Systematic Evidence Review
Heidi D. Nelson, M.D., M.P.H.a,b,d; Peggy Nygren, M.A.a,d;
Miranda Walker, B.A.a,d; Rita Panoscha, M.D.a,c,d
The authors of this article are responsible for its contents,
including any clinical or treatment recommendations. No statement in this article
should be construed as an official position of the Agency for Healthcare Research
and Quality or the U.S. Department
of Health and Human Services.
Address correspondence to: Heidi D. Nelson, M.D., M.P.H., Oregon Health & Science University, Mail Code BICC 504, 3181 SW Sam Jackson Park Road, Portland, Oregon 97239
This article first appeared in Pediatrics. Select for copyright, source, and reprint information.
Contents
Abstract
Background
Methods
Results
Conclusions
Acknowledgments
References
Notes
Abstract
Background. Speech and language development is a useful
indicator of a child's overall development and cognitive ability and is related
to school success. Identification of
children at risk for developmental delay or related problems may lead to
intervention services and family assistance at a young age, when the chances
for improvement are best. However, optimal
methods for screening for speech and language delay have not been identified,
and screening is inconsistently practiced in primary care.
Purpose. We sought to evaluate the strengths and limits
of evidence about the effectiveness of screening and interventions for speech
and language delay in preschool-aged children to determine the balance of
benefits and adverse effects of routine screening in primary care for the
development of guidelines by the U.S. Preventive Services Task Force. The
target population includes all children up to 5 years old without previously
known conditions associated with speech and language delay, such as hearing and
neurologic impairments.
Methods. Studies were identified from MEDLINE®,
PsycINFO, and CINAHL databases (1966 to November 19, 2004), systematic reviews, reference lists, and experts. The evidence review
included only English-language, published articles that are available through
libraries. Only randomized, controlled trials were considered for examining the
effectiveness of interventions. Outcome measures were considered if they were
obtained at any time or age after screening and/or intervention as long as the
initial assessment occurred while the child was < 5 years old.
Outcomes included speech and language measures and other functional and health
outcomes such as social behavior. A total of 745 full-text articles met our
eligibility criteria and were reviewed. Data were extracted from each included
study, summarized descriptively, and rated for quality by using criteria
specific to different study designs developed by the U.S. Preventive Services
Task Force.
Results. The use of risk factors for
selective screening has not been evaluated, and a list of specific risk factors
to guide primary care physicians has not been developed or tested. Sixteen
studies about potential risk factors for speech and language delay in children
enrolled heterogeneous populations, had dissimilar inclusion and exclusion
criteria, and measured different risk factors and outcomes. The most consistently reported risk factors
included a family history of speech and language delay, male gender, and
perinatal factors. Other risk factors reported less consistently included
educational levels of the mother and father, childhood illnesses, birth order,
and family size.
The
performance characteristics of evaluation techniques that take < 10 minutes
to administer were described in 24 studies relevant to screening. Studies that
were rated good-to-fair quality reported wide ranges of sensitivity and
specificity when compared with reference (sensitivity 17%-100%; specificity 45%-100%).
Most of the evaluations, however, were not designed for screening purposes, the
instruments measured different domains, and the study populations and setting
were often outside of primary care. No "gold standard" has been developed and
tested for screening, reference standards varied across studies, few studies
compared the performance of > 2
screening techniques in 1 population, and comparisons of a single screening
technique across different populations are lacking.
Fourteen good- and fair-quality
randomized, controlled trials of interventions reported significantly improved speech
and language outcomes compared with control groups. Improvement was demonstrated in several
domains including articulation, phonology, expressive language, receptive
language, lexical acquisition, and syntax among children in all age groups
studies and across multiple therapeutic settings. Improvement in other functional outcomes such
as socialization skills, self-esteem, and improved play themes were
demonstrated in some, but not all, of the 4 studies that measured them. In
general, studies of interventions were small and heterogeneous, may be subject
to plateau effects, and reported short-term outcomes based on various
instruments and measures.As a result,
long-term outcomes are not known, interventions could not be compared directly,
and generalization is questionable.
