[island911]

Here we go...

https://www.science.org/content/blog-post/search-long-covid

https://www.medscape.com/viewarticle/974572

https://www.medscape.com/viewarticle/962479 (nice video here)

Get this..

There was no statistical difference in pulmonary function (spirometry, lung volume, etc.), and no statistical differences in any of the cardiovascular tests (echocardiograms, etc.) But the median distance walked in a six-minute walking test was lower for the post-Covid patients as compared to the controls (560 meters versus 595). But even then, the changes in walking distance did not correlate with PASC symptoms. The only variables in patient histories and so on that correlated with a greater likelihood of showing PASC were being female or having a self-reported history of anxiety disorders, but as you can see from the above, nothing really tracked at the biochemical level.

bold mine

Essentially the test tracked people who actually had covid and control people who were told that they had covid. The people who did not have covid (but told that they did) reported 'long covid" more so than people who actually had covid.