Developmental-behavioral surveillance and screening in primary care

INTRODUCTION — Developmental and behavioral surveillance is recommended for all children during preventive health care visits. In the United States, periodic developmental-behavioral screening is also recommended. This topic outlines the recommendations for surveillance, screening, and evaluation.

Screening for autism spectrum disorders is discussed separately. (See "Autism spectrum disorder in children and adolescents: Surveillance and screening in primary care" and "Autism spectrum disorder in children and adolescents: Screening tools".)

TERMINOLOGY

●Developmental disabilities – Developmental disabilities (also called developmental disorders) are a heterogeneous group of conditions caused by impairments in learning, language, behavior, or motor skills. Examples include intellectual disabilities, learning disorders, autism spectrum disorder, attention deficit hyperactivity disorder, cerebral palsy, and vision or hearing impairment [1].

●Developmental surveillance – Developmental surveillance is the process through which children who have developmental delay or are at risk for developmental delay are identified [2-4]. Developmental surveillance occurs at preventive care visits and consists of eliciting parental or caregiver concerns, identifying risk and resilience factors, maintaining a developmental history, making direct observations of the child and caregiver-child interactions, documenting findings, and collaborating with other providers and professionals. (See 'Approach to surveillance' below.)

●Developmental screening – Developmental screening refers to the use of a standardized test to identify asymptomatic children who are at risk for a developmental disorder; children who screen positive should undergo a developmental-behavioral evaluation [2]. (See 'Approach to screening' below.)

●Developmental-behavioral evaluation – A developmental-behavioral evaluation is a comprehensive review and assessment of development and behavior to identify a developmental disorder and develop a treatment plan [2,5]. (See 'Positive screen' below.)

EPIDEMIOLOGY — Developmental and behavioral problems are common in children and adolescents. The 2018 Annual Report from the Centers for Disease Control and Prevention estimates that 16.7 percent of children have a developmental disability or a developmental delay [6]. In a nationally representative cross-sectional survey (1997-2016), the caregiver-reported prevalence of intellectual disability, autism spectrum disorder (ASD), and other developmental delays among children age 3 through 17 years ranged between 6 and 15 percent, depending upon how the questions were worded [7-9].

It is estimated that 20 to 25 percent of youth in the United States will meet criteria for a mental health disorder with severe impairment (defined by endorsement of "a lot" or "extreme" impairment in daily activities or "severe or very severe" distress) during their lifetime [10]. Anxiety disorders are most common, followed by behavioral disorders, mood disorders, and substance use disorders. The median age of onset in a national survey of adolescents aged 13 to 18 years varied with the disorder:

●Anxiety – 6 years

●Behavioral disorders (eg, attention deficit hyperactivity disorder [ADHD], oppositional defiant disorder, conduct disorder) – 11 years

●Mood disorders – 13 years

●Substance use disorders – 13 years

The prevalence of developmental disabilities has increased since the 1990s, with most of the increase due to ASD and ADHD [7]. Factors hypothesized to have contributed to the increased prevalence include increased awareness and improved identification, increased survival of children born preterm, increased survival of children born with congenital anomalies and genetic disorders, and increased prenatal risk factors such as older parental age and multiple births. The prevalence of specific conditions is discussed separately. (See "Intellectual disability in children: Evaluation for a cause", section on 'Prevalence' and "Autism spectrum disorder (ASD) in children and adolescents: Terminology, epidemiology, and pathogenesis", section on 'Prevalence' and "Attention deficit hyperactivity disorder in children and adolescents: Epidemiology and pathogenesis", section on 'Prevalence'.)

BENEFITS OF SURVEILLANCE AND SCREENING — The combination of surveillance and screening for developmental-behavioral problems in children increases early identification [11-13], enabling earlier intervention, which is associated with improved outcomes [14-21]. National survey data in the United States suggest that the combination of surveillance and screening is associated with increased receipt of early intervention services compared with surveillance or screening alone (6.4 to 8.4 percent versus 2.7 to 3.6 percent) [22].