Conclusions. Use of risk factors
to guide selective screening is not supported by studies. Several aspects of screening have been inadequately studied
to determine optimal methods, including which instrument to use, the age at
which to screen, and which interval is most useful. Trials
of interventions demonstrate improvement in some outcome measures, but
conclusions and generalizability are limited.
Data are not available addressing the effectiveness
of screening in primary care, role of enhanced surveillance by primary care
physicians before referral for diagnostic evaluation, non-speech and language and long-term benefits
of interventions, and adverse effects of screening and interventions.
Keywords: speech and language delay and disorders, preschool children, screening, interventions.
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Background
Speech and language development is
considered by experts to be a useful indicator of a child's overall development
and cognitive ability1 and is related to school success.2-7 Identification of children at risk for
developmental delay or related problems may lead to intervention services and
family assistance at a young age when chances for improvement are best.1 This
rationale supports preschool screening for speech and language delay, or
primary language impairment/disorder, as a part of routine well-child care.
Several types of speech and language
delay and disorders have been described,8 although terminology varies (Table 1).
Expressive language delay may exist without receptive language delay but often
they occur together in children as a mixed expressive/receptive language delay.
Some children also have disordered language. Language
problems can involve difficulty with grammar (syntax), words or vocabulary
(semantics), the rules and system for speech sound production (phonology),
units of word meaning (morphology) and the use of language particularly in
social contexts (pragmatics). Speech problems may include stuttering or
dysfluency, articulation disorders, or unusual voice quality. Language and
speech problems can exist together or by themselves.
Prevalence
rates for speech and language delay have been reported across wide ranges. A recent Cochrane review summarized
prevalence data on speech delay, language delay, and combined delay in
preschool and school-aged children.9 For preschool-aged children, 2 to 4.5
years old, studies that evaluated combined speech and language delay reported
prevalence rates ranging from 5% to 8%,10,11 and studies of language delay have
reported prevalence rates from 2.3% to 19%.9,12-15
Untreated speech and language delay in preschool children has shown
variable persistence rates (from 0% to 100%), with most studies reporting 40%
to 60%.9 In 1 study, two-thirds of preschool
children who were referred for speech and language therapy and given no direct
intervention proved eligible for therapy 12 months later.16
Preschool-aged
children with speech and language delay may be at increased risk for learning
disabilities once they reach school age.17 They may have difficulty reading in grade
school,2 exhibit poor reading skills at age 7 or 8,3-5 and have difficulty with written language,6 in particular.
This may lead to overall academic underachievement7 and, in some cases, lower IQ scores18 As adults, children with phonological
difficulties may hold lower skilled jobs than their non-language-impaired
siblings.19 In addition to persisting speech- and language-related
underachievement (verbal, reading, spelling), language-delayed children have
also shown more behavior problems and impaired psychosocial adjustment.20,21
Assessing children for speech and
language delay and disorders can involve a number of approaches, although there
is no uniformly accepted screening technique for use in the primary care
setting. Milestones for speech and
language development in young children are generally acknowledged.22 Concerns for delay arise if there are no
verbalizations by the age of 1 year, if speech is not clear, or if speech or
language is different from that of other children of the same age. Parent
questionnaires and parent concern are often used to detect delay.23 Most formal instruments were designed
for diagnostic purposes and have not been widely evaluated for screening. Instruments constructed to assess multiple
developmental components, such as the Ages and Stages Questionnaire,24 Clinical Adaptive Test/Clinical Linguistic and Auditory Milestone Scale,25 and Denver Developmental Screening Test,26 include speech and language
components.Instruments designed for specific
communication domains include the McArthur Communicative Development Inventory,27 Ward Infant Language Screening Test,
Assessment, Acceleration, and Remediation (WILSTAAR),28 Fluharty Preschool Speech and Language
Screening Test,29 Early Language Milestone Scale,30 and several others.
