Content of this journal is licensed under a Abstract
Background:
This study investigates the language development of children at risk for developmental language disorder (DLD) 2 years after initial assessment and evaluates the impact of parental training on language outcomes.
Methods:
Sixteen children (9 boys and 7 girls) who were at risk for DLD 2 years ago and whose parents were trained after the initial assessment were re-evaluated. During the study period, children’s language development was evaluated using the Denver II Developmental Screening Test and the Turkish Adaptation of the Test of Early Language Development (TEDIL). Parents’ perceptions of their children’s language skills were also assessed.
Results:
At the second evaluation, 31.25% of the children were diagnosed with DLD, while 68.75% reached a normal language development level. TEDIL test results showed a significant increase in expressive and overall spoken language scores in children without DLD. Parents reported that their children’s overall levels of communication, expression, and intelligibility increased significantly over 2 years.
Conclusion:
In this study, it was determined that some of the children at risk of DLD were diagnosed with DLD after 2 years. Long-term follow-ups of children at risk of DLD were also observed. Early parent training is beneficial in supporting language development in children at risk for DLD, emphasizing the importance of early intervention.
Main Points
Risk of developmental language disorder (DLD) can be identified in children before it occurs.
In the literature, longitudinal studies on the level of language skills of children at risk of DLD in the following years are limited.
Children at risk of DLD should be identified and followed up before its occurrence.
Children at risk for DLD seem to benefit from early parent training in terms of language development, highlighting the significance of early intervention.
Introduction
Language impairment can be defined as an individual’s difficulty in understanding the person with whom he or she communicates, creating barriers in learning environments and in expressing himself or herself verbally.1,2
In the multinational and multidisciplinary Delphi Consensus CATALISE panel organized to reach a consensus on the definition and terminology of language disorder, the subgroups “Developmental Language Disorder (DLD)” and “X-Linked Language Disorder” were included under the umbrella term of language disorder. A diagnosis of developmental language disorder is made when children reach the age of 5 years and their receptive and/or expressive language problems are not due to any biomedical cause.3 The term “at risk of developmental language disorder” (”rDLD”) is used for children at risk of developing a developmental language disorder before the age of 5 years.4
The phonology, morphology, syntax, semantics, pragmatics, word-finding skills, verbal learning, and memory skills of children with developmental language impairment may be affected, but problems in these skills may be observed individually or in various combinations.5-9 The first signs of delay in the acquisition of the syntactic component of language in developmental language disorder are observed between 18 and 24 months of age, with problems in making spontaneous word combinations.10,11 Limited expressive vocabulary and language delay in the early period have been shown to be risk factors for the persistence of language problems in the later period.12-14
In the literature, longitudinal studies on the level of language skills of children with rDLD in the following years are limited. In general, the studies are cross-sectional, and there is no long-term follow-up with children. In these studies, it is not known how many children will be diagnosed with DLD in the future. Furthermore, it is not clearly stated whether the families of these children were given post-assessment informative education and how many of them received post-assessment speech and language therapy. Therefore, the primary aim of this study was to evaluate the language development of children with rDLD an average of 2 years after the initial assessment and to determine whether they would be diagnosed as having DLD. The secondary aim was to examine the change and effect of factors that may affect language development, such as productive time, screen exposure, interactive play, reading, peer interaction, and speech and language therapy, in the 2 years after the initial assessment.
In addition, this study aimed to examine the changes in language skills between children with and without DLD in terms of variables such as gender, parental age, maternal education, paternal education, kindergarten attendance, special education attendance, receiving speech and language therapy, reading books, change in phone/tablet use, spending interactive time, and receiving intensive education.
Material and Methods
The study was conducted at İzmir Bakırçay University University, Faculty of Health Sciences, Department of Speech and Language Therapy, with the İzmir Bakırçay University ethics committee (Approval No:1596/ Decision No:1576, Date:02.05.2024).
Participants
Two years ago, 25 children who presented to the Hacettepe University Hospitals Department of Speech and Language with the complaint of language delay and who were included in the study according to the following inclusion and exclusion criteria were called for re-evaluation. Characteristics of the children : (a) receptive language and/or expressive language development not compatible with chronological age; (b) bilateral peripheral hearing at the normal limit; (c) chronological age between 24 months and 48 months; (d) Turkish as the first language; (e) no additional disability; (f) being “normal” except for language development in the Denver II Developmental Screening Test; and (g) never having received speech and language therapy before. The exclusion criteria were having severe reading comprehension problems and severe hearing problems. This study was conducted with 16 children (9 boys and 7 girls) with a mean age of 64.4 ± 6.27 months who were invited to participate in the study by calling the parents of the children in this study and who volunteered to participate. The sociodemographic characteristics of the participants are shown in Table 1.
