Stability of the ADI-R
10
scored above the cut off for autism on the RSI domain; 15 (42.9%) scored above the cut off on the VC
domain; 28 (80%) scored above the cut off on the NVC domain and 30 (85.7%) scored above the cut
off on the RBSP domain. McNemar tests revealed no statistically significant differences with regard to
the number of participants meeting algorithm criteria for autism on any of the domains or on the total
score between T1 and FU.
Seven children (20%) who met ADI-R criteria for autism at T1 no longer met algorithm criteria at FU.
Two of these met Risi et al.’s (2006) broader criteria for ASD on the ADI-R; 5 failed to meet either the
autism criteria or the Risi et al. (2006) broader ASD criteria on the ADI-R at FU (see Measures
section). Among the 7 children who no longer met full ADI-R criteria, 3 failed to meet criteria on one
domain (RBSP domain), 3 did not meet criteria on 2 domains (two on RSI and VC domains, one on
NVC and RBSP domains) and one did not meet criteria on any domain.
Further analysis was conducted to explore differences between those children whose ADI-R algorithm
classification remained stable and those who no longer met criteria for autism at FU (see Table 2;
Mann Whitney U tests employed due to small and unequal N in groups). Those children with less
stable classifications had significantly higher VABS ABC age equivalent scores (U = 33.5, N = 34, p
= .01), VABS ABC standard score (U = 37.0, N = 35, p = .01), VABS communication age equivalent
(U=35.5, N=35, p= .01) and VABS daily living age equivalent scores (U=36.5, N = 35, p = .01) at T1.
No other significant differences were identified.
(Insert Table 2 about here)
Domain and total scores