The global prevalence of developmental delay in children is reported as 1-3%, while World Health Organization (WHO) estimates that 15% of the world’s population lives with some form of disability [3,4]. There is a paucity of community-based data from lower and middle income countries (LMIC), but a similar or higher prevalence is expected [5]. Due to improving maternal and child health care and better neonatal and child survival, there is now a large group of children at high risk for developmental delay in these countries. In addition, the proportion of children experiencing poverty, ill-health, malnutrition and lack of early stimulation – factors that adversely affect attaining optimum developmental potential – are much more in comparison to high income countries [1].

One of the main reasons for lack of community-based data from India is the absence of routine developmental screening and surveillance. Developmental surveillance is the longitudinal process of identification and monitoring of newborns and children at high risk [6]. This comprises of eliciting parental concerns, acquiring developmental history, identifying risk and protective factors, evaluation, and maintenance of records [7]. Screening is the brief cross-sectional process of evaluating children by screening tools with good psychometric qualities (sensitivity and specificity >70-80%), that have been norm-referenced and standardized on populations representative of the target population [5-7]. In developed countries, both strategies are core components of the health, education and social care systems [8]. The American Academy of Pediatrics (AAP) recommends developmental surveillance of high-risk children at each health visit from birth to 3 years, and routine screening of low-risk children at 9, 18, and 24/30 months or earlier if concerns are elicited [7]. Screening for behavioral disorders and academic/learning disorders is also recommended [9]. Hix-Small, et al. [10] reported an increase in screening in USA after these guidelines were framed, though it is still far from ideal. Lack of screening means delay in detection, initiation of intervention, increased morbidity and parental anguish, more health service utilization and poorer prognosis [11].

In India, there are multiple challenges to practice of universal developmental surveillance and screening. Parents are unaware of the existence and need of these services. Health care seeking is prioritized for acute illnesses which are not appropriate opportunities for screening. A heterogeneous population of doctors with variable proficiency caters to the health needs of Indian children. If parents express concerns, they are often given false assurances without proper appraisal. Well-child visits are primarily for immunization with a few perfunctory questions asked about development, if at all. This was documented in a study of perceptions and practices of 90 pediatricians from Gujrat [12]. Most participants (97.3%) reported parents expressing developmental concerns but only 13.6% used structured tools for evaluation. Reasons cited by those relying on informal assessment were time constraints (72%), non-availability of treatment or referral options (45%), and inability to use screening tools (28%). Contrary to this common misconception, informal evaluation has been proved unreliable in detecting developmental delay. Recognition is difficult in early childhood unless specifically looked for in a structured way, since changes in development are rapid, there is intra-domain overlap, and early indicators are often subtle.

At present, exposure and training in formal developmental screening and assessment is lacking in the post-graduate pediatric curriculum. Pediatricians may be cognitively aware but lack the necessary psycho-motor and communication skills to screen effectively. There is a scarcity of developmental pediatricians. Available assessment tools are mostly of international origin, which are expensive, not easily available, and require training and accreditation. Recommendations for developmental screening by the Indian Academy of Pediatrics (IAP) are yet to be formulated. Although the ‘Persons with Disabilities Act, 1995’ states that ‘children should be screened annually to detect high risk cases’, the process is not outlined [13]. In 2013, the ‘Rashtriya Bal Swasthya Karyakram (RBSK)’ was launched by the Government of India, which aims at screening for defects at birth, diseases, deficiencies and development delays including disabilities (4 D’s) in children between 0 to 18 years [14]. It is envisioned that pre-school children will be screened by Anganwadi workers using age-appropriate developmental checklists in the periphery and the positive cases will be re-assessed by trained personnel at the secondary and tertiary care levels. Once this swings into action there will naturally be an upsurge of pediatric consultations by concerned parents, which will need to be tackled responsibly. Reviews of screening tools that may be used in LMICs are available but are hampered by lack of clear guidelines or practice algorithms [5,15,16].

This article aims at sensitizing pediatricians, reviewing certain general (not domain-specific) developmental screening and monitoring tools validated for use in Indian under-five children, and proposes an office practice paradigm.

