• Date: OpenClinica dates are presented as dates in the Data Mart. This makes it easy to perform calculations and to transform the output format.

• Single-Select or Radio Button: Single-select Items allow selection of a single value from a list, using either a radio button or pulldown control. The possible values are stored as a list of underlying data values (normally integers) and corresponding labels. The Data Mart presents each single-select Item as two columns in the database. The first column stores the value, and the second column stores the label.

• Multi-select or Checkbox: For example, Race – Check all that apply. Multi-select or checkbox Items will appear as one Boolean column per possible selection. The column name will reflect the label, for example, i_dm00_race_asian.