A specific diagnosis is most often made by a speech and language specialist using
a battery of instruments.Once a child
has been diagnosed with a speech and/or language delay, interventions may be
prescribed. Therapy takes place in various settings including speech and
language specialty clinics, home, and schools or classrooms. Direct therapy or group therapy provided by a
clinician, caretaker, or teacher can be child centered and/or include peer and
family components. The duration of the intervention varies. Intervention
strategies focus on 1 or more domains depending on individual needs, such as
expressive language, receptive language, phonology, syntax, and lexical
acquisition. Therapies can include naming objects, modeling and prompting,
individual or group play, discrimination tasks, reading, and conversation.
It is not clear how consistently
clinicians screen for speech and language delay in primary care practice. In 1 study, 43% of parents reported that
their young child (aged 10 to 35 months) did not receive any type of
developmental assessment at their well-child visit, and 30% of parents reported
that their child's physician had not discussed how the child communicates.31 Potential barriers to screening include
lack of time, no clear protocols, and the competing demands of the primary care
visit.
This evidence review focuses on the strengths and
limits of evidence about the effectiveness of screening and interventions for
speech and language delay in preschool age children. Its objective is to determine the balance of
benefits and adverse effects of routine screening in primary care for the
development of guidelines by the U.S. Preventive Services Task Force (USPSTF). The target population includes all children
up to age 5 years without previously known conditions associated with speech
and language delay, such as hearing and neurological impairments. The evidence
synthesis emphasizes the patient's perspective in the choice of tests,
interventions, outcome measures, and potential adverse effects, and focuses on
those that are available and easily interpreted in the context of primary
care.It also considers the
generalizability of efficacy studies performed in controlled or academic
settings and interprets the use of the tests and interventions in
community-based populations seeking primary health care.
Return to Contents
Methods
Analytic Framework and Key Questions
Evidence reviews for the USPSTF follow a
specific methodology32 beginning with the development of an analytic
framework and key questions in collaboration with members of the USPSTF. The analytic framework represents an outline
of the evidence review and includes the patient population, interventions,
outcomes, and adverse effects of the screening process (Figure 1, 17 KB). Corresponding key questions examine a chain of evidence
about the effectiveness, accuracy, and feasibility of screening children age 5
years and younger for speech and language delay in primary care settings (key
questions 1 and 2), adverse effects of screening (key question 3), the role of
enhanced surveillance in primary care (key question 4), effectiveness of
interventions for children identified with delay (key questions 5, 6, and 7),
and adverse effects of interventions (key question 8).
Studies addressing key question 1,
corresponding to the overarching arrow in the analytic framework, would include
all components in the continuum of the screening process, including the
screening evaluation, diagnostic evaluation for children identified with delay
by the screening evaluation, interventions for children diagnosed with delay,
and outcome measures allowing determination of the effectiveness of the overall
screening process.Enhanced surveillance
in primary care relates to the practice of closely observing children who may
have clinical concern for delay but not of the degree warranting a referral
("watchful waiting").Outcome measures
in this review include speech and language specific outcomes as well as
non-speech and language health and functional outcomes such as social behavior,
self-esteem, family function, peer interaction, and school performance. Key questions 5 examines whether speech and
language interventions lead to improved speech and language outcomes. Key question 6 examines whether speech and
language interventions lead to improved non-speech and language outcomes. Key question 7 evaluates the subsequent
effects of improved speech and language, such as improved school performance at
a later age.
Literature Search and Selection
Relevant studies
were identified from multiple searches of MEDLINE®, PsycINFO, and CINAHL
databases (1966 to November 19, 2004). Search terms were determined by investigators
and a research librarian and are described elsewhere.33 Articles were also obtained
from recent systematic reviews,34,35 reference
lists of pertinent studies, reviews, editorials, and Web sites, and by
consulting experts.In addition,
investigators attempted to collect instruments and accompanying manuals,
however, these materials are not generally available and must be purchased,
which limited the evidence review to published articles.
