European Journal of Disorders of Communication, 27,247-264 (1992) 0 The College of Speech and Language Therapists, London

247

Language screening in preschool Chinese children V. Wong, P. W. H. Lee, F. Lieh-Mak and C. Y. Yeung University of Hong Kong, Queen Mary Hospital, Hong Kong

P. W. L. Leung Hong Kong Polytechnic

S. L. Luk University of Otago, Dunedin, New Zealand

E. Yiu University of Hong Kong

ABSTRACTS The incidence of language delay in Chinese preschool children was studied by a stratified proportional sampling of all 3 year olds in Hong Kong. The Developmental Language Screening Scale (DLSS) devised for use with Cantonese speaking children was used to identify children with language delay. Of 855 children sampled in the stage I screening procedure, 4%, 2.8% and 3.3% were identified as having delay in verbal comprehension, expression or both respectively. The stage II clinical diagnostic study included a randomly selected group of children screened in stage I with or without any associated behavioural problem. Among these, 3.4% were identified as having a language delay using the Reynell Language Developmental Scale (RDLS) with a criterion of language age of less than or equal to two-thirds of the chronological age; 3% had specific language delay using the criteria of language age less than or equal to two-thirds the chronological age and developmental age more than or equal to two-thirds the chronological age. More boys were found to have language delay, although this was not statistically significant. La frkquence du retard d a m l'acquisition du langage chez les enfants chinois d'iige prkscolaire a ktk ktudite au moyen d'kchantillonnages proportionnels stratifiks au sein de la l'ensemble de la population des enfants de 3 ans de Hong-Kong. L'on a utilist 1'Echelle de Dkpistage pour le Dkveloppement du Langage (Developmental Language Screening Scale, O M DLSS), dkja m b e au point pour les enfants de langue cantonaise, pour identifier ceux souffrant de retard linguistique. Parmi les 885 enfants prklevts par kchantillonnage pour le premier stade du processus de dkpistage, il s'est rkvklt que les pourcentages de retards en ce qui concernait la comprthension verbale, l'expression verbale, O M une combinaison de ces deux facteurs, ttaient, respectivement, de 4%, 2.8% et 3.3%. Le deuxieme stade de l'ktude diagnostique clinique concernait un groupe d'enfants stlectionnks au hasard parmi ceux qui avaient dkja ktk examinks au premier stade, et dont certains prksentaient en plus des probkmes de comportement alors que d'autres n'en avaient pas. Dans le nombre il s'est trouve que 3.4% souffraient de retards du langage d'apr2s l'Echelle de Reynell (Reynell Language Development Scale, O M R D LS) avec un crit2re d'iige linguistique infkrieur O M kgal aux 213 de I'iige chronologique, et que 3% souffraient de retard sptcifique du langage en utilisant un iige linguistique de 213 de l'iige chronologique et un iige de dtveloppement suptrieur OM kgal aux 213 de l'ii e chronologique. Davantage de garcons que de filles souffaient de retards du langage, mais la Jffkrence n'e'tait pas statistiquement significative.

248

WONG, LEUNG, LUK, LEE, LIEH-MAK, YEUNG AND YIU

Die Pravalenz der Sprachentwicklungsstorung bei chinesischen Vorschulkindern wurde an Hand von einer schichtenformigen, proportionierten Stichprobe von allen dreijahrigen Kindern in Hong Kong studiert. Urn die Kinder rnit einer Sprachentwicklungsstorung zu identifizieren, haben wir die Developmental Language Screening Scale ( DLSS) angewendet, die fur den Gebrauch bei kantonesisch sprechenden Kindern entwickelt wurde. Von den 855 Kindern, die wir in der ersten Phase der Stichprobe getestet haben, haben wir bei jeweils 4, 2.8, 3.3% eine Entwicklungsverzogerung des Sprachverstandnisses, des Ausdrucks oder beides festgestellt. In der zweiten Phase der klinischen, diagnostischen Studie haben wir eine randomisierte Gruppe von Kindern ausgewahlt, die in der ersten Phase gepriift wurden und die rnit oder ohne Verhaltensprobleme waren. Von diesen hatten 3.4% laut der Reynell Language Development Scale eine Sprachentwicklungsverzogerung, d. h. Sprachalter 5 213 des eigentlichen Alters; 3 % eine Teilleistungsschwache, d. h. Sprachalter 5 213 des eigentlichen Alters und Entwicklungsalter 2 213 des eigentlichen Alters. Wir haben gefunden, dass mehr Jungen eine Sprachentwicklungsverzogerunghatten, obgleich dieses statistisch nicht signifikant war.

Key words: language delay, language comprehension, language expression.

INTRODUCTION

Speech and language disorders are the most common developmental problems in preschool children. The prevalence of language delay in preschool children is reported to be between 3% and 15%. (Jenkins, Bax & Hart, 1970; Bax, 1972; Marge, 1972; Rutter, 1972; Sheridan, 1973; Randall, Reynell & Curwen, 1974; Bax & Hart, 1976; Richman, 1976, 1978; Tumoi & Ivanoff, 1977; Fundudis, Kolvin & Garside, 1979; Bax, Hart & Jenkins, 1980; Chazan, Laing, Bailey & Jones, 1980; Silva, 1980, 1981, 1987; Drillien & Drummond, 1983) (Ingram, T. T., 1963, unpublished data). The wide range of incidence rate is due to difference in criteria adopted for defining language delay. Earlier epidemiological studies used criteria-referenced approaches and relied on expressive language only, as there was a lack of standardised tests of language development (Morley, 1965; Herbert & Wedell, 1970) (Ingram, T. T., 1963, unpublished data). More recent studies have evaluated both verbal comprehension and verbal expression in defining language delay (Randall et al. 1974; Richman, 1976, 1978; Silva, McGee & Williams, 1983). At present there is still no general agreement as to where the cut-off point for language delay in the normal distribution should be drawn. In school-age children, 1% are said to have ‘severe’ developmental language delay and 4 5 % to have sequelae of earlier language difficulties (MacKeith & Rutter, 1972). The importance of screening for language delay lies in the rationale that early identification and intervention may improve the outcome (Cooper, Moodley & Reynell, 1979). Many preschool children with milder language delay improve with age (Herbert & Wedell, 1970). In a study on the prevalence of language delay in 3 year olds, Richman (1976) emphasised that ‘decision about what constitutes abnormality would be strengthened if prognostic validation data were available’. Longitudinal studies of developmental language delay (Stevenson & Richman, 1976; Fundudis et al., 1979; Richman, Stevenson & Graham, 1982; Silva et al., 1983) have demonstrated an association of language delay with an increased risk of lower intelligence, reading difficulties, behaviour problems and psychiatric disorders later in childhood. This study is part of an epidemiological survey of the prevalence of behaviour

