The Prevalence of Speech and Language Disorders in Patients Referred to Speech Therapy Clinics of Hamadan University of Medical Sciences from 2013 to 2022

EXTENDED ABSTRACT

Background

Speech and language are among the most complex functions of the human brain, and impairment in these functions can substantially affect communication and participation [1]. In children, speech and language disorders may be accompanied by social isolation, mental-health difficulties, learning disability, behavioral problems, and reduced educational achievement [2]. The American Speech-Language-Hearing Association defines prevalence as the number or proportion of affected individuals in a population during a specified period [3]. Reliable prevalence information is therefore relevant both to public-health planning and to speech-language pathologists who must estimate rehabilitation needs and design appropriate services [4]. Previous studies have reported markedly different prevalence estimates depending on the population, age range, sex distribution, language, setting, and classification system. Population and school-based studies have described voice disorders, stuttering, speech-sound disorders, and other communication disorders at different rates [4-14], while studies of patients attending speech-therapy clinics have also shown considerable variation in the relative frequency of speech-sound disorders, language delay, stuttering, and other diagnoses [15-17]. These differences indicate that local service data are needed for practical rehabilitation planning. Since no comprehensive prevalence study had been conducted using the archived records of the speech-therapy clinics affiliated with Hamadan University of Medical Sciences after establishment of the rehabilitation services, the present study aimed to determine the distribution of speech and language disorders among patients referred to these clinics from 2013 to 2022 and to examine differences according to age and sex.

Methods

This descriptive-analytical cross-sectional study used a census of archived clinical records. All available records from four speech-therapy clinics affiliated with Hamadan University of Medical Sciences were reviewed over a 10-year period from 2013 to 2022: Imam Khomeini Comprehensive Clinic, Mobasher Kashani Comprehensive Clinic, the speech-therapy unit of Farshchian Teaching Hospital, and the speech-therapy unit of Be'sat Teaching Hospital. In total, 1,468 records were entered into the initial census. Data were extracted with a researcher-designed checklist containing six main components: year of record creation, clinic name, age, sex, speech/language disorder, and medical diagnosis. Trained researchers reviewed the archived records and entered the required information in coded form without patient names. Records were not automatically excluded when one major variable was missing because other variables in the same record could remain informative; instead, the number of missing observations was reported for each analysis. Data were analyzed in SPSS version 16. Frequency distributions and percentages were calculated. Chi-square tests were used to assess differences in the distribution of speech and language disorders by sex and by age group, and the contingency coefficient was reported to indicate the degree of association. Statistical significance was defined as P<0.05. The project was approved by the Ethics Committee of Hamadan University of Medical Sciences (IR.UMSHA.REC.1402.508), and archived patient information was handled confidentially.

Results

Among all records, the article reports that 67.9% of clients were male and 32.1% were female. Age was incompletely recorded in 51 cases. Among the records with usable age information, the largest group comprised children aged 3-6 years: 741 clients, reported as 51.3% of referrals. The remaining age groups included 134 children younger than 3 years (9.1%), 285 individuals aged 6-18 years (19.4%), and 257 adults older than 18 years (17.5%). Speech/language diagnosis was not correctly recorded in 34 files; analysis of the remaining 1,434 records showed that speech-sound production disorder was the most frequent diagnosis, with 278 cases (18.9%). Speech and language delay was reported in 265 cases (18.1%), fluency disorder in 264 (18.0%), voice disorder in 177 (12.1%), developmental language disorder in 135 (9.2%), swallowing disorder in 36 (2.5%), aphasia in 29 (2.0%), dysarthria in 25 (1.7%), dyslexia in 14 (1.0%), and apraxia of speech in 5 (0.3%). The source article also reports that 191 clients (7.6%) had two or more speech and language disorders; the most frequent combinations were speech/language delay with speech-sound disorder (37 cases, 2.5%), developmental language disorder with speech-sound disorder (29 cases, 2.0%), and fluency disorder with speech-sound disorder (11 cases, 1.2%).

