Over 40% of children who had speech errors at age 4 still had them at age 7, according to the Early Language in Victoria Study (Morgan et al., Journal of Pediatrics 2017). Persistence is concentrated rather than random: children whose errors were disordered rather than delayed were twice as likely to have poor speech at 7, and 3.6% of UK 8-year-olds still met criteria for a persistent speech sound disorder (Wren et al., JSLHR 2016). Treatment is also delivered in short blocks: most UK therapists in one survey offered phonological intervention once a week for 9-12 sessions in total (Hegarty et al., IJLCD 2018). This roundup looks at the speech sound side of early communication problems. We aggregated data from the National Institute on Deafness and Other Communication Disorders (NIDCD), the CDC’s National Center for Health Statistics, the American Speech-Language-Hearing Association (ASHA), the U.S. Department of Education, population cohorts in Australia, the UK and the US, Cochrane, and recent trials and meta-analyses published through 2026.
TL;DR
- 8 to 9% of young children have a speech sound disorder, and roughly 5% still have noticeable speech disorders by first grade (NIDCD Quick Statistics 2025).
- 3.4% of 4-year-olds met criteria for SSD in an Australian community cohort of 1,494 children (Eadie et al., Dev Med Child Neurol 2015).
- 3.6% of 8-year-olds had persistent SSD (95% CI 3.1 to 4.0) in the UK ALSPAC cohort (Wren et al., JSLHR 2016).
- Over 40% of children with errors at 4 still had errors at 7 (Morgan et al., Journal of Pediatrics 2017).
- 55% of 4-year-olds with SSD had phonological delay, 10% suspected atypical speech motor control (Ttofari Eecen et al., Dev Med Child Neurol 2019).
- 69% of UK therapists deliver phonological intervention once a week, for 9-12 sessions in total (Hegarty et al., IJLCD 2018).
- 76.5% of children aged 3 to 6 improved at least one functional level after 20 hours or more of therapy (Jacoby et al., AJSLP 2002).
- Ultrasound visual biofeedback shows a pooled d2 of 1.32 across 16 studies (Yiu et al., IJLCD 2026).
- 89% of school SLPs treat speech sound disorders, with 20 such students per caseload on average (ASHA 2024 Schools Survey).
- 22.1% of children with SSD developed a reading disability by ages 7-9, versus 5.4% of controls (Peterson et al., JSLHR 2009).
- 66.7% of children with SSD plus a language impairment developed a reading disability, versus 10.3% without one (Peterson et al., JSLHR 2009).
1. Prevalence by Age: A Number That Shrinks With Every Birthday
The headline figure depends on the age you sample and the cut-off you apply. The NIDCD’s 8 to 9% prevalence in young children comes from broad screening definitions, while population cohorts with stricter case definitions land between 3.4% and 3.8%. Both are correct for what they measure, and the gap between them is the space where most “watch and wait” decisions are made.
What does not change across studies is the age gradient. Parent-reported voice, speech or language disorders in the 2012 National Health Interview Survey fall by more than half between ages 3-6 and ages 11-17, and each of the follow-up cohorts in section 2 finds fewer children meeting criteria at its later checkpoint. ASHA’s practice portal frames the span bluntly: estimates for 4- to 6-year-olds range from 2.1% to 23%, and 1% to 2% of young adults still show residual or persistent speech errors (ASHA Practice Portal, Speech Sound Disorders: Articulation and Phonology).
| Metric | Value | Source |
|---|---|---|
| Prevalence of speech sound disorders in young children | 8 to 9% | NIDCD Quick Statistics on Voice, Speech, Language 2025 |
| Children with noticeable speech disorders by first grade | Roughly 5% | NIDCD Quick Statistics on Voice, Speech, Language 2025 |
| Children 3-17 with a speech disorder lasting a week or longer in the past 12 months | 5.0% | CDC NCHS Data Brief No. 205 (2012 NHIS) |
| Any voice, speech or language disorder, ages 3-6 / 7-10 / 11-17 | 10.8% / 8.8% / 4.3% | NIDCD Quick Statistics 2025 (2012 NHIS) |
| SSD at age 4, Australian community cohort (n = 1,494) | 3.4% | Eadie et al., Dev Med Child Neurol 2015 |
| Speech delay at age 6, US Midwest sample (n = 1,328); boys vs girls | 3.8%; 4.5% vs 3.1% | Shriberg, Tomblin and McSweeny, JSLHR 1999 |
| Persistent SSD at age 8, UK ALSPAC cohort (n = 7,385) | 3.6% (95% CI [3.1, 4.0]) | Wren et al., JSLHR 2016 |
| Young adults with residual or persistent speech errors | 1% to 2% | ASHA Practice Portal (citing Flipsen 2015) |
Boys outnumber girls in every cohort here. In the ALSPAC cohort, persistent SSD affected 4.6% of boys and 2.5% of girls, a 1.8:1 ratio (Wren et al., JSLHR 2016), and ASHA cites a ratio of about 2:1 in grade-school children. School-identified rates run lower still: a four-stage identification process across 10,425 Australian primary students found 1.06% with a speech sound disorder (McKinnon et al., LSHSS 2007). Most recent available data for the US age gradient: NIDCD Quick Statistics, updated July 2025 but built on the 2012 NHIS.
