The Denver Developmental Screening Test (DDST) is a widely used assessment for examining the developmental progress of children from birth until the age of 6, devised in 1969. The DDST was originally designed at the University of Colorado Medical Center, Denver, USA.
There were concerns raised from that time about specific items in the test and, coupled with changing normal values, it was decided that a major revision of the test was necessary in 1992 (the DENVER II).
Developmental delay occurs in up to 15% of children under 5 years of age. This includes delays in speech and language development, motor development, social-emotional development and cognitive development.
Parents are usually the first to pick up signs of possible developmental delay, and any concerns parents have about their child's development should always be taken seriously. However, the absence of parental concern does not necessarily mean that all is well.
The main purpose of developmental assessment depends on the age of the child:
- Tests may detect neurological problems such as cerebral palsy in the neonate.
- Tests may reassure parents or detect problems in early infancy.
- Testing in late childhood can help detect academic and social problems early enough to minimise possible negative consequences (although parental concern may be just as good a predictor for some problems).
The move to targeted examinations at ages 2 and 3.5 years, rather than routine, has raised concerns that some conditions (eg, pervasive developmental disorder) may be missed. No developmental screening tool can allow for the dynamic nature of child development. A child's performance on one particular day is influenced by many factors. Development is not a linear process - it is characterised by spurts, plateaux and, sometimes regressions.
Screening has gradually been replaced by the concept of developmental surveillance. This is a much broader concept. It involves parents, allows for context and should be a flexible, continuous process.
The DENVER II Developmental Screening Test
The test consists of up to 125 items, divided into four parts:
- Social/personal: aspects of socialisation inside and outside the home - eg, smiling.
- Fine motor function: eye/hand co-ordination, and manipulation of small objects - eg, grasping and drawing.
- Language: production of sounds, and ability to recognise, understand and use language - eg, ability to combine words
- Gross motor functions: motor control, sitting, walking, jumping, and other movements
Ages covered by the tests range from 2 months to 71 months.
What differentiates the DENVER II from other screening tests?
- It enables the tester to compare a child's development with that of over 2,000 children who were in the standardised population, like a growth curve.
- It consists of items in which a sub-sample (race, less educated parents, gender and place of residence), which varied a clinically significant amount from the composite sample, are identified and their norms provided in the DENVER II Technical Manual.
- It provides a broad variety of standardised items to give a quick overview of the child's development.
- It also contains a behaviour rating scale.
- The test is primarily based upon an examiner's actual observation rather than parental report.
- No special training is required.
- The test takes approximately 20 minutes to administer and interpret.
- There may be some variation in time taken, depending on both the age and co-operation of the child.
- Interviews can be performed by almost anyone who works with children and medical professionals.
- The items are recorded through direct observations of the child plus, for some points, the mother reports whether the child is capable of performing a given task.
- Younger infants can sit on their mother's lap.
- The test should be given slowly.
Interpretation of the test
- The data are presented as age norms, similar to a growth curve.
- Draw a vertical line at the child's chronological age on the charts; if the infant was premature, subtract the months premature from chronological age.
- The more items a child fails to perform (passed by 90% of his/her peers), the more likely the child manifests a significant developmental deviation that warrants further evaluation
Concerns should prompt referral to a general or developmental paediatrician:
- Most paediatricians would prefer to see children early rather than late.
- If development appears normal then reassuring anxious parents is always rewarding. On the other hand, if there is developmental delay, intervention at the earliest possible time can make a significant difference to outcome.
Sensitivity rates are reported as between 56-83% for the DENVER II, but specificity may be as low as 43%, rising to 80%. There is a danger of unnecessary referral.
However, children over-referred (false positives) because of developmental screens may perform lower on measures of intelligence, language, and academic achievement than other children. These children may therefore also benefit from interventions such as intensive, supported nursery places.
Further reading & references
- Child Health Surveillance and Screening: A Critical Review of the Evidence; Australian Government National Health and Medical Research Council, 2002
- Glascoe FP; Parents' evaluation of developmental status: how well do parents' concerns identify children with behavioral and emotional problems? Clin Pediatr (Phila). 2003 Mar;42(2):133-8.
- Tebruegge M, Nandini V, Ritchie J; Does routine child health surveillance contribute to the early detection of children with pervasive developmental disorders? An epidemiological study in Kent, U.K. BMC Pediatr. 2004 Mar 3;4:4.
- Oberklaid F, Efron D; Developmental delay--identification and management. Aust Fam Physician. 2005 Sep;34(9):739-42.
- Bellman M, Byrne O, Sege R; Developmental assessment of children. BMJ. 2013 Jan 15;346:e8687. doi: 10.1136/bmj.e8687.
- Screening Tools - Denver II; Developmental Screening Toolkit for Primary Care Providers
- Glascoe FP; Are overreferrals on developmental screening tests really a problem? Arch Pediatr Adolesc Med. 2001 Jan;155(1):54-9.
Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. EMIS has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.
Dr Hayley Willacy
Dr Colin Tidy
Dr Adrian Bonsall