A Systematic Review of Neurodevelopmental Tools for Preterm Infants During Infancy: Mapping the Components Across Infant Age Quarters

Abstract

With an increasing rate of preterm birth (PTB) and survival rates, PTB-related impairments have become a critical concern that requires early screening and intervention. Though there are multiple neurodevelopmental tools available, their complexity in administration, limits their usage. This research intends to systematic review the available neurodevelopmental assessment tools to map their components in relevant domains in each age quarter of a preterm infant’s life to give a quick reference guide for clinical practice in India. A systematic review was undertaken using key keywords linked to preterm newborns and neurodevelopmental assessment in PubMed, Scopus, ProQuest, and gray literature published from 2000 to 2023. The initial search identified 30 neurodevelopmental tools, but only 10 were included in the analysis due to accessibility constraints. The first quarter concentrated on a great deal on primitive reflexes, which might serve as early warnings of a red flag. Although these tools are used in research, most lack extensive psychometric evaluations specific to preterm populations, raising concern validity and geographical sensitivity, especially in India. There is critical need to establish the psychometrics of the identified tools in preterm population. The components plotted over infant age quarters may be used by health care professionals for a quick reference. Inaccessibility of tools being the major hinderance in pediatric evaluation, these charted components may serve a practical reference frame work for establishing a comprehensive tool that might require less or minimal training suitable for low- and middle-income countries like India.

INTRODUCTION

The World Health Organization reports that the escalation in preterm birth instances is a major global health concern, with 153 million infants being delivered prematurely, accounting for more than 10% of all live births in the last decade. Despite a recent decline in preterm infant mortality, co-morbidities and long-term neurodevelopment problems make preterm birth a major concern.[1,2,3]

Approximately 15% of preterm infants fall into the diagnosis of cerebral palsy. Research indicates that one in two preterm newborns have a neurodevelopmental disorder, and the rate rises with age. These developmental disabilities persist into adolescence and adulthood and increases their dependency on caregiver. This impacts their productivity and quality of life.[2,4,5]

With over 200 million children worldwide exhibiting developmental disorders, there is a need for rigorous monitoring of all children, not just preterm infants, is needed to reduce neurodevelopmental disorders. Failure to address these issues early on may reduce productivity later in life, perpetuating poverty and slowing national growth.[6]

Early identification and intervention within the first few years of life helps reducing the disability rates and enables children to reach developmental milestones. The use of standardized outcome measures is recommended for effective developmental monitoring to identify the need for early intervention, as interventions during this critical period have a higher success rate.[6,7,8,9]

A survey conducted among child clinicians in the United States found that standardized outcome assessments are rarely implemented in practice, hindering research translations. This could be due to the perceived complexity of administration, time constraints, and the need for additional training in using these tools.[7,10]

Although training clinicians on assessment tools may pose challenges, a lack of standardized assessment methods may impede the efficacy of diagnostic and early intervention initiatives.[7] India being top on the list of preterm births in the last decade, there is an immediate need for developing a neurodevelopmental tool. However, financial constraints limit the accessibility and use of many neurodevelopmental tools in India.[1]

One potential solution could be the development of a simple, cost-effective tool that requires minimal or no additional training for administration. This review aims to systematically identify and map the components of existing neurodevelopmental tools for preterm infants, organizing these components by the infant’s age quarters (0–3 months, 4–6 months, 7–9 months, and 10–12 months) to provide a comprehensive reference guide for clinicians to monitor the development of preterm infants efficiently, even in busy practices where clinicians may not have time to go through each scale individually. These sorted components could lay the groundwork for a new, more efficient tool that can be administered in a shorter time frame with minimal training.[10,11,12]

Several reviews have been conducted on screening tools for neurodevelopment; however, there is a gap in the exploration of components that are utilized in detecting developmental signs of preterm infants from 0 months of corrected gestational age to 1 year of life. Despite the enlistment of neurodevelopmental tools in various studies, the specific key domains that these tools target and the components/signs used as indicators within those domains remain unexplored.[4,13,14,15]

Also, this study aims to categorize scales based on the domains they focus on during specific quarters of an infant’s life, aiding researchers and clinicians in selecting the most suitable tool for developmental assessments.