Table 1.
Comparison of Sociodemographic Characteristics of Children with and without DLD
| Non-DLD (n = 11) | DLD (n = 5) | P | |
|---|---|---|---|
| Mother education median (min-max) | 16 (5-18) | 5 (5-16) | .247 |
| Father education median (min-max) | 12 (5-16) | 12 (5-16) | .464 |
| Mother Age median (min-max) | 37 (29-46) | 39 (29-46) | .955 |
| Father Age median (min-max) | 38 (32-48) | 40 (36-48) | .333 |
| Child age (months) median (min-max) | 63 (55-73) | 67 (58-78) | .495 |
DLD, developmental language disorder.
Procedure
In this study, firstly, the parents of the children who were evaluated 2 years ago and whose families were educated about language development were called and invited to the study for re-evaluation by giving information about the study. The Denver Developmental Screening Test II and Turkish Early Language Development Test-TEDIL, which were performed in the first evaluation, were performed again. In addition, the language development of the child was questioned not only with standardized tests but also according to family opinion. The whole process of the study is summarized in Figure 1.
Figure 1.
Summary of the procedure for the study.
Assessment Tools
The Denver II Developmental Screening Test:
The test is used to detect possible developmental problems in apparently healthy children. It consists of 134 items grouped into 4 sections: personal-social, fine motor-sensory, language, and gross motor. The application of the test starts at the point appropriate for the child’s age and is scored as “pass,” “remain,” “impossible,” and “reject.” According to the scores, it is interpreted as “normal,” “abnormal,” “suspicious,” and “untestable.”15 Turkish adaptation of the Test of Early Language Development (TEDIL) is a norm- referenced test that aims to measure the receptive and expressive language skills of children aged 2-7 years and 11 months. The test contains 76 items. The standard scores of receptive, expressive, and overall spokenlanguage scores are calculated according to the child’s response. Children who score between 85 and 115 standard points on the TEDIL receptive and expressive language subtests can be identified as children in the normal range, while those who score below 85 standard points can be identified as children whose receptive and/or expressive language development is below the general average.16
Language Assessment of the Child Based on Family Counseling:
According to the family's opinion, 4 components were evaluated: general communication level, comprehension level, expression level, and intelligibility of the child’s speech. The questions were: “What do you think is your child’s level of communication? Please rate between 0 and 4,” “What do you think your child’s level of understanding is? Please rate between 0 and 4,” “What do you think is your child’s level of expression? Please rate between 0 and 4,” “What do you think is your child’s speech intelligibility? Please rate between 0 and 4.” Families were asked to rate each question item as very good: 0, good: 1, average: 2, bad: 3, very bad: 4. They were asked to answer this for 2 years ago and for the current situation. Parental Training (Family Education) A comprehensive training program was offered to families to support the language development of children at risk of DLD. During the training process, approximately 2 hours were spent with each child and his or her family, during which time stories were read, games were played, and developmental and language tests were conducted. During the tests, breaks of approximately 20 minutes each were taken. In addition, 40 minutes of video recordings were taken to observe children’s skills such as storytelling, taking turns, and establishing common interests. During the training, families were interviewed one-on-one for at least 30 minutes without children, and during this interview, methods of communicating with children and supporting language development were explained in detail. Families were advised on the points they should pay attention to when communicating with children: how to attract children’s attention, turn-taking skills, establishing common interests, asking questions, and telling stories. In addition, how to increase speech attempts according to the needs of the child, how to expand what they speak, how to provide instructions, motivate, confirm, set limits, make eye contact, and increase the stay at the table in communication techniques were shown practically. During the training, detailed information about what language and speech are, the general language development of children, the target development levels of each child, and what needs to be done to reach these levels was presented. Factors affecting speech and language development were discussed, and families were informed about behavior training and rule-setting for children. Warnings were given about how daily routines can be used in language development, playtime and materials, reading techniques, and television use. In addition, resources were suggested for activities at home to improve attention, language development, and general development; daycare centers were recommended for children; and child mental health consultation was recommended. Hearing tests were performed for each child, and treatment was recommended when necessary. Families were informed about the risks that children may face if the recommendations were not followed.
