TABLE 3 Selected Level 1 and 2 ASD Screening Measures

Screening Tool Age Format (No. of Items) Time to Complete, min Reported Sensitivity Reported Specificity Selected Key References Availability
Level 1a
    CHAT 18–24+ mo Parent interview or questionnaire and interactive (parent: 9; clinician: 5) 5 0.18–0.38b; 0.65c 0.98–1.0b; 1.0c Baron-Cohen et al,267 Baron-Cohen et al,272 Baird et al,19 Scambler et al273 Download: www.autismresearchcentre.com/tests/chat_test.asp
    CHAT, Denver Modifications 18–24+ mo Parent interview or questionnaire and interactive (parent: 9; clinician: 5) 5 0.85c 1.0c Scambler et al273 CHAT scoring modifications; available in Scambler et al273
    Checklist for Autism in Toddlers-23 (CHAT-23) 16–86 mo (all had mental ages of 18–24 mo) Parent interview or questionnaire and interactive (parent: 23, clinician: 5) 10 0.84–0.93c (part A); 0.74c (part B) 0.77–0.85c (part A); 0.91c (part B) Wong et al274 Combination of M-CHAT and CHAT items; protocol available in Wong et al274
    CAST 4–11 y Questionnaire completed by parent (37) 10 0.88–1.0d 0.97–0.98d Scott et al,275 Williams et al,235 Williams et al276 Download: www.autismresearchcentre.com/tests/cast_test.asp
    M-CHAT 16–48 mo Questionnaire completed by parent (23) 5–10 0.85d 0.93d Dumont-Matthieu and Fein,277 Robins et al268 Download: www.dbpeds.org/media/mchat.pdf or www.firstsigns.org/downloads/m-chat.pdf; for scoring: www.firstsigns.org/downloads/m-chat_scoring.PDF
    Pervasive Developmental Disorders Screening Test-II, Primary Care Screener (PDDST-II PCS) 18–48 mo Questionnaire completed by parent (22) 10–15 0.92c 0.91c Siegel269 Purchase: PsychCorp/Harcourt Assessment (www.harcourtassessment.com)
Level 2
    Asperger Syndrome Diagnostic Scale (ASDS) 5–18 y Questionnaire completed by parent, teacher, or clinician (50) 10–15 0.85c Myles et al,278 Campbell270 Purchase: Pro-Ed (www.proedinc.com)
    Autism Behavior Checklist (ABC) ≥18 mo Behavioral checklist completed by interviewer (57 ) 10–20 0.38–0.58c 0.76–0.97c Krug et al279 Purchase: Pro-Ed (www.proedinc.com) as part of the Autism Screening Instrument for Educational Planning (ASIEP-2)
    Autism Quotient (AQ)–Adolescent Version 11–16 y Questionnaire completed by parent (50) 15 0.89c 1.0c Baron-Cohen et al280 Download: www.autismresearchcentre.com/tests/aq_adolescent_test.asp
    Autism Spectrum Screening Questionnaire (ASSQ) 6–17 y Questionnaire completed by parent (27) 10 0.62–0.82c (parent); 0.65–0.70c (teacher) Ehlers et al281 Questions are included as an appendix in Ehlers et al281
    Childhood Autism Rating Scale (CARS) >2 y Behavioral checklist completed by trained interviewer/ observer (15) Variable 0.92–0.98c; 0.94c 0.85c Eaves and Milner,282 Perry et al,283 Schopler et al284, Sevin et al285 Purchase: Western Psychological Services (www.wpspublish.com)
    Gilliam Asperger's Disorder Scale (GADS) 3–22 y Questionnaire completed by parent, teacher, or clinician (32) 10 Gilliam,286 Campbell270 Purchase: Pro-Ed (www.proedinc.com)
    Gilliam Autism Rating Scale–2nd Edition (GARS-2) 3–22 y Questionnaire completed by parent or teacher (42) 5–10 Gilliam287 Purchase: Pro-Ed (www.proedinc.com)
    Krug Asperger's Disorder Index (KADI) 6–21 y Questionnaire completed by parent or clinician (32) 15–20 0.78c 0.94c Krug and Arick,288 Campbell270 Purchase: Pro-Ed (www.proedinc.com)
    Pervasive Developmental Disorders Screening Test-II, Developmental Clinic Screener (PDDST-II, DCS) 18–48 mo Questionnaire completed by parent (14) 10–15 0.73c 0.49c Siegel269 Purchase: PsychCorp/Harcourt Assessment (www.harcourtassessment.com)
    Pervasive Developmental Disorders Screening Test-II, Autism Clinic Severity Screener (PDDST-II, ACSC) 18–48 mo Questionnaire completed by parent (12) 10–15 0.58c 0.60c Siegel269 Purchase: PsychCorp/Harcourt Assessment (www.harcourtassessment.com)
    Screening Tool for Autism in Two-Year-Olds (STAT) 24–36 mo Interactive, requires specific training (12) 20 0.92d 0.85d Stone et al,289 Stone et al290 Author: Wendy Stone, PhD (triad@vanderbilt.edu)
    Social Communication Questionnaire (SCQ) (formerly the Autism Screening Questionnaire [ASQ]) ≥4 y Questionnaire completed by parent (40) 5–10 0.85–0.96c 0.67–0.80c Berument et al,291 Rutter et al292 Purchase: Western Psychological Services (www.wpspublish.com)

The measures were selected on the basis of availability of some published psychometric properties (in English) with scoring instructions and pass/fail cutoffs or the equivalent.

a Level 1 tools are most likely to be used in primary care settings.

b Population-based sample.

c Clinical sample.

d Clinical and population-based samples.Adapted from Coonrod EE, Stone WL. Screening for autism in young children. In: Volkmar FR, Paul R, Klin A, Cohen D, eds. Handbook of Autism and Pervasive Developmental Disorders. 3rd ed. Vol 2. Hoboken, NJ: John Wiley & Sons; 2005:707–729; Campbell JM. Diagnostic assessment of Asperger's disorder: a review of five third-party rating scales. J Autism Dev Disord. 2005;35:25–35; and Rutter M, Bailey A, Lord C, et al. The Social Communication Questionnaire (SCQ) Manual. Los Angeles, CA: Western Psychological Services; 2003.