1. The implications of poor receptive vocabulary at school entry in terms of adult literacy outcomes
James Law
Professor of Language and Communication Science
and Director
Centre for Integrated Healthcare Research, Edinburgh
JORSEN Conference – Manchester Metropolitan University

2. What we will be covering..
The association between language and both demographic and within child factors at school entry;
How this association feeds into performance in adulthood;
Potential implications..

3. Our research questions
What is the extent of the relationship between proximal, distal and biological factors and specific language impairment (SLI) at school entry?
To what extent does the pattern of association differ for non-specific language impairment (N-SLI)?
What is the risk associated with early SLI and N-SLI in terms of literacy at 34 years?

4. The data source?
British Cohort Study (BCS70), one of Britain's richest research resources for the study of human development;
Over 18,000 persons living in Great Britain who were born in one week in April 1970;
Data available about the cohort members at birth, 5, 10, 16, 26, 30 and most recently in 2004 when aged 34 years;
Wide range of information collected from parent’s report, school report, tests and medical examinations;
Excluded children whose first language was not English and whose ethnicity was not white European.

5. The measures At five years At ten years At 34 years
The English Picture Vocabulary Test
The Copying Designs Test
At ten years
The Edinburgh Reading Test
At 34 years
Level 2 literacy (equivalent to GCSE A-C and above)

6. More detail on adult literacy
At age 34 core dimensions of literacy at the requisite levels to match national curriculum standards - 30 multiple choice questions extracted from the 2002 Skills for Life Survey;
Questions were presented on a computer and cohort members selected from four alternative answers. Of the 30 questions only 20 would be attempted by any single respondent. Answers to an initial set of 10 questions determined whether they went on to answer 10 questions at a higher or lower level of difficulty;
Questions concentrated on reading comprehension, writing composition, grammar, punctuation, spelling and handwriting. The test has a good overall reliability of 0.87;
Possible to distinguish between scores at Entry Level, reflecting literacy performance below GCSE G-grade standards (that is, below the level expected of an 11 year old at the start of their secondary education), and scores at Level 1 (GCSE D-G grade standard) or Level 2, indicating literacy performance at GCSE A-C grade standard, or higher.

7. The three groups of interest
Typical language group
Language and Copying scores above -1SD
Non-specific language impairment (N-SLI)
Language more than 2 SD below the mean. Copying score more than 1 SD below the mean
Specific language impairment (SLI)
Language more than 2 SD below the mean. Copying score above -1SD

8. Sample derivation BCS70 cohort members at birth 17196
Cohort members at 5 years
13135
English spoken at home & white European
12099
Completed EPVT & Copying Designs Test
11330
Typical language
9613
N-SLI
195
SLI
211
Poor copying typical language
1311

9. Sample derivation BCS70 cohort members at birth 17196
Cohort members at 5 years
13135
English spoken at home & white European
12099
Completed EPVT & Copying Designs Test
11330
Typical language
9613
N-SLI
195
SLI
211
Poor copying typical language
1311

10. The “exposures” of interest
Distal factors
Child gender
Age mother left school
Mother single parent
Proximal factors
Persons per room ratio
Child had some kind of pre-school
Parent read to child in past week
Parent a poor reader
Biological and developmental risk
Mother smoked during pregnancy
Child small for dates
Child behavioural difficulties (neurotic/anti-social)
Child seen a speech and language therapist

11. Measuring associations
The analyses measure associations NOT causes - using odd ratios
The odds ratio is a way of calculating the probability of someone achieving something, winning, having a disease etc.relative to the probability that they will not do so;
So if a horse has a 60% probability of winning (and therefore a 40% chance of losing) the odds of it winning is 60/40 or 1.5;
An odds ratio of 0.5 means that the outcome is half as likely to occur in the target group. An odds ratio of 2.0 means that it is twice as likely to occur.

12. What we will be covering..
The association between language and both demographic and within child factors at school entry;
How this association feeds into performance in adulthood;
Potential implications..

13. At five years N-SLI SLI Distal Gender 0.68 0.64** Mo.minimal schooling
1.73*
1.28
Mo.single parent
2.49*
0.47
Proximal
Overcrowding
2.46***
1.40
No preschooling
2.53***
1.71**
Parent not reading to child
1.71*
1.12
Parent a poor reader
4.91***
2.72**
Biological risk
Mo. Smoked during pregnancy
0.86
1.19
Small for dates
4.08***
1.49
Behaviour – neurotic
3.42***
1.17
Behaviour – antisocial
2.32***
1.32
Seen an SLT
6.26***
2.40*

14. Implications at five?
Corroboration of existing data on the association between poor language skills and demographic factors
Particular things to note:
Gender
Importance of proximal factors especially parental reading
Preschool experience
SLI/N-SLI imbalance

15. What we will be covering..
The association between language and both demographic and within child factors at school entry;
How this association feeds into performance in adulthood;
Potential implications..

16. Parent not reading to child 1.20* Parent a poor reader 1.62*
Poor reading at 34 years
Receptive language at 5
SLI
1.39
N-SLI
3.72***
Distal factors
Gender
1.04
Mo.minimal schooling
1.71***
Mo.single parent
1.41*
Proximal factors
Overcrowding
1.38***
No preschooling
1.19*
Parent not reading to child
1.20*
Parent a poor reader
1.62*
Biological risk
Mo. Smoked during pregnancy
1.12*
Small for dates
1.32
Behaviour – neurotic
0.96
Behaviour – antisocial
1.39**
Seen an SLT
1.35

17. Implications at 34?
If you look at SLI or N-SLI on their own both predict 34 year literacy.
The association with SLI disappears once you add demographic factors.
The odds associated with N-SLI also halves once demographic factors are added
Note the effect of proximal factors and of anti-social behaviour

18. What we will be covering..
The association between language and both demographic and within child factors at school entry;
How this association feeds into performance in adulthood;
Potential implications..

19. Potential implications
Early language difficulties (both SLI and N-SLI) are strongly associated with demographic factors;
The long term implications for literacy and mental health are clear for N-SLI group, less so the SLI group;
The picture for criminality is more complex;
In terms of risk for social exclusion the N-SLI is clearly a very worrying group and they are easily identifiable at 5 years;
We need to develop an understanding of what can be done in terms of environmental modification to mitigate the effects of these poor early profiles. SEN or public health?
There is more that can be done to link adult outcomes with changes across childhood (eg school transitions) and across the life course.

20. With thanks to: Robert Rush, statistician QMU
Ingrid Schoon and Sam Parsons, Centre for Longitudinal Studies, Institute of Education, London
The authors acknowledge the support of the Economic and Social Science Research Council (RES ).