Communication techniques to improve language development were shown as a model, and these techniques were discussed in detail. Families were guided on how to apply these techniques to support their children’s language development. The training process encouraged families to actively participate in their children’s language development and ensured that they were informed about strategies to support language development. In this way, it aimed at improving children’s language skills with the correct guidance of the parents and reduce the risk of DLD.
Statistical Analysis
The data obtained were analyzed with SPSS 26 (IBM SPSS Corp.; Armonk, NY, USA). For descriptive analyses, categorical variables were evaluated as numbers and percentages, and numerical variables were evaluated as median (minimum-maximum). The change in the data before and after the test was analyzed by the Wilcoxon test for dependent groups.
After the second evaluation, comparisons between children with and without DLD were made using the Mann-Whitney U test. Fisher’s exact test was used to compare categorical data. P < .05 was accepted as the significance level.
Results
In the second assessment, 2 girls (28.57% of the girls) and 3 boys (33.33% of the boys) in total failed the Denver II language section again, and the same 5 children scored below 85 points on the TEDIL verbal language standardized composite score. These 5 children were diagnosed with DLD because they were now 5 years old. While 68.75% of the 16 children who participated in the study caught up with their normal peers in terms of language development, 31.25% were found to have DLD.
There was no statistically significant difference between the groups (DLD and non-DLD) in terms of mother’s education, father’s education, parents’ age, or children’s age (P > .05) (Table 1).
In all children, DLD and non-DLD, the TEDIL receptive language standard scores did not show a statistically significant difference between the secondand initial values (P > .05). However, TEDIL expressive language and overall spoken language standard scores increased statistically significantly in all children and non-DLD groups(P = .002 and P = .004, respectively). While there was no statistically significant change in the scores of expressive language and verbal combined language in children with DLD at the last assessment, 2 scores increased statistically significantly in children without DLD except for “TEDIL Receiving Language” scores (Table 2).
Table 2.
Changes in the Participants’ TEDIL Scores in the Last Evaluation Compared to the First Evaluation
| n | Before Median (Min-Max) | After Median (Min-Max) | P | ||
|---|---|---|---|---|---|
| All children | 16 | TEDIL Receiving Language | 81.0 (68-100) | 87.5 (52-106) | .205 |
| TEDIL Expressive Language | 75 (50-97) | 93.5 (54-114) | .002 | ||
| TEDIL Overall SpokenLanguage | 79.5 (56-87) | 89 (44-110) | .004 | ||
| Non-DLD | 11 | TEDIL Receiving Language | 88 (73-100) | 92 (80-106) | .119 |
| TEDIL Expressive Language | 82 (53-97) | 95 (91-114) | .004 | ||
| TEDIL OverallSpoken Language | 83 (56-87) | 94 (84-110) | .003 | ||
| DLD | 5 | TEDIL Receiving Language | 72 (68-86) | 80 (52-80) | 1.000 |
| TEDIL Expressive Language | 68 (50-74) | 72 (54-84) | .273 | ||
| TEDIL OverallSpoken Language | 63 (60-68) | 71 (44-78) | .500 |
TEDIL, test of early language development.
“When the gender-based first and second assessment results were analyzed, the TEDIL expressive score increased statistically significantly in both girls and boys (P < .05) (Table 3). While therewas a significant difference in the “TEDIL Overall Spoken Language” score in the second evaluation compared to the first evaluation in girls, there was nosignificant difference in the score of boys (Table 3).
Table 3.
Cha nge in Gender-Based TEDIL Results
| n | Before Median (Min-Max) | After Median (Min-Max) | P | ||
|---|---|---|---|---|---|
| Girls | 7 | TEDIL Receiving Language | 86 (68-99) | 86 (76-103) | .866 |
| TEDIL Expressive Language | 82 (50-97) | 93 (72-114) | .046 | ||
| TEDIL Overall SpokenLanguage | 83 (61-87) | 88 (70-110) | .018 | ||
| Boys | 9 | TEDIL Receiving Language | 76 (70-100) | 92 (52-106) | .155 |
| TEDIL Expressive Language | 74 (53-82) | 94 (54-108) | .015 | ||
| TEDIL Overall SpokenLanguage | 68 (56-85) | 90 (44-108) | .051 |
TEDIL, test of early language development.
