The contribution of population studies to
understanding SLCN:
The whole is greater than the sum of its parts
Sheena Reilly
11th May 2015 – Born Talking Seminar - Norwich
Outline
•
Setting the scene about population studies
• Population vs clinical studies: it’s not a competition
• What is the value of population studies?
•
What have we learned?
• Trajectories
• Predictors
• Associations
• The SLI story
• Data from series of longitudinal, population studies
•
Why are we frustrated by some of the findings?
2
Bridget Taylor – Seminar 1 Jan 2015
3
• Birth cohorts
• Community cohorts
• Clinical cohorts or case series
4
5
A population view of language
Population:
5.8 million;
1.2 million children
6
A population view of language
7
Community – Language focused studies
Early language in Victoria Study ELVS
• 6 metropolitan local government areas (LGAs)
• ABS - Socioeconomic Indexes for Areas used to select LGAs
•
Maroondah & Whitehorse (high SES)
•
Banyule & Brimbank (middle SES)
•
Whittlesea & Casey (low SES)
8
Longitudinal Clinical or Case series
• Manchester Language Study – Conti-Ramsden
•
•
The largest UK study of individuals with a history of SLI.
•
A random sample of all 7 year old children who were
attending language units in England in 1995.
Late Talkers Cohort – Rescorla
•
53 mother–child dyads from middle class or upper middle
class white families.
9
Population view of low language
Populations
Clinic presenters
10
11
Receptive and expressive language & non-verbal performance at 4 and 7 years of age.
Help seeking behaviour shown in the 12 months prior
4 years of age
100
81
50
50
81
100
Expressive Language
150
150
4 years of age
50
85
100
Non-verbal IQ
Help sought
150
50
No help sought
85
Help sought
7 years of age
No help sought
100
50
81
Receptive Language
100
81
50
150
7 years of age
150
150
100
Non-verbal IQ
50
85
100
Non-verbal IQ
Help sought
150
50
85
100
Non-verbal IQ
150
No help sought
Help sought
No help sought
12
Receptive and expressive language at 4 and 7 years of age: help seeking behaviour in the 12
months prior
Receptive
Expressive
13
Summary of similarities/differences
Population/community
All children or representative sample of children
with condition
Clinical
Sub-group of children with condition
May be referred or self selected because of
particular traits e.g. higher parent concern
Full range of ability(s)
Likely to be more severe or have co-morbidities
Prospective information available
Retrospective re early development
Typically Longitudinal
Cross sectional or Longitudinal
Inbuilt comparison group
Control group* (recruited if available)
Can extrapolate findings to population
Findings only relevant to clinical cohort
*information about early development of control group often retrospective
14
Bridget Taylor – Seminar 1 Jan 2015
15
Understanding SLCN
• Focus on complex interactions within and between
environmental and biological systems
• Holistic, not reductionist
• Ability to concurrently study speech, language and fluency
noun!
receptive!
grammar
pragmatics
expressive
verb!
Acknowledgments: Jeff Craig
16
Access to populations has permitted study of language and its interconnectedness to:
•
Other aspects of communication
•
Literacy
•
Education
•
Psychosocial development
•
Samples that will be large enough to permit analysis of gene-environment interactions
17
Population health gains
18
Outline
•
•
Setting the scene about population studies
•
Population vs clinical studies: it’s not a competition
•
What is the value of population studies?
What have we learned?
•
Trajectories
•
Associations
•
The SLI story
•
•
Data from series of longitudinal, population studies
Why are we frustrated by some of the findings?