The secondary inquiry aims to outline the domains covered by the tools, components within each domain, examiners involved, evaluation time frames, cut-off values, and the psychometrics of the identified tool in assessing preterm infants.

Procedure

A systematic review was undertaken to investigate available neurodevelopmental tools, with the review registered in PROSPERO after a pilot search across selected databases such as PubMed, Scopus, and ProQuest (Prospero id: CRD42023472505).

Search strategy

A thorough search was conducted in electronic databases from September 2023 to October 2023, covering Scopus, PubMed, ProQuest for published works, and ProQuest gray search for unpublished works. Keywords related to NICU, preterm, neurodevelopment, and outcome measures were utilized, with a refined strategy achieved through repeated searches with Boolean operators [Supplementary File 1].

Supplementary File 1.

Search strategy/Key-terms and results in databases

Data base	Query	Results
PUBMED	(((((((((“Preterm infant”[Title/Abstract] OR “preterm birth”[Title/Abstract] OR “Premature infant”[Title/Abstract] OR “Preterm newborn”[Title/Abstract] OR preemie[Title/Abstract] OR “Premature birth infants”[Title/Abstract] OR “Immature infants”[Title/Abstract] OR “Early neonate”[Title/Abstract] OR “Preterm neonate”[Title/Abstract] OR “Neonatal premature*”[Title/Abstract] OR “Infant premature”[Title/Abstract]) OR (“Infant, premature” OR “Premature birth”[MeSH Terms])) AND (Neurobehavior*[Title/Abstract] OR Neuromotor[Title/Abstract] OR Motor[Title/Abstract])) AND (Tool[Title/Abstract] OR outcome[Title/Abstract] OR screen*[Title/Abstract] OR evaluat*[Title/Abstract])) NOT (Feed*[Title] OR breastfeed*[Title] OR swallow*[Title])) NOT (Review*[Title/Abstract] OR perspective[Title/Abstract] OR meta-analysis[Title/Abstract])) NOT (Visual[Title] OR Visuo-motor[Title])) NOT (Pig[Title] OR animal[Title] OR rat[Title] OR mouse[Title])) NOT (Hemorrhag*[Title] OR posthaemorrhag*[Title])) NOT (Communic*[Title]) Filters: Free full text, from 2000-2023 Sort by: Publication Date	471
SCOPUS	(TITLE-ABS-KEY (“Preterm infant” OR “preterm birth” OR “Premature infant” OR “Preterm newborn” OR preemie OR “Premature birth infants” OR “Immature infants” OR “Early neonate” OR “Preterm neonate” OR “Neonatal premature*” OR “Infant premature”) AND TITLE-ABS-KEY (neurobehavior* OR neuromotor OR motor) AND TITLE-ABS-KEY (tool OR outcome OR screen* OR evaluat*) AND NOT TITLE (feed* OR breastfeed* OR swallow*) AND NOT TITLE-ABS-KEY (review* OR perspective OR meta-analysis) AND NOT TITLE (visual OR visuo-motor) AND NOT TITLE (pig OR animal OR rat OR mouse) AND NOT TITLE (hemorrhag* OR posthaemorrhag*) AND NOT TITLE (communic*)) AND PUBYEAR>1999 AND PUBYEAR<2024 AND (LIMIT-TO (DOCTYPE, “ar”)) AND (LIMIT-TO (LANGUAGE, “English”)) AND (LIMIT-TO (OA, “all”))	874
PRO QUEST	((((((abstract(“Preterm infant” OR “preterm birth” OR “Premature infant” OR “Preterm newborn” OR preemie OR “Premature birth infants” OR “Immature infants” OR “Early neonate” OR “Preterm neonate” OR “Neonatal premature*” OR “Infant premature”) AND abstract (Neurobehavior* OR Neuromotor OR Motor) AND abstract (Tool OR outcome OR screen* OR evaluat*) NOT title (Feed* OR breastfeed* OR swallow*) NOT abstract (Review* OR perspective OR meta-analysis) NOT title (Review* OR perspective OR meta-analysis) NOT title (Visual OR Visuo-motor) NOT title (Pig OR animal OR rat OR mouse) NOT title (Hemorrhag* OR posthaemorrhag*) NOT title (Communic*)) AND stype.exact(“Scholarly Journals”)) AND la.exact(“English”) AND pd (2000-2023)) AND stype.exact(“Scholarly Journals”)) AND la.exact(“English”)) AND stype.exact(“Scholarly Journals”)) AND la.exact(“English”) AND pd (2000-2023) Limit by: Full text	87

