Using the Ages & Stages Questionnaire to assess later effects of an infant intervention promoting language in primary care.

BACKGROUND: Positive relational experiences during infancy have a profound impact on child development and are critical for future health and school readiness. We have been evaluating a simple finger puppet intervention that takes one minute and costs $1USD to deliver in the primary care setting to promote caregiver-infant interactions. We explored using developmental trajectories to determine later outcomes of our early intervention program by comparing trajectories to age 36 months to assess optimal intervention timing when delivered in early versus late infancy. METHODS: Three cohorts were enrolled and given a puppet at 2 months (early intervention) and 6 or 12 months (late intervention). Child development was assessed using the Ages & Stages Questionnaires (ASQ-3), which were independently collected during well visits. Scanned ASQ-3 forms from 2 to 36 months were obtained retrospectively through the electronic medical record. To compare longitudinal scores at different ages, all raw scores were first converted to z-scores. Longitudinal mixed effects models examined the trajectories of participant ASQ-3 scores over time by comparing the average intercepts and slopes. RESULTS: Of 180 children enrolled, 172 (96%) completed 2 or more ASQ-3 questionnaires and were included in the analysis, with a mean of 4.9 and a total of 843 questionnaires. Most children (85%) were on government-sponsored insurance. There were no statistical differences comparing cohort intercepts, while early intervention had a significant difference in slope compared to late intervention for the Personal-Social domain (0.12, p=0.018), resulting in higher predicted scores at 36 months. Early compared to late intervention had a difference in slope approaching significance for Communication (0.14, p=0.056) and the combined non-motor score (0.33, p=0.052). There were no significant differences in slope for Problem Solving (0.05, p=0.48), Gross Motor (-0.009, p=0.84), Fine Motor (0.06, p=0.22), and total ASQ-3 (0.32, p=0.17) scores. CONCLUSIONS: Finger puppets may provide a simple and scalable way to encourage responsive caregiver-infant interactions promoting language and social-emotional development, especially when provided in early versus late infancy. Our trajectory analysis also demonstrates a useful and potentially cost-effective approach to evaluating long-term developmental outcomes of an early intervention.

Using Finger Puppets in the Primary Care Setting to Support Caregivers Talking With Their Infants: A Feasibility Pilot Study.

Disadvantaged children often show disparities in early language development. We tested the feasibility, acceptability, and preliminary efficacy of introducing finger puppets in the primary care setting at the 2-month well visit to support caregivers talking with their infants. Caregivers completed a sociodemographic survey and were contacted by phone 2 weeks later to assess initial usage and satisfaction. Ages & Stages Questionnaires (ASQ-3) were independently recorded at well visits. A family cumulative risk score was calculated from the sociodemographic survey. Thirty-four caregiver-child pairs were enrolled. Caregivers reported high satisfaction with the intervention. ASQ-3 Communication and Total scores at 6, 12, and 18 months were significantly higher for high puppet users across all age levels with no significant interactions with age or cumulative risk. Finger puppets provide a low-cost way to promote language-rich interactions. Preliminary evidence suggests that high puppet usage may have long-lasting effects on child development and should be further evaluated.

Combining Two Developmental Screening Tests to Improve Predictive Accuracy.

OBJECTIVE: Single developmental screening tests are insufficient for supporting clinical decisions, showing less than 50% of those referred are actually delayed. Combining two tests can address this problem. We used likelihood ratios (LR) to evaluate the predictive value (PV) of combining the Ages and Stages Questionnaires (ASQ) and Parents Evaluation of Developmental Status (PEDS) screening tests. METHODS: We used data from Limbos and Joyce that included information on the ASQ, PEDS, and an age-appropriate diagnostic assessment of delay on 328 children (ages 12-60 months) drawn from primary care. LRs were calculated for each of the available ASQ/PEDS combinations then rank ordered. PV was examined using different LRs to define referral and nonreferral thresholds. RESULTS: Setting the referral threshold at LR 2.0 for combined scores decreased the number of false positives from 66 to 28, increased false negatives from 6 to 9 with positive predictive value (PPV) improving significantly from 30% to 47% (P < .05). Sensitivity dropped from 82% to 74% and specificity improved from 72% to 90%. When the LR referral threshold increased, PV improved but an inconclusive group emerged that required more information for decision-making. CONCLUSIONS: Combining the ASQ and PEDS significantly improved predictive accuracy of a referral in a single threshold analysis. Predictive value improved further as requirements for referral increased and an inconclusive group needing further study was recognized. Systematic research is needed to identify what readily available information will assist decision making in this group.

Cumulative risk, the cognitive home environment and vocabulary in early childhood.

