Sorry I do not have any statistics to share, nor have I personally been involved with anyone who lost a valid claim at Tribunal, but I think it highly unlikely that anyone with a genuine claim would lose out by going to Tribunal.
If it is likely that an award will be reduced, the judge usually advises them in advance and they then have the opportunity to withdraw their appeal, so if they have got any sense, they withdraw and keep what they have got.
Those who don’t succeed have probably not fully understood the criteria for getting an award and have a false expectation. I have drafted appeals for claimants who I have warned do not have a strong case, but it their right to appeal, so we help them to understand the process.
Unfortunately we rarely get feedback after the event, but overall, the vast majority, over 70%, do succeed in increasing their award at Tribunal.
The Tribunal panel is completely independent of the DWP and consists of a judge, a doctor and someone with experience of disability, maybe disabled themselves, or a support worker, for example. They start from scratch with fresh, impartial eyes.