Table 3.
Research summaries for the Infant-Toddler Checklist (ITC) and First-Year Inventory (FYI).
| Probe questions | ITC [59] | FYI [60] | |
|---|---|---|---|
| Sample/participants | |||
| Was the sample appropriate in size and scope? | Low-risk community sample; large to start with (10,479), but attrition was high for the reference standard evaluation phase; 184 at the end; 14% of high-risk sample. | Yes, population study; mailed to almost 6,000 and got a 25% return rate. 699 filled out developmental and ASD screening questionnaires after child's third birthday. | |
| How representative was the sample? | These parameters were not reported. | Although the sample was diverse, there were a disproportionate number of Caucasian and highly educated families responding to later phases of the screening study. | |
| Were there exclusion criteria based on other disabilities? | They specified that no exclusion criteria were exercised for either the population sample or the follow-up. | It was specified that children born preterm were excluded. | |
|
| |||
| Screening instrument | |||
| Was there anything about how the screener was administered that would be different from its intended use in a nonresearch, community setting? | No. | No. | |
| Were there any issues regarding the way it is scored in the study? | Note that the ITC can be failed in four different ways—low score on either or both of two subscales, total score; there may be differences in true and false positives given the source of fail criterion. | The authors explored predictive validity based on several different ways of using subscales scores and total score. | |
|
| |||
| Reference standard | |||
| Did all children receive a BED from in-person evaluations? How extensive was the information available to the clinician making the Best Estimate Diagnosis? | Cognitive, ADOS-T, and ADI-R; children seen every 6 months up to three years of age. They evaluated children every 6 months and gave “at-risk” dx's of ASD from 12 to 18 months, “provisional” dx's from 19 to 31 months, and established dx's from 32 to 36 months with ADI-R. Five children with provisional dx's no longer had dx at the last evaluation. | Mixed—some children brought in for Best Estimate Diagnosis including all information, ADOS, and occupational therapy evaluation (n = 9). Three others were determined to have ASD based on diagnostic evaluations submitted by parents. Those evaluations all used the ADOS. | |
| Were the reference standard evaluators blind to the screener risk status of the children? | Not reported. | Yes. | |
| What diagnostic outcome categories were used to test prediction from screener to reference standard? | ASD, LD, DD, and no diagnosis. LD and DD defined by Mullen Scores, “other” by parameters such as motor delay. | ASD, other DDs' diagnosis, or treated through EI services, developmental concerns (no diagnosis but concerns), and no concerns. | |
|
| |||
| Timing and flow | |||
| Was there excessive attrition through any phase of screening and evaluation? | Out of 10,479, there were 1316 fails. Out of those, only 346 were referred for testing by the researchers, with a list of practical reasons why the others might have been missed. Out of 346 they lost another 232 for a variety of reasons, so in the end they worked with 184 high-risk children plus 41 TD children referred as a comparison group. | No. | |
| Were there conditions besides attrition that filtered the negative and positive screens from the original screening to the reference standard diagnostic testing phase? | No. | No issues—they were able to make some assessment of developmental status of all 699. | |
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| |||
| Evaluation | |||
| How were performance/predictive values calculated? | They combined ASD with other DDs to calculate PPV because they were considering the ITC a broadband screener. | They were not able to see the FYI negatives in person but did have parents report diagnoses, EI services, developmental concerns, and two parent-rated screening questionnaires for DD and ASD symptoms. | |
| Was performance/prediction for younger versus older children explored? | Screened at 12–15 months. But their breakdown showed that diagnosis was less stable at 12–18 months and became more stable towards 24 months. |
N/A—all screened at 12 months. | |
|
| |||
| Performance | |||
| What were the performance/predictive values? | PPV = .75 for all disabilities. PPV = .20 ASD alone. |
Total score PPV = .14. NPV = .99. Se = .44. Sp = .97. |
Two-domain cutoff PPV = .31. NPV = .99. Se = .44. Sp = .99. |
| What was the developmental level of children detected? | IQs ranged widely but did include higher functioning children: MSEL Composite (M = 100; SD = 15). M = 78.6. SD = 17.5. Range = 49–106. |
Sample size includes higher-functioning children but difficult to characterize because 9 children had ASD and only 6 had Mullen Composite scores; four were average or higher and two were very low. M = 94.7. Range = 62–127. |
|
| Of the false positives for ASD, what proportion had other developmental or learning disabilities? | 69.7%. | 65% (who met total score cutoff). 85% (who met two-domain cutoff). |
|
ITC = Infant-Toddler Checklist; ASD = autism spectrum disorder; FYI = First-Year Inventory; BED = Best Estimate Diagnosis; ADOS-T = Autism Diagnostic Observation Schedule-Toddler Module; ADI-R = Autism Diagnostic Interview-Revised; dx = diagnosis; LD = language disorder; DD = developmental disability; EI = early intervention; TD = typically developing; PPV = positive predictive value; NPV = negative predictive value; Se = sensitivity; Sp = specificity; MSEL = Mullen scales of early learning; M = mean; SD = standard deviation.