2. Spontaneous Resolution and Persistence: Error Type Beats Severity
The resolution data argue for triage, not blanket waiting. In the Early Language in Victoria Study, over 40% of children with speech errors at age 4 still had errors at age 7, and speech symptomatology, meaning the kind of errors a child made, was the only significant predictor of outcome (P = .02) (Morgan et al., Journal of Pediatrics 2017). Children with delayed (developmentally typical but late) errors were more likely to resolve; children with disordered errors were twice as likely to have poor speech outcomes at 7.
The UK picture is similar. In an English longitudinal cohort, 56% of children who met SSD criteria at 3 and a half still met them at 5 (33 of 59 retested), and the ALSPAC predictors of persistence at 8 included early functional signs, such as being hard for strangers to understand at 38 months, alongside hearing history and suspected coordination problems. Children in the “suspected atypical speech motor control” group overlap with the motor-planning profile covered in our childhood apraxia of speech statistics.
| Metric | Value | Source |
|---|---|---|
| Children with speech errors at 4 who still had errors at 7 (ELVS, n = 1,494 assessed at 4) | Over 40% | Morgan et al., Journal of Pediatrics 2017 |
| Poor speech outcome at 7, disordered vs delayed errors at 4 | Twice as likely | Morgan et al., Journal of Pediatrics 2017 |
| Children with SSD at 3 and a half still meeting SSD criteria at 5 (33 of 59) | 56% | Hayiou-Thomas et al., J Child Psychol Psychiatry 2017 |
| Subtypes at age 4 (n = 126): phonological delay / consistent atypical / inconsistent / suspected atypical motor control / articulation only | 55% / 20% / 15% / 10% / 0% | Ttofari Eecen et al., Dev Med Child Neurol 2019 |
| Odds of persistent SSD at 8 if sometimes or rarely intelligible to others at 38 months | OR 2.38 [1.66, 3.40] | Wren et al., JSLHR 2016 |
| Odds if a parent reports difficulty pronouncing certain sounds at school age | OR 5.59 [3.94, 7.94] | Wren et al., JSLHR 2016 |
| Odds after tympanostomy tube insertion up to age 8 | OR 2.18 [1.30, 3.64] | Wren et al., JSLHR 2016 |
| Age boundary for normalization of significant speech delay (10 children followed for 7 years) | About 8.5 years | Shriberg, Gruber and Kwiatkowski, JSHR 1994 |
Context note: the Victorian subtype data come from 126 children identified within a community sample of 1,607 (Ttofari Eecen et al., Dev Med Child Neurol 2019). The 8.5-year normalization boundary is from a very small, older longitudinal sample and should be read as a clinical landmark rather than a population rate.
3. Treatment Dosage and Duration: Short Blocks, Few Hard Numbers
Dosage is the least standardized part of phonological care. A survey of 166 UK speech and language therapists found that 69% delivered intervention once per week, typically for a total of 9-12 sessions, with a range of five to 30 sessions; 41.4% ran sessions lasting 21-30 minutes and 59.4% elicited targets 10-30 times in single words per session (Hegarty et al., IJLCD 2018). Thirty production attempts in a session is a low number next to the up to 250 structured trials per session used in recent research protocols.