Screening tools currently in use in India include those developed and validated in high-income countries, translations of the above in Indian languages, and indigenously developed tools. Each type has its own problems. In addition to the drawbacks outlined earlier, internationally acclaimed tools may not be suitable for our populations due to presence of items that are culturally alien or which lose context after translation. They also require validation on large reference groups comprising of healthy children of the target population without conditions averse to development like iron deficiency anemia, malnutrition, poverty, and decreased stimulation [17]. Translations may be understandable but still face the aforementioned drawbacks, unless validated. Indian tools are language and culturally suitable, have been validated but may not have optimal psychometric properties since most were originally developed largely for community surveys by health workers. Taking these aspects into consideration, a list of screening tools for developmental delay popularly in use or validated in Indian settings was compiled and those that could be administered by pediatricians in any office setting were reviewed. Tools screening for behavior problems or specific domains or overt disability were not included.

To be able to compare tools qualitatively, it is essential to understand their characteristics. Table I outlines the definitions and acceptable standards of commonly used psychometric parameters. These are important for making educated decisions regarding quality. If screening tools are not used for their intended purpose (i.e. screening tools being used for diagnosis or in children outside the intended age range), reliability gets compromised. Choice of tools also differs according to level of risk for developmental delay; high-risk children being those with biological and/or environmental risk factors. Constituent items of tools may be historically based (milestones, opportunity-based skills), performance-based or both. In contrast to developed counties, parental interviews are not as reliable in LMICs due to poorer literacy levels, unawareness of milestones and possibility of socially acceptable responses being given due to associated social stigma [5,15,16]. Interpretation of a screening result as pass or fail is done by comparing with scores derived from standardized population norm-references or pre-decided performance criterion.

TABLE I Definitions and Acceptable Standards of Development Tool Related  Psychometric Properties 

Hypothetically, an ideal screening tool for Indian children is a brief, inexpensive tool with good psychometric properties, available in Indian languages, comprising of purely developmental/culturally-adapted items, that has been validated on representative healthy Indian children and requiring minimal training [17]. Such a designer tool does not exist in reality; so each pediatrician has to make an educated choice best suited for individual practice. Developmental tools of international origin are compared in Table II. Only two of these have been validated in Indian children.

TABLE II Comparison of Developmental Screening Tools of International Origin 

The Denver Developmental Screening Test (DDST) is a very popular and frequently used international screening test [18-20]. However, its low specificity (43%) leads to over identification of false positives, parental apprehension, and burden on the system for diagnosis and intervention. Hence it is no longer considered appropriate for the purpose of screening. The Bayley Infant Neuro-developmental Screen (BINS) has been used for monitoring children at moderate to severe high risk [21,22]. Though psychometric properties are acceptable, its drawbacks are lack of validation in Indian children and inability to screen children beyond 2 years of age. The Ages and Stages Questionnaire (ASQ) is a parent- completed questionnaire with acceptable properties [23]. In a study by Juneja, et al. [24], ASQ was validated against the Developmental Scale for Assessment of Indian Infants. After being translated into Hindi and substitution of a few culturally inappropriate items, this version of ASQ was administered to parents by an interviewer to screen children aged 4,10,18 and 24 months with both high and low risk. The overall sensitivity in detecting developmental delay was 83.3% (higher for the high-risk children), specificity 75.4% and negative predictive value 84.6%. ASQ has the potential to be used in India after being translated into local languages if interviewer- administration replaces parent-completion when required.

Studies in the West have shown that asking parents about development concerns is reliable for assessment [25]. Parent Evaluation of Developmental Status (PEDS) considers concerns as either ‘not predictive’ or ‘predictive’ of developmental disabilities. The latter categorizes children as having High, Moderate or Low risk of developmental disabilities. Each is linked with related management protocols: referral, more screening or continued surveillance, respectively. PEDS has been found reliable in other developing countries; however, there is limited literature from India [19,26,27]. The only available study from India was by Malhi, et al. [28] in which it was compared with Developmental　Profile　II　(DP II) and Vineland Social Maturity Scale. Psychometric properties were found to be sub-optimal. The authors suggested that PEDS could be used to identify children requiring in-depth screening in situations involving time constraints. The limitations of this study were use of another screening tool as gold standard and a small sample size. Further research is warranted before its value in the Indian context is clarified [5,15]. Developmental Profile III is an updated version of DP II that screens for developmental delay in five key areas [29,30]. Its norms are based on a large representative sample of typically developing American children. Although used in India frequently in numerous research studies, it is yet to be validated in Indian children.