The response to developmental-behavioral interventions is greatest in early childhood [23]. Children who are identified after school entry miss the opportunity to participate in early developmental or early childhood services. Children with undetected developmental delays are at increased risk for social and emotional problems, early school problems, and school failure [2].

Early identification permits earlier treatment of underlying medical conditions that may present with developmental-behavioral problems (eg, metabolic disorders). Early identification also permits caregivers to better match their expectations to their child's abilities, to provide developmentally appropriate activities and stimulation, and to feel that they are doing all that they can to assist their child [18,24,25]. In observational studies, developmental surveillance and screening also have been associated with increased numbers of caregivers reporting that their concerns were addressed and questions answered [26].

In before-and-after observational studies and randomized trials, developmental-behavioral surveillance and screening are associated with increased identification of developmental-behavioral concerns, increased referrals to early intervention services, and increased numbers of children qualifying for early intervention services [11-13]. In addition, universal screening may decrease disparities in identification of developmental delays [27].

Systematic reviews, prospective observational studies, and a few randomized trials have demonstrated better short- and long-term outcomes when developmental problems or risk factors associated with developmental problems are identified early and services are provided, particularly for children at increased risk [14-21,28-31]. Early developmental/childhood intervention services for children with developmental disabilities have been associated with decreased need for special education services during the school years, higher graduation rates, reduced teen pregnancy rates, higher employment rates, and a decrease in criminal behavior and violence [19,23]. Several studies have demonstrated benefits of early intervention sustained for 15 to 49 years after the intervention [28,32-34].

PERCEIVED HARMS AND BURDENS OF SURVEILLANCE AND SCREENING — Potential harms anticipated by clinicians in delivering developmental surveillance and screening are related to false positive results, false negative results, and the burden of surveillance and screening.

●False positive results – Potential harms of false positive surveillance or screening include [35-37]:

•Unnecessary developmental evaluation; high numbers of false positive screens may overwhelm evaluation centers with referrals (a limited resource in many settings)

•Undue anxiety or stigma for caregivers

False positive results can be minimized by choosing screening tests that have been validated in the general population and have a specificity of at least 70 percent [38,39]. (See 'Choice of screening test' below.)

●False negative results – False negative results fail to identify or delay identification of children with developmental-behavioral problems, resulting in under-referral or delayed referral to early intervention services.

False negative results can be minimized by choosing screening tests that have been validated in the general population and have a sensitivity of at least 70 percent [38,39]. (See 'Choice of screening test' below.)

●Burden of screening – The process of screening may increase the burden on the pediatric practice (by requiring additional time or documentation). In a pilot project that evaluated the implementation of the 2006 American Academy of Pediatrics recommendations of developmental and behavioral screening, participating practices struggled with completion of screening, making appropriate referrals to early intervention programs and medical specialists, and tracking referrals [40].

Limited time is a commonly reported barrier to screening. In the 2016 American Academy of Pediatrics Periodic Survey, the most frequently reported limitation to developmental screening was time available during a visit, although the percent of respondents reporting available time as a barrier decreased from 80 to 57 percent between 2002 and 2016 [41]. Although some providers view the time that it takes to provide screening as a burden, an observational study found no change in visit duration after implementation of broad-based developmental screening [26].

APPROACH TO SURVEILLANCE — Developmental surveillance is the process through which children who may have a developmental delay or be at risk for a developmental delay are recognized [2,3]. It is performed at every well-child visit and at any time a concern is raised [2,42]. We follow the approach to developmental surveillance recommended by the American Academy of Pediatrics (AAP) [2]:

●Elicit and attend to caregiver concerns – Ask if the caregivers have any concerns about their child's development, behavior, or learning. Observational studies suggest that parental estimates of their child's development are accurate [43]. Caregiver concerns are an effective method for early detection of developmental and behavioral problems, but lack of caregiver concerns does not exclude developmental delay [44-46].

●Maintain a developmental history – Maintain a developmental history to review at subsequent visits. Reviewing the developmental history over time can identify developmental abnormalities or deviations (eg, achievement of skills out of typical sequence, regression of skills) that warrant further investigation (eg, for metabolic disorders, cerebral palsy, autism spectrum disorder).