Medical diagnosis was not documented in 1,017 of the 1,468 records. Among the 451 records with a recorded medical diagnosis, the most frequent conditions were laryngeal injury (95 cases, 21.1%), cleft lip/palate (52, 11.6%), cerebral palsy (49, 10.9%), attention-deficit/hyperactivity disorder (39, 8.7%), seizure disorder (37, 8.1%), intellectual disability (36, 8.0%), stroke (35, 7.8%), Down syndrome (24, 5.7%), hearing loss (22, 4.7%), traumatic brain injury (12, 2.7%), autism (11, 2.4%), rare syndromes (10, 2.0%), microcephaly (6, 1.3%), and phenylketonuria or other metabolic syndromes (5, 1.1%). Significant differences in the distribution of speech and language disorders were found between males and females (chi-square=69.34, df=33, P=0.001), although the contingency coefficient of 0.215 indicated a low degree of association between sex and disorder type. A much stronger relationship was found between age group and disorder type (chi-square=1443.33, df=30, P=0.001; contingency coefficient=0.688). Age-specific patterns were clinically distinct. Within the source Table 2, 70.9% of speech-sound disorder cases, 68.1% of speech/language delay cases, and 55.6% of fluency disorder cases occurred in the 3-6-year age group. In contrast, 92.2% of voice-disorder cases and 88.9% of aphasia cases occurred in adults older than 18 years, whereas 92.9% of dyslexia cases occurred in the 6-18-year group. These patterns support the central finding that preschool-aged children represented the largest group of clinic referrals and carried a substantial burden of the most common developmental communication disorders. The distribution by age is reproduced in Table 2 using the values reported in the original article.

Table 2. Distribution of speech and language disorders by age group.

Values are reproduced from the original article; percentages are those reported in the source table.

Conclusion

The study found that speech and language disorders were most frequently represented among children aged 3-6 years attending the affiliated speech-therapy clinics. Speech-sound production disorder, speech/language delay, and fluency disorder were the three most frequently recorded diagnoses, and disorder type differed significantly according to both age and sex, with a stronger association for age. The authors therefore emphasized more systematic prevention, early identification, and screening of preschool children with direct involvement of speech-language pathologists. The results may also inform allocation of rehabilitation personnel and services within Hamadan University of Medical Sciences. Interpretation should account for the study's reliance on archived records, including incomplete, repeated, illegible, or inconsistently recorded information; the authors recommended more accurate and integrated electronic record systems for future service-based epidemiological studies.

Keywords: Language Development Disorders, Language Disorders, Speech Disorders, Speech Sound Disorder, Stuttering

