Index of Watershed Integrity (IWI) and Index of Catchment Integrity (ICI) was developed by research team lead by Scott Leibowitz in the Western Ecology Division The Center for Medicare and Medicaid Services (CMS) databases are protected health data. Access to this data will need to be requested through the CMS.gov. This dataset is not publicly accessible because: EPA cannot release personally identifiable information regarding living individuals, according to the Privacy Act and the Freedom of Information Act (FOIA). This dataset contains information about human research subjects. Because there is potential to identify individual participants and disclose personal information, either alone or in combination with other datasets, individual level data are not appropriate to post for public access. Restricted access may be granted to authorized persons by contacting the party listed. It can be accessed through the following means: Contact authors. Format: R files, SAS files, excel, CSV. This dataset is associated with the following publication: Jagai, J., A. Krajewski, M. Jimenez, M. Murphy, S. Leibowitz, and D. Lobdell. Watershed integrity and associations with gastrointestinal illness in the United States. JOURNAL OF WATER AND HEALTH. IWA Publishing, London, UK, 17(6): 978-988, (2019).