Association of sibling presence with language development before early school age among children with developmental delays: A longitudinal study

Background/purpose: Having siblings is a crucial ecological factor in children's language development. Whether siblings play a role in the language development of children with developmental delays remains unknown. This study therefore aimed to assess the association between sibling presence and changes in language trajectories of children with developmental delays before reaching early school age.Methods: This retrospective cohort-sequential longitudinal study analyzed data from an institution designated by Taiwan's Ministry of Health and Welfare for assessing and identifying young children with developmental delays between December 2008 and February 2016. We included 174 children, aged 10-58 months (mean [standard deviation (SD)], 31.74 [10.15] months), with developmental delays who underwent at least three waves of evaluation. The final evaluation occurred at 37-90 months of age. Data collection spanned over an age from 10 to 90 months. The primary outcome was language delays as determined by boardcertified speech-language pathologists.Results: Of the 174 participants (131 boys), 64.94 % (n Z 113) had siblings. The likelihood of both receptive language delay and expressive language delay for participants with siblings increased gradually from 10 to 90 months and exceeded that of participants without siblings, respectively (adjusted odds ratios [aOR], 1.04, 1.04; 95 % confidence interval [CI], 1.01-1.07, 1.01-1.07; P Z 0.014, 0.020).Conclusion: Having siblings does not necessarily positively associate with language development in children with developmental delays. Clinicians should consider the association of sibling presence with language development for these children in a broader familial-ecological context before they reach early school age. Copyright 2021, Formosan Medical Association. Published by Elsevier Taiwan LLC. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/bync-nd/4.0/).