LANGUAGE SCREENING IN PRESCHOOL CHINESE CHILDREN

249

disorder and language delay in 3-year-old Chinese children in Hong Kong. Among a total population of 6 million people, more than 98% are Chinese in ethnic origin, with Cantonese as the main dialect. A random survey of households with 3 year olds was undertaken to identify children with behaviour disorder and/or language delay. This paper reports the prevalence of language delay. METHOD Stage I Screening Study

A sample of all 3-year-old children was selected in Hong Kong through a stratified proportional sampling method. Altogether 82 kindergartens, 10 childcare centres, 10 maternal and child health clinics and 1 special child-care centre were enrolled. At the time of planning the study (September 1986), Government statistics showed that 90% of the 3-year-old children in Hong Kong were attending either kindergartens or child-care centres. All kindergartens in Hong Kong are run on a private basis and are under the supervision of the Education Department. The majority of child-care centres are administered by voluntary agencies or directly by Government and are looked after by the Social Welfare Department. The plan was to obtain a representative sample by first screening the kindergartens and child-care centres, and for those not attending either of these types of institution (an estimated lo./,), contact would be made through the registration of the maternal and child health clinics (MCHs). The limitation of this method was that those not attending either school or MCHs, a proportion estimated to be about 1% of the population, assuming that school and MCH attendance were independent, would not be covered. Sampling based on MCH records alone was not feasible for two reasons. First, although in Hong Kong over 90% of children under 1 year of age attend the MCHs, attendance drops sharply after the first year of life. Secondly, previous experience of trying to engage the parents and children from MCHs in a local language development study only achieved about a 50% success rate despite vigorous efforts to contact them. Sampling on a door-to-door basis was also impracticable because the refusal rate was expected to be high. The plan called for a sample size of 1000. As it was calculated that 80% of 3 year olds were attending kindergartens and 10% child-care centres, the design was to sample 80 kindergartens and 10 child-care centres, stratified according to geographical region, whether private or aided, and the size of the school (small kindergartens to be clustered together), and to recruit 10 children from each. Letters were therefore sent to the kindergartens and childcare centres followed by telephone contacts. After obtaining consent, the school was asked to provide a list of the children whose chronological age was between 3;O years and 3;12 years in that month. Random selections were then carried out to obtain 15 subjects in each school (10 5 reserves in case of parental refusal). The class teachers of the kindergartens or child-care

+

250

WONG, LEUNG, LUK, LEE, LIEH-MAK, YEUNG AND YIU

centres were asked to fill in the teacher’s questionnaire. Research assistants visited the school within days and interviewed the parents. Starting from November 1986, about 10 kindergartens were screened every month. By June 1987, a total of 82 kindergartens had been screened (6 of them were from clusters). In July 1987, 10 child-care centres and 1 special nursery were screened. Attempts were made to reach the estimated 10% of children not attending kindergartens, nurseries or child-care centres through the MCHs. The plan was to contact a random sample of 1000 households with children of the right age via 10 randomly selected MCHs (stratified according to five geographical regions); from these 1000 children, it was expected that about 100 (10%) would not be attending either kindergartens or child-care centres and thus would complete the sample. In August 1987, therefore, a list of 3000 households with children of the right age was prepared from each MCH because previous experience indicated a contact rate by telephone of around 33%. Telephone calls were made starting from the beginning of the list and moving to the next one if the telephone was engaged or unanswered, going back to the start when the 300 were exhausted. The telephoning stopped when 100 random contacts had been made for each MCH. After an introduction, family members were asked on the phone whether their children were attending a kindergarten or child-care centre or had been enrolled in a kindergarten or child-care centre for the coming September (the beginning of the academic year in Hong Kong). (Note that by August, usually all children will be enrolled for the coming year.) Only those doing neither of these were included in our study. The parents of these children were then interviewed in the MCHs following the sample procedure as for the kindergartens. Measures Language screening The children were screened for language delay using the Developmental Language Screening Scale (DLSS) (Lee Luk, Yu & Bachonshone, 1985) (see Appendix). The DLSS was designed for local use in the form of a parent interview. The design of the language screening scale was guided by the following considerations:

1. The scale has to be simple enough to be administered by a wide variety of personnel with different professional backgrounds to serve its role in large-scale screening of children’s language problems. 2. Language abilities covered by the scale should be easily and objectively measurable and observable to reduce subjectivity and unreliability. 3. Items in the scale should be comprehensive and representative of the wide range of language functions. 4. The scale should be applicable to widely divergent population groups, whatever their motivation and language sophistication, as well as existence of psychological or behavioural problems. A parental interview format was adopted. Non-cooperation and stranger anxiety effects of direct testing are thus reduced. Items in the scale were adapted for local use from core contents of well-documented language scales

LANGUAGE SCREENING IN PRESCHOOL CHINESE CHILDREN

25 1

(Mecham, 1953; Reynell, 1969; Wing, 1981). Parental observations of their children’s everyday language behaviours are used as objective data with which the children’s language development is being observed. The items of the test are grouped under six different areas reflecting the full range of language competence in developing children. 0