Investigators reviewed all abstracts
identified by the searches and determined eligibility of full-text articles
based on several criteria. Eligible articles had English-language abstracts,
were applicable to U.S. clinical practice, and provided primary
data relevant to key questions. Studies of children with previously diagnosed
conditions known to cause speech and language delay
(e.g., autism, mental retardation, Fragile X, hearing loss, degenerative and
other neurological disorders) were not included because the scope of
this review is screening children without known diagnoses.
Studies of risk factors were included if
they focused on children age 5 years or younger, reported associations between
predictor variables and speech and language outcomes, and were relevant to
selecting candidates for screening.
Otitis media as a risk factor for speech and language delay is a complex
and controversial area and was not included in this review.
Studies of techniques to assess speech and language
were included if they focused on children aged 5 years and younger, could be
applied to a primary care setting, used clearly defined measures, compared the
screening technique to an acceptable reference standard, and reported data
allowing calculation of sensitivity and specificity. Techniques
that take 10 minutes or less to complete that could be administered in a
primary care setting by nonspecialists are most relevant to screening and are
described in this report. Instruments
taking more than 10 minutes and up to 30 minutes or for which administration
time was not reported are described elsewhere.33 In general, if the instrument was administered by primary care
physicians, nurses, research associates, or other nonspecialists for the study,
it was assumed that it could be administered by nonspecialists in a
clinic.For questionable cases, experts
in the field were consulted to help determine appropriateness for primary care.
Studies
of broader developmental screening instruments, such as the Ages and Stages
Questionnaire and Denver Developmental Screening Test, were included if they
provided outcomes related to speech and language delay specifically.
Only RCTs were considered for examining
the effectiveness of interventions. Outcome measures were considered if they
were obtained at any time or age after screening and/or intervention as long as
the initial assessment occurred while the child was aged 5 years or
younger. Outcomes included speech and
language measures as well as other functional and
health outcomes as previously described.
Data Extraction and Synthesis
Investigators reviewed 5,377 abstracts
identified by the searches. A total of
690 full-text articles from searches and an additional 55 non-duplicate
articles from reference lists and experts met eligibility criteria and were
reviewed. Data were extracted from each study,
entered into evidence tables, and summarized by descriptive methods. For some studies of screening instruments, sensitivity and
specificity were calculated by the investigators if adequate data were
presented in the paper. No
statistical analyses were performed because of heterogeneity of studies.
Investigators independently rated the quality of studies using criteria
specific to different study designs developed by the USPSTF (Appendix A).32
The quality of the study does not
necessarily indicate the quality of an instrument or intervention but may
influence interpretation of the results of the study. Select Appendix B for a list of excluded studies of instruments and reasons for exclusion.
Return to Contents
Results
Key Question 1. Does Screening for Speech and Language Delay Result
in Improved Speech and Language as well as Improved Other Non-speech and Language
Outcomes?
No studies directly addressed this question.
Key Question 2. Do Screening Evaluations in the Primary Care Setting
Accurately Identify Children for Diagnostic Evaluation and Interventions?
Key Question 2a. Does Identification of Risk Factors Improve
Screening?
Nine studies conducted in English
speaking populations,36-44 and 7 studies from non-English speaking
populations45-51 met inclusion criteria (Table 2). The
most consistently reported risk factors include a family history of speech and
language delay, male gender, and perinatal risk factors; however, their role in
screening is unclear. A list of specific risk factors to guide primary care
physicians in selective screening has not been developed or tested.