According to family opinion (4 components were evaluated: general communication level, comprehension level, expression level, and intelligibility of the child’s speech); in the child language assessment analysis of 16 children with rDLD , a significant difference was found for these 4 variables (P < .05) (Table 4).
Table 4.
Change in rDLD Child Language Assessment Results According to Family Opinion
| n | Before Median (Min-Max) | After Median (Min-Max) | P | |
|---|---|---|---|---|
| rDLD comprehension | 16 | 1.50 (1-4) | 0 (0-1) | <.001 |
| rDLD expression | 16 | 3 (2-4) | 0 (0-2) | <.001 |
| rDLD General communication level | 16 | 3 (2-4) | 0 (0-2) | <.001 |
| rDLD intelligibility | 16 | 3 (2-4) | 0 (0-2) | .001 |
rDLD: Risk of Developmental Language Disorder
There was no statistically significant difference between the groups in terms of sibling status, going to nursery, going to special education, peer interaction, interactive book reading, change in phone and tablet use, spending interactive time, intensive education, or going to a speech and language therapist (P > .05) (Table 5).
Table 5.
Comparison of the Factors That May Affect Language Development of Children with and without DLD
| DLD | Non-DLD | P | ||
|---|---|---|---|---|
| Sibling status | None | 5 | 8 | .509 |
| There is | 0 | 3 | ||
| Going to nursery | Yes | 5 | 9 | 1.000 |
| No | 0 | 2 | ||
| Special education | Yes | 2 | 2 | .547 |
| No | 3 | 9 | ||
| Go to SLP | Yes | 2 | 2 | .547 |
| No | 3 | 9 | ||
| Spending time with peers | Yes | 3 | 10 | .214 |
| No | 2 | 1 | ||
| Reading a book | There is | 2 | 10 | .063 |
| None | 3 | 1 | ||
| Phone tablet use | Decreased | 4 | 8 | 1.000 |
| Same | 1 | 3 | ||
| Interactive time | Same | 2 | 2 | .547 |
| Increased | 3 | 9 | ||
| Intensive training | Yes | 2 | 8 | .299 |
| No | 3 | 3 |
DLD, developmental language disorder; SLP, speech and language pathologist.
Discussion
In this study, the changes in the language development levels of children at risk for DLD 2 years later and the factors that may have an effect on these changes were analyzed. Changes in children’s language skills were assessed with standardized tests such as Denver and TEDIL, while language assessment was based on subjective parental reports. Since the children are now 5 years old, it was possible to determine whether they were diagnosed with DLD according to the delay in their current language skills. Factors such as parental age, education, reading books, and spending interactive time that may affect language development between children with and without DLD were also analyzed. In addition, in this study, the language development of children over 2 years was also compared based on gender.
In this study, it was determined that 31.25% of children at risk of DLD had DLD. This situation shows that children at risk of DLD should be followed up in the long term. In addition, it is a pleasing finding that 68.75% of the children initially considered at risk were not diagnosed with DLD.
In the literature, male gender is stated as a risk factor for DLD.17,18 Chilosi et al (2023), in their review of language development and disorders in both sexes, stated that evidence suggests that the female sex has a neurobiological advantage over the male sex in the early stages of language acquisition and that males are more vulnerable to language delay and language disorders.19 In this study, more individuals with DLD were found to be male. However, when the language results at the first and last assessments were compared in this study, it was observed that the expressive language and verbal language composite scores of the children increased statistically significantly at the second assessment in all participants, both boys and girls, compared to the first assessment after 2 years. When gender-based changes in language development were examined, similar progress was observed in both boys and girls, suggesting that both genders developed similarly. This finding shows that although boys are at greater risk in language development, as stated by Bishop and Leonard (2014), significant improvements can be achieved with appropriate counseling.20
Two years later, a statistically significant increase was observed in children’s expressive language at the second assessment compared to the first assessment, both for all participants and for boys and girls separately. The lack of an increase in receptive language scores is an expected result because children were within normal limits at the first assessment. The children were determined to be at risk for DLD in the first evaluation because their expressive language scores were below 85. The increase in expressive language standard scores in these children 2 years later increased overall spoken language scores. In the literature, in a study that divided children at risk of DLD into experimental and control groups with and without intervention, children were followed up until the age of 3.21 In this study, Ward stated that 85% of the control group showed language delay at the age of 3, but only 5% of the experimental group showed language delay. McGillion et al. (2017) showed in their randomized controlled trial that it is possible to increase carer contingent talk with a low-intensity intervention and that this is effective in supporting vocabulary development for infants in the short term. They also pointed out that follow-up interventions may be necessary to ensure benefits that will last until school entry.22 It was observed that this study’s findings were consistent with the findings in the literature and that there was a significant increase in expressive language and verbal language composite scores with the training provided. The common point of these studies is that either training or intervention was given to children at risk of DLD. In this study, providing education to support the language development of children may be the major factor in obtaining these findings. In addition, it is thought that the long-term follow-up conducted within the scope of this study may pave the way for further studies.
