How can I use Drush to determine if a module is being used or not in a multisite architecture? I have a multisite architecture that has over 30 sites. 

In one specific site search_api_solr version 7.x-1.0RC5 is installed, and I can see that it's enabled and being used in the module list.

In the common sites/all/modules folder search_api_solr 7.x-1.0-rc2 is there. When I do drush pm-list | grep search I can see that it's listed but "Not Installed."

Does this mean that none of the 30+ sites is using this module and it's safe to delete it? Or is that command simply telling me that it's not being used by the default install?

If the latter, how can I use Drush to tell me what specific sites are making use of modules in the common sites/all/modules directory?

EDIT:

@greg_1_anderson

I tried your solution with:

drush @sites pm-info search_api_solr --field=status

On each line of the output after hitting y I get something like:

.appdrupal#mysite.example.com &gt;&gt; blahblah : some.description

looks like the above output is 3 columns. Possible values for that 'blahblah' column seem to be numerous (requires, required by, type, title, description, version, date, package, 'group', files.. etc, etc..) nothing to denote if it's enabled)

I can see a couple times in the 'blahblah' "status", but it's not singled out. Ultimately this creates 1000s of lines of output. I tried to add | grep status but it hanged (I gave it 120 seconds).

Drupal is 7.26 and Drush version is 5.9 - thoughts?
This works in Drush 6.x and later:

$ cd /path/to/drupalroot
$ drush @sites pm-info MODULENAME --fields=status
You are about to execute 'pm-info devel' non-interactively (--yes forced) on all of the following targets:
  /path/to/drupalroot#default
  /path/to/drupalroot#other
Continue?  (y/n): y
.path.to.drupalroot#other   &gt;&gt;  Status   :  enabled
.path.to.drupalroot#default &gt;&gt;  Status   :  enabled