English-language studies include case
control,37,39-41,43 cross sectional,36,38,42 and prospective cohort44
designs. Most studies evaluated risk for language delay with or without
speech delay, and 1 restricted the evaluation to expressive language only.44 Family history was the most consistent
significantly associated risk factor in 5 of 7 studies that examined it.37,39,41-43 Family history was defined as family
members who were late talking or had language disorders, speech problems, or
learning problems. Male gender was a
significant factor in all 3 of the studies examining it.37,39,42 Three37,41,43 of 5 studies reported an association
between lower maternal education level and language delay, while 341-43 of 4 studies evaluating paternal
education level reported a similar relationship. Other associated risk factors that were reported
less consistently included childhood illnesses,36,40 born late in the family birth order,42 family size,39 older parents39 or younger mother43 at birth, and low socioeconomic status
or minority race.40 One study that evaluated history of
asthma found no association with speech and language delay.39
The 7 studies assessing risk in
non-English speaking populations included case-control,47 cross-sectional,45 prospective-cohort,48-51 and concurrent-comparison46 designs. Studies evaluated several types
of delay including vocabulary,46 speech,45 stuttering,47 language,48-51 and learning.49-51 Significant associations were reported
in the 2 studies evaluating family history,45,48 and 1 of 2 studies evaluating male gender.51 Three
of 4 non-English language studies, including a cohort of more than 8,000 children
in Finland,51 reported significant associations with
perinatal risk factors such as prematurity,50,51
birth difficulties,45 low birth weight,50,51 and sucking habits.45 An association with perinatal risk
factors was not found in the 1 English language study that examined low birth
weight.43 Other associated risk factors reported
less consistently include parental education level,49,50 and family factors such as size and
overcrowding.50,51 These studies did not find associations
with mother's stuttering or speaking style or rate,47 mother's age,51 or child temperament.46
Key Questions 2b & 2c. What Are Screening Techniques and How
Do They Differ by Age? What Is the Accuracy of Screening Techniques and How Does It Vary by Age?
A total of 22 articles reporting
performance characteristics of 24 evaluations met inclusion criteria.33 Studies utilized several different
standardized and nonstandardized instruments (Table 3), although many were not designed specifically for screening purposes. Results of instruments were
compared with those of a variety of reference standards and no gold standard
was acknowledged or used across studies, which limited comparisons between
them.
The studies provided limited demographic
details of subjects, and most included predominantly white children with
similar proportions of boys and girls. One study enrolled predominantly black children52
and another, children from rural areas.53 Study sizes ranged from 2554 to 2,59011 subjects. Testing was conducted in general health
clinics, specialty clinics, day care centers, schools, and homes by
pediatricians, nurses, speech and language specialists, psychologists, health
visitors, medical or graduate students, teachers, parents, and research
assistants.Studies are summarized below
by age categories according to the youngest ages included, although many
studies included children in overlapping categories.
Ages 0 to 2 years. Eleven studies
from 10 publications utilized instruments taking 10 minutes or less to
administer for children up to 2 years old including the Early Language
Milestone Scale,30,55 Parent Evaluation of Developmental
Status,56 Denver Developmental Screening Test II
(language component),57 Pediatric Language Acquisition Screening Tool for Early Referral,52 Clinical Linguistic and Auditory Milestone Scale,58 Language Development Survey,59-61 Development Profile II,57 and the Bayley Infant Neurodevelopmental
Screener62 (Table 4). Of these studies, 6 tested expressive and/or
receptive language,30,52,55,57,62 3 expressive vocabulary,59-61 1, expressive language and articulation,56 and 1, syntax and pragmatics.58
For the 10 fair- and good-quality studies that provided data to determine sensitivity and
specificity, sensitivity ranged from 22% to 97% and specificity from 66% to
97%.30,52,56-62 Four studies reported sensitivity and
specificity of 80% or more using the Early Language Milestone Scale,30 the Language Development Survey,59-60 and the Clinical Linguistic and Auditory
Milestone Scale.58 The study of the Clinical Linguistic and Auditory Milestone Scale also determined sensitivity and specificity by age,
and reported higher sensitivity/specificity at age 14 to 24 months (83%/93%)
than 25 to 36 months (68%/89%) for receptive function, but lower sensitivity/specificity
at age 14 to 24 months (50%/91%) than 25 to 36 months (88%/98%) for expressive
function.58A study