Before screening in Rayyan, three reviewers validated the search strategy results from all databases. The eligibility criteria encompassed original research studies utilizing neurodevelopmental tools to detect the signs of neurodevelopment, neuromotor maturity, and early neurodevelopmental disorders up to 1 year of age. Articles published between January 2000 and October 2023 were selected. The inclusion criteria encompassed all neurodevelopmental tools used for preterm infants up to 1 year of corrected age, regardless of whether they were designed for screening, surveillance, or comprehensive assessment, whereas conference proceedings, abstract-only studies, in vitro research, protocols, and non-English publications were excluded. Study selection involved primary and secondary screenings by two blinded reviewers using the Rayyan software, with conflicts resolved through discussion or consultation with a third reviewer if needed. Tools that were not open access or readily accessible were excluded from the final review. The process of study selection is elaborated in Figure 1.

Figure 1.

PRISMA flowchart

Microsoft Excel (Office 2021) was used to extract the data. Data extraction on tool domains, components carried out by two authors, and the components of the neurodevelopmental assessment tool were charted according to infants’ age quarter (0 to 3 months, 4 to 6 months, 7 to 9 months, and 10 to 12 months) and domains. The tools were charted according to the domains they focus on in a particular quarter of infants and presented as Supplementary File 2 ^{(269.1KB, pdf)} .

RESULTS

A thorough screening process was conducted, involving the removal of duplicate entries from 1,475 English articles published between 2000 and 2023, resulting in the identification of 252 articles implementing neurodevelopment screening tools for preterm infants in their first year of life. Tools used in more than two studies were established as selection criteria for further analysis.

A total of 30 commonly used neurodevelopmental tools were identified through a literature survey and expert consensus, with 10 accessible tools undergoing systematic analysis which included Alberta Infant Motor Scale (AIMS), Amiel Tison Neurological Evaluation at Term (ANAT), Ages and Stages Questionnaire–3 (ASQ–3), Centre for Disease Control (CDC) Developmental Checklist, Denver Developmental Screening Test (DDST) II, Hammersmith Infant Neurological Examination (HINE), Hammersmith Neonatal Neurological Examination (HNNE), Infant Neurological International Battery (Infanib), Neurosensory Motor Developmental Assessment (NSMDA), and Trivandrum Developmental Screening Chart (TDSC). The entire list of 30 tools identified is enlisted in Supplementary File 3. The basic information of the 10 tools used for neurodevelopmental assessment infants born preterm from 0 months to 1 year of corrected gestational age is presented in Table 1.

Supplementary File 3.

Tools identified via review and expert opinion

Tool
Bayley Scales of Infant Development III
General movement assessment
Alberta Infant Motor Scale
Test of Infant Motor Profile
NICU Neurobehavioral Network Scale
Denver Developmental Screening Test II
Griffith Mental Development
Neurobehavioral Assessment of Preterm Infant
Neuro-Sensory Motor Developmental Assessment
Infant Motor Profile
Ages and stages 3
NBAS
Peabody Development Motor Scale
Hammersmith Neonatal Neurological Examination
Amiel Tison Neurological Assessment at Term
Assessment of Preterm Infant Behavior
INFANIB
Brazelton Neonatal Behavioral Assessment Scale
Hammersmith Infant Neurological Examination
Prieme neuro
Infant Behavior questionnaire
Battelle’s Development Inventory
Neonatal Neurobehavioral Examination
Gesell Developmental Scale
Infant Behavior Questionnaire
Tou-wen Infant Neurological Examination
Developmental assessment of young children
Trivandrum Developmental Screening Chart
CDC Developmental Check list
Development Assessment Scale for Indian Infants

Table 1.