0

0

0 0

0

Subscale A (verbal comprehension) - this asseses the child’s basic awareness and understanding of receptive spoken language. A section on assessment of the child’s basic competence in understanding prepositions is also included. Subscale B (verbal expression) - this assesses the child’s intentional use of speech for language-related functions. The extent of the child’s use of question forms as well as the clarity of the child’s speech are also assessed. Subscale C (non-verbal comprehension) - this measures the child’s awareness and understanding of non-verbal language including gestures and facial features. Subscale D (non-verbal expression) - this assesses the child’s ability and proficiency in the use of non-verbal expressions for language-related functions. Subscale C (interest in communication) - this assesses the child’s preferred mode of communication (e.g. spoken language, gestures or mime), and willingness to communicate as well as his or her inclination in sharing interests through communication. This subtest is included as a measure of a possible mitigating factor affecting the discrepancy sometimes observed in children manifesting a marked difference in their level of language performance compared to their actual language competence. Subscale F (abnormalities of speech) - this is also included to assess the presence of language abnormalities either in the production of speech sounds, or in the contents of the language use. As the meaning of the Cantonese speech sounds depends crucially on lexical tones as well as intonation, a special section is included in the ‘Abnormalities of speech’ subtest documenting whether or not the child has specific problems in the mastery of the tonal nature of the spoken language.

The validation of DLSS in a normal preschool population has been presented in a separate paper (Lee, Luk, Bachonshone, Lau, Wong & KO, 1990). Behaviour screening The children were screened for behaviour problems using two instruments which had been translated into Chinese for local use.

1. Behaviour screening questionnaires (BSQ) (Richman & Graham, 1971): this is a semi-structured parental interview. The interviewers rate the parental information on a 3-point scale in 12 areas of problematic behaviour. The total score is 24 with a cut-off point of 1 10 to indicate the presence of behavioural disorder. 2. Preschool behaviour checklist (PBCL) (McQuire & Richman, 1986): this is a teacher-rating scale with 22 items. Each item is scored on a 3-point scale with a total score of 44. A cut-off score of 2 12 identifies children with behavioural or emotional disorder. Stage II Clinical Diagnostic Study

First, a one in ten random sample was selected from the whole sample irrespective of their scores on the screening instruments. For the remaining

WONG, LEUNG, LUK, LEE, LIEH-MAK, YEUNG AND YIU

252

children, all those who scored higher than the cut-off points in both the BSQ (lo+) and PBCL (12+) were requested to join the second stage of the study. Also, a one in two random sampling was used for those children who scored higher than the cut-off point on either the BSQ or the PBCL. These cut-off points were used locally in our pilot studies and found to be acceptable. The second stage entailed a semi-structured interview with the parents, a clinical interview with the child and a short interview with the class teacher by child psychiatrists. The children were assessed for language development and non-verbal intelligence using the Reynell Language Developmental Scale (Cantonese version) (Reynell, 1969, 1977; Reynell & Huntley, 1985; Hong Kong Society for Child Health and Development, 1987) and Griffiths Mental Developmental Scale (subscales D - eye-hand coordination and subscale E - performance) (Griffiths, 1970, 1984), respectively. These were performed by developmental paediatricians, clinical psychologists and/or speech and language therapists. To reduce test bias and subjectivity, all examiners were blind to the results of the first stage screening and to each others’ assessment results. Measures Language assessment: Reynell Developmental Language Scale (RDLS) The RDLS has been translated into Cantonese and standardised for local use. In order to standardise for age differences (in months), the comprehension and expression age were divided by the chronological age to give language quotients in comprehension LQ(C) and expression LQ(E) respectively. The total language quotient (total LQ) was the sum of LQ(C) and LQ(E). Non-verbal assessment: G-ths Mental Developmental Scale (GMDS) Among the five subscales in GMDS, scales D (eye and hand coordination) and E (performance) were utilised to give an estimation of non-verbal intelligence. The Griffiths Scale was standardised by dividing the developmental age of scale D and E by the chronological age to give a developmental quotient of DQ(D) and DQ(E) respectively. The total DQ was the sum of DQ(D) and DQ(E). The result of behaviour screening has been reported in a separate paper, (Luk, Bachonshone & Leung, 1990). Criteria for language delayed include the following: 1. Stage I: children who scored less than 2 standard deviations in the scales B in DLSS were considered as having delay in verbal A, B, A comprehension, verbal expression or both, respectively. 2. Stage 11: the criteria were adopted from Richman’s epidemiological study on language delay and behavioural problems in 3-year-old children (Richman, 1976, 1978). The child’s measured language age was compared to his or her chronological age. If the language age on the Verbal Comprehension Scale and the Verbal Expression Scale is equal or less than two-thirds of the chronological age the age is regarded as having language delay.

+

LANGUAGE SCREENING IN PRESCHOOL CHINESE CHILDREN

253

Specific language delay is defined as language age in RDLS equal to or less than two-thirds the verbal age as defined by GMDS equal to or more than two-thirds the chronological age. RESULTS

Stage I Screening Study

Eight hundred and fifty-five children (431 boys, 424 girls), aged 36-48 months (mean f standard deviation = 43 f 2.8) were sampled. All were of Chinese origin with Cantonese as the main dialect. Stage II Clinical Diagnostic Study

The total sample consisted of 226 children (124 boys, 102 girls) with age ranging from 36 to 48 months (mean f standard deviation = 43 f 2.7). One boy was too shy to express himself. Thus, the expression score and total score were omitted for one case. Scores in DLSS Subscales (Table 1)

There was a significant male-female difference in language scores in subscales B, D and A B. Thus, girls score better in verbal expression ( P = O.OoOO), non-verbal expression ( P = 0.03) and both verbal comprehension and expression ( P = 0.0001).

