The system looks for qualifiers with Export_Code ‘HC-TIER1’, ‘HC-TIER2’ and ‘HC-TIER3’ to indicate enrolment in the trail at tier 1, 2 and 3 respectively.

Exiting the trial (and the tier) is indicated by a following clinical item with an EXPORT_CODE of ‘HC-EXIT’.

Enrolments must precede an exit, if present. Every exit must be preceded by an enrolment. Standardised clinical items are available for Communicare that use Rule Codes to ensure proper sequencing. Using the standard clinical items is strongly recommended.

Using enrolments and exits in and improper sequence will yield unpredictable results. For example, enrolling at tier 1 then at tier 2 without first exiting tier 1 is not supported.