REFERENCES

1. Damico JS, Müller N, Ball MJ. Labeling as a Sociocultural Process in Communicative Disorders. The Handbook of Language and Speech Disorders. 2021;:5-32. DOI: 10.1002/9781119606987.ch1
2. Parving A. Hearing screening--aspects of epidemiology and identification of hearing impaired children. Int J Pediatr Otorhinolaryngol. 1999;49 Suppl 1:S287-292. PMID: 10577823 DOI: 10.1016/s0165-5876(99)00177-9
3. Lubker BB. Epidemiology: An essential science for speech-language pathology and audiology. J Commun Disord. 1997;30(4):251-67. PMID: 9208362 DOI: 10.1016/s0021-9924(97)00002-6
4. McKinnon DH, McLeod S, Reilly S. The prevalence of stuttering, voice, and speech-sound disorders in primary school students in Australia. Lang Speech Hear Serv Sch. 2007;38(1):5-15. PMID: 17218532 DOI: 10.1044/0161-1461(2007/002)
5. Lyberg-Åhlander V, Rydell R, Fredlund P, Magnusson C, Wilén S. Prevalence of voice disorders in the general population, based on the Stockholm public health cohort. J Voice. 2019;33(6):900-5. PMID: 30126692 DOI: 10.1016/j.jvoice.2018.07.007
6. Roy N, Merrill RM, Gray SD, Smith EM. Voice disorders in the general population: prevalence, risk factors, and occupational impact. Laryngoscope. 2005;115(11):1988-95. PMID: 16319611 DOI: 10.1097/01.mlg.0000179174.32345.41
7. Abou Ella M, Saleh M, Habil I, El Sawy M, El Assal I. Prevalence of stuttering in primary school children in Cairo-Egypt. Int J Speech Lang Pathol. 2015;17(4):367-72. PMID: 25739414 DOI: 10.3109/17549507.2015.1010583
8. Sedaghati L, Foroughi R, Shafiei B, Maracy MR. Prevalence of dyslexia in first to fifth grade elementary students Isfahan, Iran. Audiol. 2010;19(1):94-101. Link
9. Beitchman JH, Nair R, Clegg M, Patel P. Prevalence of speech and language disorders in 5-year-old kindergarten children in the Ottawa-Carleton region. J Speech Hear Disord. 1986;51(2):98-110. PMID: 3702369 DOI: 10.1044/jshd.5102.98
10. Tchoungui Oyono L, Pascoe M, Singh S. The prevalence of speech and language disorders in French-speaking preschool children from Yaoundé (Cameroon). J Speech Lang Hear Res. 2018;61(5):1238-1250. PMID: 29710276 DOI: 10.1044/2018_JSLHR-L-16-0400
11. Maasoomi Jahandizi H. Prevalence Of Speech Disorders Among Zanjan Primary School Students In 2000. J Adv Med Biomed Res. 2001;9(36):17-21. Link
12. Karbasi SA, Fallah R, Golestan M. The prevalence of speech disorder in primary school students in Yazd-Iran. Acta Med Iran. 2011;49(1):33-7. PMID: 21425069
13. Soleimani A, Mohammadi H, Khazaei H, Ertiahi F. Prevalence of speech disorders among Kermanshah primary schoolchildren. J Kermanshah Univ Med Sci. 2011;15(3):e79362. Link
14. Yavari A, Fatehi F, Dalvand H, Valizadeh A, Moradzadeh R, Mirhoseini FS. Prevalence of speech disorders in Arak primary school students, 2014-2015. J Arak Univ Med Sci. 2016;19(6):87-94. Link
15. Naseh H. Study on disorders of referrer of exceptional education to speech therapy clinic of Bandar Abbas during 2004-2005. Hormozgan Med J. 2006;10(3):273-279. Link
16. Rezania K, Pourarian S. Prevalence of Speech Language Disorders in Monolingual Persian Children With Normal Development During 2012-2016. J Rehabilitation Science & Research. 2019;6(4):183-187. DOI: 10.30476/jrsr.2019.81230.0
17. Mehri A, Faghih Zadeh S, Mousavi SZ. Prevalence of speech and language disorders in patients referring to the Speech therapy clinic in Tehran Rehabilitation Faculty during 10 years. Sci J Rehabilitation Med. 2016;5(2):132-140. DOI: 10.22037/jrm.2016.1100183
18. Keating D, Turrell G, Ozanne A. Childhood speech disorders: reported prevalence, comorbidity and socioeconomic profile. J Paediatr Child Health. 2001;37(5):431-436. PMID: 11885704 DOI: 10.1046/j.1440-1754.2001.00697.x
19. Ravi SK, Sumanth P, Saraswathi T, Basha Chinoor MA, Ashwini N, Ahemed E. Prevalence of communication disorders among school children in Ballari, South India: A cross-sectional study. Clin Epidemiol Glob Health. 2021;12:100851. DOI: 10.1016/j.cegh.2021.100851
20. Shriberg LD, Tomblin JB, McSweeny JL. Prevalence of speech delay in 6-year-old children and comorbidity with language impairment. J Speech Lang Hear Res. 1999;42(6):1461-81. PMID: 10599627 DOI: 10.1044/jslhr.4206.1461
21. Schneider W, Ennemoser M, Roth E, Küspert P. Kindergarten Prevention of Dyslexia: Does Training in Phonological Awareness Work for Everybody?. J Learn Disabil. 1999;32(5):429-36. PMID: 15510432 DOI: 10.1177/002221949903200508
22. Duff MC, Proctor A, Yairi E. Prevalence of voice disorders in African American and European American preschoolers. J Voice. 2004;18(3):348-53. PMID: 15331107 DOI: 10.1016/j.jvoice.2003.12.009