INTRODUCTION: Early home support for language development is critical for later developmental progress. Paediatricians have the opportunity to identify families at risk of failing to provide this support in infancy but often lack simple tools to do so. This study explores the potential of a simple count of sociodemographic risk factors, a cumulative risk (CR) index, to identify families likely to need help in providing literacy support from an early age. METHODS: CR scores were calculated for 308 families who completed the STIMQ and MacArthur Communicative Development Inventory (MCDI) at 11-15 months) and 197 (64%) again at 23-37 months. Analysis of variance with linear contrasts examined the effect of CR on the STIMQ and the MCDI at baseline and follow-up. Correlation analysis explored the relationship between STIMQ and MCDI. RESULTS: At both baseline and follow-up, CR index showed a significant effect (p<0.006) on the STIMQ along with a significant linear trend for STIMQ scores to decrease as CR increased (p<0.05-0.005). No significant effects of CR effects on MCDI were observed at baseline or follow-up, whereas MCDI percentiles correlated significantly (p<0.03-0.001) with STIMQ scores (r=0.18-0.26.) at both times. CONCLUSIONS: The CR index is a simple tool that can help identify families needing support for providing a language stimulating home environment in the first 2 years before long-term ill effects of sociodemographic barriers are established.

Evaluating developmental screening in clinical practice.

OBJECTIVE: To demonstrate a method of evaluating accuracy of developmental screening modeled on the evidence-based medical literature. METHOD: A retrospective review was performed on 418 children screened with the Denver II by a trained technician. Two models for analyzing screening data were examined, using predictive values and likelihood ratios (LR+ and LR-). RESULTS: The technician, working at 20% time, screened 44% of eligible children. There were 129/418 (31%) children with Suspect Denver II results, 115/418 who were referred, 81/115 (70%) who were evaluated by Early Intervention, and 64/81 (79%) who qualified for services. The uncorrected positive predictive value for the Denver II alone (44%) was insufficient to meet the preset standard of 60%, but the LR+ of 4.16 indicated a significant contribution of test information to improving predictive value. Combining test results with information from the parent-technician conference to achieve a referral decision resulted in an uncorrected predictive value of 56%, which rose with correction for children referred but not evaluated to 72% (LR+ 10.33). Negative predictive values and likelihood ratios of a negative test and a non-referral decision achieved recommended levels. Parents who expressed concern were significantly more likely to complete recommended evaluation than those who did not (82% vs 58%, p < .01). Results were in the same range as in published studies with other screening tests but showed three areas for improvement: screening more children, more carefully supervising some referral decisions, and getting more children to evaluation. CONCLUSION: Levels of predictive accuracy above 60% can be obtained by combining different types of information about development to make decisions about referral for more complete evaluation. Systematic study of such combinations could lead to improved predictive accuracy of screening programs and support attempts to close the gap between referral and evaluation.

Relationship between the cognitive environment and vocabulary development during the second year of life.

OBJECTIVE: To examine the relationship between characteristics of the cognitive environment at age 10 to 18 months and vocabulary at age 18 to 30 months. DESIGN: Analysis of baseline and follow-up data on 157 families participating in a comparison of 2 anticipatory guidance programs. SETTING: Children's Hospital outpatient department serving low-income families. PARTICIPANTS: Parents of children aged 10 to 18 months at baseline who participated in a follow-up telephone interview at age 18 to 30 months. MAIN OUTCOME MEASURES: Three subscales of the StimQ (reading, parental involvement in developmental activities, and parental verbal responsivity [PVR]) and the short form of the MacArthur Communicative Development Inventories. RESULTS: Vocabulary score percentiles dropped significantly between baseline and follow-up, with scores for bilingual families showing a greater decrease than those for English speaking-only families. StimQ subscale scores increased with maternal education and increased between baseline and follow-up. Multiple regression analysis showed that baseline variables accounted for 25% of the variance in follow-up vocabulary score percentile, with significant contributions from baseline expressive vocabulary (P < .001), PVR (P = .01), and home language (P = .03) scores. Seventy-seven percent of children with PVR scores less than 4 had follow-up vocabulary scores at or less than the 25th percentile, with an associated likelihood ratio of 4.33. However, 35% of children with a PVR score of 4 also had vocabulary scores less than the 25th percentile at follow-up, with an associated likelihood ratio of 0.67. CONCLUSIONS: The StimQ is a clinically useful method for assessing early environmental factors that influence vocabulary development. The PVR subscale score was the best StimQ predictor of later vocabulary delay and may be useful in identifying children needing referral for evaluation.

Evaluating bias in validity studies of developmental/behavioral screening tests.

This commentary describes six potential problems and sources of bias that are often overlooked and under-reported in validity studies of developmental/behavioral screening tests, namely, 1) problems with small samples, 2) verification bias, 3) inappropriate/non-equivalent test bias, 4) procedural bias, 5) incomplete reporting of results, and 6) spectrum bias. These issues are then applied to review an unusually complete published report of a screening test validity study along with a discussion of how results may affect application in different settings.

What the clinician really needs to know: questioning the clinical usefulness of sensitivity and specificity in studies of screening tests.

This article challenges the American Academy of Pediatrics recommendations for use of sensitivity and specificity in evaluating the validity of developmental screening tests. It emphasizes the clinician's need to know the prevalence of delay in the population to be screened and to estimate predictive values for that population. If one knows the prevalence, sensitivity and specificity can be useful in deriving predictive values but must meet the assumption of stability. Four common, often unrecognized, sources of instability in estimates of sensitivity and specificity are examined, namely, verification bias, small sample sizes, construct-irrelevant variance, and errors in choice and use of diagnostic procedures.