4.2 OID Overview

What are OpenClinica Object Identifiers (OIDs)?

OIDs are identifiers used in OpenClinica to uniquely identify various entities. These identifiers are generated by OpenClinica and made available to Users on multiple screens. OIDs can be found by navigating the user interface (UI) or by downloading the study metadata file. Data import/export and Rules utilize these OIDs.   

OpenClinica generates OIDs for the following entities

• Studies
• Sites
• Study Event Definitions
• Study Subjects
• Item Groups
• Items
• CRFs and CRF Versions
• Rule Definitions

When building Rules, we will focus on the OIDs and universal objects that are specific to rules creation which are:

• Study Event Definition OIDs
• CRF and CRF Version OIDs
• Item Group OIDs
• Item OIDs

In addition to the above OIDs, OpenClinica 3.3 introduced two additional universal objects for use with Rules using an EventAction – STARTDATE and STATUS. These two objects are available in all studies, and the object name does not change, so every study has a STARTDATE object and a STATUS object available for use.

How OIDs are generated :

When OpenClinica generates OIDs, there is a formula that is used for each of the different entities. All OIDs of the system must be alpha numeric, they must be in all uppercase, they may not contain whitespaces but may use underscores. Often, the OID will reflect the entity name and may contain additional identifiers to ensure uniqueness within the study.

For Study Event Definition OIDs:

• All Study Event Defnitions OIDs begin with SE_
• Open Clinica will use the characters of the Study Event Definition name (removing any whitespaces or special characters), up to 28 characters
• If the first 28 characters of the Study Event Definition name match the first 28 characters of another Study Event Definition Name, the system will append the OID with an underscore and a 3 digit, randomly generated number. The system does this to ensure uniqueness
• Example: Study Event Definition Name = Baseline Visit Study Event Definition OID = SE_BASELINEVISIT

For CRF and CRF Version OIDs:

• CRF OIDs:

As mentioned above users can view these OIDs on various screens. Heres a guide to find them.   

• Study Event Definitions
• View OIDs by going to Tasks > Build Study > Event Definitions > View
• Study Subjects
• View OIDs by going to Subject Matrix and clicking on the View icon for a specific subject.
• Item Groups & Items
• View OIDs by going to Tasks > Manage and Monitor Data> CRFs click on the View icon of the (original) CRF and then click on the Metadata icon of a specific version.
• CRFs and CRF Versions
• View OIDs by going to the > Manage and Monitor Data> CRFs>  click on the View icon of the (original) CRF
• Rule Definitions
• View OIDs by going to Tasks > Study Setup> Manage and Monitor Data> Rules  >click on the View icon of a specific rule Assignment