The Consensus
The Assessment of Developmental Coordination Disorder
Assessment of DCD has a variety of purposes including identification, diagnosis and planning for intervention. It is recognised that the type of assessment undertaken will influence the intervention process and goals.
DSM-IV-TR criteria
The group agreed to accept DSM-IV-TR (2000) as the most suitable set of diagnostic criteria currently available. However, some concerns regarding the application of the criteria are presented below:
- Criterion A. “Performance in daily activities that require motor coordination is substantially below that expected given the person’s chronological age and measured intelligence. This may be manifested by marked delays in achieving motor milestones (e.g., walking, crawling, sitting), dropping things, “clumsiness”, poor performance in sports, or poor handwriting. ” (DSM-IV-TR, 2000 p. 58).
We recommend the use of an individually administered and culturally appropriate, norm referenced test of general motor competence to apply Criterion A. The cut off point for Criterion A should be applied to performance at or below the 5th percentile. (Observational checklists may be used as an initial screening tool.). It is recognised that the 5th percentile is arbitrary, and can be seen as both too high and too low. For example, if the usual statistics are employed, 2 standard deviations (approximately 2.5%) is the common marker. Conversely, 15% is a figure that is often used and, although we would recommend monitoring children within this figure, it is not practical to use as a defining percentage for the condition. Thus, we would recommend 5% as being both reasonable and part of custom and practice in both clinical and research settings.
- Criterion B. “The disturbance in criterion A significantly interferes with academic achievement or activities of daily living.” (DSM-IV-TR, 2000 p. 58).
We consider that establishing a direct link between poor motor coordination and academic achievement is complex. However, the specific skill of handwriting is usually affected, and is known to adversely affect academic achievement and should therefore be assessed.
Assessment should reflect culturally relevant developmental norms relating to activities of daily living tasks and should include consideration of self-care, play, leisure and schoolwork (including handwriting, PE and tool use) and the views of the child, parents, teachers and relevant others.
- C. “The disturbance is not due to a general medical condition (e.g., cerebral palsy, hemiplegia or muscular dystrophy) and does not meet criteria for a Pervasive Developmental Disorder.”
A conventional neurological examination should be conducted to rule out major neurological conditions (e.g. definite disorders of posture, tone, reflexes)
- D. If mental retardation is present, the motor difficulties are in excess of those usually associated with it.”
Ideally, a measure of IQ should be made to establish the general level of intellectual ability. Where this is not feasible a teacher’s opinion or other relevant data such as national tests are acceptable. As noted above, children with measured or presumed IQ below 70 should not be given a diagnosis of DCD. Differential diagnosis is primarily covered by the application of Criteria C and D above.