Table 6. Above acceptable internal consistency of the SCQ for all items and three domains for diagnostic groups except the typically developing group.

SCQ domains	Autism Cronbach’s α (95% CI)	NDD Cronbach’s α (95% CI)	TH Cronbach’s α (95% CI)	Overall sample Cronbach’s α (95% CI)	Autism McDonald’s Ω (95% CI)	NDD McDonald’s Ω (95% CI)	TD McDonald’s Ω (95% CI)	Overall sample McDonald’s Ω (95% CI)
All items	0.93 (0.90– 0.95)	0.83 (0.78–0.88)	0.41 (0.25–0.57)	0.95 (0.94–0.96)	0.88 (0.02–0.91)	0.81 (0.75–0.76)	0.41 (0.25– 0.57)	0.95 (0.94–0.96)
Reciprocal social interaction domain	0.85 (0.79–0.89)	0.77 (0.69– 0.83)	0.39 (0.19–0.55)	0.89 (0.86–0.91)	0.81 (0.72– 0.88)	0.76 (0.58– 0.83)	0.12 (0.05–0.27)	0.88 (0.86–0.91)
Communication domain	0.74 (0.65–0.82)	0.72 (0.63–0.80)	0.22 (0.00–0.45)	0.91 (0.90– 0.93)	0.67 (0.11– 0.75)	0.50 (0.34–0.64)	0.22 (0.00–0.45)	0.80 (0.75–0.85)
Repetitive behaviours domain	0.70 (0.58–0.79)	0.68 (0.57– 0.77)	0.39 (0.22– 0.56)	0.80 (0.77–0.84)	0.63 (0.45–0.76)	0.67 (0.58– 0.77)	0.39 (0.22– 0.56)	0.79 (0.75– 0.83)