Tools included in the review and its basic information

	Tool name	Country origin	Year of development	Proctor	Intended periods of assessment	Domains assessed	No. of items	Cutt off scores suggestive of abnormality or delay
1	Alberta Infant Motor Scale (AIMS)	Canada	NA	HCP and parents	0–18 months	Gross motor assessed in 4 fundamental positions	58	Less than the 10th percentile for 4th month and 5th percentile for 8th month
2	Amiel Tison Neurological assessment at term	Paris	2002	HCP		Neurosensory function and spontaneous motor activity, passive muscle tone, axial motor activity, primitive reflexes, palate and tongue, adaptedness to manipulations during assessment, feeding autonomy	35	Score 2 in any component
3	Ages and Stages Questionnaire–3 (ASQ-3)	London	2009	HCP and parents	2 months to 66 months of age (21 timepoints)	Personal–social, gross motor, fine motor, problem-solving and communication	30	Failing in two areas
4	CDC Developmental Milestone checklist	America	2004	HCP and parents	2 months to 60 months	Motor, cognitive, social–emotional, and language- communication.	24	Failing in any one component
5	Denver Developmental Screening Tool (DDST) II	Colorado	1992	HCP	1 month to 6 years of age	Gross motor, fine motor, language, and personal/social skills	104	Failing to meet up to 75 percentile of a component is caution. Failing to meet up to 90 percentile of component is delay. One delay/two cautions: abnormal More than 2 delays: warrants intervention
6	Hammersmith Neonatal Neurological Examination (HNNE)	Britain	1980	HCP	Term/term equivalent age to 3 months	Posture, tone patterns, angles, reflexes, movements, abnormal signs, orientation and behavior	34	Score<30: sub-optimal neurobehavior
7	Hammersmith Infant Neurological Examination (HINE)	London	NA	HCP	3–12 months of age	Neurological examination, milestones, and behavioral state	37	At 3 months: <57 At 6 months: <60 At 9 months: <63 At 12 months: <66
8	Infant Neurological International Battery (INFANIB)	USA	1985	HCP	0–18 months of age	Muscle tone, French angles, and primitive reflex	20	4 months: <48 8 months: <68
9	Neuro Sensory Motor Development Assessment (NSMDA)	Queensland	1989	HCP	1 month to 6 years of age	Gross motor, fine motor, neurological status, infant movement patterns, posture and balance	Varies for different age groups	Normal: 6 to 8 Minimal motor problem: 9 to 11 Mild motor problem: 12 to 13 Moderate motor problem: 14 to 19 severe motor dysfunction: 20 to 25 Profound motor dysfunction: >25
10	Trivandrum Development Screening Chart (TDSC)	India	2013	HCP	0–6 years	Cognitive, motor, vision, hearing, and communication	27 items	Any unattained skill behind the vertical line indicates a delay

NA–not available, HCP–healthcare professionals. Intended periods of assessments are in terms of corrected gestational age

The 10 tools were systematically categorized in alignment with the study objectives, which will be detailed in subsequent sections.

AIMS

AIMS can be utilized to monitor infants from birth to 18 months, offering several advantages in clinical settings. The assessment can be spread over a week if needed, minimizing the need for reevaluation in cases where completion in a single session is not feasible.

AIMS is advantageous as it requires minimal handling of the child, can be completed in any order, and focuses on observing infants in fundamental positions of supine (9 items), sitting (12 items), standing (16 items), and prone (21 items). It assesses spontaneous motor movements while considering the child’s age and situation, providing both quantitative and qualitative insights into movement quality and quantity alongside their posture.[16]

The scoring methodology of the tool is straightforward, requiring the examiner to select between two options: “observed” (1 point) or “not observed” (0 points). Cut-off scores were established based on the 10^th percentile for infants at 4 months and the 5^th percentile for infants at 8 months of age. AIMS has exhibited exceptional sensitivity, particularly for infants aged between 4 and 12 months.