19
Knowledge From Our Longitudinal Studies
•
Typical and disrupted phenotypes (trajectories) of language
development
•
Environmental and biological factors predicting variation
•
Social, psychological and educational development
•
Health care, education, welfare and societal costs
•
Potential for intervention and factors influencing efficacy
20
21
Data collection points
8mth
1
2
3
4
5
6
7
Q
Q
Q
Q
Q
Q
A
A
A
A
Q
T
A
Q
T
A
8
9
Q
10
11
Q
T
A
C
12
13
14
Q
T
C
child
child
child
child & parent
child
Q : parent-report questionnaire
A : face-to-face assessment (child and/or adult)
T: Teacher report
C: child self report
22
ELVS is measuring
•
Language & communication
•
General development & health
•
Family history
•
Socio-demographic details
•
Mental health & family stress factors
•
Parent-child interactions
•
Child behaviour & temperament
23
ELVS Cohort
• N = 1910
• 50.5% male, 49.5% female
• 3.1% (60) premature (<36 weeks)
• 2.8% (53) non-singletons
• 6% (127) speak a language other than English in the
home (~ 50 different languages spoken)
24
Language: Expressive vocabulary at 2 years
n =1742
O
679
234.7
287.7
words
261.3
* MB-CDI: Fenson et al, 1994
(Reilly et al Pediatrics 2007; Reilly et al IJSLP 2009)
Mean
SD
Range
Total
261.3
162
0 - 679
Girls
287.7
159.7
0 - 679
Boys
234.7
160.6
0 - 679
Late talkers* at 2 years
19.7% (n = 333)
261.3
679
O
< 79
Average
words
39
< 119
Average
Words
65
* MB-CDI: Fenson et al, 1994
(Reilly et al Pediatrics 2007; Reilly et al IJSLP 2009)
words
27
2 years
4 years
4 years
Impaired
Impaired
5%
late talkers
19%
14%
typical
impaired
14%
20.6
%
impaired
6%
typical talkers
typical
81%
75%
7 years
typical
6%
impaired
6%
typical talkers
79.4%
2 years
typical
73.4%
7 years
Impaired
4%
late talkers
19%
typical
15%
impaired
6%
typical talkers
typical
81%
75%
28
Five substantive classes
Typical - development in the typical range at each age
Precocious (late) - typical development in infancy followed by high probabilities of
precocity from 24 mths onwards
Impaired (early) – delayed development in infancy followed by typical language
development thereafter
Impaired (late) -Typical development in infancy but delayed
from 24 mths onwards
Precocious (early) - high probabilities of precocity in
early life followed by typical language by 48 mths
Ukoumunne et al 2011
29
Characteristics indicative of social advantage were more commonly found in
the classes with improving profiles.
Okoumunne et al 2012
Characteristics indicative of social advantage were more
commonly found in the classes with improving profiles.
30
And between 4 and 7 years
100
80
60
60
80
100
CELF-4 Expressive Language Score
120
Expressive Language
120
Receptive Language
4
5
6
7
4
Child's age in years
High (32.7%)
Medium (53.1%)
5
6
7
Child's age in years
Low (14.2%)
High (27.1%)
Medium (57.9%)
Mean score and 95% confidence interval presented, groups derived by Latent Class Analysis
Low (15.0%)
Language at 4 and change from 4 to 7
CELF core age 4 (z score)
Change from 4-7 (z score)
Mean
diff
-0.04
95% CI
p
95% CI
(-0.13, 0.04)
0.31
Mean
diff
-0.03
0.19
(0.13, 0.25)
0.00
0.11
(0.04, 0.18) 0.00
16-18 vs. post school -0.06
(-0.25, 0.12)
0.51
-0.16
(-0.38, 0.05) 0.13
Less than 16
0.14
(-0.05, 0.34)
0.14
-0.07
(-0.30, 0.16) 0.54
Young Mum2
-0.24
(-0.46, -0.01) 0.04
0.10
(-0.17, 0.37) 0.46
Disadvantage (1 sd)
Family language
ability (1 sd)
Maternal Education
p
(-0.13, 0.07) 0.61
Non English Speaking -0.84 (-1.09, -0.58) 0.00
0.61
(0.31, 0.91) 0.00
Background
1adjusted for child’s gender, IQ, autism, developmental delay, and birth order
2up to age 24 at child’s birth
32
Individual language & literacy trajectories
for 20 children selected at random
Taylor et al 2014
33
Language and literacy patterns
2,792 CHILDREN
4 years
2474 start middle-high
318 start low
198
188
120
6 years
2286
308 low
2484
196
220
112
8 years
2264
332 low
2460
222
110
10 years
381 finish low
271
2189
2411 finish middle-high
34
34
5 most common language and literacy patterns
from 16 possible patterns for 2792 children
Age 4
Age 6
Age 8
Age 10
Language
Language
Language
Literacy
Middle-High Middle-High Middle-High Middle-High
n
%
1915
69
202
7
Middle-High Middle-High Middle-High
118
4
Middle-High Middle-High Middle-High
Low
Low
Low
Low
Low
Middle-High
27
1
Low
Low
Low
Low
26
1
• Start on-track and stay on-track is the most common pattern
• Start behind and stay behind is the least common pattern
35
Acknowledgements
• Language & Learning Group, Division of Mental Health, Norwegian
Institute of Public Health
•
Synnve Schjolberg, Group Leader
•
Imac Zambrana
•
Eivind Ystrom
•
Norwegian Research Council
•
Norwegian Ministry for Education
•
Dept Psychology, University of Oslo
•
Francisco Pons
36
Trajectories of Language Delay from age 3 to 5
Language Delay at 5 years
Language Delay
at
3 years
Yes
No
Total
Yes
318 (3%)
529 (5%)
847 (8%)
No
688 (6.5%)
9 052 (85.5%)
9 740 (92%)
Total
1 006 (9.5%)
9 581 (90.5%)
10 587 (100%)
Language Delay at 5 years
Language Delay
at
3 years
Yes
No
Total
Yes
318 (3%)
529 (5%)
847 (8%)
No
688 (6.5%)
9 052 (85.5%)
9 740 (92%)
Total
1 006 (9.5%)
9 581 (90.5%)
10 587 (100%)
Persistent; Transient; Late-Onset
37
What about the recovered the late talkers?