The outcome data that do exist point the same way: total exposure matters. In a sample of 126 US kindergarten to second-grade children, the total number of therapy sessions received in a year positively predicted gains in percentage of consonants correct, while the number of individual (one-to-one) sessions was negatively associated with gain (Farquharson, Tambyraja and Justice, LSHSS 2020). In a randomized trial of 54 preschoolers, the same 24 sessions of multiple oppositions therapy worked better when delivered three times a week for 8 weeks than once a week for 24 weeks (Allen, JSLHR 2013).
| Metric | Value | Source |
|---|---|---|
| UK therapists delivering phonological intervention once per week (n = 166) | 69% | Hegarty et al., IJLCD 2018 |
| Typical total number of sessions per block (range) | 9-12 (5 to 30) | Hegarty et al., IJLCD 2018 |
| Children aged 3-6 improving at least one functional communication level after 20+ hours of therapy (n = 234) | 76.5% | Jacoby et al., AJSLP 2002 |
| Children improving two levels / more than two levels | 38.5% / 18.5% | Jacoby et al., AJSLP 2002 |
| Length of a treatment cycle in the cycles approach | 5 to 16 weeks | ASHA Practice Portal, Speech Sound Disorders |
| Therapy duration flagged as a potential factor in good outcomes | Longer than 8 weeks | Law, Garrett and Nye, JSLHR 2004 |
| Residual /r/ error trial: treatment sessions and average weeks to complete | 19 sessions; 8.8 weeks | Preston et al., JSLHR 2026 |
| Average structured practice trials per child across that trial (biofeedback vs motor-based) | 4,528.3 vs 4,560.0 | Preston et al., JSLHR 2026 |
Context note: the review literature on intensity is thin. A systematic review screened 580 articles and found 7 that met inclusion criteria, only one of them phase III research; it concluded that higher treatment intensity was favourable over lower intensity for childhood apraxia of speech and speech sound disorders (Kaipa and Peterson, Int J Speech Lang Pathol 2016). The 76.5% figure is from a single hospital sample and predates current outcome registries (most recent available data: Jacoby et al. 2002).
4. Treatment Approaches and Effect Sizes: Moderate Average, Wide Spread
The pooled evidence says therapy works for phonology, with an effect that is real but moderate on average. The Cochrane review by Law, Garrett and Nye found SMD=0.44 (95%CI: 0.01,0.86) for children with phonological difficulties, no difference between group and individual delivery, and much weaker evidence for receptive language (Cochrane Database of Systematic Reviews 2003). That review dates from 2003, so treat it as the most recent available Cochrane estimate rather than a current one.
Newer trials are narrowing in on specific techniques rather than “therapy versus no therapy”. A 2026 meta-analysis of ultrasound visual biofeedback (Yiu et al., IJLCD 2026) pooled 16 studies at d2 = 1.32, but with I2 = 97.0% heterogeneity and signs of publication bias, so the average hides results ranging from -0.26 to 4.78. A randomized trial of 108 children aged 9-15 with residual /r/ errors found that biofeedback produced more generalization to untreated words than motor-based treatment, although the groups were not significantly different at post-treatment (p = .28) (Preston et al., JSLHR 2026).
| Metric | Value | Source |
|---|---|---|
| Effect of therapy on phonological outcomes (25 studies in the meta-analysis) | SMD=0.44 (95%CI: 0.01,0.86) | Law, Garrett and Nye, Cochrane 2003 |
| Group vs individual intervention | SMD=0.01 (95%CI: -0.26,1.17) | Law, Garrett and Nye, Cochrane 2003 |
| Intervention effect on phonological awareness (22 group-design studies, ages 3-18) | g = 0.710, 95% CI [0.504, 0.917] | Laasonen et al., IJLCD 2026 |
| Ultrasound visual biofeedback, pooled accuracy effect (16 studies, 192 participants in the review) | d2 = 1.32, 95% CI [0.54, 2.10] | Yiu et al., IJLCD 2026 |
| Median accuracy on untreated /r/ words, pre to post: biofeedback vs motor-based | 5.97 to 49.2 vs 9.16 to 42.86 | Preston et al., JSLHR 2026 |
| Early-treatment acoustic progress, biofeedback vs motor-based alone | 2.4 times faster | McAllister et al. primary outcome, as reported in Preston et al., JSLHR 2026 |
| Preschoolers making functional gains in speech intelligibility | 77% | ASHA NOMS Pre-K Registry 2022, via ASHA Value of School-Based SLP Services for Preschoolers 2024 |
| Improvement in consonant production after SLP-directed services | 13%-16% | ASHA Value of School-Based SLP Services for Preschoolers 2024 |
Context note: usual community care can look weak in trials. In a Bristol randomized trial of 159 preschool children, the difference in phonology error rate was -4.4 (95% CI -12.0 to 3.3; P=0.26), and 70% of all children still had substantial speech and language deficits after 12 months (Glogowska et al., BMJ 2000). A systematic review of preschool interventions included 26 studies and found the evidence concentrated in seven of 11 intervention subcategories (Wren et al., IJLCD 2018). ASHA’s 2024 summary also reports that preschoolers with SSD generalize gains to 4 untargeted consonants and that intensive treatment yields 3 times more improvement in consonant production than no treatment (ASHA, The Value of School-Based Speech-Language Pathology Services for Preschoolers 2024).
