Speech Therapists Express Concern over CDC’s Updated Childhood Development Guidelines

Speech therapists, including ASHA and the INFORMED SLP, express concern over the American Academy of Pediatrics (AAP) and (Center for Disease Control) CDC speech language milestones changes. The new guidelines mean the average age at which children are expected to perform specific tasks, such as initiating conversation or saying their first words, will be delayed by a few months. Initially, the CDC suggested a 24-month-old would have mastered an average of 50 words. However, the new guidelines say these skills should be expected to emerge sometime between 30 and 48 months.

ASHA and the INFORMED SLP Views Regarding the CDC Speech Language Milestones Changes:

These are some notable changes made by AAP/CDC in the developmental milestones about which ASHA members have expressed concerns, including the following:

• The criteria established by the AAP working group and the milestones added for the 15- and 30-month health supervision visits resulted in a 26.4% reduction and 40.9% replacement of previous CDC milestones.
• One-third of the retained milestones were transferred to different ages; 67.7% of those transferred were moved to older ages.
• Approximately 80% of the final milestones had normative data from ≥1 source.
• Social-emotional and cognitive milestones had the least normative data.
• These criteria and revised checklists can support developmental surveillance, not the clinical decisions during developmental screening and assessment.
• Gaps in developmental data were identified, particularly for social-emotional and cognitive milestones.

ASHA also cited some recommendations regarding the CDC speech language milestones changes. Meanwhile, the INFORMED SLP won’t disagree that the CDC’s old milestone lists needed some updates. Here are some of the changes that they liked:

• Added 15- and 30- month checklists to align with children’s well-child visits
• The reduced overall number of milestones to decrease information overwhelm and redundancy
• An adjusted language of milestones to be more parent-friendly by eliminating vague terms and making items easily observable in daily life
• Fleshed out the social-emotional milestones to help with the early identification of autism

Where things got dicey:

One of the CDC’s changes was to adjust milestones to represent what most children are doing by a certain age. They were trying to eliminate “warning signs” from their lists, and instead, any missed milestone would cause concern. They can get behind this logic because it should provide more precise guidance on when to act in these cases. The theory is not about lowering developmental expectations but rather listing them at the 25th percentile instead of at the 50th.

Because many children fall between the 5th and 25th percentiles, the INFORMED SLP looked into Zubler et al.’s methods for determining these milestones to see how they came up with their conclusions. Thankfully, they described their methods and provided a table listing all the sources considered when deciding on each milestone, so it is clear where this information comes from. 

Here are the two things we take issue with: 

• The sources they cite don’t back up their milestones.

They looked at all sources they refer to for the “50 words by 30 months” milestone, and they found that none of those sources backed up this number. Not only that but some of their studies are dated or limited. For example, there was a 40-child longitudinal study with white children in 1998.

• SLPs were not included as subject matter experts.

The milestones were derived by the consensus of a group of “subject matter experts.” The group consisted of developmental-behavioral, neurodevelopmental, general pediatricians, child and developmental psychologists, and a special education professor. The INFORMED SLP also gives their last comment about CDC speech-language milestones changes here.