+

Table 1 : Mean and standard deviations (s.d.) of scores in DLSS (stage I). Total

A B C D E A + B

Boys

Girls

Mean

(s.d.)

Mean

(s.d.)

Mean

(s.d.)

t

P

12.47 23.25 4.87 9.31 7.86 35.71

(1.91) (2.84) (1.12) (1.0) (1.58) (4.12)

12.42 22.98 4.8 9.27 7.87 35.39

(2.04) (3.25) (1.19) (0.97) (1.69) (4.63)

12.52 23.52 4.94 9.37 7.85 36.04

(1.77) (2.32) (1.08) (1.02) (1.48) (3.49)

1.2 4.8 2.6 2.1 0.3 3.8

NS o.oO0o NS 0.03 NS O.OOO1

NS = non-significant.

Scores in RDLS and GMDS (Table 2)

Girls obtained a higher language quotient on verbal expression ( P = 0.01) or both verbal comprehension and expression ( P = 0.01) than boys in RDLS. Girls also scored better than boys in the D scale (eye-hand coordination) in GMDS ( P = 0.04). Comparison of Sex Differences in Children with Language Delay (Table 3)

In stage I using DLSS, more boys had delay in all aspects of language development, although not reaching statistical significance. The prevalence of language delay using the various subscales varied from 2.8% to 4.8%.In stage I1 using RDLS, eight children (six boys, two girls), i.e. 3.4%, were identified as having language delay with language age in verbal comprehension and verbal

WONG, LEUNG, LUK, LEE, LIEH-MAK, YEUNG AND YIU

254

Table 2 : Mean and standard deviations of scores in RDLS and GMDS (stage 11).

Total

Boys

Girls

Mean score

(s.d.)

Mean score

(s.d.)

Mean score

(s.d.)

t

P

1.0 0.94 1.96 1.19 1.13 2.31

(0.2) (0.17) (0.33) (0.17) (0.19) (0.33)

1.0 0.93 1.93 1.17 1.12 2.3

(0.26) (0.18) (0.37) (0.19) (0.02) (0.37)

1.0 0.96 2.0 1.2 1.14 2.34

(0.17) (0.16) (0.29) (0.14) (0.18) (0.29)

1.7 2.6 2.2 2.1 1.2 1.5

NS 0.01 0.03 0.04 NS NS

LQ ( C ) LQ (El LQ (Total) DQ (Dl DQ (El DQ (Total)

RDLS = Reynell Developmental Language Scale. GMDS = Griffiths Mental Developmental Scale. language age (months) LQ = language quotient = in RDLS; C = comprehension; E = expression. chronological age (months) developmental age (months) . DQ = developmental quotient = in GMDS; D = eye-hand coordination. E = chronological age (months) pei'formance. NS = non-significant.

Table 3: Sex difference in DLSS with score I 2 s.d.

Total

Girl

BOY

DLSS

n

%

n

A

34

4

23

B

24

2.8

17

C

27

3.2

16

D

41

4.8

21

E

25

2.9

15

A + B

28

3.3

17

Mean score (s.d.) n

6.52 (2.21) 9.82 (4.59) 1.68 (0.70) 6.33 (0.91) 2.60 (1.45) 17.94 (7.67)

11

7 11 20 10 11

Mean score (s.d.)

6.09 (2.25) 12.71 (6.29) 1.72 (0.64) 6.10 (1.68) 3.50 (1.26) 23.36 (8.02)

t 0.53

P 0.60

-1.26

0.22

-0.15

0.88

0.55

0.58

-1.59

0.12

-1.79

0.08

expression equal to or less than two-thirds the chronological age. More boys were identified but the difference was not statistically significant as the number was too small. Seven children (five boys, two girls), i.e. 3%, were identified as having specific language delay using the criteria of language age in RDLS equal to or less than two-thirds the chronological age and developmental age equal to or more than two-thirds the chronological age. DISCUSSION

The prevalence of language delay in 3-year-old Chinese children is 4% for language comprehension, 2.8% for language expression and 3.3% for language

LANGUAGE SCREENING IN PRESCHOOL CHINESE CHILDREN

255

comprehension and expression, as screened by the Developmental Language Screening Scale (DLSS) designed for local use. This was similar to the language study of the Dunedin Multidisciplinary Health and Development Study (3%, 2.5% and 3% respectively) (Silva, 1987). The cut-off point for defining language delay has not been universally defined. Most of the children with milder language delay will catch up later. Some may have persistent problems in language, intellectual function or reading at school age (MacKeith & Rutter, 1971). The validation of a screening instrument is essential before drawing the cutoff point for language delay. We used a cut-off point of less than two standard deviations below the mean in the scoring of DLSS because these children also scored less well in the stage I1 diagnostic study with RDLS (Lee et al., 1990). B scores in DLSS and There was also a significant correlation between A language quotient in comprehension ( P < 0.002) and expression ( P < 0.001) of RDLS (Lee et al., 1990). Due to limitations in staff available it was not possible to perform RDLS on all 855 children in the initial screening study in all areas of Hong Kong. A comparison of DLSS as a screening instrument (to be used by trained research workers which could be completed by interviewing parents 3r caretakers in 10 minutes) with RDLS (which must be performed by professionals with a minimum of 30 minutes’ assessment time) B was carried out in this project. The correlation of DLSS, especially A subscale (verbal comprehension and verbal expression) with language quotients (verbal comprehension, verbal expression or both) of RDLS was statistically significant at the P < 0.001 level (Lee et al., 1990). Thus, with good correlation and validation, the DLSS could be considered as a useful and time-saving language screening instrument for use with Chinese Cantonese-speaking children. There were more boys with language delay in both stage I and I1 studies although the difference did not reach statistical significance. Boys also scored lower in the normal distribution of the scoring system. Interestingly, all the children with specific language delay in the stage I1 study were boys. The incidence of language delay as identified in a selected random sample of children in the stage I1 study was 3.4% (8/233). The prevalence of both general and specific language delay as defined in the stage I1 study might be higher because this group consisted of half of those screened out for behaviour problem in the stage I study. As it is well known that behaviour problems may be associated with language delay and vice versa (Richman, 1976, 1978), this figure might over-estimate the degree of language delay in the stage I1 study. However, the 3.4% prevalence rate was not an excessive bias as compared to 3.3% in the stage I screening study. In Hong Kong, the majority of the population is Chinese in origin with Cantonese as the main dialect. All the 855 children sampled in the stage I study came from families with Cantonese as the main dialect. The DLSS had been translated to a Cantonese version and tested on 265 Cantonese speaking boys aged 1&36 months recruited from nurseries and kindergartens (Lee et al., 1985). In the present study, the normative data on 855 children aged 3& 48 months were obtained. As the study design aimed at random sampling of all the 3-year-old children, the prevalence of 3.3% was representative of the magnitude of language delay in a Chinese community.

