Agree with you timkiely that it does appear that the screening to remove the responders to SC does not appear to have worked very well. It does seem that the participants enrolled were on an improvement trajectory with SC – not hard to treat at all.
The clue for the researchers that this was going wrong could have been the screening rates. If you imagine hard to treat comprises say 20%then around 80% should be being rejected.
Instead it seems only a handful of potentially eligible participants who had received SC for 1 month previously were screened out through wound size change (set pretty high at 30%).
On your other point.
I think the three year unhealed statistic from the Harding study that gets quoted on this forum is a little misleading. Yes the average was near three years (33 months) but the median was only 10 months. So very right skewed. You probably had a handful of cases that had had wounds that were years years old.
Harding noted that there was a positive trend for bette rresults for the shorter wound duration. Specifically in the 17 (out of 45) participants with wounds >24 months only 4 actually healed; the majority didn’t heal.
With the benefit of hindsight if you could wave a magic wand. The trial should have had a run in period of say first 10 cases to SC.Follow-up for 12 weeks and you would have seen very good response. And then realised your aim of producing an enriched sample of hard to treat wasn’t being achieved from your criteria.