5. Who Gets Treated: School Caseloads and Public Services
Speech sound disorders are the constant on school caseloads even as the mix around them changes. 89% of full-time school-based SLPs treated students with speech sound disorders in 2024, a share that has stayed between 89% and 94% since 2006, while the average number of SSD students per caseload drifted from 23 to 20 and autism caseloads more than doubled from 6 to 14 (ASHA Schools Survey Report: SLP Caseload and Workload Characteristics Trends 2004-2024). For staffing levels and caseload sizes overall, see our SLP workforce and caseload statistics.
Access is uneven by age and group. Among U.S. children with any voice, speech or language disorder, 59.7% received intervention services in the past year, with 64.3% of White, 51.7% of Hispanic and 49.9% of Black children served (NIDCD Quick Statistics 2025). Teenagers are the least likely to be in services, which matters because the residual errors described in section 1 are exactly what persists into those years.
| Metric | Value | Source |
|---|---|---|
| School SLPs treating students with speech sound disorders, 2024 (2008 peak) | 89% (94%) | ASHA 2024 Schools Survey, Caseload and Workload Trends |
| Average SSD students per school SLP caseload, 2024 vs 2006 | 20 vs 23 | ASHA 2024 Schools Survey, Caseload and Workload Trends |
| Average autism spectrum disorder students per caseload, 2024 vs 2006 | 14 vs 6 | ASHA 2024 Schools Survey, Caseload and Workload Trends |
| Children ages 3 through 5 served under IDEA Part B, fall 2023 | 888,485 | U.S. Department of Education, 47th Annual Report to Congress on IDEA 2025 |
| Share of those children with speech or language impairment | 31.7% | U.S. Department of Education, 47th Annual Report to Congress on IDEA 2025 |
| Students ages 5 through 21 served under IDEA with speech or language impairment (share of resident population) | 17.9% (1.8%) | U.S. Department of Education, 47th Annual Report to Congress on IDEA 2025 |
| Children with speech problems who received a speech intervention service | 67.6% | CDC NCHS Data Brief No. 205 (2012 NHIS) |
| Intervention receipt for any communication disorder, ages 3-6 / 7-10 / 11-17 | 59.8% / 61.3% / 42.6% | CDC NCHS Data Brief No. 205 (2012 NHIS) |
Context note: IDEA’s “speech or language impairment” category combines speech and language and is the next most common category after developmental delay for ages 3 through 5 (U.S. Department of Education, 47th Annual Report to Congress on IDEA 2025). Most recent available data on intervention receipt by age: CDC NCHS Data Brief No. 205, June 2015, using the 2012 NHIS.
6. Literacy and Co-occurring Conditions: The Risk Travels With Language
The reading risk attached to a speech sound disorder is real but conditional. 66.7% of children with SSD plus a language impairment developed a reading disability by ages 7-9, compared with 10.3% of children with SSD alone, and 5.4% of controls (Peterson et al., JSLHR 2009). In other words, an isolated speech sound problem roughly doubles the control rate (10.3% against 5.4%), while a co-occurring language impairment pushes it to more than twelve times that rate (66.7 divided by 5.4 is 12.4).