When the language skills of children were analyzed according to parental statements, it was reported that expressive and general communication skills increased, according to the families, in all children with rDLD. However, this increase was not significantly observed in the standardized TEDIL and Denver tests in children with DLD. This situation shows that it may not always be sufficient to evaluate according to family statements. In the literature, it is also pointed out that care should be taken when evaluating family statements.23 Because situations that are considered normal according to families may cause children to be assessed late and to start therapy late. This may affect children’s future academic and social success. Similar to hearing screening at certain age intervals, children’s language skills should also be screened. In this way, situations that families do not care about, overlook, or consider normal can be prevented. This situation, which is frequently encountered in clinics and causes obstacles in development, may occur when speech and language therapists state that children’s language development is not compatible with their peers and that they should receive therapy, while families consider their children’s language development as normal and think that it will improve on its own. This may lead to children not benefiting from the therapy and not listening to the recommendations of the speech-language pathologist (SLP). For this reason, first, families should be educated about the process of language development in children, and their knowledge and awareness should be increased.
As a remarkable point in this study, contrary to the TEDIL reseptive language scores, the families of children with rDLD thought that their children’s comprehension skills increased. Here, families may have focused on comprehension skills the most in language skills. In their study, Schachinger-Lorentzon et al. (2018) pointed out that parents of children with mixed language disorders were more concerned about speech than language, while their awareness of language comprehension skills was low. They also state that children with DLDuse non-verbal cues to communicate and that parents of these children have difficulty distinguishing that they only understand the communication situation but do not understand the spoken language.24 In this study, it is thought that the fact that families focus on language comprehension skills may be due to the education provided.
Studies have shown that parental age and education are important in the development of children’s language skills.25-27 However, in this study, no statistically significant difference was found between the education and age of the parents of children with and without DLD. This led us to focus on other factors, such as the education received between the groups and the family’s contribution to language development (such as reading books, playing interactive games, and screen exposure).
In the literature, there are studies examining the effects of reading books on the language development of children at risk of developmental language delay.
When the studies were analyzed, Sénéchal and LeFevre (2002) reported that children’s exposure to books was associated with the development of vocabulary and listening comprehension skills within the scope of their 5-year longitudinal study.28 Roberts, Jergens, and Burchinal (2005) examined how home literacy predicts children’s language and emergent literacy skills between the ages of 3 and 5. They reported that the general responsiveness and support of the home environment were the strongest predictors of children’s language and early literacy skills and contributed over and above certain measures of literacy practice in predicting children’s early language and literacy development.29 Although the positive effects of book reading on language development are mentioned in the literature, Storkel et al. (2019) stated that although interactive book reading continues to show promise as an effective vocabulary learning intervention for children with DLD, further studies are needed to increase the effectiveness of this treatment approach. They also concluded that differences in the dose and frequency of interactive book reading do not appear to affect vocabulary learning in children with DLD when administered with sufficient intensity.30 It was emphasized that studies to increase the effectiveness of book reading are needed. In this study, no significant difference was found between reading books and language development. This was thought to be due to the small sample size.
This study has some limitations. The first is that the number of participants consisted of 16 children. Another limitation is that the parent language assessment consists of only 4 general questions. A detailed parental language assessment questionnaire was not conducted. Future studies can be carried out with more participants by applying a more detailed parental questionnaire. One of the limitations was the lack of a control group. As these children were at risk of developing DLD, it was not feasible and would raise ethical concerns to form a group that received no parental training, which hindered the robustness of the results.
In conclusion, in this study, it was determined that some of the children at risk of DLD were diagnosed with DLD after 2 years. It was observed that long-term follow-up of children at rDLD and raising awareness among families are of great importance. In language assessments, it has been observed that not only home statement but also standardized tests should be performed. The education given to families was effective in supporting children’s language development and reducing the rDLD. This study emphasizes the positive effects of family education on children’s language development and provides a basis for future studies. This study once again confirms that early family education plays a critical role in supporting children’s language development.
