TABLE 2.
Delays in Diagnosis, as a Function of Selected Demographic Characteristics
| WUSTL N = 205 (179 families) | Emory N = 181 (165 families) | UCLA N = 131 (108 families) | Einstein N = 67 (65 families) | All Sites N = 584 (517 families) | Cross Site Comparison ANOVA, P | Mean ADI-R Social (Verbal Subjects)a | Mean ADI-R RRB (Verbal Subjects)b | IQ Associationc | Verbal Versus Nonverbal Subjects t testsd | |
|---|---|---|---|---|---|---|---|---|---|---|
| Age in months at study enrollment, mean (SD) | 127.0 (62.4) | 93.1 (48.4) | 131.0 (62.0) | 113.8 (49.7) | 115.9 (59.0) | <.001 | — | — | — | — |
| Age in months at parental first concerns, mean (SD) | 26.7 (23.0) | 20.3 (12.5) | 22.3 (14.8) | 19.1 (12.7) | 23.0 (17.9) | <.001 | −0.09 | −0.18** | 0.08 | Verbal = 24 m; nonverbal = 17 m; P <.001 |
| Age in months parent first shared concerns with a professional, mean (SD) | 36.9 (29.6) | 23.8 (17.2) | 26.8 (16.3) | 23.2 (17.6) | 29.1 (23.1) | <.001 | −0.05 | −0.09 | 0.16** | Verbal = 31 m; nonverbal = 20 m; P <.001 |
| Age in months at initiation of services, mean (SD) | 49.9 (30.4) | 36.5 (24.0) | 41.3 (20.7) | 35.5 (32.6) | 42.3 (27.5) | <.001 | −0.00 | −0.10 | .14** | Verbal = 45 m; nonverbal = 29 m; P <.001 |
| Age in months child received ASD diagnosis mean (SD) | 80.0 (58.1) | 57.9 (37.4) | 55.6 (43.7) | 54.3 (48.5) | 64.9 (49.6) | <.001 | −0.09 | −0.18** | 0.16** | Verbal = 71 m; nonverbal = 36 m; P <.001 |
| Delay in diagnosis, months, mean (SD) | 53.0 (54.1) | 38.1 (35.2) | 31.8 (37.0) | 35.0 (41.5) | 42.3 (45.1) | <.001 | −0.06 | −0.12* | 0.14** | Verbal = 47 m; nonverbal = 20 m; P <.001 |
| Median household income at time of first concerns | $28 000 | $50 000 | $36 000 | $45 000 | $37 000 | <.001 | −0.04 | 0.12 | 0.06 | P <.99 |
| Parental level of education: college degree | 25.1% | 43.2% | 21.5% | 31.3% | 30.2% | <.001 | −0.14* | 0.05 | .10* | P <.93 |
| Proportion of subjects with IDe | 29.4% | 49.1% | 36.7% | 12.5% | 35.2% | <.001 | — | — | — | — |
RRB, restricted and repetitive behavior; WUSTL, Washington University in St. Louis; —, not applicable.
a
Mean ADI-R social domain scores; Pearson correlation coefficient.
b
Mean ADI-R restricted and repetitive behavior domain scores; Pearson correlation coefficient.
c
Participants with ASD IQ-Proxy score; Pearson correlation coefficient.
d
Comparison of means for verbal versus nonverbal subjects as a function of delay in diagnosis variables.
e
For a more detailed analysis of cognitive scores across sites and by measure, refer to Supplemental Table 7.
*
Indicates P value significant at .05 level (2-tailed). ** Indicates P value significant at .01 level (2-tailed).