That pattern holds in the newest synthesis. A 2025 meta-analysis of 290 effect sizes found that children with speech sound difficulties trail peers on language (Hedges’ g = -0.60) and reading (Hedges’ g = -0.58), and that longitudinal studies show “persistent or increasing group differences over time” (Walquist-Sørli et al., JSLHR 2025). Co-occurrence with fluency problems is a smaller but recurring overlap, explored further in our stuttering demographics statistics.
| Metric | Value | Source |
|---|---|---|
| 4-year-olds with SSD who also had a language disorder | 40.8% | Eadie et al., Dev Med Child Neurol 2015 |
| 4-year-olds with SSD who had poor pre-literacy skills | 20.8% | Eadie et al., Dev Med Child Neurol 2015 |
| Children with SSD (identified at 5-6) who developed a reading disability by 7-9, vs controls | 22.1% vs 5.4% | Peterson et al., JSLHR 2009 |
| Reading disability: SSD with language impairment vs SSD without | 66.7% vs 10.3% | Peterson et al., JSLHR 2009 |
| School-age children in SSD therapy with word-decoding deficits (n = 120, K-2) | Just over 25% | Tambyraja, Farquharson and Justice, JSLHR 2020 |
| Concurrent gap vs controls: language / reading | g = -0.60 / g = -0.58 | Walquist-Sørli et al., JSLHR 2025 |
| Longitudinal gap vs controls: language / reading | g = -0.85 / g = -0.50 | Walquist-Sørli et al., JSLHR 2025 |
| Children with SSD who also stutter | Approximately 8% | ASHA Practice Portal (citing Unicomb et al. 2020) |
Context note: risk tends to stick within a school year. Children in school-based SSD therapy who were at reading risk at the start of the year were likely to still be at risk at the end of it (Tambyraja, Farquharson and Justice, JSLHR 2020). In the UK cohort described in section 2, the SSD group’s word reading at age 8 sat at z = -0.80 (Hayiou-Thomas et al., J Child Psychol Psychiatry 2017). Long-term follow-up remains sparse: a 2026 systematic review screened 3,697 papers and found only 15 unique studies of long-term speech outcomes in moderate-to-severe childhood SSD (Garrett, Tukel and Morgan, IJLCD 2026).
Summary: Pediatric Phonological Disorder by the Numbers
| Metric | Value | Source |
|---|---|---|
| Speech sound disorder prevalence in young children | 8 to 9% | NIDCD Quick Statistics 2025 |
| SSD at age 4 (Australian cohort, n = 1,494) | 3.4% | Eadie et al. 2015 |
| Persistent SSD at age 8 (UK, n = 7,385) | 3.6% | Wren et al. 2016 |
| Young adults with residual speech errors | 1% to 2% | ASHA Practice Portal |
| Errors at 4 still present at 7 | Over 40% | Morgan et al. 2017 |
| Disordered vs delayed errors, poor outcome at 7 | Twice as likely | Morgan et al. 2017 |
| SSD at 3 and a half still present at 5 | 56% | Hayiou-Thomas et al. 2017 |
| Phonological delay share of SSD at age 4 | 55% | Ttofari Eecen et al. 2019 |
| UK therapists offering intervention once a week | 69% | Hegarty et al. 2018 |
| Typical total sessions per block | 9-12 | Hegarty et al. 2018 |
| Improved one or more functional levels after 20+ hours | 76.5% | Jacoby et al. 2002 |
| Therapy effect on phonology | SMD=0.44 | Law, Garrett and Nye, Cochrane 2003 |
| Ultrasound biofeedback pooled effect | d2 = 1.32 | Yiu et al. 2026 |
| Preschoolers with functional gains in speech intelligibility | 77% | ASHA NOMS Pre-K Registry 2022 |
| School SLPs treating SSD, 2024 | 89% | ASHA 2024 Schools Survey |
| Ages 3-5 under IDEA Part B with speech or language impairment | 31.7% | U.S. Department of Education 2025 |
| Children with speech problems receiving a speech intervention | 67.6% | CDC NCHS Data Brief 205 |
| Reading disability, SSD plus language impairment vs SSD alone | 66.7% vs 10.3% | Peterson et al. 2009 |
| Children in school SSD therapy with word-decoding deficits | Just over 25% | Tambyraja et al. 2020 |
| Longitudinal language gap vs peers | g = -0.85 | Walquist-Sørli et al. 2025 |
Methodology and Sources
- NIDCD, Quick Statistics About Voice, Speech, Language (last updated July 2025; builds on the 2012 NHIS and earlier prevalence studies)
- CDC NCHS Data Brief No. 205, Communication Disorders and Use of Intervention Services Among Children Aged 3-17 Years (2015, 2012 NHIS data)
- ASHA Practice Portal, Speech Sound Disorders: Articulation and Phonology
- ASHA Schools Survey Report: SLP Caseload and Workload Characteristics Trends 2004-2024 (August 2024)