The developmental history can be obtained by asking, "What changes have you seen in your child's development since our last visit?" and by observing or asking about age-specific skills in the various domains of development (ie, social-emotional, language/communication, cognitive, motor).

The skills in the tables below were compiled by an expert working group convened by the Centers for Disease Control and Prevention [47]. Most (80 percent) are supported by normative data. Among other inclusion criteria, the skills were chosen to be achievable by ≥75 percent of children at ages corresponding to health supervision visits; to be easily observable in the natural setting by caregivers of different social, cultural, and ethnic backgrounds; and to demonstrate progression with age.

•0 to <12 months (table 1A)

•12 to <30 months (table 1B)

•30 months to 5 years (table 1C)

●Observe caregiver-child interactions – Make accurate observations of the child and parent-child interaction (eg, the warmth, caring, and responsiveness of the caregiver to the child's cues, as well as the extent to which the child looks to the caregiver for comfort and support) [48].

●Identify risk and protective factors – Identify a child's risk and protective factors. Children with multiple established risk factors should have more frequent visits for ongoing surveillance or may be referred for a developmental-behavioral evaluation [2,49,50]. (See 'Developmental or behavioral evaluation' below.)

•Risk factors – Risk factors for developmental and behavioral problems include [49,51-55]:

-Prenatal exposures (eg, infections, alcohol, smoking)

-Birth complications (eg, prematurity or low birth weight)

-Perinatal infections (eg, herpes simplex virus, Zika virus [56,57])

-Medical conditions (eg, lead poisoning, congenital heart disease [58,59])

-Genetic conditions (eg, Down syndrome, fragile X syndrome)

-Adverse childhood or family experiences (eg, poverty, including housing or food insecurity; exposure to racism; abuse or neglect) [51-53]

-Parental/caregiver unemployment or mental health problems (eg, depression, anxiety, substance use)

-Parents/caregivers with limited education/literacy [60]

-Teenage parents

•Protective/resilience factors – Factors that protect against developmental and behavioral problems include [20,23]:

-Strong connections within a loving, supportive family

-Active caregiver-child engagement (eg, teaching, soothing, back-and-forth conversation, sharing books, etc)

-Opportunities to interact with other children

-Opportunities to grow in independence in an environment with appropriate structure

●Record findings and plans – Maintain an accurate record of the process and findings of surveillance across visits. This should include specific actions or plans (eg, earlier follow-up, referrals). (See 'Follow-up' below.)

●Collaborate with other providers and professionals – Other professionals (eg, early intervention, daycare providers) who work with the child and caregivers may be able to provide observations or findings that contribute to the identification of developmental delays.

Developmental-behavioral surveillance is supported by multiple professional societies including the Canadian Task Force on Preventive Health Care [4].

APPROACH TO SCREENING — Developmental screening refers to the use of a standardized test to identify asymptomatic children at risk for a developmental disorder; children who screen positive should undergo developmental-behavioral evaluation [2]. Developmental-behavioral evaluation is necessary to diagnose developmental-behavioral disorders. (See 'Positive screen' below.)

Our approach to developmental-behavioral screening is largely consistent with that recommended by the American Academy of Pediatrics (AAP) [2,38,61].

Rationale — The use of standardized screening tests may enhance clinical impressions formed through developmental surveillance. Clinical impressions of development and behavior are less accurate than validated screening tests, and relying on surveillance alone may miss children with developmental-behavioral problems who would benefit from intervention [2,11,35]. In a systematic review of heterogeneous studies of primary care identification of developmental-behavioral problems without validated screening tests, the sensitivity ranged from 14 to 54 percent and specificity ranged from 69 to 100 percent [35].

When to screen

Children <4 years — We provide developmental-behavioral screening with a validated test [2]:

●Any time a caregiver or clinician has concerns about development (eg, not sitting by age 9 months, lack of joint attention by 12 months); the screening test may be targeted to the concern (eg, motor development, attention). (See 'Patient and practice characteristics' below.)