Dale et al (2014) Am J Speech-Language Pathology 2014
Longitudinal study of twins from age 2 years
Tracked language development at 4, 7 and 12 years
Resolved late talkers:
No more at risk of later language imp.
than age and gender matched controls
Recommend:
Periodic monitoring of recovered late talkers &
Screening child in low normal range at school
entry for signs of late language difficulties
38
Predictors
39
Predicting Outcomes at 2 & 4 years
2 years:
12 putative risk factors/predictors did NOT strongly
predict outcomes
Variation explained (4.3% & 7.0%) by any 1 risk factor
was small.
4 years:
Variance explained at 4 years was around 20%
Addition of late talking status (2 years) helped explain
23.6% (rec) and 30.4% (exp) language status.
Reilly et al Pediatrics 2007 & 2010
40
Persistent Language Difficulties at 5 years
3% (n=318) of overall sample had persistent language difficulties
38% of children with language delay at 3 years had language
difficulties at both time points
Odds of having a persistent language problem:
•
Doubled - for boys
•
Doubled - family history of late talking
•
Doubled - poor comprehension skills at 18mths
•
Increased – lower paternal education
Eadie et al 2014
41
Transient Language Difficulties at 5 years
5% (n=529) of overall sample had transient language
difficulties between 3 and 5 years
Odds of having a transient problem:
•
Increased - family history of
•
•
late talking or
speech difficulties
•
Increased - poor comprehension skills at 18mths
•
Doubled – lower levels of maternal education
•
Increased – higher birth order
Eadie et al 2014
42
Across international studies

4, 5, & 8 year old findings corroborate that
More than half of the late talkers do not present with
language difficulties at school entry
 Trajectories that broadly represent persistent,
transient and late onset language impairment exist
across languages
 Poor early comprehension skills are a strong &
consistent predictor of persistent problems,
particularly for girls
 Family history of speech, language & literacy
difficulties is important & may be a discriminating
factor regarding language trajectories

Eadie et al 2014
43
Associations
The association between child language
problems and social, emotional &
behavioural difficulties from 4-7 years
A population-based longitudinal study
Associations
In a population-based sample of 4-7 year old children
To examine cross-sectional relationship between Low
Language and SEB Difficulties @ ages 4, 5 and 7
To describe the pathways of LL and SEB Difficulties
over time
Measures of key constructs
Construct
4yo
Language
CELF-P2* CELF-4^
SEB Difficulties SDQ#
5yo
SDQ
7yo
CELF-4
SDQ
*Clinical Evaluation of Language Fundamentals – Preschool Edition (2nd)
^ Clinical Evaluation of Language Fundamentals – 4th Edition – Australian Edition
# Strengths and Difficulties Questionnaire
47
Strengths & Difficulties Questionnaire
SDQ Domain
Hyperactivity/inattention
Conduct problems
Peer problems
Emotional problems
Prosocial behaviour
Total Difficulties
Score
