Table A3.
Characteristics of the 27 selected primary studies.
| Authors, Year, Reference | Study Design, Setting |
Participants | Age (Months) | Language of Assessment | Language Domain/Task | Test/Assessment Tool |
|---|---|---|---|---|---|---|
| Azab and Ashour, 2015 [91] |
Observational, cross-sectional; clinical setting |
N = 60 (30 DLD + 30 TD) | 48–70 | Arabic | -Prosody | -Protocol of prosodic assessment; Clinical criteria: -Arabic language test |
| Benavides et al., 2018 [99] |
Observational, cross-sectional; clinical setting |
N = 770 (184 DLD + 586 TD) 4 y = 73 DLD + 189 TD 5 y = 63 DLD + 245 TD 6 y = 48 DLD + 152 TD |
48–72 | Spanish (Mexico) | -Expressive grammar | Tamiz de Problemas de Lenguaje (Morphology task and sentence repetition task) Clinical criteria: -Subtests of BESA = Bilingual English–-Spanish Assessment. -CELF-4 = Clinical Evaluation of Language Fundamentals -MLU = mean length of utterance |
| Bello et al., 2018 [86] |
Observational, longitudinal; clinical setting |
N = 35 LT | T0: 29 T1: 34 |
Italian | - Receptive and expressive lexicon -Socio-conversational abilities |
Clinical criteria: -MacArthur–Bates Infant and Toddler Communication Development Inventories. (Italian version of the MB-CDI Short and Long Form) -Parole in Gioco-PiNG, Test of noun and predicates comprehension and production -Questionnaire of socio-conversational abilities- ASCB |
| Chilosi et al., 2019 [88] |
Observational, longitudinal; clinical setting |
N = 50 LT | T0:28 T1:36 T2:48 |
Italian | -Expressive lexicon -Expressive grammar -Syntactic comprehension |
Clinical criteria: -MacArthur–Bates Infant and Toddler Communication Development Inventories. (Italian version of the MB-CDI) -Grid for the Analysis of Spontaneous Speech (GASS). -COVER test of syntactic comprehension |
| Collisson et al., 2015 [93] |
Experimental, cross-sectional; clinical setting |
N = 54 (16 DLD + 38 TD) | 42–58 | English | -Receptive and expressive lexicon -Expressive grammar |
Clinical criteria: -CELF-P2 = Clinical Evaluation of Language Fundamentals -Preschool 2 -PPVT-4 = The Peabody Picture Vocabulary Test—Fourth Edition |
| Conway et al., 2018 [78] |
Observational, longitudinal; home setting |
N = 197 former LT | T0 24 T1:36 T2:48 |
Australian English | -Receptive and expressive lexicon -Receptive and expressive grammar |
Maternal speech in mother–infant interaction Clinical criteria: -The Preschool Language Scale (PLS-4) -The Clinical Evaluation of Language Fundamentals Preschool Edition (CELF-P2) |
| Eisenberg et al., 2019 [98] |
Observational, cross-sectional; setting non specified |
N = 62 (31 LT and 31 TD) | 36 | American English | -Expressive lexicon -Expressive grammar |
-Fluharty Preschool Speech and Language Screening Test–2ed Clinical criteria: -SPELT-P2 = Structured Photographic Expressive Language Test–Preschool, Second Edition. -MLUm = mean length of utterance in morphemes. -IPSyn = Index of Productive Syntax. -FVMC = finite verb morphology composite. |
| Gudmundsson, 2015 [95] |
Observational, cross-sectional; home + clinical setting |
N = 1132 (general population) | 15–38 | Icelandic | -Receptive and expressive language | Toddler Language and Motor Questionnaire |
| Hadley et al., 2016 [85] |
Observational, longitudinal; clinical setting |
N = 45 TD | T0: 21 T1: 24 T2: 27 T3: 30 |
American English | -Expressive lexicon -Expressive grammar |
-Word and sentences version of MB-CDI (21, 24, 27, 30 months). -Recordings of spontaneous language (21–30 months) obtaining measures of expressive language abilities: total length of complete and interpretable utterance, number of word types, mean length of utterance in morphemes (24 and 30 months), measures of vocabulary as number of different nouns and verbs |
| Haman et al., 2017 [74] |
Observational, cross-sectional; school setting |
N = 639 TD | 36–82 | Lithuanian, isiXhosa, Finnish, Afrikaans, British English, South African English, German, Luxembourgish, Norwegian, Swedish, Catalan, Italian, Hebrew, Polish, Serbian, Slovak and Turkish | -Expressive lexicon | Cross-linguistic lexical tasks (LITMUS-CLT) |