●At specific well-child visits; routine universal and periodic screening may identify problems missed with surveillance alone or screening at a single point in time; repeated screening permits identification of developmental-behavioral problem as they emerge [2,11].

We provide developmental-behavioral screening at the following well-child visits:

•9-month visit – Screening at the 9-month visit may identify motor (table 2), vision, hearing, or communication problems. It also provides an opportunity to educate caregivers about developmental screening and to encourage them to pay attention to language and communication skills [2].

•18-month visit – General developmental screening at the 18-month visit may identify fine and gross motor delays (table 2), language delays, and symptoms of autism spectrum disorders (ASD).

Specific screening for ASD is recommended at the 18-month visit and is discussed separately. (See "Autism spectrum disorder in children and adolescents: Surveillance and screening in primary care", section on 'ASD screening' and "Autism spectrum disorder in children and adolescents: Screening tools".)

•24-month visit – Repeating ASD-specific screening at the 24-month visit facilitates identification of children with ASD who were missed at the 18-month screening.

In addition to ASD-specific screening, we provide general developmental screening at the 24-month visit if the patient/family may have difficulty returning for the 30-month visit.

•30-month visit – Screening at the 30-month visit may identify motor (table 2), language, and cognitive delays.

The benefits of developmental-behavioral screening were demonstrated in a multicenter randomized trial that compared developmental screening using validated screening tests (Ages & Stages Questionnaire-II and Modified Checklist for Autism in Toddlers) with office assistance, validated tools without office assistance, and milestone-based developmental surveillance in 2103 children <30 months of age [11]. Developmental delays were identified in 21 percent of children. Validated screening tests with and without office assistance increased identification of delays (23 and 27 versus 13 percent), referrals to early intervention (20 and 18 versus 10 percent), and qualification for early intervention services (7 and 5 versus 3 percent). Validated screening tools also decreased time to identification and referral. Among children referred to early intervention, there was no difference in the percentage eligible for services, suggesting that use of screening tests did not result in over-referral.

These findings are supported by before-and-after observational studies demonstrating an association between validated screening tests and increased identification of developmental-behavioral concerns, increased referrals to early intervention services, and increased numbers of children qualifying for early intervention services [12,13]. Although these are surrogate outcomes and studies demonstrating improved clinically important outcomes in children who were screened compared with those who were not screened are lacking [4], there appears to be general consensus that early intervention is associated with improved cognitive and social outcomes [23].

Children ≥4 years

●Four-year old visit – Developmental-behavioral screening at the four-year visit should focus on school readiness (social-emotional well-being, caregiver engagement in the child's education, promotion of the five Rs [reading, rhyming, routines, rewards, relationships] and risk factors for developmental problems) and motor skills [62]. Screening at age 4 years provides the opportunity for remediation before kindergarten entry to optimize successful kindergarten participation and peer interaction [61]. (See "School readiness for children in the United States", section on 'Readiness of the child'.)

●Children ≥5 years – We agree with the AAP Task Force on Mental Health recommendation to screen asymptomatic children ≥5 years annually for mental health disorders and impaired psychosocial functioning with a validated behavioral screening test [63].

Additional indications for mental health screening include:

•Psychosocial concerns identified by the caregivers

•Family disruption

•Poor school performance

•Behavioral difficulty

•Recurrent somatic complaints

•Involvement of a social service or juvenile justice agency

Choice of screening test — Screening tests identify patients who warrant further evaluation; they are not reference standards that result in diagnosis.

Screening test performance — Terms that are used to describe screening test performance or quality of measurements include sensitivity, specificity, positive and negative predictive value, likelihood ratios, concurrent validity, and predictive validity (table 3). These terms are discussed separately. (See "Glossary of common biostatistical and epidemiological terms" and "Evaluating diagnostic tests".)

Tests with high sensitivity have few false negative results, minimizing missed or delayed diagnosis; tests with high specificity have few false positive results, minimizing over-referral. Sensitivity and specificity >70 percent is generally acceptable for developmental-behavioral screening tests [38,39], although the threshold may vary with the targeted condition and the consequences of a false negative or false positive result.

