Just seen this thread...
I'm something of an expert on DVTs having had two of them. The first resulted in a PE and was the classic case of a long-haul flight (in this case HKG-AMS) on a staff ticket so no choice of seat; i ended up at the back of the 747, in the middle of five (i think) surrounded by Asian seamen going to join a ship somewhere and who smoked the entire flight (it was a long time ago). The treatment involved five nights in Bart's, a heparin drip and some uncomfortable procedures. (Plus the use of Warfarin, the continued use of which would have meant the cancellation of my medical).
The second was two years ago and I also had not been near an aeroplane for some years. It also resulted not only in a PE (the pain from which immediately identified the cause to me) but also pleurisy and double pneumonia. In the years between the two events the treatment has changed dramatically. Far from being in hospital for four or more nights (as I expected) I was seen, treated and discharged all in the same day. No mention of Warfarin and the only heparin was a small injection. I was sent home with antibiotics and a month's supply of a relatively new drug which it seems is now used in these cases - Rivaroxaban, trade name Xarelto. I take one small tablet every day. Whilst I still use compression stockings when I take a long-haul flight, the Rivaroxaban is the life saver for me.
As a short-haul pilot (c15000 hours) I never thought to wear compression stockings.