Background characteristics, such as cleft type (Choa et al., 2014; Klintö et al., 2022), age (Lohmander, 2011), and sex (Klintö et al., 2022; Willadsen et al., 2017) may influence the speech results. Thus, the risk of participant selection bias needs to be considered in research on cleft palate speech. Additional malformations and/or syndromes may also be confounding variables (Klintö et al., 2021; Persson et al., 2002). Hearing impairment is more common among children with cleft palate than without (Flynn et al., 2009) and could be a confounding variable (Baker et al., 2021; Lohmander et al., 2021). Speech intervention could also be an influencing variable (Sand et al., 2022). Therefore, information on hearing and speech intervention (age at intervention, number of visits, and other dose measures) is desirable in studies on cleft palate speech.
References
* Baker S, Wren Y, Zhao F, Cooper F. Exploring the relationship between conductive hearing loss and cleft speech characteristics in children born with cleft palate. International Journal of Pediatric Otorhinolaryngology, 2021;148:110820.
* Choa RM, Slator R, Jeremy A, Robinson S, Franklin D, Roberts A, Winter R, Extence H, Collard M, Clark V. Identifying the effect of cleft type, deprivation and ethnicity on speech and dental outcomes in UK cleft patients: A multi-centred study. Journal of Plastic, Reconstructive & Aesthetic Surgery, 2014;67:1637–1643.
* Flynn T, Möller C, Jonsson R, Lohmander A. The high prevalence of otitis media with effusion in children with cleft lip and palate as compared to children without clefts. International Journal of Pediatric Otorhinolaryngology, 2009;73:1441–1446.
* Klintö K, Eriksson M, Abdiu A, Brunnegård K, Cajander J, Hagberg E, Hakelius M, Havstam C, Mark H, Okhiria Å, Peterson P, Svensson K, Becker M. Inter-centre comparison of data on surgery and speech outcomes at 5 years of age based on the Swedish quality registry for patients born with cleft palate with or without cleft lip, BMC Pediatrics, 2022;22:303.
* Klintö K, Sporre M, Becker M. Speech in a consecutive series of children born with cleft lip and palate with and without syndromes and/or additional malformations. BMC Pediatrics, 2021;21:309.
* Lohmander A. Surgical intervention and speech outcomes in cleft lip and palate. In S. Howard & A. Lohmander (Eds.), Cleft palate speech: Assessment and intervention (pp. 55–85). Wiley-Blackwell; 2011.
* Lohmander A, Westberg LR, Olsson S, Tengroth BI, Flynn T. Canonical babbling and early consonant development related to hearing in children with otitis media with effusion with or without cleft palate. Cleft Palate-Craniofacial Journal, 2021;58:894–905.
* Persson C, Elander A, Lohmander-Agerskov A, Söderpalm E. Speech outcomes in isolated cleft palate: Impact of cleft extent and additional malformations. Cleft Palate-Craniofacial Journal, 2002;39:397–408.
* Sand A, Hagberg E, Lohmander A. On the benefits of speech-language therapy for individuals born with cleft palate: A systematic review and meta-analysis of individual participant data. Journal of Speech, Language, and Hearing Research, 2022;65:555–573.
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