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We have read with great interest the study on the parent-based
language intervention  and congratulate the authors, as this study is
unique in the German area with regard to the randomised design.
However, we would like to point out to the readers some additional
information on the context of the reported results.
According to the register entry in clinicaltrials.gov , th...
According to the register entry in clinicaltrials.gov , the study
included “children with receptive and/or expressive language abilities
below norm range” with “receptive and expressive language abilities”
assessed by the German language tests SETK-2 and SETK 3-5 as the primary
outcome variables. Secondary outcomes were further language assessments
and cognitive and social-emotional development.
The analysis in Archives of Disease in Childhood , however,
represents only a segment of the actual study. This concerns the study
population as well as the set of outcome variables:
• Study population: The results described in the publication actually
refer only to a subgroup (58 children with specific expressive language
delay) of the original study population (78 children randomised in total,
including 20 children with receptive-expressive delay). If planned a
priori, subgroup analyses may yield relevant information about the
possible benefit of interventions for specific indications. It remains
unclear whether the subgroup analysis was planned beforehand in this
study. Furthermore, it is not stated in the publication that the results
only refer to a subgroup of children. Rather, the flowchart in Figure 1
conveys the impression that only 58 children were randomised in the first
• Outcome variables: Of all variables assessed at the age of 2½ and 3
years, only the results on language production are presented. In a German
publication from 2007 , interim results from 54 children with receptive
and/or expressive language delay were presented on all 4 subtests of SETK-
2 (i.e. the primary outcome variables), yielding non-significant results
on the 2 comprehension subtests. According to the main author, further
secondary language variables and cognitive/socio-emotional assessments are
still being analysed.
Both facts involve the risk of bias of the results due to the
selective reporting [see 4].
According to published literature, late talkers with circumscribed
expressive delays have a high rate of spontaneous remission without
treatment . For children with receptive-expressive language delay, the
difficulties are much more likely to be of persistent nature . All the
more valuable would be an intervention that also shows an effect in this
group of children. We are looking forward to the publication of the
results of the subgroup of children with receptive-expressive language
delay as well as all the endpoints assessed (the last follow-up is planned
for the age of 8).
Julia Kreis, Stefan Lange, Fueloep Scheibler and Guido Skipka
1. Buschmann A, Jooss B, Rupp A, Feldhusen F, Pietz J, Philippi H.
Parent-based language intervention for two-year-old children with specific
expressive language delay: a randomised controlled trial. [Epub ahead of
print] doi:10.1136/adc.2008.141572. Arch Dis Child 2008.
2. University of Heidelberg (Department of Pediatric Neurology -
Children's Hospital). Effectiveness of Early Parent-Based Language
Intervention [online]. Access on: 15.08.2008. URL:
3. Buschmann A, Jooss B, Blaschtikowitz H, Koch-Graus A, Schumacher
D, Heggen I et al. Frühe Sprachförderung. In: Karch D, Pietz J (Eds).
Aktuelle Neuropädiatrie 2006. Nürnberg: Novartis Pharma; 2007. 79-85.
4. Higgins J, Green S, (Eds). Cochrane handbook for systematic
reviews of interventions. Version 5.0.0 [updated February 2008]. Oxford:
The Cochrane Collaboration; 2008.
5. Law J, Boyle J, Harris F, Harkness A, Nye C. Prevalence and
natural history of primary speech and language delay: findings from a
systematic review of the literature. Int J Lang Commun Disord 2000; 35(2):
Competing interests: None