• 25 items
• Parent report
• 3-point scale - not true, somewhat true, certainly true
48
Movement between groups over time
Typical Language & Typical SEB
Only Low Language
Only SEB Difficulty
Low Language & SEB Difficulty
49
4 years of age
n (%)
5 years of age
%
7 years of age
%
610
(79%)
84%
78%
76
(10%)
9%
13%
59
(8%)
5%
6%
26
(3%)
2%
3%
Typical Language
& Typical SEB
Only Low
Language
Only SEB
Difficulty
Low Language
& SEB Difficulty
50
4 years of age
%
5 years of age
%
7 years of age
%
610 (79)
84
78
9
13
5
6
2
3
45%
10
45%
3%
8%
26 (3)
No Low Language
& No SEBD
Low Language
only
SEBD
only
Low Language
& SEBD
51
4 years of age
%
5 years of age
%
7 years of age
%
84
78
9
13
5
6
2
3
568 (93)
79
29 (5)
12 (2)
1 (0)
34 (45)
10
34 (45)
2 (3)
6 (8)
38 (64)
1 (2)
8
19 (32)
1 (2)
5 (19)
8 (31)
3
5 (19)
8 (31)
Typical Language
& Typical SEB
Only Low
Language
Only SEB
Difficulty
Low Language
& SEB Difficulty
52
5 years of age
%
4 years of age
%
7 years of age
%
561 (87)
568 (93)
79
29 (5)
84
12 (2)
50 (8)
6 (1)
1 (0)
21 (29)
34 (45)
10
34 (45)
2 (3)
9
6 (8)
3 (4)
6 (8)
38 (64)
19 (50)
1 (2)
3 (8)
8
19 (32)
1 (2)
8 (31)
42 (58)
5
13
12 (32)
4 (11)
6
2 (13)
5 (19)
3
78
28 (4)
5 (31)
5 (19)
2
8 (31)
Typical Language
& Typical SEB
3 (19)
3
6 (38)
Only Low
Language
Only SEB
Difficulty
Low Language
& SEB Difficulty
53
Summary
• Strong relationship between LL & SEB problems
in children aged 4, 5 & 7 years of age
• LL children experience more SEB difficulties
• Great fluidity & complexity in both language and
SEB development over time
54
The SLI story
55
“LANGUAGE IMPAIRMENT”
(JOHNSON & RAMSTAD)
“HEARING MUTISM”**
FUNCTIONAL (COEN)
“CONGENITAL
WORD
DEAFNESS”
(MCCALL) “DELAYED SPEECH
DEVELOPMENT”
(FROSCHELS)
(MOYER)
FIRST REPORTED BY GALL
(WILDE)
(BENEDIKT)
BROADBENT
UCHERMANN
LAVRAND
WYLLIE
1822 1853 1865 1866 1872 1873
“CONGENITAL
APHASIA”
(VAISSE)
1874 1880 1886 1891 1893 1894 1897 1898 1911
1917
DEVELOPMENTAL
APHASIA
(MORLEY, COURT,
MILLER & GARSIDE)
CLARUS
BASTIN
LIMITATIONS IN
ATTENTION AND MEMORY
HYPOTHESIZED TO PLAY
AN IMPORTANT ROLE
(TREITEL)
DEVELOPMENTAL
APHASIA
(BENTON)
“INFANTILE
APHASIA”
(GESELL &
AMATRUDA)
“DEVIANT
LANGUAGE”
(LEONARD)
”DEVELOPMENTAL
APHASIA”
(INGRAM & REID)
“CONGENITAL AUDITORY
IMPERCEPTION”
(WORSTER-DROUGHT
& ALLEN)
“CONGENITAL VERBAL
AUDITORY AGNOSIA”
(KARLIN)
SLI
(FEY & LEONARD)
“DEVELOPMENTAL
LANGUAGE
IMPAIRMENT”
(WOLFUS,
MOSCOVITVH &
KINSBOURNE)
"INFANTILE SPEECH”
(MENYUK)
1918 1929 1947 1954 1955 1956 1964 1968 1972
”DEVELOPMENTAL
APHASIA”
(E.G.KERR)
WALDENBURG
“DELAYED LANGUAGE”
(P. WEINER)
1974
1975 1980 1981 1983
“DEVELOPMENTAL
LANGUAGE
DISORDER"
(ARAM & NATION)
"DELAYED SPEECH”
(LOVELL,
HOYLE & SIDDALL)
"DEVELOPMENTAL
APHASIA”
(EISENSON)
“SPECIFIC
LANGUAGE
DEFICIT”
(STARK AND TALLAL)
“SPECIFIC
LANGUAGE
IMPAIRMENT”
(E.G.LEONARD)
Introduction of the term ‘specific’ and SLI
Reilly et al 2014
56
“LANGUAGE IMPAIRMENT”
(JOHNSON & RAMSTAD)
“HEARING MUTISM”**
FUNCTIONAL (COEN)
“CONGENITAL
WORD
DEAFNESS”
(MCCALL) “DELAYED SPEECH
DEVELOPMENT”
(FROSCHELS)
(MOYER)