Amiel tison

The Amiel Tison assessment comprises 35 items distributed among five domains, with scores ranging from 0 (normal) to 2 (severely abnormal). This simplified scoring system assists in delineating the clinical profile of infants. The evaluation method involves grading based on critical signs, crucial in identifying prenatal brain damage.[17]

The Amiel Tison scale has demonstrated its validity through neurophysiopathological studies. The scores derived from this assessment can serve as a guiding parameter for the early rehabilitation of children up to the age of 6 years. Specifically, the scores from the Amiel Tison scale, focus on five key items including active tone in the flexor and extensor tone in the neck, passive tone in the axial body, non-nutritive sucking, visual fixing and tracking, and active tone in the body axis, have been identified as predictive for the following 2 years.

ASQ -3

ASQ-3 is a parent-administered tool designed for preliminary screening of children aged 2 to 66 months. This tool is beneficial in that this can be used for longer periods of screening, there by helping to monitor the developmental progress from the early stages of life up to 6 years.[18]

It evaluates children across 30 components in five major domains, including personal–social, gross motor, fine motor, problem-solving, and communication at a series of 21 intervals providing insights into age-matched developmental progress at various intervals.[18]

ASQ-3 demonstrates strong psychometric properties with sensitivity ranging between 0.70 to 0.90, specificity range between 0.76 to 0.91, and 0.92 test–retest reliability[18]

Children failing in two areas were flagged for further clinical attention. Though this method lacks sensitivity, it is followed because of its specificity and clinical feasibility.[18]

CDC developmental milestone checklist

The CDC developmental milestone checklist, developed in collaboration with the American Academy of Pediatrics, encompasses 24 items tailored for various age groups from 2 to 60 months. It encompasses four developmental domains: motor, cognitive, social–emotional, and language-communication.[19]

CDC was initially developed in 2004 and updated in 2019 based on the 75^th percentile age of milestone achievement gathered from the data of children visiting well-baby clinics and a literature search.[20]

The CDC tool requires no specific training and can be administered by parents. Scoring is uncomplicated, categorizing children who reach age-appropriate milestones as “pass” and those exhibiting delays in any expected component as “fail,” prompting referral to pediatric clinics.[19]

However, there have been widespread debates regarding the perceived lowering of standards and the exclusion of crawling from the milestone list in the updated version of the CDC.[20] A study conducted in Israel demonstrated that children reached milestones earlier than anticipated in CDC, suggesting the necessity for evidence-based analysis of milestone norms across different regions to enhance individualized developmental surveillance.[21]

DDST II

The DDST II is a screening tool renowned for its predictive value in identifying minor and major motor abnormalities in children, encompassing both term and preterm infants. It comprises 104 components across four domains: gross motor, fine motor, language, and personal/social skills, tailored for children aged 1 month to 6 years.[22]

The DDST offers a user-friendly training package and a comprehensive assessment tool to ensure assessment reliability, enabling long-term clinical tracking of psychomotor development disorders in children.[23]

Children failing to meet the 75–90 percentiles of a component are labeled as “caution” necessitating follow-up, whereas those scoring below 90 are classified as “delayed.” One delay or two cautions in a child may indicate potential abnormal development, whereas more than two delays are suggestive of abnormalities requiring early intervention, aiding in clinical decision- making.[23]

HINE

The HINE neurological examination is commonly used from 3 to 12 months following the HNNE assessment.

The comprehensive scale comprises 37 items divided into three sections namely neurological examination (26 items), milestone (8 items), and behavioral state (3 items). However, scoring only considers the neurological examination section, with each item scored from 0 to 3. A total score of 78 is possible, with scores below specific thresholds at different ages indicating a higher risk of CP.[24]

Scores less than 57, 60, 63, and 66 during the corrected gestation age of 3 months, 6 months, 9 months, and 12 months indicate that the child is at higher risk of CP, whereas a score below 40 at any age group is a predictor of CP.[25]

The well-defined criteria for early CP prediction enhance the clinical value of HINE, particularly in monitoring high-risk infants.

