Updating Tests, Test Sets, and Test Set Items

I have established a connection between our automated testing tool and QAComplete through the web services.  I have successfully tested reading from and writing to the Test Library.  Now I want to take the next step, and write test results from our automation tool to QAComplete.  



The tests in the automation tool are set up in suites of tests, a structure which I have replicated in QAComplete as Tests gathered in TestSets.  I would like to write the automated test results to QAComplete. 



Question is: what fields do I need to update in QAComplete?  

Each individual Test's LastRunStatus?  

Each TestSetItem's LastRunStatus?

Each TestSet's LastRunStatus?

All of the above?



The user guide isn't really very clear on this.



Thanks for your help.



Rino