The four ASD assessments
Last updated
Last updated
The 3di has a bank of nearly 900 questions, of which around 200 are involved in ASD diagnoses. Remember you can see every single question in the .
Within the 3di's autism provision, there are four different assessments. These were developed and added to the software over many years of research and use. The four ASD assessments are:
ICD-10 extended
ICD-10 brief
DSM-5 extended
DSM-5 brief
Each ASD assessment has a corresponding set of questions (a ), a scoring algorithm, and a set of tables in the generated . In the latest 3di versions, there are therefore up to four sets of report tables, corresponding to each of the four assessments.
Recall from that a report can be generated at any stage of completion of the 3di's questions, even before answering a single question. If you generate a report having answered no questions at all, you get a boring but structurally complete report, full of notes telling you why scores could not be computed. The structure of the report is not determined by the questions answered, but instead by which of the two report buttons you clicked. To see the older ICD-10 report tables you need to enable this option via the .
Picking the appropriate ASD route in the will allow you to complete just the necessary questions for that assessment, thus populating the corresponding report components.
You can also fill in sufficient questions to complete more than one assessment: the 3di report will fill in whatever report components it can. It was common in earlier versions of the 3di to complete questions on a combined route which covered both the ICD-10 brief and DSM-5 extended assessments. If you set out to fill in the full route for an algorithm but have to miss some questions for whatever reason, that's fine too: the report will tell you about the missing data and attempt to make a sensible adjustment.
There are two flavours of report corresponding to two buttons in the :
Report (with ASD_extended). The full report. For patient number 1, this generates a Word document named Report_000001.docx.
Report ASD_brief. The brief report. For patient number 1, this generates a Word document named ASD_000001.docx.
The 3di was initially developed as a research tool starting around the year 1999 at the Great Ormond Street Institute of Child Health under the direction of Professor David Skuse. Its first ASD assessment was built around an amalgamation of ICD-10 and DSM-IV criteria. The World Health Organisation's International Statistical Classification of Diseases and Related Health Problems, 10th revision (ICD-10) came into effect on 1 Jan 1993. Meanwhile the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) was published in 1994. The 3di treated the two systems as broadly equivalent.
The first assessment in the 3di interview, now known as the ICD-10 extended, was based on 134 questions, and designed for research use where there was sufficient time for such a thorough assessment.
Over the next 25 years there were several developments. Among young people in the UK, the prevalence of autism grew from a fraction of a percent to several percent. Demand grew for a quicker autism informant interview for use in CAMHS clinics where there was less time available for assessment. This led to the development of the ICD-10 brief assessment.
DSM-5 came into effect in 2013, followed by ICD-11 on 1 Jan 2022. The 3di was updated with a new DSM-5 extended assessment for autism in 2013. Finally in late 2022 the DSM-5 brief assessment was released.
Comparing DSM-5 and ICD-11, we consider that by design the two sets of criteria are so similar that ASD outcomes (and many others) can be reported as DSM-5 or as ICD-11. The 3di always references DSM-5 because the APA got there about 7 years before the WHO; you can substitute one term for the other in your reports or perhaps reference neither.
This was the first ASD algorithm implemented in the 3di, around 2004. Its scoring is based on 134 questions. The corresponding route is ASD_extended (ICD-10).
This was the second ASD algorithm implemented in the 3di, around 2009. Its scoring is based on 61 questions. The corresponding route is ASD_brief (ICD-10).
This was the third ASD algorithm implemented in the 3di, around 2013. Its scoring is based on 177 questions. The corresponding route is ASD_extended (DSM-5 Crit A + B).
This output of this algorithm appears only in the extended Word report, and not in the brief Word report, under the heading DSM-5: ASD extended assessment.
This was the fourth ASD algorithm implemented in the 3di, in 2022. Its scoring is based on 66 questions. The corresponding route for this algorithm is named ASD_brief (DSM-5 Crit A+B).
This output of this algorithm, despite having 'brief' in the name, appears in both the brief and extended Word reports, under the heading DSM-5: ASD brief assessment.
The details of the ICD-10 algorithms 1 and 2 are explained in three files found in the 3di installation folder under the Reference subfolder. ASD_three-domain_scales_defined and ASD_diagnosis_flowcharts_3_domain describe the algorithm, while ASD_scales_Ref details which individual questions contribute to each subscale.
The details of the DSM-5 algorithms 3 and 4 are explained in two files found in the 3di installation folder under the Reference subfolder. DSM-5_ASD_scoring describes the algorithm, while again ASD_scales_Ref details which individual questions contribute to each subscale.
Currently, the 3di software is not suitable for assessments of adults.
The ASD routes contain only the questions which contribute to the scoring tables in the report. They do not contain the Interview Setup questions and details about the referral. For a richer report, you can complete these in advance using , or during the interview via the .
This original 3di assessment was announced in .
In recent 3di versions, if you still want to see ICD-10 report components you need to visit the . This output of this algorithm appears only in the extended Word report, and not in the brief Word report. In the extended Word report the corresponding tables appear under the heading ICD-10 ASD.
The derivation and validation of this assessment was published in .
In recent 3di versions, if you still want to see ICD-10 report components you need to visit the . This output of this algorithm appears only in the brief Word report, and not in the extended Word report. In the brief Word report the corresponding sections appear under heading ICD-10 ASD.
You may have heard about this assessment. This was part of a research project and you can read the paper . It was a standalone, pen-and-paper tool which drew on the 3di but was never implemented in the software, and presently there are no plans to do so.