ADT_A27 - Cancel pending admit

Segment structure for the ADT_A27 message in HL7 v2.5.1. Cardinality is shown as [min..max]; groups are in bold.

• MSH Message header [1..1]
• EVN Event type [1..1]
• PID Patient identification [1..1]
• PD1 Patient additional demographic [0..1]
• PV1 Patient visit [1..1]
• PV2 Patient visit - additional information [0..1]
• DB1 Disability [0..*]
• OBX Observation/result [0..*]