FIRST REPORTED BY GALL
(WILDE)
(BENEDIKT)
BROADBENT
UCHERMANN
LAVRAND
WYLLIE
DEVELOPMENTAL
APHASIA
(MORLEY, COURT,
MILLER & GARSIDE)
“DELAYED LANGUAGE”
(P. WEINER)
DEVELOPMENTAL
APHASIA
(BENTON)
“INFANTILE
APHASIA”
(GESELL &
AMATRUDA)
“DEVIANT
LANGUAGE”
(LEONARD)
“CONGENITAL
APHASIA”
(VAISSE)
”DEVELOPMENTAL
APHASIA”
(E.G.KERR)
WALDENBURG
CLARUS
BASTIN
LIMITATIONS IN
ATTENTION AND MEMORY
HYPOTHESIZED TO PLAY
AN IMPORTANT ROLE
(TREITEL)
“DEVELOPMENTAL
LANGUAGE
IMPAIRMENT”
(WOLFUS,
MOSCOVITVH &
KINSBOURNE)
"INFANTILE SPEECH”
(MENYUK)
1822 1853 1865 1866 1872 1873 1874 1880 1886 1891 1893 1894 1897 1898 1911 1917 1918 1929 1947 1954 1955 1956 1964 1968 1972
“CONGENITAL VERBAL
AUDITORY AGNOSIA”
(KARLIN)
1974
1975 1980 1981 1983
“DEVELOPMENTAL
LANGUAGE
DISORDER"
(ARAM & NATION)
”DEVELOPMENTAL
APHASIA”
(INGRAM & REID)
“CONGENITAL AUDITORY
IMPERCEPTION”
(WORSTER-DROUGHT
& ALLEN)
SLI
(FEY & LEONARD)
"DELAYED SPEECH”
(LOVELL,
HOYLE & SIDDALL)
"DEVELOPMENTAL
APHASIA”
(EISENSON)
“SPECIFIC
LANGUAGE
DEFICIT”
(STARK AND TALLAL)
“SPECIFIC
LANGUAGE
IMPAIRMENT”
(E.G.LEONARD)
Descriptions of clinical cases or series of cases
Case control studies
Observation has driven theoretical approaches
Epidemiology
Medicine, Paediatrics, Speech Pathology, Linguistics, Developmental Psychology
Reilly et al 2014
57
Tomblin and Nippold 2014
Typical Language
SLI
SLI
NSLI
Non-Specific LI
58
50
Expressive Language
81
100
150
Expres
sive lanSLI
gua(expressive)
ge versus non-verbal IQ
Low Language
versus
50
86
20.6%
100
with
Low
non-v
erbal Language
IQ
SpecificLanguageImpairment
Typical development
•DTypical
• Typical
language
Typical
eveloplanguage
mental De+laLow
y NV
typ
ical langu+ag
e- lowNV
non-verbal score
• Low Language + Low NV
• Low Language + Typical NV
59
150
150
1 00
81
50
50
81
100
R ecept ive Lang uage
150
Receptive language versus non-verbal IQ at 4 years
100
Non-verbal IQ
50
100
Non-verbal IQ
15
Specific language lmpairment
Developmental delayed
Normal development
Good language - poor non-verbal IQ
50
81
100
Expressive Language
Normal development
Good language - poor non-verbal IQ
85
Expressive language versus non-verbal IQ
150
150
Expressive language versus non-verbal IQ at 4 years
Specific language impairment
Developmental delayed
50
150
100
85
81
50
50
Receptive Language
Expressive Language
Receptive and Expressive Language standard scoresReceptive
and non-verbal
performance
language versus
non-verbal IQ
4 years
7 years
85
100
Non-verbal IQ
Specific language impairment
Normal development
150
50
85
100
Non-verbal IQ
Specific language lmpairment
Normal development
150
^ Language
& NV
IQ within Good
normal
range;
☐ LowIQNV IQ & Language
range;
Developmental
delayed
language
- poor non-verbal
Developmentalwithin
delayed normal
Good
language - poor non-verbal IQ
X – SLI;  - Low Language and NV IQ
60
•
Two cohorts - Two countries
•
Different language measures
•
Iowa - children with SLI and NSLI continuously distributed across range
of scores
•
The two categories derived from recognised cutpoints are somewhat
arbitrary.