A study was conducted with preterm infants with co-morbidities such as plagiocephaly and hydrocephalus, with the goal of determining the 3-month findings of HINE with a 2-year developmental outcome, and they discovered that 17 children had cerebral palsy and 21 children had developmental disabilities. The poor predictivity advised that, if utilized, HINE should be examined in tandem with General Movement Assessment to improve predictability.[26]

HNNE

The HNNE evaluation can be conducted from term/term equivalent age up to 3 months corrected-gestation age. It consists of 34 items assessing various aspects of neurobehavior and takes about 15 min to complete.[27]

Scoring ranges from 0 to 34, with scores below 30 indicating suboptimal neurobehavior. The scoring system shows acceptable inter-rater reliability with ICC > 0.7 in categorizing scores as optimal or suboptimal. Though the specificity is questionable, HNNE demonstrates good sensitivity with MRI findings.[27]

INFANIB

INFANIB is a specialized scale for monitoring preterm infant development, also applicable to high-risk infants in intensive care units secondary to meningitis, heart failure, etc.[28]

It aids in clinical decision-making by categorizing infants as having normal or abnormal neurodevelopment, influencing post-intensive care follow-up decisions.[28]

The evaluation assesses infants by thoroughly analyzing neurodevelopmental indicators such as muscle tone, French angle, and primitive reflexes in various fundamental positions such as supine, prone, standing, sitting, and on suspension.[28]

The classification system divides children into abnormal, transitory, and normal categories, with specific cut-off scores designated for different age groups. For example, infants under 4 months are considered abnormal if they score below 48, whereas infants over 8 months are abnormal if they score below 68.

Although the assessment tool demonstrates good sensitivity, it lacks the ability to predict future neurodevelopment outcomes, necessitating multiple evaluations to confirm neurodevelopment status.[29]

NSMDA

The NSMDA scale is applicable for children aged 1 month to 6 years, encompassing 6 domains: gross motor, fine motor, neurological status, infant movement patterns, posture, and balance, as well as sensory-motor function.[30]

The advantage of this scale is that it categorizes the level of motor dysfunction rather than binary categorization of normal and abnormal. Functional grade scores of the scale can be categorized as normal motor function (scores between 6 to 8), minimal motor problem (scores between 9 to 11), mild motor problem (scores between 12 to 13), moderate motor problem (scores between 14 to 19), severe motor dysfunction (scores between 20 to 25), and profound motor dysfunction (scores greater than 25) offering a broader spectrum for clinical decision-making and treatment planning.[31]

These scores have shown reliability and validity in predicting motor impairment, even in children without cerebral palsy, indicating its efficacy in identifying developmental delays. Notably, scores at 8 months, 2 years, and 4 years correlate significantly with motor scores at 13 years.[32]

TDSC

TDSC, a tool comprising 27 items designed by MKC Nair at the Center for Child Development, Government Medical College, Thiruvanandapuram, is intended for children aged between 0 and 6 years. It exhibits an acceptable reliability and was formulated by incorporating 17 selected test items from the BSID, facilitating easy administration at the community level for developmental screening.[33]

The TDSC has shown favorable sensitivity and specificity (66.7% and 78.85%, respectively) compared to DDST II in both clinical and community settings, establishing its feasibility for screening across different sectors.[34]

In contrast to DDST II, TDSC was developed to be user-friendly for individuals at any level within the community. Its interpretation is straightforward, where any unattained skill falling below a horizontal line on the sheet indicates a developmental delay.[33,34]

Although the TDSC is culturally adapted for Indian populations and demonstrates sound psychometric properties in detecting delays, it is not suitable for assessing developmental age or diagnosing developmental delays.[33]

Psychometrics of identified tools in assessing preterm infants

After conducting the component analysis, the studies focusing on the evaluation of the psychometric properties of these tools, particularly in relation to preterm infants, were taken into account. The psychometric properties of each tool, along with the quantity of studies that have examined each individual psychometric property, are depicted in Table 2.

Table 2.