Funding Statement
The authors declared that this study has received no financial support.
Footnotes
Ethics Committee Approval: The study was approved by the Ethics Committee of İzmir Bakırçay University (Approval No: 1596, Date: 02.05.2024).
Informed Consent: Written informed consent was obtained from the participants’ parent/legal guardian/next of kin who agreed to take part in the study.
Peer-review: Externally peer-reviewed.
Author Contributions: Concept –Concept – D.Ç., M.M.P., C.Y., A.K.; Design – D.Ç., M.M.P., C.Y., A.K.; Supervision – A.K., G.Ö.; Resources – D.Ç., C.Y.; Materials – A.K., G.Ö., Ç.E., E.K.T.; Data Collection and/or Processing – D.Ç.; Analysis and/or Interpretation – M.M.P., G.Ö., Ç.E., E.K.T.; Literature Search – A.K., G.Ö.; Writing Manuscript – D.Ç., C.Y.; Critical Review – A.K., G.Ö.
Declaration of Interests: The authors have no conflict of interest to declare.
Data Availability Statement:
The data that support the findings of this study are available upon request from the corresponding author.
References
- 1. Tomblin JB Records NL Buckwalter P Zhang X Smith E O’Brien M. . Prevalence of specific language impairment in kindergarten children. J Speech Lang Hear Res. 1997;40(6):1245 1260. (doi: 10.1044/jslhr.4006.1245) [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2. Leonard LB. . Specific language impairment across languages. Child Dev Perspect. 2014;8(1):1 5. (doi: 10.1111/cdep.12053) [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3. Bishop DV Snowling MJ Thompson PA Greenhalgh T and the CATALISE-2 consortium. . Phase 2 of CATALISE: A multinational and multidisciplinary Delphi consensus study of problems with language development: terminology. J Child Psychol Psychiatry. 2017;58(10):1068 1080. (doi: 10.1111/jcpp.12721) [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4. St Clair MC Forrest CL Yew SGK Gibson JL. . Early risk factors and emotional difficulties in children at risk of developmental language disorder: A population cohort study. J Speech Lang Hear Res. 2019;62(8):2750 2771. (doi: 10.1044/2018_JSLHR-L-18-0061) [DOI] [PubMed] [Google Scholar]
- 5. Akagündüz N Kiriş M Parlak MM. . An evaluation of the Speech and Language skills of children who pass school-age hearing screening tests according to risk factor. B-ENT. 2023;19(4):232 241. [Google Scholar]
- 6. Baş B, PM. İşitme Kayıplı Çocuklarda İletişim ve Bilişsel Fonksiyonlar. Akademisyen Kitabevi; 2022. [Google Scholar]
- 7. McGregor KK. . Semantics in child language disorders. In: Handbook of Child Language Disorders. Psychology Press; 2017:392 415. [Google Scholar]
- 8. McGregor KK Oleson J Bahnsen A Duff D. . Children with developmental language impairment have vocabulary deficits characterized by limited breadth and depth. Int J Lang Commun Disord. 2013;48(3):307 319. (doi: 10.1111/1460-6984.12008) [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9. Gray S. . Word Learning by Preschoolers with Specific Language Impairment; 2005. [Google Scholar]
- 10. Rescorla L. . Age 17 language and reading outcomes in late-talking toddlers: support for a dimensional perspective on language delay. J Speech Lang Hear Res. 2009;52(1):16 30. (doi: 10.1044/1092-4388(2008/07-0171)) [DOI] [PubMed] [Google Scholar]
- 11. Lee EC Rescorla L. . The use of psychological state terms by late talkers at age 3 . Applied Psycholinguistics, 2002;23(4): 623 641. [Google Scholar]
- 12. Reilly S. The Early Language in Victoria Study (ELVS): A prospective, longitudinal study of communication skills and expressive vocabulary development at 8, 12 and 24 months. Int J Speech Lang Pathol. 2009;11(5):344 357. [Google Scholar]
- 13. Miniscalco C Westerlund M Lohmander A. . Language skills at age 6 years in Swedish children screened for language delay at 2½ years of age. Acta Paediatr. 2005;94(12):1798 1806. (doi: 10.1111/j.1651-2227.2005.tb01856.x) . [DOI] [PubMed] [Google Scholar]