+

+

5-14

2.5-3 .5 3-3.5 4-1 7

733

-

Isle of Wight (referral)

British survey

ll 1970

160

703

NCDS

Normal population in London

Random sample in London

1973

1974

1976

15 496

USA

1972

3

3

7

3.9 4.9 6.5

1972

944

Newcastle longitudinal study (health visitors)

1965

3-5

-

Edinburgh, Aberdeen, survey

3.9

114

Total no.

1963

Population studied

Newcastle longitudinal study

~~~~~

1954

Year

Age (years)

11 0.9 4

-

5.6

13.8

-

10 8

Expressive LD = LA 5 30 m 31.2 Severe expressive LD = LA 5 2/3 CA 22.7 Specific expressive LD = LA 5 2/3 nonverbal MA 14.2

+

VC 5 2 s.d. VE 5 2 s.d. VC VE 5 2 s.d.

Marked speech defects

Delayed language acquisition

Handicapping language delay Severe specific language deficiency

0.8

0

2 0.6

z

D

Z G)

-c rn c

-7;

D

T z

rn

c

rn rn

r

7;

c

r

-0

z

c

rn

I-

G)

e

d

m

cn

h,

3.1 0.4

-

6.2

-

1

-

10 5 0.7

-

Unintelligible speech Unintelligible speech Unintelligible speech Specific developmental disorder of language

-

0.71 0.75

-

-

6

(Oh)

Prevalence

-

Rate per lo00

3Y - few single words SY - limited connected speech

Incomplete sentences (definite language delay Unintelligible speech Incomplete sentences Unintelligible speech

Criteria for language delay

Table 4: Prevalence of language delay in various studies.

931

600

855

Dunedin multidisciplinary development study (New Zealand)

Language Development Survey (USA)

Stratified sampling of all 3-year-old Chinese children in Hong Kong

1987

1989

1992

4 2.8 3.3

-

VC 5 2 s.d. (A scale) VE I2 s.d. (B scale) VC + VE I 2 s.d. (A (DLSS)

3

l Child Development Study; DLSS = Developmental Language Screening Scale; RDLS = Reynell Developmental Language Scale. prehension; VE = verbal expression. elay; CA = chronological age; MA = mental age; LA = language age.

+ B scale)

10

-

45-51

-

3.2-1 2.4 4.4-11.4

-

Fewer than 30 words or no combination (vocabulary checklist for parents)

+

VC I2 s.d. VE 9 2 s.d. VC VE I2 s.d (RDLS)

14 5.5

-

4

6-1

2

3

Delay in VCNE both compared with CA Articulatory problems

2-5

5334

Dundee development screening programme

1983

First-stage screening Second-stage screening for those with definite or ‘possible’ problem

7 320

99.5% of children born in England and Wales over a 6-year period

1980

Not talking adequately

Not using words at 3 years

3.9-4.3

3 4-5

Central London

1980

323

3

Newcastle upon Tyne

-

1979

900

Kindergarten and grade I children (Canada)

1971

rn

n rn z

0

I-

z

0

rn

v)

$ rn

0

P

I 0

0

v)

2 -u n

G)

zz

rn

n rn

0

v)

R

D

c

G)

6 z

258

WONG, LEUNG, LUK, LEE, LIEH-MAK, YEUNG AND YIU

As the RDLS has been translated and standardised for Cantonese-speaking children (Hong Kong Society for Child Health and Development, 1987), the percentage of children with language delay in the stage I1 study (3.4%) could also reflect the problem in the Chinese community although the figure may be higher due to inclusion of a selected group of children with behaviour problems. Thus, the prevalence of language delay in our Chinese preschool children showed similar trends to those reported in English-speaking communities of the UK, USA, Canada and New Zealand (Spence, Walton, Miller & Court, 1954; MacKeith & Rutter, 1972; Randall et al., 1974; Richman, 1976; Tuomi & Ivanoff, 1977; Silva, 1980; Rescorla, 1989) (Table 4). There are many different dialects in Chinese. Mandarin is the universal dialect particularly in northern China and Taiwan whereas Cantonese is the main dialect of southern Chinese. Most of the residents in Hong Kong originated from southern parts of China. Although there have been no reports of the magnitude of the language problem in Chinese communities with different dialects, this study serves to show that there is a similar trend in language problems in Chinese preschool children as in other ethnic groups. It is difficult to obtain a precise figure for children with language delay due to a lack of consensus on the definition used. We believe that children who are functioning at a level about 2 standard deviations below the norm on standardised language tests are at significant risk for future problems in language-related areas. Various studies have demonstrated an increased risk of lower intelligence, lower reading skills, increased risk of behaviour problem and psychiatric disorder in those with language delay detected in the preschool years (Jenkins et al., 1970; MacKeith & Rutter, 1972; Peckham, 1973, 1978; Sheridan, 1973; Stevenson & Graham, 1975; Calman & Richardson, 1976; Stevenson & Richman, 1976; Cantwell & Baker, 1977; Cantwell, Baker & Mattison, 1979; Fundudis et al., 1979; Fergusson, 1980; Baker & Cantwell, 1982; Stevenson, 1984; Bishop & Adams, 1990). Follow-up study of those screened in stages I and I1 are now being undertaken at the age of 7 years with intelligence tests, language tests and reading tests in order to elucidate the prognostic significance and stability of early language delay in Chinese children. If language problems persist or show an increased risk of educational or social difficulties in our school-age Chinese children, screening for language delay and earlier intervention strategies may hopefully help to prevent these problems in our community. ACKNOWLEDGEMENTS This project was funded by the Hong Kong Society for Child Health and Development. We are grateful to all the kindergartens, child-care centres and maternal and child health clinics which participated in this project: Dr W. Ho, Dr L. KO, Dr T. L. Kwok, Dr M. T. Poon, Dr Y. P. Tang, Miss K. Chan, Miss P. Chan, Miss I. Kwok, Mr J. Lau, Miss P. Miu, who helped in collecting the data and Mr J. Baconshone for statistical analysis. Valuable assistance was provided by the Education Department and the Medical and Health Department.