Psychometric properties of neurodevelopmental tools

Name of the Scale	Inter-rater reliability	Intra- rater reliability	Content validity	Concurrent Validity	Predictive Validity	Sensitivity	Specificity
AIMS	(3) ◆	-	-	(5) ◆	(2) ◆	(1) ◆	(1) ◆
ANAT	(1) ◆	-	-	-	-	(1) ◆	(1) ◆
ASQ-3	(1) ◆	-	-	-	-	(3) ◆	(3) ◆
CDC	-	-	-	-	-	(1) ◆	(1) ◆
DDST II	(1) ◆	-	-	-	-	(1) ◆	(1) ◆
HINE	-	-	-	-	-	(2) ◆	(2) ◆
HNNE	(1) ◆	-	-	-	-	(4) ◆	(4) ◆
INFANIB	-	-	-	-	-	(2) ◆	(2) ◆
NSMDA	-	-	-	-	-	-	-
TDSC	-	-	-	-	-	-	-

Alberta Infant Motor Scale (AIMS), Amiel Tison Neurological Evaluation at Term (ANAT), Ages and Stages Questionnaire – 3 (ASQ – 3), Centre for Disease Control (CDC) Developmental Checklist, Denver Developmental Screening Test (DDST) II, Hammersmith Infant Neurological Examination (HINE), Hammersmith Neonatal Neurological Examination (HNNE), Infant Neurological International Battery (INFANIB). The number in parentheses indicates the number of studies, and the diamond signifies the presence of the component in the article

Supplementary File 4 ^{(201.6KB, pdf)} delineates the psychometric properties of the tools used for assessing preterm infants.

DISCUSSION

This study is distinctive as it is the initial research to analyze and classify the existing neurodevelopmental tools based on specific domains in each quarter of an infant’s life, considering characteristics, evaluation time points, proctors, and charting components of each scale. Our findings align with previous studies but uniquely map these components across specific age quarters, providing a comprehensive reference guide for clinicians. By including all neurodevelopmental tools, regardless of their primary use, the study ensures a holistic approach that can accommodate various clinical needs, from initial screening to detailed developmental assessments.

From the results [Supplementary File 4 ^{(201.6KB, pdf)} ], it can be inferred that scales such as NSMDA, CDC developmental checklist, and TDSC have been widely used in research and in practice by HCP to monitor preterm infant growth. These tools have not been tested for their psychometrics in the field of preterm infants, questioning their validity and reliability in assessing infants born preterm.

The study did not identify any scale that had all types of psychometrics established. The scales identified in the study have not been found to be established for content validity. Scales including HINE, AIMS, ASQ-3, and HNNE have been tested for multiple psychometrics, giving a base to be recommended for evaluating high-risk infants. Excluding ASQ 3, the other tools require training to be administered limiting the use of tools across various sectors. ASQ has been tested for reliability, sensitivity, and specificity but not against its validity in preterm infants. Although ASQ 3 is a parent-administered tool, when they are being translated to regional languages, it is identified that the tool requires the assistance of HCP to complete the scoring, again limiting the actual purpose and sensitivity of the tool.[12] Most tools lack comprehensive psychometric evaluations specific to preterm populations, particularly in the context of India, raising concerns about their validity and sensitivity.

Practical implementations

The aforementioned instruments can be broadly categorized into two types based on their utilization. One form consists of chart types with percentile ranges, whereas the other form comprises month-specific checklists. Each type of scale presents its own set of advantages. For example, checklist tools such as ASQ 3 pay attention to intricate details within every interval, without considering the achievement of milestones at previous ages. A child must be followed from the initial point to comprehend the developmental trajectory effectively.

Conversely, charting tools, such as DDST II, aid in grasping the developmental trajectory and age-appropriate accomplishments at any given period. Screening tools such as HINE necessitate scoring by specialists, but they provide information on the normal development of specific milestones for each period in a concise manner. For instance, HINE, when evaluating sitting, delineates the normal type of sitting for each month, facilitating comprehension of the developmental process and assisting in clinical decision-making.

Although DDST II and TDSC are adaptations of BSID tailored for Indian culture, it is important to note that the outcomes of both assessments differ significantly, with the former being more sensitive and the latter being more specific. Neither test can serve as a diagnostic tool. TDSC surpasses DDST II in terms of reproducibility, time efficiency, and simplicity for utilization by community workers.[34]

DASII, a tool specific to India derived from BSID, has shown inconsistency in presenting the cutoff for developmental delay, making it challenging to interpret the results. Future studies should focus on validating the existing cutoff points to enhance the research applicability of the scale.[55]

Among the scales considered, the CDC checklist and ASQ can be administered by parents, with the former being easier to score, and potentially more suitable for parents as it eliminates the need for complex calculations. Research is needed to evaluate the practicality and effectiveness of both scales among parents.