- 14. Singleton NC. . Late Talkers: Why the Wait-and-See Approach Is Outdated; vol 65(1). Pediatric Clinics; 2018:13 29. [DOI] [PubMed] [Google Scholar]
- 15. Anlar B Yalaz K. . Denver II Developmental Screening Test, Adaptation and Standardization in Turkish Children. Hacettepe University; 1995. (Denver II, Tarama G. Testi, Turk Cocuklarina Uyarlanmasi Ve Standardizasyonu. Hacettepe Universitesi), Ankara, Turkey. [Google Scholar]
- 16. Topbaş S Güven S. . TEDİL: Türkçe Erken Dil Gelişim Testi Kullanım Klavuzu . TC: Detay Yayıncılık, 2013. [Google Scholar]
- 17. Reilly S, Wake M, Ukoumunne OC. Predicting language outcomes at 4 years of age: findings from Early Language in Victoria Study. Pediatrics. 2010;126(6):e1530-e1537. (doi: 10.1542/peds.2010-0254) . [DOI] [PubMed] [Google Scholar]
- 18. Zubrick SR. Late Language Emergence at 24 Months: an epidemiological study of prevalence, predictors, and covariates. J Speech Lang Hear Res. 2007;50(6):1562-1592. (doi: 10.1542/peds.2010-0254) . [DOI] [PMC free article] [PubMed] [Google Scholar]
- 19. Chilosi AM Brovedani P Cipriani P Casalini C. . Sex differences in early language delay and in developmental language disorder. J Neurosci Res. 2023;101(5):654 667. (doi: 10.1002/jnr.24976) . [DOI] [PubMed] [Google Scholar]
- 20. Bishop DV Leonard LB. . Speech and Language Impairments in Children: Causes, Characteristics, Intervention and Outcome. Psychology press; 2014. [Google Scholar]
- 21. Ward S. . An investigation into the effectiveness of an early intervention method for delayed language development in young children. Int J Lang Commun Disord. 1999;34(3):243 264. [DOI] [PubMed] [Google Scholar]
- 22. McGillion M, Pine JM, Herbert JS, Matthews D. A randomised controlled trial to test the effect of promoting caregiver contingent talk on language development in infants from diverse socioeconomic status backgrounds. J Child Psychol Psychiatry. 2017;58(10):1122 1131. (doi: 10.1111/jcpp.12725) . [DOI] [PubMed] [Google Scholar]
- 23. Paul R Norbury C. . Language Disorders from Infancy Through Adolescence-E-book: Language Disorders from Infancy Through Adolescence-E-book. Elsevier Health Sciences; Amsterdam; 2012. [Google Scholar]
- 24. Schachinger-Lorentzon U Kadesjö B Gillberg C Miniscalco C.. Children screening positive for language delay at 2.5 years: language disorder and developmental profiles. Neuropsychiatr Dis Treat. 2018;14:3267 3277. (doi: 10.2147/NDT.S179055) . [DOI] [PMC free article] [PubMed] [Google Scholar]
- 25. Hoff E. . How social contexts support and shape language development. Dev Rev. 2006;26(1):55 88. [Google Scholar]
- 26. Hoff E. . The specificity of environmental influence: socioeconomic status affects early vocabulary development via maternal speech. Child Dev. 2003;74(5):1368 1378. (doi: 10.1111/1467-8624.00612) . [DOI] [PubMed] [Google Scholar]
- 27. Hoff-Ginsberg E. . The relation of birth order and socioeconomic status to children’s language experience and language development. Appl Psycholinguist. 1998;19(4):603 629. [Google Scholar]
- 28. Sénéchal M, LeFevre JA. Parental involvement in the development of children’s reading skill: A five‐year longitudinal study. Child Dev. 2002;73(2):445 460. (doi: 10.1111/1467-8624.00417) . [DOI] [PubMed] [Google Scholar]
- 29. Roberts J Jergens J Burchinal M. . The Role of Home Literacy practices in preschool children’s language and emergent literacy skills . 2005. [DOI] [PubMed] [Google Scholar]
- 30. Storkel HL Komesidou R Pezold MJ Pitt AR Fleming KK Romine RS. . The impact of dose and dose frequency on word learning by kindergarten children with developmental language disorder during interactive book reading. Lang Speech Hear Serv Sch. 2019;50(4):518 539. (doi: 10.1044/2019_LSHSS-VOIA-18-0131) [DOI] [PMC free article] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
The data that support the findings of this study are available upon request from the corresponding author.