testing expressive vocabulary using the Language Development Survey indicated
higher sensitivity/specificity at age 2 years (83%/97%) than at age 3 years
(67%/93%).60
Ages 2 to 3 years. Ten studies in 9 publications used
instruments taking 10 minutes or less to administer for children aged 2 to 3
years including the Parent Language Checklist,11 Structured Screening Test,63 Levett-Muir Language Screening Test,64 Fluharty Preschool Speech and Language
Screening Test,53,65 Screening Kit of Language Development,66 Hackney Early Language Screening Test,54,67 and Early Language Milestone Scale68 (Table 5). All studies tested expressive
and/or receptive language.11,53,54,63-68 In addition, 3 studies tested
articulation53,65 and 1 tested syntax and phonology.64
For the 8 fair and good-quality studies providing data
to determine sensitivity and specificity, sensitivity ranged from 17% to 100%
and specificity from 45% to 100%. Two studies reported sensitivity and
specificity of 80% or better using the Levett-Muir Language Screening Test64 and the Screening Kit of Language Development.66 The study of the Screening Kit of Language Development
reported comparable sensitivity/specificity at ages 30 to 36 months (100%/98%),
37 to 42 months (100%/91%), and 43 to 48 months (100%/93%).66
Ages 3 to 5 years. Three studies used instruments taking 10
minutes or less to administer including the Fluharty Preschool Speech and
Language Screening Test,69 Test for Examining Expressive
Morphology,70 and the Sentence Repetition Screening
Test71 (Table 6). Of these, 2 studies tested
expressive and receptive language and articulation,69,71 and 1 tested expressive vocabulary and
syntax.70 The 2 fair-quality studies reported
sensitivity ranging from 57% to 62% and specificity from 80% to 95%.66,69,71
Systematic review. A
Cochrane systematic review of 45 studies, including most of the studies cited
above, summarized the sensitivity and specificity of instruments taking 30
minutes or less to administer.34 Sensitivity of instruments for normally
developing children ranged from 17% to 100%, and for children from clinical
settings it ranged from 30% to 100%.
Specificity ranged from 43% to 100%, and 14% to 100% respectively. Studies considered to be of higher quality
tended to have higher specificity than sensitivity (t=4.41, P<0.001),
however, high false-positive and false-negative rates were reported often.34
Key Question 2d. What Are the Optimal Ages and Frequency
for Screening?
No studies addressed this question.
Key Question 3. What Are the Adverse Effects
of Screening?
No studies addressed this question.
Potential adverse effects include false-positive and false-negative
results. False-positive results can erroneously label children with normal
speech and language as impaired, potentially leading to anxiety for children
and families and further testing and interventions. False-negative results would miss identifying
children with impairment, potentially leading to progressive speech and
language delay and other long-term effects including communication, social, and
academic problems.In addition, once
delay is identified, children may be unable to access services because of
unavailability or lack of insurance coverage.
Key Question 4. What Is the Role of Enhanced Surveillance by Primary
Care Clinicians?
No studies addressed this question.
Key Question 5. Do Interventions for Speech and Language Delay
Improve Speech and Language Outcomes?
Twenty-five RCTs in 24 publications
met inclusion criteria including 1 rated good,72 13 rated fair,73-85 and 11 rated poor quality (Table 7).77,86-95 Studies were
considered poor quality if they reported important differences between
intervention and comparison groups at baseline, did not use intention-to-treat
analysis, no method of randomization was reported, and there were fewer than 10
subjects in intervention or comparison groups. Limitations of studies, in
general, include small numbers of participants (only 4 studies enrolled more
than 50 subjects), lack of consideration of potential confounders, and
disparate methods of assessment, intervention, and outcome measurement. As a result, conclusions about effectiveness are limited. Although
children in the studies ranged from 18 to 75 months old, most studies included
children age 2 to 4 years old and results do not allow for determination of
optimal ages of intervention.
Studies evaluated the effects of individual or group therapy directed by clinicians
and/or parents that focused on specific speech and language domains. These include expressive and receptive
language, articulation, phonology, lexical acquisition, and syntax. Several
studies used established approaches to therapy, such as the WILSTAAR program96 and the HANEN principles.78,79,85,93
Others used more theoretical approaches, such as focused stimulation,78,79,86,87,93 auditory discrimination,83,90 imitation or modeling
procedures,76,92 auditory processing or work
mapping,85 and play narrative language.80,81 Some interventions focused on specific words
and sounds, used unconventional methods, or targeted a specific deficit.