The study’s limitations include the review’s restriction to accessible scales, limiting the insights that could have been gained from other prominent scales such as BSID. However, many scales reviewed were developed based on BSID III, indicating that essential components of BSID were incorporated. The repetition of domains and components among the reviewed scales suggests a common pattern followed by most developmental assessment tools, which may be applicable to tools not covered in this review. Nonetheless, future research should consider including other tools to validate this hypothesis.

The tools reviewed in this analysis consist of a developmental checklist that adopts a vertical approach. It is crucial to recognize that development is a continuous process, necessitating the creation of a tool that not only functions as a checklist but also as a guide for overseeing the process. For example, the tool should examine the progression from the hands to the midline to hands crossing midline, which facilitates rollover, instead of solely concentrating on components specific to certain months. This method enables parents or clinicians to identify soft signs earlier, allowing for prompt screening and intervention.

The absence of standardized terminology and varying cutoff ranges in tools for the same components underscores the requirement for a tool with culturally specific components, cutoff values, and universally accepted terminology to simplify administration.[15]

The establishment of psychometric properties of specified instruments within preterm populations is of paramount importance. The delineated elements throughout various stages of infancy can serve as a practical point of reference for healthcare providers in India. The lack of availability of these instruments poses a substantial obstacle in the assessment of children’s health, hence these elements could aid in the creation of a comprehensive tool that necessitates minimal training and expenses, appropriate for the implementation in countries with lower to middle-income levels such as India. The analysis underscores the pressing necessity for screening tools that are both affordable and accessible to enhance the early neurodevelopmental outcomes of preterm infants in India.

The outcomes derived from this analysis can offer guidance to healthcare practitioners in India, furnishing them with a structured approach for conducting neurodevelopmental evaluations on preterm infants. This can improve the prompt identification of developmental delays and facilitate timely interventions, which are critical for enhancing long-term results. The design of economical and accessible instruments customized to the Indian setting can help alleviate the financial challenges encountered by numerous healthcare facilities within the nation.

CONCLUSION

This investigation has provided an in-depth analysis of tools and components utilized in each tool across all domains based on corrected gestational age. Tools designated for the 0–3 months period emphasize primitive reflexes and neurological evaluations, as they form the basis for later developed voluntary movements. Social communication and interaction are among the noticeable indicators for identifying neurobehavioral disorders. The study offers clinical recommendations regarding the application of specific components for age-appropriate skills, streamlining the clinician’s decision-making process by enabling them to focus on indicators rather than the entire scale, which could be time-consuming. Nevertheless, this serves as a guiding framework and not diagnostic criteria.

Author contributions

V K: Conceptualization, data curation, formal analysis, screening, final proof validation, project administration, approval of final version

M M: Data curation, formal analysis, final proof validation. Project administration, approval of final version

A J R: Framing search strategy, screening, charting of data, drafting manuscript, review and editing, approval of final version

S S: Framing search strategy, screening, charting of data, drafting manuscript, approval of final version

B C: Methodology, supervision, visualization, review and editing, approval of final version

S S: Supervision, methodology, visualization, review and editing, proof correction, approval of final version

P M: Supervision, methodological guidance, review and editing, proof correction, approval of final version

M B M: Framing search strategy, screening, charting of data, drafting manuscript, review and editing, approval of final version

D R: Charting of data, writing original draft, review and editing, approval of final version

S S: Extraction of data, writing original draft, review and editing, approval of final version.

Conflicts of interest

There are no conflicts of interest.

Supplementary File 2

Components split across domains and infant life quarters

Supplementary File 4

Psychometric properties of neurodevelopmental assessment tools for preterm infants from 0 month of corrected gestational age to 1 year of age

Funding Statement

Part of Indian Council Medical Research funded study (IIRP-2023- 7817/F1).