@OneToMany (mappedBy="patient", fetch = FetchType.EAGER,orphanRemoval = false)
public Set<OutboundMessage> getOutboundMessages()
{
    return outboundMessages;
}

@ManyToOne (fetch=FetchType.EAGER)
@JoinColumn(name = "id_patient")
public Patient getPatient()
{
    return patient;
}

The DELETE statement conflicted with the REFERENCE constraint "FKqjpga9w6wp3qk26ox9pg252d9". The conflict occurred in database "MDHIS", table "dbo.tblOutboundMessage", column 'id_patient'.