•
Children with SLI only differed in language severity scores - significantly
higher mean language scores than children with NSL
61
Marked social gradient for language outcomes:
Three large scale population studies:
- Millenium Cohort Study (MCS) British Abilities Scale - Naming Vocabulary
at 5 years by Index of Multiple Deprivation quintile
- Growing up in Scotland (GUS) British Abilities Scale – Naming Vocabulary
at 5 years by Index of Multiple Deprivation quintile
- Early Language in Victoria Study (ELVS) Clinical Evaluation of Language
Fundamentals (CELF-P2) Core Language at Five years by SEIFA Quintiles
Law et al 2013; Reilly et al 2013; Reilly et al 2014
62
MCS
GUS
ELVS
63
Are outcomes different depending on classification
Findings from three longitudinal population studies:
- Dollaghan (2004): 3 -4 year olds
- Tomblin et al 2013: 10 and 16 year olds
- Law et al 2009:
34 year olds
64
Dollaghan (2004)
620 participants drawn from a larger study (n=6000) of otitis media
in a socio-demographically diverse population in Pittsburgh, USA.
At 3-4 years Language scores were evenly distributed
- No evidence of an SLI taxon.
- Children with SLI were not a qualitatively distinct group
65
Tomblin et al – Iowa study
Psychosocial outcomes* for 6 year olds (SLI and NSLI) at 10 and 16 years of age
SLI & NSLI significantly greater levels of behaviour problems than typical controls
SLI & NSLI - similar patterns in psychosocial outcomes at both ages.
16 years: children with poor language - less socially skilled regardless of
performance IQ.
Conclusion: poor language skills at school entry confers elevated risk for
psychosocial problems both in the middle and end of the school years.
Risk NOT altered by the child’s performance IQ.
*Achenbach Child Behavior Checklist (CBCL) Teacher Report Form
66
Law et al 2009
Having SLI and N-SLI at 5 years was associated with:
Adult literacy difficulties:
N-SLI group (OR: 4.35); SLI group (OR 1.59)
Adult mental health difficulties:
Low employment:
SLI group (OR 2.24) than for the N-SLI group (OR1.88).
Long term risk of early language difficulties is important
In each case significant predictors of adult outcomes were social factors
67
Outline
•
Setting the scene about population studies
• Population vs clinical studies: it’s not a competition
• What is the value of population studies?
•
What have we learned?
• Trajectories
• Predictors
• Associations
• The SLI story
• Data from series of longitudinal, population studies
•
Summary
•
Why are we frustrated by some of the findings?
68
Summary
• Trajectories
69
Preschool (3 years)
70
Kindergarten (4 years)
71
Primary school (5 years)
72
Primary school (6 years)
73
Primary school (7 years)
74
Set priorities for research into Language Impairment
Development of practical tools:
Risk prediction tools that will zero in on children destined for lasting Language Impairment
75
• Not linear
• The way language develops is complex and can accelerate,
plateau and sometimes go backwards.
• These fluctuating developmental pathways make it hard to
accurately predict persistent Language Impairment
• A strong biological trajectory dominant in the early years;
social disadvantage helps explain more variance in
outcome by 4 years.
• Gap may widen by 4 years - possibly because of
cumulative exposure to less rich language environments
76
Summary
•
Contrasting with fluidity to age 4, language ability across the
child population is better delineated from ages 4 to 7
•
But there is potential for change in the individual child
•
Family language environment was the most salient social risk
factor
77
Clinical and Public Health implications
• Activation and acceleration rates vary
• Surveillance rather than screening approach may be
required
• Language development - vulnerable to further
disruption by social disadvantage in the later
preschool years.
• While sobering, offers a fairly prolonged window of
early childhood during which these impacts could be
genuinely prevented, rather than simply ameliorated.
78
Summary
• Predictors
79
Predictors
•
•
Unlikely to be helpful in screening for language delay in the
earlier years (< 2 years)
More helpful in identifying children with Low Language by 4
years
Recommendation
• Language promotion activities in infants younger than 24
months – targeted and based on the level of communication
skills displayed
80
Summary
• Associations
81
Summary
• Strong relationship between LL & SEB problems
in children aged 4, 5 & 7 years of age
• LL children experience more SEB difficulties
• Great fluidity & complexity in both language and
SEB development over time
82
Summary
• SLI
83
• Remove ‘specific’ and use the term Language
Impairment (LI)
• Abandon the exclusionary criteria*
• Whilst they are convenient for experimental research
they do not reflect the real world where symptoms
and conditions may overlap and co-morbidity may
emerge over time.
