Impact of Accurate 30-Day Status on Operative Mortality: Wanted Dead or Alive, Not Unknown

The STS Adult Cardiac Surgery database data that had been submitted to a regional quality initiative were compared to a hospital claims database to assess what effect, if any, would supplying missing data provided by the latter affect the reported STS 30-day mortality rates.  The STS database currently counts as “alive” any patient that has unknown status at 30 days.  
Findings: 

An excessive 22% of patients had unknown 30-day mortality status.
The missing  data was able to be reduced down to 7% by incorporating the data from the hospital claims database.  
Finally, the study found that, if the external data for CABG patients were included for these hospitals, the true 30-day mortality observed/expected ratio would be increased to 1.30 from 1.27.  Thus, at present, the current method for reporting STS data underestimates the true 30-day mortality.

Should centers make an effort to include missing data provided from external administrative databases in order to improve the accuracy of STS reported outcomes?  Should STS mandate such an inclusion of data?