 2022 were used. As of 12/31/2022, there were 37,384 enrolled survivors: 5.0% were aged ≤21 years on 9/11/2001, 45.9% females, and 31.2% non-Hispanic Whites. A total of 24,148 (64.6%) were certified for at least one WTC-related condition, including neoplasms (36.0%), aerodigestive disorders (35.6%) and mental health conditions (18.6%); 22.9% were certified for more than one category. Certification rates of some WTC-related conditions differed by sex, age and race/ethnicity. WTC survivor population is diverse in sex, age and race/ethnicity, with a high proportion certified for certain WTC-related health conditions, providing great opportunities for research in various areas.

The World Trade Center Health Registry (WTCHR) was established in 2002 as a public health resource to monitor the health effects from the World Trade Center (WTC) disaster. We evaluated the representativeness of the WTC youth population (<18 years on 11 September 2001) by comparing the distributions of age, gender, race/ethnic groups, and income to 2000 census data for the matched geographic area, including distance from disaster. There were 2379 WTCHR enrolled children living in Lower Manhattan south of Canal Street on 11 September 2001, along with 752 enrolled students who attended school in Lower Manhattan but were not area residents. The WTCHR sub-group of children who were residents was similar to the geographically corresponding census population on age and sex. Black and Hispanic children are moderately overrepresented at 0.9% and 2.4% in the WTCHR compared to 0.8% and 1.7% in census population, respectively, while lower-income households are slightly under-represented, 28.8% in the WTCHR and 30.8% for the corresponding census information. Asian children appear underrepresented at 3.0% participation compared to 6.3% in the census. While the demographics of WTCHR youth are somewhat skewed, the gaps are within expected patterns of under-representation observed in other longitudinal cohorts and can be effectively addressed analytically or through targeted study design.