Outcomes were measured by subjective reports from parents,77,78,80,85 and by scores on standardized
instruments, such as the Reynell Expressive and Receptive Scales,74,77 the Preschool Language Scale,72,75,85 and the MacArthur Communicative
Development Inventories.80,93
The most widely used outcome measure was mean length utterances, used by
6 studies.73,75,77,80,85
Studies rated good or fair quality are
described below by age categories according to the youngest ages included,
although many studies included children in overlapping categories
Ages 0 to 2 years. No studies
examined this age group exclusively, although 1 good-quality study enrolled
children 18 to 42 months old.72 The
clinician-directed, 12-month intervention consisted of 10-minute weekly
sessions focusing on multiple language domains, expressive and receptive
language, and phonology. Treatment for receptive auditory comprehension led to
significant improvement for the intervention group compared with control group,
however, results did not differ between groups for several expressive and
phonology outcomes.72
Ages 2 to 3 years. One good-72 and 6 fair-quality studies77-80,84,85 evaluated speech
and language interventions for children who were 2 to 3 years old. Studies
reported improvement on a variety of communication domains including
clinician-directed treatment for expressive and receptive language,80 parent-directed therapy for expressive delay,77,78 and clinician-directed receptive auditory
comprehension.72 Lexical acquisition was improved with both clinician-directed therapy84,91 and group therapy approaches.84 In 3 studies, there were no between group
differences for clinician-directed expressive72,85 or receptive language therapy,72,85 parent-directed expressive or receptive
therapy,85 or parent-directed phonology treatment.79
Ages 3 to 5 years. Five fair-quality studies reported significant
improvements for children 3 to 5 years old undergoing interventions compared
with controls,73,74,76,81,82 while 2 studies
reported no differences.75,83 Both group-based interventions81 and clinician-directed interventions74 were successful in improving expressive and
receptive competencies.
Systematic review. A Cochrane systematic review included a meta-analysis utilizing data
from 25 RCTs of interventions for speech and language delay for children up to
adolescence.35 Twenty-three of these studies
also met criteria for this review and were included in Table 7,72-92,95 and 2
trials were unpublished. The review reported results in terms of standard mean
differences (SMD) in scores for a number of domains (phonology, syntax, and
vocabulary). Effectiveness was considered significant for both the phonological
(SMD=0.44; 95% CI, 0.01-0.86) and vocabulary (SMD=0.89; 95% CI, 0.21-1.56)
interventions. Less effective was the receptive intervention (SMD=-0.04; 95%
CI, 0.64-0.56), and results were mixed for the expressive syntax intervention
(SMD=1.02; 95% CI, 0.04-2.01). In the
analysis, when interventions were comparable in duration and intensity, there
were no differences between interventions when administered by trained parents
or clinicians for expressive delays. Use of normal-language peers as part of
the intervention strategy also proved beneficial.81
Key Question 6. Do Interventions for Speech and Language Delay
Improve Other Non-Speech and Language Outcomes?
Four good-72 or fair-quality80,81,85 intervention studies included functional
outcomes other than speech and language.
Increased toddler socialization skills,80 improved child self-esteem,85 and improved play themes81 were reported for children in intervention
groups in 3 studies. Improved
parent-related functional outcomes included decreased stress80 and increased positive feelings toward
their children.85 Functional outcomes that were studied
but did not show significant treatment effects included well being, levels of
play and attention, and socialization skills in 1 study.72
Key Question 7. Does Improvement in Speech and Language Outcomes
Lead to Improved Additional Outcomes?
No studies addressed this question.
Key Question 8. What Are the Adverse Effects of Interventions?
No studies addressed this question. Potential
adverse effects of treatment programs include the impact of time and cost of
interventions on clinicians, parents, children, and siblings. Loss of time for
play and family activities, stigmatization, and labeling may also be potential
adverse effects.
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