Epidemiology Data Service Center

Year(s): Year or years of the database, which is equivalent to the year or years to which the data refer unless otherwise noted. The format of this information also indicates how the data are stored across databases. The following examples illustrate the year format conventions:

1995 = single database containing data collected during the 1995 period
1995, 1996, 1997 = three separate databases, one containing data collected during the 1995 period, one containing data collected during the 1996 period, and one containing data collected during the 1997 period
1995-1997 = single database containing data collected over the three one-year periods of 1995, 1996, and 1997
1995-97 = single database containing data collected during the one three-year period of 1995 through 1997

Source: Organization that produced the database.

Access: Indicates any limitations on access of the database. General access databases are owned by the EDSC and are available without limitations. Restricted databases, which have limited access, are either owned by a person or department other than the EDSC, or are owned by the EDSC but are not freely available.

Data source: Method or instrument by which data were collected. Includes interviews, medical records, physical exams, surveys, vital records, etc.

Universe: Population of persons or other elements to which the data refer and from which the study sample was selected.

Data type: Describes the form of the database. Raw databases contain data in the form of individual records and variables, and usually require the use of statistical programming software in order to analyze them. Summary databases contain aggregate data, usually in tables or other similar formats, and generally do not require the use of statistical programming software.

Records: Number of records in database, if applicable.

Variables: Number of variables in database, if applicable.

Subject(s): General topic or topics covered by the database. Subject areas are behavior, cost and utilization, demographics, disease-specific/registry, general health and nutrition, health care facilites and services, vital events, and other.

Description: Information about the contents of the database.