Indian screening tools, that were designed for community surveys but can be used for office practice, are compared in Table III. These are easy to perform and interpret, inexpensive, and have been norm-referenced and standardized in representative populations. The main drawback is less than acceptable psychometric properties. Normative data of both Baroda Developmental Screening Test (BDST) and Trivandrum Developmental Screening Chart (TDSC) are derived from the Bayley Scales of Infant Development (BSID) which has not been re-validated since its inception more than 20 years ago [31]. The same drawback lies in the Indian Council Medical Research Psychosocial Developmental Screening Test (ICMR-PDST) [32,33]. In the TDSC validation study, the gold standard that was used was not a diagnostic tool but DDST (no longer considered suitable): so the results may be considered questionable until re-validated against a more robust gold standard [34].

TABLE III  Comparison of Indian Developmental Screening Tools

Two promising screening tools may become available for use in the near future. The first – Guide for Monitoring Child Development (GMCD) – is a parental report-based development monitoring tool for children between 0 to 3.5 years originally developed in Turkey [8]. It comprises of 7 items pertaining to developmental concerns, and takes 5-10 minutes to administer. The sensitivity and specificity are 86% and 93%, respectively. It also has an intervention package that helps in supporting normal development and managing developmental difficulties. A five-year project ‘Development of International guide for monitoring child development’ is currently underway in India, Turkey, Argentina and South Africa since 2010 [5]. The aim of this project is to standardize GMCD for universal use in children irrespective of demographic, cultural or linguistic considerations. The project also aims at examining an approach in which monitoring is done at community health clinics by trained personnel.

The second new kid-on-the-block is the INCLEN Neurodevelopmental Screening Test (NDST) that was developed by the composite efforts of a team of neuro-developmental experts from India and abroad. It screens for 10 neurodevelopmental disorders (NDD): Autism Spectrum Disorders, Learning Disorder, Attention Deficit and Hyperactivity Disorder, Vision Impairment, Hearing Impairment, Intellectual Disability, Speech and Language Disorders, Epilepsy, Cerebral Palsy and other Neuro-Muscular Disorders. Diagnostic criteria (Consensus Clinical Criteria) have been developed for establishing each diagnosis which are sequentially applied according to an algorithm when the screening test is positive [35]. Application of the NDST in a recently concluded multi-centric validation study in rural, urban, hilly and tribal areas revealed that the prevalence of ≥1 NDD in children aged 2-9 years ranged between 7.5-18.5% [36].

Setting up routine screening practice involves creating parental awareness and demand, finding the right opportunity, tool selection, acquisition and training in administration, scoring, interpreting results and counselling. This entails planning when, where, and how screenings will be accomplished, devising a method for documenting observations and maintaining records, communicating results to parents, referring to experts for further evaluation when required and scheduling future screenings. Parents can be sensitized by information pamphlets and office displays. Since visits for acute illnesses are not appropriate opportunities; a practical option would be to club screening with pre-existing scheduled visits like immunization and vitamin A prophylaxis. A system needs to be devised to document results, maintain and update records at subsequent visits. Comparison with previous records helps to recognize potential developmental problems or regression, deviancy or dissociation. Experience from other countries has shown that time actually gets saved since it takes the same time that would otherwise have been spent in unstructured questioning and answering other parental queries. Ultimately evaluation time becomes predictable, detection rate increases, parent and provider satisfaction level increases and office attendance increases as parents start appreciating the monitoring process.

Based on the advantages and drawbacks of the tabulated tools and until consensus statements are formulated by expert groups, the authors suggest a potential practice paradigm for pediatricians based on degree of risk of developmental delay (Fig. 1).. Pr. Preliminary steps involve creating awareness, procuring tools according to the type of patients encountered (low-risk, high-risk or both), and achieving competency in administration, scoring and interpretation. The schedule of screening and follow up monitoring will differ according to level of risk.

