It is helpful to communicate in advance what is the specific agenda of each meeting, so that people can make an informed decision on whether to attend.

Also, it may be helpful to have the meeting organizer send meeting notes after every meeting, including action items assigned to specific people. The notes don't need to be extensive, but there better be an executive summary of what decisions were made, if any, and any unexpected roadblocks that were found.

That's how things were done at one of the mega corps where I was employed and it worked great.