LANGUAGE SCREENING IN PRESCHOOL CHINESE CHILDREN

259

APPENDIX Development Language Screening Scale: Parents' Form Name of Child : Sex/Age Respondent : Father/Mother/Grandmother/Others

Interview Date Check ( d )all appropriate items

A. VERBAL COMPREHENSION I.

General: 1. Responds when name is called ................................................. W{EB%m&R+iEE! 2. Responds when spoken to even when name is not mentioned .......... 0

0 0

Idill!s.&iffvff ' SB*W~F.illEI% ' E # ! m @ G & E

0

3. Understands simple phrases used in familiar contexts .................... H%MBHf%W%bJ'$* CgCW-fB&f?S%+% MIPIIPII: tssxm riswzi

4. Knows meaning of some words without contextual cues ................. mjEj

-D

$3 &!'$bJJu@,&,F% C 4c;C @

0

0

5 . Follows instructions involving two named objects ......................... ~TLLW{EM@#%JPk

6. Can be sent out of room to fetch two objects ............................... UJLLWfE E%LA %*M#&Ll

0

0

krn%J#

0 0

0

7. Follows a sequence of three consecutive commands ...................... RTL l M B IddB,%tl% I @@ BJ3E4f

0

0

8. Understands instructions involving decisions, i.e., if . . . then instructions ......................................................................... W{BR'Z--DW * t@n%%&@&%?? miha : haRd%%.8PW haRElf#lnk%M&BfB

0

0

7

11. Prepositions: 1. Understands the meaning of the following words: {E:sal'8:sai.24fw-: *Rr$i in ............................................. %Tr€fi under ........................................ %lafi on ............................................ %t%@ behind ....................................... 2% before ....................................... 2 f% after.. .........................................

0 0 0 0 0 0

B. ABILITY TO USE SPEECH I. Grammar: 1. Makes any sounds at all ........................................................

0

qLL%EEm-%%s

0

2. Babbles, or coos, without meaning .......................................... qLJfRsw%EKX%sfff&bP

0

0

3. Babbles, or makes noise meaningfully ...................................... 0 ~ ~ B ~ f ~ ~ W J u B ~ % X X 4 ~ f ~ E - D ~ f @ ~ % ~ 4. One definite word.. .............................................................. 0 0

SS-fBT

0

~

~~

* Reproduced with permission from The Hong Kong Journal of Puediatrics (1990), 1, pp. 1-22.

WONG, LEUNG, LUK, LEE, LIEH-MAK, YEUNG AND YIU

260

5. Gives names of two or more people or things when asked ............. 0 Pm74EuBR * qLJSBR@dUkb3A%W%$5

0

6. Spontaneously names two or more objects or people in the

.....................................

............

7. Speaks two-word phrases ......................................................

s%rnm%@e&@%o 8. Speaks longer than two-word phrases with nouns and verbs, missing out linking words ......................................................

0

0 0

~Ll,%%arnm~El@~ 0

9. Appropriate use of words other than nouns and verbs ............ (e.g. adjectives) ...............................

0

l%7$5ROB%7;t%- SB3#fI&%T

0

10. Spontaneous use of sentences with linking words about present.. .... B%BmqLl%-DRJTMfiFL&m

11. Forms sentences using because ............................................... BBR r m m ~ T P B ~ 12. Forms sentences using but ........................................

a~m

WFW

13. Talks about present, past, and future with complex grammatical constructions ...................................................................... ijJLJSFLh ’ %J&B%%%%

0

0

0 0

0

0

11. Asking questions: 1. Asks questions using simple overlearnt phrase(s) .........................

0

~6Si@Hf%%%JQPMMB ? 2. Uses the following ffiBn? : Where? ....................................................... 0 t?Dw What? ........................................................ 0 &@I Who? ......................................................... 0 %!% Why? .............................................. .... ( ) When?. ....................................................... 0 How? ......................................................... 0

111. Intelligibility: 1. Some speech, but mostly unintelligible ...................................... .&$-PWj&d&

9

{Bt%BfI&A%WSaBf!ZE&t?W

0

0

2. Only a few words (3+ at least) intelligible ...................................

0

{ESn!$&%td&fffI&AWt%i!e@Sa ZiI’PG4i 0

3. People who know the child well can understand but with some guessing .............................................................................. ,Llf2fBSA u T ~ ~ ~ & ~ ~ ~ ~ I I ~ ~ t % ~ I I ~ ~ ~ W 4. People who know the child well can understand without the need to guess ....................................................................... Z,&f2f - &A I%;CClkh~U#MfE.It?W 5. Strangers can understand with some guessing .............................. FSY A nTLl A& kIkBll!Z.R t?W 6. Strangers can understand without the need to guess ......................

0

0

9

0

0 0

0

BffiYAh;l’b’,l,iC %if6 Sa EII#

,i$f l W

C. COMPREHENSION OF NON-VERBAL COMMUNICATION I. Gestures: 1. Understands meaning of head nodding and head shaking ............... rESa%SaB.%n ’ %nm,e.iY?

0

0

0

LANGUAGE SCREENING IN PRESCHOOL CHINESE CHILDREN

2. Understands meaning of thumbs up ......................... {E sa%

sa !9%&#%

261

0

B5.d.F~ ?

3. Understands meaning of shaking of hands

