Suggestion on marking process as Complete based on process variable

I have to integrate my Web-Application via REST API to Camunda. My Camunda process will be running on JBOSS server.
In process a STATUS (process execution variable) is maintained, process will end with STATUS value as APPROVED/REJECTED.
By checking the status of my process-instance via REST API using process-instance-id I can know whether a process is COMPLETED or not. But, my web-application has to consider a value of STATUS.

So, what can be the best approach for web-application to be notified with value of STATUS. Shall, I call a REST endpoint of my web-application before process ends in Camunda or shall I push STATUS value to MQ and web-application consumes from that MQ or shall my web-application hit Camunda REST API to check process variable value based on process-instance ID.

Looking for suggestions on this.