File Discussions

The information presented for most files is organized in a consistent manner under the categories described below. These categories correspond to the icons introduced in Orientation for the Reader. In some file discussions, the use of the categories is dropped to minimize exact duplication of information. In such cases, references to other file discussions containing relevant information are included. The Reference/Resource Files, Public Use Files (PUFs) and Beneficiary Encrypted Files (BEFs) are described briefly, and again reference other data chapters where appropriate. By using the tables of contents and icons, the reader will be able to find information regarding a specific file easily and quickly. To establish a context for the file discussions, the reader is encouraged to review the introductions to the data chapters and file groups.

File Creation

File Creation includes a discussion of the data collection method and file population or sample. The process of creating the file is discussed, including cut-off points for including data, date of file maturation, and Quality Assurance (QA) measures executed when the file is created. For files derived from other files, the parent file is referenced and the method of derivation is discussed. Issues of file availability, including years for which the file is available and length of the file creation cycle, also are addressed.

File Maintenance

A description of the file update cycle and QA measures involved in updating and maintaining the file are provided in File Maintenance. The information in File Maintenance is closely related to that in File Creation. Text may be repeated across these categories or they may reference one another.

File Structure and Usage

File Structure and Usage describes the type of information contained in the file or database. A general description of the data elements that comprise the file and the unit of analysis are also included. Known data limitations at the file level are discussed when applicable, as are general uses of the file to both the research and policy making communities.

Data Structure and Usage

Data samples, data availability, and data usage are addressed under Data Structure and Usage. The type of variables on each record, total number of records in each file, and a discussion of known data limitations at an element level are provided. The information in Data Structure and Usage is closely related to that in File Structure and Usage. Text may be repeated across these categories or they may reference one another.

Methods of Access

Methods of Access discusses the various means available for file access. Many files can be accessed by one or more of CMS's online access systems such as the Decision Support Access Facility (DSAF), Mainframe CMS Customer Information System (HCIS) or Enrollment Database Workbench (EDBW). This part of the file discussion highlights these systems and addresses their current functions. Other methods of accessing the files, such as through flat files or SAS datasets, are also discussed. When applicable, the Methods of Access section identifies the CMS files available for purchase as a BEF or a PUF.

Migration of Data

Continuity of data in the changing CMS data processing environment is addressed in Migration of Data. For example, if the method of data storage has changed for a file, the ancestor file is identified, and the relationship between the former and new file is explained. This section also addresses future plans for data storage.

List of Data Elements

Data element lists for the files discussed within a chapter will appear in the future on the CMS web site at www.cms.hhs.gov. These lists include the full names of the elements in the file, descriptions, and coding categories. The data element lists are generated from the CMS Data Dictionary which is maintained by OIS, EDG, Division of Data Services (DDS).

Overview of CMS Data | Data Organization | File Discussion | Overview of Data | OIS