| Hsu and Iyer, 2016 [75] |
Observational, longitudinal; setting not specified |
N = 1064 general population | T0: 15 T1: 36 T2: 53 |
American English | -Gesture production -Receptive and expressive lexicon |
-MacArthur–Bates Communicative Development Inventory (MB-CDI) Clinical criteria: -Reynell Development Language Scales (RDLS, 3 years) -Preschool language scale-3 (PLS-3, 4.5 years) |
| Kademann et al., 2015 [87] |
Observational, longitudinal; clinical setting |
N = 86 (46 LT + 40 TD) | T0: 24 T1: 36 T2: 54 |
German | -Receptive and expressive lexicon -Expressive grammar -Phonology - Narrative production -Metaphonology -Verbal memory -Lexical access -RAN (rapid automatized naming) |
Clinical criteria: -SETK-4-5: sentence comprehension (VS), morphological production (plural formation—MR), sentence memory (SG) -Subtest Vocabulary of K-ABC battery |
| Kim et al., 2016 [84] |
Observational, longitudinal; clinical setting |
N = 206 with delayed language development (79 DLD + 19 TD + other pathologies) | 29.7 (average age) | Korean | -Receptive and expressive lexicon -Receptive and expressive grammar |
-Korean version of Ages and Stages Questionnaire (K-ASQ), -MacArthur–Bates Communicative Development Inventories short Korean version (MB- CDI-K) Clinical criteria: -SELSI (Sequenced Language Scale for Infants), -PRES (Preschool Receptive–expressive Language Scale) |
| Klem et al., 2015 [96] |
Observational, longitudinal; school setting |
216 TD monolingual children | T0: 51 T1: 63 T2: 75 |
Norwegian | -Sentence repetition -Expressive grammar |
-Sentence repetition test -‘Grammatic Closure’ from Illinois Test of Psycholinguistic Abilities (ITPA) |
| Lüke et al., 2017 [79] |
Experimental, longitudinal; clinical setting |
N = 59 TD Recruitment strategy emphasized families in which a sibling or one of the parents had a history of language impairment. |
T0: 12 T1: 24 |
German | -Gesture comprehension and production -Receptive and expressive lexicon -Receptive and expressive grammar |
-Analysis of gestural behavior (pointing) at 1;0 year in a semi-natural setting with their caregivers Clinical criteria: -SETK-2 -FRA-KIS |
| Lüke et al., 2020 [80] |
Observational, longitudinal (14 sessions from 1 to 6 years); clinical setting |
N = 42 children (TD: N = 32; LD: N = 10 (at 24 months); of children with LD, N = 2 with DLD from age 3. Same recruitment strategy as in [79]. |
T0: 1;0; T1: 1;2; T2: 1;4; T3: 1;6; T4: 1;9; T5: 2;0; T6: 2;6; T7: 3;0; T8: 3;6; T9: 4;0; T10: 4;6; T11: 5;0; T12: 5;6; T13: 6;0. |
German | -Gesture production and comprehension -Receptive and expressive lexicon -Receptive and expressive grammar -Sentence repetition |
-Analysis of gestural behavior (pointing) at 1;0 year in a semi-natural setting with their caregivers -Iconic gesture test to assess comprehension of iconic gestures at 3;0, 4;0 and 5;0 years Clinical criteria: -German version of the MB-CDI (at 24 months) -ELFRA (at 12 months) -FRAKIS and SETK-2 (at 24 and 30 months) -SETK 3-5 and PDSS (at 36 months) -P-ITPA (at 48, 60, 72 months) -TROG-D (at 60, 72 months) and receptive language |
| Marini et al., 2017 [76] |
Observational, longitudinal; clinical setting |
N = 293 (260 TLD + 33 LT) | T0: 32 T1: 41 |
Italian | -Non-word repetition -Expressive lexicon -Phonology/Articulation -Receptive and expressive grammar -Narrative production |
-Non-word repetition -Language Development Survey (LDS) -Home Literacy Environment Questionnaire (HLEQ) Clinical criteria: -Batteria per la Valutazione del Linguaggio in Bambini dai 4 ai 12 anni (BVL_4-12) |
| Marini et al., 2020 [94] |
Observational, cross-sectional; clinical setting |
N = 40 (TD: N = 24; DLD: N = 16) |
64 | Italian | -Phonology/Articulation -Receptive and expressive grammar -Narrative production |
Inhibition test (NEPSY-II) Clinical criteria: -Batteria per la Valutazione del Linguaggio in Bambini dai 4 ai 12 anni (BVL_4-12) |
| Morgan et al., 2020 [82] |