- ASHA, The Value of School-Based Speech-Language Pathology Services for Preschoolers (updated August 2024; NOMS Pre-K Registry 2022)
- U.S. Department of Education, 47th Annual Report to Congress on the Implementation of IDEA (2025, fall 2023 data)
- Eadie et al., Speech sound disorder at 4 years, Dev Med Child Neurol 2015
- Morgan et al., Who to Refer for Speech Therapy at 4 Years of Age Versus Who to Watch and Wait, Journal of Pediatrics 2017
- Ttofari Eecen et al., Validation of Dodd’s Model for Differential Diagnosis, Dev Med Child Neurol 2019
- Wren et al., Prevalence and Predictors of Persistent Speech Sound Disorder at Eight Years Old, JSLHR 2016
- Shriberg, Tomblin and McSweeny, Prevalence of speech delay in 6-year-old children, JSLHR 1999
- Shriberg, Gruber and Kwiatkowski, Developmental phonological disorders III, JSHR 1994
- McKinnon et al., Prevalence of stuttering, voice, and speech-sound disorders in primary school students in Australia, LSHSS 2007
- Hayiou-Thomas et al., When does speech sound disorder matter for literacy?, J Child Psychol Psychiatry 2017
- Hegarty et al., Intervention for children with phonological impairment: knowledge, practices and intervention intensity in the UK, IJLCD 2018
- Jacoby et al., The Number of Individual Treatment Units Necessary to Facilitate Functional Communication Improvements, AJSLP 2002
- Allen, Intervention efficacy and intensity for children with speech sound disorder, JSLHR 2013
- Farquharson, Tambyraja and Justice, Contributions to Gain in Speech Sound Production Accuracy, LSHSS 2020
- Kaipa and Peterson, A systematic review of treatment intensity in speech disorders, Int J Speech Lang Pathol 2016
- Law, Garrett and Nye, The efficacy of treatment for children with developmental speech and language delay/disorder, JSLHR 2004
- Law, Garrett and Nye, Speech and language therapy interventions for children with primary speech and language delay or disorder, Cochrane 2003
- Laasonen et al., Intervention Effects on Phonological Processing, IJLCD 2026
- Yiu et al., The Effectiveness of Ultrasound Visual Biofeedback in Articulation Therapy, IJLCD 2026
- Preston et al., Rhotic Generalization Is More Rapid in Biofeedback Than Motor-Based Treatment, JSLHR 2026
- Glogowska et al., Randomised controlled trial of community based speech and language therapy in preschool children, BMJ 2000
- Wren et al., A systematic review and classification of interventions for speech-sound disorder in preschool children, IJLCD 2018
- Peterson et al., What influences literacy outcome in children with speech sound disorder?, JSLHR 2009
- Tambyraja, Farquharson and Justice, Reading Risk in Children With Speech Sound Disorder, JSLHR 2020
- Walquist-Sørli et al., Are Speech Sound Difficulties Risk Factors for Difficulties in Language and Reading Skills?, JSLHR 2025
- Garrett, Tukel and Morgan, Long-Term Speech Outcomes in Moderate-to-Severe Childhood Speech Sound Disorder, IJLCD 2026
- NCES Condition of Education, Students With Disabilities (updated May 2024, 2022-23 data)
- Data watch: prevalence estimates conflict because definitions differ. The NIDCD’s 8 to 9% for young children rests on broad screening studies (Shriberg 1999; Law et al. 2000), the NHIS 5.0% is parent-reported, and the Australian 3.4% at age 4 uses a standard score of 79 or below, so none of these should be subtracted from one another to estimate a resolution rate. IDEA’s speech or language impairment category mixes speech and language: the 47th Annual Report gives 17.9% for ages 5 through 21 in fall 2023, while NCES reports 19% of all students ages 3-21 served under IDEA in 2022-23 (NCES Condition of Education, Students With Disabilities, updated May 2024), a different denominator and year. Several anchors are old: the Cochrane review (2003), the Jacoby dosage study (2002), the NHIS-based age and access figures (2012 data) and the Shriberg normalization study (1994) are the most recent available data for those measures. The ASHA 2024 Schools Survey response rate was 25.6%, down from 69.7% in 2004. Newer data expected: ASHA’s 2026 Schools Survey reports, the 48th IDEA Annual Report to Congress, and further outcome papers from the C-RESULTS residual /r/ trial.
Last updated: October 18, 2026. We update this roundup quarterly, and the next refresh is expected when ASHA publishes its 2026 Schools Survey reports.