• Agree definition and criteria for research and test
these in existing population studies to inform clinical
services and policy
* All of them?
84
Outline
•
Setting the scene about population studies
• Population vs clinical studies: it’s not a competition
• What is the value of population studies?
•
What have we learned?
• Trajectories
• Predictors
• Associations
• The SLI story
• Data from series of longitudinal, population studies
•
Summary
•
Why are we frustrated by some of the findings?
85
New knowledge
•
Access to populations has revealed levels of complexity not
recognisable in case-control designs.
•
More complex than persistent vs resolution
•
Appreciation of continuities and fluctuations with
fluidity -continuing into school years
•
IQ discrepancy not relevant to long term language outcomes
•
Exclusion criteria create convenient ‘research’ groups
•
•
Maybe important for imaging studies
Social gradient strong – language hyper sensitive to disadvantage
86
Fitting policies and services to language
patterns
• The job of fitting policies and services to language
patterns is easier if language patterns are stable and
predictable
• The job of fitting policies and services to language
patterns is NOT easy when language patterns are
unstable and unpredictable
• Based on the patterns we see, we have to ask the
question, “How well do policies and services fit these
language patterns?
Acknowledgement to Cate Taylor CRE conference 2014
87
Fitting population patterns to clinical context
•
Speech pathologists
•
The patterns you observe in children in specialist service systems may not fit the
patterns we see in the general population
•
Your job is to change growth trajectories
•
Unstable growth patterns provide more scope for change than stable growth
patterns (e.g., height)
Acknowledgement to Cate Taylor CRE conference 2014
It’s called curiosity
88
Shifting to personalised and population medicine
• “….. clinicians have a responsibility to the population
they serve, to the patients they never see, as well as to
the patients who have consulted/been referred.
• “….. clinicians, while still focused on the needs of the
individual …… when in the consultation, also make
decisions about the allocation and use of resources to
maximise value for all the people….they serve
• “This is different from management of a service for the
patients who present to the service”.
Gray, A. (2013). The art of medicine: The shift to personalised
and population medicine. The Lancet, 382, 200-2001.
89
‘The new responsibilities for the clinician practicing population
“speech pathology”* not only includes maximising value by
getting the right outcomes for the right patients in the right
place with the least use of resources, but also ensuring the
prevention of inequity related to age or gender or race or social
class’.
‘Population “speech pathology”* is not a new specialty, it is a
new paradigm that I believe every clinician will sooner or later
adopt, with a proportion of clinicians being allocated explicit
time for working for the whole population’.
* Inserted
90
LANGUAGE DEVELOPMENT & DISORDER:
“There are known knowns. These are
things we know that we know. There are
known unknowns. That is to say, there are
things that we know we don't know. But
there are also unknown unknowns. There
are things we don't know we don't know.”
91
Population health gains
92
Acknowledgements
• Centre for Research Excellence in Child Language -
Gold, Goldfeld, Law, McKean, Mensah, Morgan,
Tomblin, Wake,
• Early Language In Victoria Study - Bavin, Bretherton,
Carlin, Eadie, Gold, Prior, Mensah, Okoumunne,
Wake.
• Hearing Language and Literacy group - Cini, Conway,
Pezic
• Cate Taylor
93
Thankyou
Research Snapshots: late talking
www.mcri.edu.au/CREchildlanguage
95
96
97
Population health gains
98
Morbidities of language delay
Social, emotional & behavioural difficulties with language impairment @ 7 years
a N=189; b N=881
SDQ subscale
Language
impairmenta
M (SD)
No language
impairmentb
M (SD)
p value
Effect
size
Emotional
problems
Conduct problems
2.0 (2.1)
1.6 (1.7)
0.006
0.2
1.8 (1.7)
1.3 (1.5)
<0.001
0.3
Hyperactivityinattention
4.1 (2.7)
2.8 (2.3)
<0.001
0.5
Peer problems
1.2 (1.7)
0.9 (1.3)
0.005
0.2
Prosocial
behaviour
Total difficulties
8.1 (1.9)
8.4 (1.6)
0.05
-0.2
9.0 (4.7)
6.6 (4.7)
<0.001
0.5
99