Observational, longitudinal; clinical/home setting |
N = 408 (159 LT + 249 TD) | T0: 18–21 T1: 24 T2: 36 |
American English | -Communication and symbolic abilities -Receptive and expressive lexicon |
-Communication and Symbolic Behavior Scales (CSBS) -Language Development Survey (LDS) Clinical criteria: -Mullen Scales of Early Learning (MSEL) |
| Nayeb et al., 2019 [89] | Observational, longitudinal; clinical setting |
N = 105 (11 DLD + 94 TD) | T0: 30 T1: 36 |
Swedish | -Word combination | -Evaluation of word combination in child speech -Comprehension test; Clinical criteria: Reynell Development Language Scales- RDLS-III (Swedish); Evaluation of spontaneous communication |
| Puglisi et al., 2020 [100] |
Observational, cross-sectional; school setting |
Study 1: 754 TD Study 2: 100 (92 TD e 8 LD) |
Study 1: 51–65 Study 2: 60–80 |
Brazilian-Portuguese | -Phonology -Expressive lexicon -Expressive grammar |
-Screening for Identification of Oral Language Difficulties by Preschool Teachers (SIOLD) (questionnaire on phonology, vocabulary, grammar). Clinical criteria: -Expressive Vocabulary Test- Short -Test for Reception of Grammar Version 2—Short -The Brazilian Children’s Test of Pseudoword Repetition |
| Quam et al., 2020 [90] |
Observational, cross-sectional; school setting |
N = 52 (26 DLD + 26 TD) | 48–70 | American English | -Sound discrimination -Receptive and Expressive Lexicon |
-Computerized sound discrimination task Clinical criterion: -Peabody Picture Vocabulary Test, Fourth Edition (PPVT-4). -Structured Photographic Expressive Language Test—Preschool: 2nd Edition (SPELT-P2) |
| Sahli and Belgin, 2017 [97] |
Observational, cross-sectional; clinical setting |
N = 1320 (1044 TD; 276 DLD) | 0–95 | Turkish, English | -Auditory Comprehension -Expressive Communication |
Clinical criteria: -Preschool language Scale 5 ed. (PLS-5) -Preschool language Scale 4 ed. (PLS-4) |
| Sansavini et al., 2019 [81] |
Observational, longitudinal; Clinical setting |
N = 110 infants (70 American: -29 TD −41 siblings with no ASD of a child with ASD: 28 no LD, 13 LD; 40 Italian infants: −20 Full Term −20 Extremely preterm: 11 no LD, 9 LD) |
T0: 18 T1: 24 T2: 30 T3: 36 |
American English Italian |
-Gesture production -Expressive lexicon |
Analysis of deictic, conventional, and representational gestures during mother–infant play session at 18 months Clinical criteria: -MB-CDI-WS long form (American and Italian versions) at 18, 24, 30, 36 months -Mullen Scales of Early Learning (Receptive and/or Expressive Language subscales, American version) |
| Suttora et al., 2020 [77] |
Observational, cross-sectional; clinical setting |
N = 61 LT (26 Low-risk preterm; 35 Full Term) |
30 | Italian | -Expressive lexicon -Expressive grammar |
-Parental and child speech collected during a video-recorded 10-min parent–child shared book reading session. Measures: Word types, word tokens, MLU Clinical criteria: -MacArthur–Bates Communicative Development Inventories (MB-CDI) Short Form (Italian version) |
| Tomas et al., 2015 [92] |
Observational, cross-sectional; clinical setting |
N = 30 DLD | 54–71 | Australian English | -Expressive grammar -Non-word repetition |
-Question–answer elicitations of the 30 target items, presented along with picture props Clinical criteria: -PLS—Preschool Language Scale -CELF—Clinical Evaluation of Language Function -articulatory screening (non-word repetition) |
| Vehkavuori and Stolt, 2018 [83] |
Observational, cross-sectional; home/clinical setting |
N = 78 TLD | 24 | Finnish | -Communication and symbolic abilities -Receptive and expressive lexicon |
-MacArthur Communicative Development Inventories (FinCDI-SF) -Communication and Symbolic Behavior Scales, Developmental Profile, Infant-Toddler Checklist (FinCSBS) Clinical criteria: -Reynell Developmental Language Scales III (Finnish version) |
Note. TD—typically developing children; DLD—children with developmental language disorder; LT—late talkers; LD—children with language delay; ASD—Autism Spectrum Disorders.