Tests with high positive predictive value increase the likelihood that children with positive (or "failed") screening test results have the targeted developmental or behavioral condition. Tests with high negative predictive value increase the likelihood that children with negative (or "passed") screening test results do not have the condition.

Patient and practice characteristics — The choice among validated developmental-behavioral screening tests with acceptable test performance is individualized according to:

●Patient characteristics (eg, age, language spoken at home, literacy level). Screening tests are targeted to the age range in which the disorder emerges and is identifiable (table 4 and table 5).

●The targeted condition (eg, What is the prevalence? What are the consequences of false negative or false positive results?).

•Developmental screening tests – Developmental screening tests target conditions affecting the traditional developmental domains (eg, cognitive, language, motor, social). Some focus on a specific domain; others on general development. Some developmental screening tests also screen for behavioral concerns. Each developmental screening tool has its own threshold level for what is considered a "positive" test or a test that identifies increased risk (table 4 and table 6).

For general developmental-behavioral screening of children without identified concerns at periodic well-child visits, we prefer screening tests that target multiple domains (ie, broadband screens) (table 4).

For children with specific concerns (eg, language delay), we prefer domain-specific screening tests. Screening for language delay and ASD is discussed separately. (See "Expressive language delay ("late talking") in young children", section on 'Screening' and "Autism spectrum disorder in children and adolescents: Surveillance and screening in primary care", section on 'ASD screening'.)

•Behavioral screening tests – Behavioral screening tools target behavioral conditions (eg, attention deficit hyperactivity disorder), social emotional development, and self-help skills (eg, feeding, sleeping, toileting) (table 5).

In young children, challenging behavior or delayed/regressed self-help skills may be the only manifestation of social-emotional distress (eg, related to exposure to toxic stress, insufficient attachment, or innate vulnerability).

Screening tests for alcohol and substance use are discussed separately. (See "Screening tests in children and adolescents", section on 'Nicotine, alcohol, and substance use'.)

●Practice considerations (eg, Who can deliver the test? How long does it take to score and interpret? Can it be integrated into the electronic medical record?) (table 4 and table 5). Emerging evidence supports the acceptability and effectiveness of telephone and web-based developmental surveillance programs [64,65].

●Feasibility of administration (table 7).

When all else is equal, clinicians generally prioritize their choices by how long it takes to administer and score the test and cost. Participation in a quality improvement collaborative may support practice-level changes in discussion of screening results and referral [66].

FOLLOW-UP

Positive screen — When the results of a developmental-behavioral screen are "positive" or concerning, the child should undergo developmental-behavioral and medical evaluations [2]. These evaluations aim to identify developmental disorders or medical conditions that could contribute to delayed developmental or behavioral concerns. In addition, the child should be referred for early intervention/early childhood services.

Developmental or behavioral evaluation — The developmental or behavioral evaluation is a comprehensive review and assessment of a child's development and behavior to diagnose a developmental disorder and develop a treatment plan. The evaluation may include behavioral observations, thorough caregiver report of medical and developmental history, psychological testing, and/or speech and language or motor (occupational therapy/physical therapy) assessments [5].

Developmental or behavioral evaluations can be conducted by a medical specialist such as a pediatric neurologist, developmental-behavioral pediatrician, child psychiatrist, neurodevelopmental pediatrician, or pediatric physiatrist [2,5]. Evaluation by a psychologist, speech and language pathologist, audiologist, social worker, physical therapist, or occupational therapist also may be warranted, depending on the presenting concern and community availability.

●Disorder identified – If a developmental disorder is identified during the developmental or behavioral evaluation ("true positive" screening results), the child should be identified within the office as a child with special health care needs and followed more closely in the medical home [2]. Additional medical evaluation may be necessary. (See "Children and youth with special health care needs" and 'Medical evaluation' below.)