+

.................

{E sag aa !a% f73.E.Y~?

0

11. Facial expression:

1. Might understand meaning of adult’s facial expressions but would not comply to commands on basis of facial expression alone.. ... .. ( ) UJLJ Sa Q R Anti S &tF%! @@rnEi%

&&bw

W k & %?% A

r IkiEJ

R 1’1

2. Child‘s behaviour can be controlled by adult’s exaggerated facial expressions.. ................ $+El]aW&tB MJilku : I ~ ~ & ~ ~ ~ ~ ~ ~ J ~ ~ ~ ~ 3. Child’s behaviour can be controlled by small changes in adult’s facial expressions .................................................................. m ++Ug &&& 8 Eft&%@ $7’~ &t8%05 LA# %ll H@.%f r % 0

9

0 %

I

0

0

D.

ABILITY TO USE NON-VERBAL COMMUNICATION I. Expressive gestures: 1. Can copy or initiate these actions: @,%?tW&W&&%EI EWXDBfF :

.................................................................. -waving # A ........................................................ - clapping hands fb F - singing games with hand movements ....................................... 0

0

0 0 0

@%&FIB-rD1 %Blra;BfF. - act in school plays or do a little song or dance with appropriate

movements and facial expressions.. ........................................... %6@%’&33~1S’Z%%W

k’b!%bn@-D

0

F4S&MFJBBfF 0

11. Use of gestures:

1. Nods to indicate yes ..............................................................

r w i sisqso 2. Shakes head to indicate no ...................................................... rBi m m s o 111. Use of facial expressions: 1. Facial reactions easily observable and distinguishable between different emotions u g ~ . ~sad . .................................................................... angry ................................................................. m.~. happy ................................................................ R fearful ...............................................................

E. INTEREST IN COMMUNICATION I. Preferred method in obtaining needs: 1. Check the child’s most preferred method in obtaining needs, then record the score as indicated: (a) never communicate or seems never to want anything ............... &Ti%%

0

(b) screams or makes noises without specifying needs.. ................. R%%@WX;fii&Stx

0

(c) gets what he wants for himself ............................................ Eiz?fo

(d) takes you by hand and leads you to object ............................. I$ Pf% L

+Hi3qslra;*@

0

0 0

0 0 0 0

0 0 0 0

J

~

I

WONG, LEUNG, LUK, LEE, LIEH-MAK, YEUNG AND YIU

262

(e) points to objects from a distance .................................... %%SRalfO

0

....................................................

0

...............................

0

11. Willingness to communicate 1. The child communicates needs only ..........................................

0

(f) gestures or mimes.

mPFmW+z

0

(g) makes request in words ................ %PFf%Q

0

Flt%~%~Be*%m 0

2. Shows a minimal response if others initiate interaction.. ................. 0

rm

WGDEE

3. Shows a willing response if others initiate interaction.. .............

0

4. Sometimes initiates communication .......................................... WBE r m A.

0

AU~!r

m~ui~~em!!~

5. Enjoys and frequently initiates communications: mkFI AA

with adults ........................................................... Kf@#8% other children ....................................................... rY%J A strangers..............................................................

0 0 0

a& 111. Sharing of interest: 1. Responds well when attention of child is drawn to things in immediate environment .........................................................

0

f%J;CfE@u#JG&RalffE&@ 0

2. Spontaneously shares interest with others (e.g. point things out, shares or shows toys) .......................................................

0 Gives narrative accounts of experiences spontaneously .................. 0 El E! f&ldA/r) S MJbfl&R IHB&+Pu#JRR&%%%PFAR% 0

7

3.

B f9~&fE@%&Zi%Y%Dalf#i%%1 0

F. ABNORMALITIES OF SPEECH I. Echolalia: 1. Repeats words or phrases just heard like a parrot {%G?TE%{EERAdW A~@-dRfE'.W&W@%3Y%@M!%%@4f r m w t m ~ . ~r iw m t mJ 7

9

9

f5lbU : f%P-?fE

Occasionally? o r . . .......................................... Daily? ........................................................ (* score 2 points when checked)

0

( )*

2. Uses stock phrases over and over again that are not appropriate for the situation: @.Hir D J UBfiiffEEi fflr%? ' %EVi%2-m+!3!!%~E8lMfflR? Occasionally? or.. .......................................... 0 Daily? ........................................................ ( )* (* score 2 points when checked) 11. Reversal of pronouns: 1. Calls self you, or uses own name.. ............................................. R B W B Z ~r m i

2. Calls others as I .................................................................... I4lff@AWc r

m

111. Repetitive speech: 1. Often reverts to same topics regardless of context ......................... fk 6?iR I3 ,d&,A& XI:% L D I %€'#!h W B XLGKW ? 9

0

0 0

LANGUAGE SCREENING IN PRESCHOOL CHINESE CHILDREN

2 . Chatters a great deal but gives little information.. ............... f&(H , , E W ~ ~ l ~ ~ ~ ~( f+l4@;trlfll l l ~ ~ ,) , E ~ l l ~ ~ ~ ~

263

0

0

3. Frequently makes irrelevant remarks which recur in conversation ........................................................................

0

H&D*~WI~XI~~A%V~~~~~W 0

IV. Muddling of word sequences: 1. Muddles or gets words in wrong order: fb ,,EWilk66#? G W D hTF&M@

