The Empathy Quotient (EQ) and Autistic-Spectrum Quotient (AQ) were done at the start of my assessment. They're the ones that the UK's National Health Service (NHS) recommends to use across the whole service (so that would probably be you, too, MG). IIRC, both originate from well known (and somewhat controversial) scientist Simon Baron-Cohen's Autism Research Centre at Cambridge University, which may or may not have influenced the choice.
I imagine that private clinics might use different testing methods, but even they would probably want their diagnoses to be near equivalent to an NHS one, so that diagnosed patients can use them to access other state-funded services.
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