Abstract

Objective: To develop, standardize, and partly validate a developmental scale for toddlers (age, 1.6 to 3 years) attending anganwadis in India.

Methods: After the development of the 12-item Developmental Assessment Tool for Anganwadis (DATA), its internal consistency, face validity, content validity and construct validity were studied in 100 toddlers in anganwadis and were found to be appropriate. A total of 429 toddlers with a mean (SD) age of 30.9(5.2) months from 36 randomly selected anganwadis were recruited for its standardization. Raw scores were converted to standardized T-scores. Scoring pattern for domains and aggregate developmental scores were formulated.

Results: Except for one item in the original scale, all the items were endorsed by parents suggesting a good content validity. Cronbach’s a of 0.86 suggested a high internal consistency. Factor analysis replicated the 2-factor structure explaining 56% of variance. An aggregated developmental score based on the standardized T-scores demonstrated that a DATA score between 33 and 28 suggested ‘at risk’ for developing developmental delays. A score of £27 suggested already delayed milestones. A score of 27 to 16 suggested a ‘mild delay’, a score of 15 to 5 suggested a ‘moderate delay’ and £4 suggested a ‘severe delay’ in development.

Conclusion: DATA is a brief, simple and psychometrically sound measure for use in anganwadis for identifying toddlers at risk or with developmental delays. Differentially identifying toddlers at risk or with developmental delay helps in referring them for appropriate interventions.

Keywords: Anganwadi, Child, Developmental Scale, Normative, Validation

The age of inception of toddlers in to anganwadis being about 2 years, a measure to identify children at risk of developing a developmental delay or with developmental delays at 2 to 3 years will eminently suit the use of anganwadi workers. For the screening tool to be simple and locally relevant, a norm referenced developmental measure based on the reference values is required. We herein summarize two studies done to achieve this goal. The first study describes the development of the measure, Developmental Assessment Tool for Anganwadis (DATA) and its partial criterion-referenced validation. The second study documents the norm-referenced validation of the measure to identify children with developmental delay for appropriate intervention.

Conceptualization and nature of the measure: We wanted a brief scale to screen toddlers at risk for developing developmental delays and those who already have developed developmental delays while they attend the primary-care pediatric setting of anganwadis. The differential identification of these two groups of children is needed for organizing appropriate referrals. Also, we wanted the instrument to be validated for toddlers around 2½ years of age. This age threshold was important because of different reasons: (i) screening the toddler immediately after contact with anganwadi will increase false-positivity, as many of them might not have been exposed to stimulating environments; and (ii) the anganwadi worker is also not familiar with the toddler to make conclusions on ambiguous findings.

Item selection: We began by constructing a list of milestones likely to be important to toddlers at risk or with developmental delay. Items from various available developmental measures namely the Denver Developmental Screening Test (DDST), Developmental Assessment Scale for Indian Infants (DASII), The Receptive–Expressive Emergent Language Test (REEL), Vineland Adaptive Behavior Scale (VABS) were compiled. Additionally, three experts in the field of developmental pediatrics, clinical psychology and child psychiatry ranked the items collected on a 3 point scale where 1 was least important and 3 was most important and thus 24 items were selected.

Endorsement category and response category format: We decided on the dichotomous endorsement category of ‘emerged’ and ‘not emerged’ for endorsing a milestone based on fixed criteria for pass (Appendix 1). If the milestone has ‘emerged’, the age of the development of the milestone in months was noted and for milestones ‘not emerged’, a score of 0 was given by the anganwadi worker.

Standardization of score and scoring pattern: The development of the milestones recorded in the form of raw scores (means and standard deviations in months) was converted to standardized T-scores, The mean and standard deviation of various milestones that have emerged or not were converted to an equivalent T-score with a mean of 50 and a standard deviation of 10 as shown in the data analysis(6). The definition of ‘at risk’ for developmental delay and definite delay graded as ‘mild delay’, ‘moderate delay’, and ‘severe delay’ was based on the standard deviations of 1.5, 2, 3 and 4 on the lower side of the normative mean and standard deviation, using the conventional standardization principles(7).

For the scoring pattern, the emerging age in months for any skill was checked at the end of the assessment with a standardized T-score equivalent. The arithmetic average of the items in a domain formed the domain score and the arithmetic average of all the domain scores provided the final Aggregate Developmental Score (ADS).

Sample size and sampling: A list of anganwadis was collected from three geographically different districts in Kerala (Thiruvananthapuran, Kottayam and Kozhikode) and 18 anganwadis from urban and 18 anganwadis from rural areas of these districts were randomly selected. A sample of 100 toddlers were included if they were 1.6 to 3 years of age and accompanied by a parent as the primary caregiver, from the anganwadi area or anganwadi depending on the age.