●Disorder not identified – If a developmental disorder is not identified during the developmental or behavioral evaluation ("false positive" screening results), close follow-up, ongoing developmental surveillance, and age-appropriate and concern-based screening should be performed as needed [2].

Children who screen positive but whose developmental-behavioral evaluation does not identify a developmental-behavioral condition may benefit from more frequent follow-up, psychosocial supports, or primary care interventions [67-69]. In a systematic review of 48 studies, several primary care interventions for children younger than three years were associated with reduction in developmental delay (Healthy Steps, Video Interaction Project), improved cognitive or language development (Parenting Intervention, Care For Development, Touchpoints), and improved behavior (Incredible Years, Positive Parenting Program, Parent-Child Interaction Therapy, PriCARE, Video Interaction Project) [68]. A meta-analysis of 13 randomized trials concluded that early childhood development interventions delivered by health care providers in primary care may increase cognitive development; however, effect sizes were small [69].

Medical evaluation — The baseline medical evaluation of a child with a positive developmental screen should include [2]:

●Hearing evaluation (see "Hearing loss in children: Screening and evaluation")

●Vision screen (see "Vision screening and assessment in infants and children")

●Review of the newborn metabolic screen (see "Inborn errors of metabolism: Identifying the specific disorder", section on 'Newborn screening')

●Review of growth parameters, particularly head circumference (see "Normal growth patterns in infants and prepubertal children", section on 'Abnormal patterns of growth')

●Updated family, social, and environmental history looking for risk factors for developmental delays (see 'Approach to surveillance' above)

Additional evaluation may be necessary if the child is identified with a specific disorder. The evaluation depends upon the disorder, as examples:

●Autism spectrum disorder (see "Autism spectrum disorder in children and adolescents: Evaluation and diagnosis", section on 'Evaluation for associated conditions')

●Cerebral palsy (see "Cerebral palsy: Evaluation and diagnosis")

●Intellectual disability (see "Intellectual disability (ID) in children: Clinical features, evaluation, and diagnosis" and "Intellectual disability in children: Evaluation for a cause")

Early intervention or special education services

●Children <3 years – In the United States, children <3 years with suspected or confirmed developmental-behavioral problems should be referred to the state's early childhood intervention program as mandated by the Individuals with Disabilities Education Act (IDEA) Part C (also called "Zero to Three" or "early intervention" [EI]) [70-72].

Referral to EI is appropriate for children who have been identified with a developmental or behavioral problem, as well as those who are at risk (eg, those who have a positive screen but have not yet undergone developmental-behavioral evaluation) [2,70]. Diagnosis of a developmental or behavioral disorder is not necessary for EI referral. EI professionals will evaluate the child to see if they qualify for EI services and what type(s) of services are best.

The contact information for the EI office in each state is provided by Autism Speaks. A caregivers' guide for Early Intervention is available through the Center for Parent Information and Resources.

●Children ≥3 years – If a child is ≥3 years, the local school system can provide an evaluation to determine if the child is eligible for special education services through the public school system [2]. The National Early Childhood Technical Assistance Center provides local contact information. Eligibility requirements for public school special education services vary from state to state.

Parents or caregivers must request the evaluation and consent to evaluation. According to the IDEA, the evaluation must be completed by the school within 60 school days of the parent's signing the consent [71]. The evaluation is followed by an Individualized Education Program (IEP) if the child is eligible; the meeting to develop the IEP must be conducted within 30 days of determining that the child is eligible [70]. Parents and providers should check with local and state laws to determine specific local or regional timelines for school evaluations [70]. (See "Definitions of specific learning disorder and laws pertaining to learning disorders in the United States", section on 'Individuals with Disabilities Education Act'.)

Negative screen — Follow-up for children with negative (or "passed") developmental-behavioral screen is influenced by clinician and/or caregiver concerns.

No concerns — If the screen is negative and neither the clinician nor the caregivers have concerns, the child is unlikely to have a developmental or behavioral problem. The caregivers can be reassured and preventive care, including ongoing developmental surveillance and age-appropriate developmental screening, should continue as scheduled [2].

