Table 2.
Area under the curve and item-level information across diagnostic groups.
| Item | Item content | AUC | ASD | Non-spectrum | Score range |
|---|---|---|---|---|---|
| M (SD) | M (SD) | ||||
| Q1 | Clearly requests | 0.66 | 0.58 (0.70) | 0.16 (0.44) | 0–2 |
| Q2 | Express happiness | 0.59 | 0.50 (0.92) | 0.17 (0.57) | 0–4 |
| Q3 | Enjoy social touches/affection | 0.59 | 0.25 (0.49) | 0.04 (0.22) | 0–2 |
| Q4 | Directed smiling/laughing | 0.62 | 0.33 (0.52) | 0.05 (0.23) | 0–2 |
| Q5 | Response to name | 0.78 | 0.76 (0.55) | 0.15 (0.36) | 0–2 |
| Q6 | Response to voice | 0.76 | 0.94 (0.62) | 0.31 (0.49) | 0–2 |
| Q7 | “Checking in” eye gaze | 0.73 | 1.09 (0.65) | 0.46 (0.53) | 0–2 |
| Q8 | Eye gaze to get attention | 0.73 | 0.87 (0.67) | 0.29 (0.48) | 0–2 |
| Q9 | Response to directions with gestures | 0.75 | 0.90 (0.69) | 0.25 (0.46) | 0–2 |
| Q10 | Response to joint attention | 0.76 | 0.98 (0.72) | 0.25 (0.48) | 0–2 |
| Q11 | Ease of interactions | 0.72 | 0.62 (0.66) | 0.09 (0.30) | 0–2 |
| Q12 | Emotional dysregulation | 0.64 | 1.65 (1.48) | 0.94 (1.22) | 0–6 |
| Q13 | Calming behavior | 0.64 | 0.54 (0.58) | 0.27 (0.51) | 0–2 |
| Q14 | Initiation of communication | 0.73 | 0.81 (0.75) | 0.16 (0.40) | 0–2 |
| Q15 | Response to ignore | 0.54 | 1.11 (0.76) | 1.01 (0.65) | 0–2 |
| Q16 | Attention-getting behavior | 0.59 | 0.69 (0.67) | 0.47 (0.54) | 0–2 |
| Q17 | Initiation of joint attention for social purposes | 0.75 | 1.30 (0.70) | 0.57 (0.63) | 0–2 |
| Q18 | Drawing attention | 0.79 | 1.40 (0.67) | 0.53 (0.67) | 0–2 |
| Q19 | “Uh oh” response | 0.74 | 1.23 (0.84) | 0.40 (0.68) | 0–2 |
| Q20 | Hand as tool | 0.48 | 0.89 (0.86) | 0.88 (0.80) | 0–2 |
| Q21 | Gestures | 0.84 | 7.53 (3.77) | 2.54 (2.71) | 0–14 |
| Q22 | Integration of gestures, sounds, and eye gaze | 0.75 | 1.11 (0.83) | 0.32 (0.59) | 0–2 |
| Q23 | Unusual sounds | 0.58 | 1.10 (0.80) | 0.84 (0.83) | 0–2 |
| Q24 | Imitation of gestures, sounds, and words | 0.66 | 0.86 (0.68) | 0.41 (0.54) | 0–2 |
| Q25 | Unusual intonation | 0.59 | 0.33 (0.58) | 0.11 (0.38) | 0–2 |
| Q26 | Number of Words | 0.38 | 21.37 (33.46) | 28.67 (35.80) | 0–200 |
| Q27 | Loss of words | 0.60 | 0.55 (0.90) | 0.16 (0.54) | 0–1 |
| Q28 | Stereotyped phrases | 0.49 | 0.30 (0.64) | 0.28 (0.53) | 0–2 |
| Q29 | Unusual phrases | 0.49 | 0.31 (0.65) | 0.27 (0.52) | 0–2 |
| Q30 | Back and forth conversation | 0.68 | 1.68 (0.61) | 1.09 (0.84) | 0–2 |
| Q31 | Play with objects | 0.75 | 3.47 (2.97) | 1.23 (1.98) | 0–12 |
| Q32 | Play with a variety of toys | 0.63 | 0.41 (0.62) | 0.08 (0.29) | 0–2 |
| Q33 | Focus on objects rather than people | 0.78 | 1.24 (0.72) | 0.42 (0.59) | 0–2 |
| Q34 | Intense focus on a certain toy | 0.72 | 0.85 (0.78) | 0.26 (0.53) | 0–2 |
| Q35 | Sticky attention to a certain toy | 0.75 | 0.91 (0.68) | 0.28 (0.49) | 0–2 |
| Q36 | Pretend play | 0.70 | 1.30 (0.68) | 0.76 (0.66) | 0–2 |
| Q37 | Pretend play with toys | 0.74 | 5.95 (2.06) | 3.95 (2.32) | 0–8 |
| Q38 | Pretend play with two sequenced actions | 0.66 | 1.80 (0.48) | 1.35 (0.74) | 0–2 |
| Q39 | Attachment to unusual object | 0.59 | 0.47 (0.78) | 0.17 (0.46) | 0–2 |
| Q40 | Interest in other children own age | 0.76 | 1.14 (0.73) | 0.39 (0.60) | 0–2 |
| Q41 | Sensory responses | 0.64 | 1.06 (1.29) | 0.42 (0.80) | 0–8 |
| Q42 | Repetitive behaviors/body mannerisms | 0.74 | 1.61 (1.41) | 0.52 (0.91) | 0–6 |
| Q43 | Insistence on sameness | 0.71 | 1.85 (1.50) | 0.79 (1.09) | 0–6 |
| Q44 | Rituals and routines | 0.59 | 0.36 (0.61) | 0.12 (0.35) | 0–2 |
| Q45 | Unusual vocabulary | 0.54 | 0.26 (0.67) | 0.07 (0.37) | 0–2 |
| Q46 | Intense interests | 0.63 | 0.84 (1.33) | 0.23 (0.66) | 0–5 |
AUC: area under curve; ASD: autism spectrum disorder.
Bolded items were retained for the final item set.