Setting and sample: The study was conducted at randomly selected anganwadis in the three districts of Kerala (Thiruvananthapuram, Kottayam and Kozhikode), India. Toddlers (n=429) between 1.6 to 3 years of age accompanied by a parent were included in to the study from the anganwadi area or anganwadi. This sample size was adequate as a sample size of minimum of 300 participants is required when no other subgroup analysis is considered a priori(6).

Data collection: The data was collected independently by six developmental therapists with an average experience of 5.9 (1.2) years in assessing children with developmental delays. They approached the toddlers for data collection after acquiring informed consent from the parent and verbal assent from the aganwadi worker. The study was approved by the institutional review board.

In study-2, 429 toddlers participated in the study and among them 229 were boys and 200 were girls. Most of the children were from the low socio-economic status and were between the chronological ages of 18 to 50 months [mean (sd)=30.9(5.2)]. Most of the skills corresponding to the items in the measure emerged between 31 to 33 months. The normative data for referencing DATA was extrapolated from the mean ages and standard deviations at which the milestones emerged and are summarized in Table III. These raw scores converted to standard T-scores are presented in Table IV. The scoring key based on the standardized score to identify toddlers at risk for developing development delay and those who showed developmental delays are summarized in Table V.

TABLE III

Normative Data on Milestones of 2-3 Years Old Children and Extrapolated Delays 
Based on the Standard Deviations*#

* All figures in months adjusted for the decimal; # At risk= 1.5 SD; Mild delay=2 SD;
 Moderate delay = 3 SD; Severe delay =4 SD 

TABLE IV

Conversion of Raw Score to Standardized Scores for DATA Based on T scores*

*1SD delay in months in achieving a specific milestone is equivalent to 1SD in the T score

TABLE IV

Conversion of Raw Score to Standardized Scores for DATA Based on T scores*

*1SD delay in months in achieving a specific milestone is equivalent to 1SD in the T score

TABLE V

Scoring Key for DATA*

This short, simple to use and psychometrically sound measure based on the developmental norms of the anganwadi children, offers anganwadi workers a more efficient way of identifying toddlers at risk and with developmental disabilities shortly after they join anganwadis, as conceptualized.

Although the items of DATA were aimed at children from 2-3 years, the age range of the population we recruited was from 18-50 months as we wanted to cover the 4SD deviation in developmental range on both directions for the standardization procedure. The normative data on the age of emergence of various skills among the toddlers at anganwadis ranged from 31 to 33 month in this study. There is a slight overall delay among the anganwadi population than that is described in the literature [mean (SD)=27(4.6)] months for all the 12-items when compared with the original validation data of the measures conducted in high income countries. This could be explained by the low socio-economic status of the toddlers from rural background attending anganwadis. Over the past decades, toddlers from low socioeconomic background have been repeatedly shown to have delay in development and later low scores in formal intelligence tests because of malnutrition and poor environmental stimulation(9-11).

This measure has the advantage of differentiating the toddlers at risk for developing delays from those who already have mild to severe delays. This differentiation is important as toddlers at risk can be stimulated at the preschool component of anganwadis itself, whereas children with proved delays need to be referred for appropriate early interventions(13). Further, training and capacity building of the anganwadi workers can be based on a one day participatory workshop model reported previously to be effective(14), with five simple modules to sensitize them to developmental delays, the basics of normal developmental milestones, make observations about milestones in a few children from their anganwadi area, practice the DATA and finally evaluate their identification ability by comparing their DATA result with the trainer. The pre-field trial version of DATA, the assessment materials required and the assessment procedures and scoring pattern are presented in Appendix 1.

The limitations of the standardization are that subgroup analysis, like effect of gender, on the emergence of milestones was not done. The measure was administered by experienced developmental therapists, as against the intended utility by anganwadi workers. It should be remembered that these data are from pre-field trial study and hence these limitations will be addressed during the field trials of DATA.

In conclusion, DATA is a short, psychometrically strong, norm-referenced developmental scale with partial criterion referencing to identify toddlers at anganwadi who are at risk for developing develop-mental delays, and differentiate those who already have developed delays at 2½ years for appropriate interventions. In addition, we recommend that regular developmental assessments be conducted on the beneficiaries of anganwadis, every year, at three more key ages of 3½, 4½ and 5½ years to institute early intervention when required. In future, scales appropriate for these ages should be developed, standardized and validated across the country for the benefit of the anganwadi children.

We gratefully acknowledge CDPOs, Supervisors and Anganwadi workers of concerned ICDS Blocks, and Asokan N, Child Development Centre, Medical College, Thiruvananthapuram for their support during the study period.

Contributors: MKCN, PSR were involved in designing the study, analysis of data and preparation of the manuscript and will act as guarantors. RSR, MAL, SL, KR, VSP and MT were was involved in the data collection.

Funding: Child Development Centre, Medical College, Thiruvananthapuram.

Competing interests: None stated. The findings and conclusions in this study are those of the authors and do not necessarily represent the views of the funding agency.

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