Given that apparently somewhere around 1 in 70,000-100,000 persons suffer a blood clot after taking Astra-Zeneca, I'm surprised that at least some research hasn't been communicated identifying those at greater risk of clots other than "you are at greater risk if you are under 60".
As hundreds of millions of AZ vaccines have been administered and thus a relatively large number of subsequent clots have occurred, I would have thought a trend would be identified by now, thus identifying those at greater risk and allowing greater 'minimal-risk' use of AZ in the community.