Comment: One row per kind of event which begins the interval of time during which the lives of study individuals are tracked. This table establishes a controlled vocabulary for the events which mark the start of observation.
|code||character(1)||A unique single character code for the start of observation type. This code identifies the row within the database.|
|description||character varying(64)||A unique description of the start of observation type.|
|initial||boolean||A boolean value. When TRUE indicates that there may be no preceeding events. Birth is an example end event where Initial should be TRUE. This flag may impose additional requirements; this is dependent upon the table referencing the START_EVENT row. For more information see the documentation of each table which uses START_EVENT for vocabulary control. The value of this column may not be NULL.|