The online autism test cuts both ways
Among 476 adults referred for assessment, 64% of those who scored below the AQ questionnaire's cut-off did have autism. A low score is not a no - and a high score is not a yes.
We have not finished checking this source. No judgement either way. how we score evidence
Caveat on this rating: Population and construct, both load-bearing. These are 476 consecutive adults already referred to a national specialist autism service - people who had passed a referring clinician's judgement - so the predictive values are conditioned on that population and do not describe someone completing the questionnaire at home, where the proportion who are autistic is different and unknown. Sensitivity and specificity are properties of the instrument against a clinical reference standard, not verdicts on any individual score. The finding replicates in the wider literature rather than standing alone: Sizoo et al. 2015 concluded that none of the common self-report instruments has sufficient validity to predict an autism diagnosis in outpatient settings, and Wigham et al.'s 2019 systematic review found questionnaires perform markedly worse in referral streams than in samples of already-diagnosed people.
Among adults referred for autism assessment, 64% of those who scored below the questionnaire's cut-off turned out to be autistic.
Significant findings
Ashwood and colleagues gave the Autism-Spectrum Quotient - the AQ, the questionnaire most people meet online first - to 476 consecutive adults at a national assessment service, then compared each score against the diagnosis that person actually received.
It was poor at ruling autism out. Nearly two thirds of the people it scored below the cut-off were autistic anyway.
It was also poor at ruling autism in. Its specificity was 0.29, meaning most people who did not turn out to be autistic still scored above the threshold.
This was a referred population, so the exact numbers do not transfer to someone taking the test at home. What transfers is the shape of the error: it runs in both directions at once.
Worth asking
If a screener is what sent you looking, that is a reasonable thing for it to have done. Bring it to an evaluation as the reason you started asking rather than as the answer, and ask what a full assessment would check that a questionnaire cannot.
Source
Predicting the diagnosis of autism in adults using the Autism-Spectrum Quotient (AQ) questionnaire — Ashwood KL, Gillan N, Horder J, et al. (2016)
Read the source: https://doi.org/10.1017/S0033291716001082
DOI: 10.1017/S0033291716001082
How this was scored
- Study design
- not recorded
- Funding
- not recorded
- Published in
- not recorded
- Sample size
- not recorded
- Preregistered
- not recorded
- Conflicts disclosed
- not recorded
- Independent of proponent
- not recorded
- Retracted
- No
We have not finished checking this source, so there is no scoring to show yet. “We have not checked this yet” and “this is disputed” are different statements, so no scored band is shown rather than a low one.
Read the full scoring rubric, including what it can't tell you.
Published August 31, 2026.
Questions
How strong is the evidence behind this?
Resolv rates this source "not yet assessed". We have not finished checking this source. No judgement either way. One caveat travels with that badge: Population and construct, both load-bearing. These are 476 consecutive adults already referred to a national specialist autism service - people who had passed a referring clinician's judgement - so the predictive values are conditioned on that population and do not describe someone completing the questionnaire at home, where the proportion who are autistic is different and unknown. Sensitivity and specificity are properties of the instrument against a clinical reference standard, not verdicts on any individual score. The finding replicates in the wider literature rather than standing alone: Sizoo et al. 2015 concluded that none of the common self-report instruments has sufficient validity to predict an autism diagnosis in outpatient settings, and Wigham et al.'s 2019 systematic review found questionnaires perform markedly worse in referral streams than in samples of already-diagnosed people. The score is calculated from recorded facts about the source — study design, funding, publication venue, sample size, preregistration — not typed in by an editor.
What is the source for this?
Predicting the diagnosis of autism in adults using the Autism-Spectrum Quotient (AQ) questionnaire — Ashwood KL, Gillan N, Horder J, et al. (2016). DOI: 10.1017/S0033291716001082. The full source is linked on this page so you can read it yourself.
Is this medical advice?
This is information to bring to your prescriber, not medical advice and not a reason to change anything on your own. Nothing here is an instruction to stop or reduce a medication. If you are in crisis, call or text 988.
This is information to bring to your prescriber, not medical advice and not a reason to change anything on your own. Nothing here is an instruction to stop or reduce a medication. If you are in crisis, call or text 988.