*Neonates, Infants or children with ≥1 High risk factors viz., Genetic: positive family history of illness associated with neurodevelopmental morbidity; Biological: acute & chronic illnesses, nutritional (macro & micro) deprivation; Environmental: exposure to poverty, violence, neglect, teratogens, arsenic, lead, drugs, etc.; Psycho-social: illiteracy, lack of stimulation, learning opportunities, poor parenting skills, parental illness or substance abuse, maternal depression, etc.; Presence of any parental concerns regarding development. #Abnormality present at 3.5 months: refer to text (discussing parental concerns & test outcomes). Fig.1 Proposed schema of office based developmental screening and surveillance.

Discussing Parental Concerns and Test Outcomes

Parental concerns should always be asked. In the initial visit, if the parent of a low risk child expresses developmental concerns, the pediatrician is expected to discuss these with the parents and offer options of more frequent and earlier monitoring (as in the high risk group) or referral for an in-depth evaluation even if the screen is negative. If the parents opt for the former and the concerns persist at the next visit, immediate referral is warranted. If not, monitoring should continue as for the high-risk group, In this group, the first visit recommended by AAP is 4-6 months (coinciding with the 2nd or 3rd immunization visit). The corresponding immunization visit in India would be at 3.5 months. At this age, a small proportion of infants display transient benign tone abnormalities that may be mistaken as pathological. In these instances, the pediatrician should make a note in the child’s records and schedule a repeat visit after a month, without unduly alarming the parents. If it persists, in-depth evaluation would be required.

Once screening is complete, it is important to properly convey the significance of the results. If negative, parents should be reassured that development is currently appropriate, anticipatory guidance should be given about expected milestones and the necessity of returning for the next screening visit should be explained and scheduled. If positive, the implications need to be discussed in depth with the parents, and they should be counseled about the need of diagnostic evaluation and start of stimulation or intervention as indicated post evaluation. Since parents have intrinsic faith in us as health care providers of their children, it is our moral responsibility to be instrumental in arranging referrals (by providing contact details or direct communication) as well as providing continual medical help and moral support. It is good practice to develop a two-way communication system with service providers to instill confidence in parents regarding management issues.

Screening should be considered the initial step of intervention services [37]. Unfortunately, it is common practice to falsely reassure or delay referral to alleviate parental anxiety. Actual practice should be ‘Refer not defer.’ Failing to refer for diagnosis and intervention after detection on screening is considered unethical [38]. In developed countries, a referral rate of 1/6 children screened is considered optimal [39]. It is important to understand that starting multi-disciplinary intervention (speech and language therapy, occupational therapy, physical therapy, special educational services, etc) should proceed in parallel to diagnosis-establishment and not afterwards. In addition to formal intervention, pediatricians must become familiar with home-based intervention strategies that should be shared with the parents. Development oriented packages have been combined with tools like ‘Integrated Management of Child Illnesses – Care for Development’ (WHO/UNICEF), GMCD, TDSC and Developmental Assessment Tool for Anganwadis (DATA) or are already in practice at the community level via National Rural Health Mission, RBSK, Integrated Child Development Schemes, and other agencies, the details of which are available, can be practiced by parents at home, and have been proven to be beneficial [8,14,34,40-45].

Many parents and children struggle in their daily lives due to problems arising from undetected development delay. Considering the widespread prevalence of developmental problems, the pediatrician must remain vigilant. By adopting developmental screening and surveillance, one can ensure a systematic approach to children with developmental concerns and help improve their future. Both strategies are integral parts of child healthcare, benefit the individual child and society, and also protect the doctor from possible future litigation. In this review, an attempt has been made to sensitize colleagues to the importance of screening and surveillance, compare existing screening tools and propose those suitable for Indian children along with strategies for incorporation into office practice. There is a strongly felt need to develop more culturally appropriate, norm-based, valid and reliable Indian developmental screening instruments. We strongly urge that a consensus be formulated at the National level by experts on appropriate developmental surveillance and screening recommendations. Ultimately, earlier recognition of developmental delay results in better inclusion of affected individuals in society, establishment of prevalence data, educated health policy decisions, and resource allocation at the Government level.