mm : ,,w rag]

. ,mr eftti

in a few sentences) or ................................................. in many sentences? ................................................ (*score 2 points when checked)

V. Tone of voice: 1. Speaks too loudly a&W,&K+kAt$

..........................................

0

........................................... ,pfj,&~+k&j@ o

0 Speaks too monotonously, with no change in pitch o r tone.. ............ 0

2. Speaks too softly 3.

0

0 ( )*

i&@$ANiln%’ *%tl%@iBl~PB 0

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BAX, M. &HART, H. (1976). Health needs of preschool children. Arcgves of Dkeme of Childhood 51, 848. BAX, M . , HART, H. &JENKINS, s. (1980). Assessment of speech and language development in the young

child. Pediatrics 63, 350-354.

v. M. & ADAMS. c. (1990). A urosuective studv of the relationshiu between sDecific language impairment, phonological disbrdek a i d reading ietardation. Journd of Child psychology a i d Psychiatry 31, 1027-1050. CALMAN, M. & RICHARDSON, K . (1976). Speech problems in a national survey: assessments and prevalance. Child Care, Health and Development 2 , 181-202. CANTWELL, D. P. & BAKER, L. (1977). Psychiatric disorder in children with speech and language retardation: a critical review. Archives of General Psychiatry 34, 583-591. CANTWELL, D. P . , BAKER, L. & MAITISON, R. E. (1979). The prevalence of psychiatric disorder in children with speech and language disorders: an epidemiologic study. Journal of American Academy and Child Psychiatry 18, 450461. CHAZAN, M . , LAING, A . F . , BAILEY, M. s. &JONES, G. (1980). Some of our Children: The Early Education of Children with Special Educational Needs. London: Open Books. COOPER, J., MOODLEY, M. & REYNELL, J. (1979). The Developmental Language Programme. Results from a five-year study. British Journal of Disorders of Communication 14, 54-69. DRILLIEN, c. & DRUMMOND, M. (1983). Speech disorder and severe hearing loss. In Developmental Screening and the Child with Special Needs, Chap. 8, pp. 143-165. Clinics in Developmental Medicine, No. 86. London: SIMP with Heinemann Medical; Philadelphia: Lippincott. FERGUSSON, D. (1980). Some factors contributing to language development in three year old children. British Journal of Disorders of Communication 15, 205-214. FUNDUDIS, T . , KOLVIN, I. & GARSIDE, R. F. (Eds) (1979). Speech Retarded and Deaf Children: Their Psycholo ical Development. London: Academic Press. GRIFFITHS, R. f1970). The Abilities of Young Children. London: Child Development Research Centre. GRIFFITHS, R. (1984). The Abilities of Young Children, revised edn. Buckinghamshire: The Text Agency Ltd. HERBERT, G . w. & WEDELL, K . (1970). Communication handicaps of children with specific language deficiency. Paper presented at the Annual Conference of the British Psychological Society, Southampton. HONG KONG SOCIETY FOR CHILD HEALTH AND DEVELOPMENT (1987). Reynell Development Language Language Scales, Cantonese (Hong Kong) version, Manual. JENKINS, s., BAX, M. & HART, H. (1970). Behavior problems in preschool children. Journal of Child Psychology and Psychiatry 21, 5-17. LEE, P. w . H . , LUK, E. s. L . , BACONSHONE, J . , LAU, J . , WONG, v. & KO, L. (1990).The DevelopmentalLanguage Screening Scale: a validation and normative study. Hong Kong Journal of Paediatrics 1,7-22. BISHOP. D.

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P.w.H., LUK, E. s. L., YU, K . K . & BACONSHONE, I. (1985). A developmental language screening scale for use in Hong Kong. Hong Kong Journal of Paediatrics 2, 152-175. LUK, s. L., BACONSHONE, J . & LEUNG, w. L. P. (1991). Behaviour disorder in preschool children in Hong Hong. A two-stage epidemiological study. British Journal of PsychiatT 158, 213-221. MacKEITH, R. c . & R U m R , M. (1972). A note on the prevalence of speech and language disorders. In: M. Rutter & J. A. M. Martin (Eds), The Child with Delayed Speech, Chap. 4, pp. 48-51. Clinics in Developmental Medicine, No. 43. London: SIMP with Heinemann; Philadelphia: Lippincott. MCQUIRE, J. & RICHMAN, N. (1986). Screening for behavior problems in nurseries: The reliability and validity of the Preschool Behaviour Checklist. Journal of Child Psychology, Psychiatry and Allied Disciplines 27, 7-32. MARGE, M . (1972). The general problems of language disabilities in children. In: J. W. Irwin & M. Marge (Eds), Principles of Childhood Language Disab , pp. 75-98. New York: Appleton-Century-Crofts. MECHAM, MJ. (1953). Verbal Language Development Scale. American Guidance Service. MORLEY, M. E. (1965). The Development and Disorders of Speech in Childhood, 2nd edn. Edinburgh: E. & S. Livingstone. PECKHAM, c. s. (1973). Speech defects in a national sample of children aged seven years. British Journal Disorders of Communication 8, 2-8. PECKHAM, c. s. (1978). Follow-up to 16 years of school children who had marked speech defects at 7 years. Child Care, Health and Development 4, 145-157. RANDALL, D., REYNELL, J . & CURWEN, M. (1974). A study of language development in a sample of three-year-old children. British Journal of Disorders of Communication 9, F 1 6 . RESCORLA, L. (1989). The Language Development Survey: a screening tool for delayed language in toddlers. Journal of S eech and Hearing Disorder 54, 587-599. REYNELL, J . 1969 . 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Address correspondence to Dr V. Wong, Department of Paediatrics, University of Hong Kong, Queen Mary Hospital, Pokfulam Road, Hong Kong.

Received July 1991; revised version accepted May 1992.