Clinician or caregiver concerns — If the screen is negative but was performed because of clinician or caregiver concern identified through developmental surveillance, follow-up is individualized according to the type and level of concern; options include one or a combination of the following [2]:

●Referral for developmental or behavioral evaluation

●Referral for early intervention or special education services

●Referral to an early prevention program (eg, Head Start)

●Enhanced surveillance and repeat developmental-behavioral screening before the next well-child visit; more frequent follow-up helps to assure prompt referral to appropriate services or providers if additional concerns arise

RESOURCES — Resources for clinicians and parents/caregivers are provided in the table (table 8).

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Developmental screening".)

SUMMARY AND RECOMMENDATIONS

●Benefits and harms of surveillance and screening – The combination of developmental surveillance and screening for developmental-behavioral problems increases early identification, enabling early intervention, which is associated with improved outcomes. Early identification also permits earlier treatment of underlying medical conditions that present with developmental-behavioral problems. (See 'Benefits of surveillance and screening' above.)

Perceived potential harms of screening include unnecessary referrals for developmental-behavioral evaluation, undue anxiety or stigma for caregivers, missed or delayed diagnosis, and increased burden (eg, time, documentation) for pediatric practices. (See 'Perceived harms and burdens of surveillance and screening' above.)

●Approach to surveillance – Developmental surveillance is the process through which children with developmental delay or who are at risk for developmental delay are identified. It is an essential component of routine well-child care and consists of eliciting and attending to caregiver concerns, maintaining a developmental history (table 1A-C), observing parent-child interactions, identifying risk and protective factors, collaborating with other professionals, and formulating findings and plans. (See 'Approach to surveillance' above.)

●Approach to screening – Developmental-behavioral screening refers to the use of a standardized test to identify asymptomatic children at risk for a developmental disorder; children who screen positive should undergo developmental-behavioral evaluation. Screening enhances clinical impressions formed through developmental surveillance. (See 'Approach to screening' above and 'Rationale' above.)

Our approach to developmental-behavioral screening varies with age and symptoms:

•For children of all ages, we provide developmental-behavioral or mental health screening any time a caregiver or clinician has concerns about development, behavior, or mental health. The screening test may be targeted to the concern (eg, motor development, attention) (table 4 and table 5). (See 'Children <4 years' above and 'Children ≥4 years' above.)

•For children younger than four years who have no symptoms or signs of developmental-behavioral problems, we suggest periodic developmental screening (Grade 2C). We provide general developmental screening with a validated screening test at the 9-month, 18-month, and 24- or 30-month visits and screening for autism spectrum disorder at the 18- and 24-month visits (table 4). Clinical impressions of development and behavior are less accurate than validated screening tests and relying on surveillance alone may miss children with developmental-behavioral problems who would benefit from intervention. (See 'Children <4 years' above and "Autism spectrum disorder in children and adolescents: Surveillance and screening in primary care".)

•At the four-year well-child visit, we focus developmental-behavioral screening on school readiness and motor skills (table 2). (See 'Children ≥4 years' above and "School readiness for children in the United States", section on 'Readiness of the child'.)

•For children ≥5 years who have no symptoms of mental health disorders, we suggest periodic mental health screening (table 5) (Grade 2C). We provide mental health screening annually with a validated behavioral screening test. (See 'Children ≥4 years' above.)

●Follow-up

•Positive screening test – Children who have a positive screening test should undergo developmental-behavioral or mental health evaluation, medical evaluation, and be referred for early intervention or early childhood services. (See 'Positive screen' above.)

•Negative screening test – If the screen is negative and neither the clinician nor the caregiver have concerns, ongoing developmental surveillance and age-appropriate developmental-behavioral surveillance should continue as scheduled. If the screen is negative but was performed because of clinician or caregiver concern, follow-up is individualized according to the type and level of concern. (See 'Negative screen' above.)

ACKNOWLEDGMENT — The UpToDate editorial staff acknowledges Angela LaRosa, MD, and Frances Page Glascoe, PhD, who contributed to an earlier version of this topic review.