The face of postural tachycardia syndrome – insights from a large cross‐sectional online community‐based survey, 2019, Raj et al

Open access at https://onlinelibrary.wiley.com/doi/full/10.1111/joim.12895

 

So why the 93% white? Doesn't that suggest that this may not be a representative sample?

 

It may reflect how it was accessed and / or promoted.

 

Yes, badly worded, that! Quite an assumption and no regard to possible limits of research method used.

 

As most of the researchers are American, you'd expect at least a quarter of the respondents to be non-white: https://en.m.wikipedia.org/wiki/Race_and_ethnicity_in_the_United_States

 

Which would also suggest that the 94% female may be similarly biased.

 

There is a case study in Family Doctor - A Journal of the New York State Academy of Family Physicians, winter 2018, Vol 6, no.3 pp30-31

(Same edition as the Dimmock, Levine, Wilder article on ME/CFS, sorry haven't worked out how to do links yet)

29 year old African American male medical student, struggling for diagnosis, then who even with a positive TTT result had to get a 2nd opinion to confirm POTS diagnosis, as considered to affect predominantly Caucasian young women.