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Screening: Speech and Language Delay in Preschool Children
Conclusions
Studies are not available addressing the overarching key question about the effectiveness of screening (key question 1), adverse effects of screening (key question 3), the role of enhanced surveillance in primary care (key question 4), long-term effectiveness of interventions on non-speech and language outcomes for children identified with delay (key questions 7), and adverse effects of interventions (key question 8). No studies determine the optimal ages and frequency for screening (key question 2d). Relevant studies are available regarding the use of risk factors for screening (key question 2a), techniques for screening (key question 2b and 2c), and effectiveness of interventions on short-term speech and language and non-speech and language outcomes for children identified with delay (key questions 5 and 6).
The use of risk factors for selective screening has not been evaluated and a list of specific risk factors to guide primary care physicians has not been developed or tested. Sixteen studies about potential risk factors for speech and language delay in children enrolled heterogeneous populations, had dissimilar inclusion and exclusion criteria, and measured different risk factors and outcomes. The most consistently reported risk factors included a family history of speech and language delay, male gender, and perinatal factors. Other risk factors that were reported less consistently included educational levels of the mother and father, childhood illnesses, birth order, and family size.
Although brief evaluations are available and have been used in a number of settings with administration by professional and nonprofessional individuals, including parents, the optimal method of screening for speech and language delay has not been established. The performance characteristics of evaluation techniques taking 10 minutes or less to administer were described in 24 studies relevant to screening. Studies rated good-to-fair quality reported wide ranges of sensitivity and specificity when compared with reference standards (sensitivity 31% to 100%; specificity 45% to 100%). In these studies, the instruments providing the highest sensitivity and specificity included the Early Language Milestone Scale, Clinical Linguistic and Auditory Milestone Scale, Language Development Survey, Screening Kit of Language Development, and the Levett-Muir Language Screening Test. Most of the evaluations, however, were not designed for screening purposes, the instruments measured different domains, and the study populations and settings were often outside primary care. No gold standard has been developed and tested for screening, reference standards varied across studies, few studies compared the performance of 2 or more screening techniques in 1 population, and comparisons of a single screening technique across different populations are lacking.
RCTs of multiple types of interventions reported significantly improved speech and language outcomes compared with control groups. Improvement was demonstrated in several domains including articulation, phonology, expressive language, receptive language, lexical acquisition, and syntax among children in all age groups studied and across multiple therapeutic settings. However, studies were small, heterogeneous, may be subject to plateau effects, and reported short-term outcomes based on various instruments and measures. As a result, long-term outcomes are not known, interventions could not be directly compared to determine optimal approaches, and generalizability is questionable.
There are many limitations of the literature relevant to screening for speech and language delay in preschool-aged children including lack of studies specific to screening as well as difficulties inherent in this area of research. This evidence review is limited by use of only published studies of instruments and interventions. Data about performance characteristics of instruments, in particular, are not generally accessible and are often only available in manuals that must purchased. Interventions vary widely and may not be generalizable. In addition, studies from countries with different health care systems, such as the U.K., may not translate well to U.S. practice.
Although speech and language development is multi-dimensional, the individual constructs that comprise it are often assessed separately. Numerous evaluation instruments and interventions that accommodate children across a wide range of developmental stages have been developed to identify and treat specific abnormalities of these functions. As a result, studies include many different instruments and interventions that are most often designed for purposes other than screening. Also, studies of interventions typically focus on 1 or a few interventions. In clinical practice, children are provided with individualized therapies consisting of multiple interventions. The effectiveness of these complex interventions may be difficult to evaluate. Adapting results of this heterogeneous literature to determine benefits and adverse effects of screening is problematic. Also, behavioral interventions are difficult to conduct in long-term randomized trials, and it is not possible to blind parents or clinicians. Randomizing children to therapy or control groups when clinical practice standards support therapy raises ethical dilemmas.
Speech and language delay is defined by measurements on diagnostic instruments in terms of a position on a normal distribution. Measures and terminology are inconsistently used and there is no recognized gold standard. This is challenging when defining cases and determining performance characteristics of screening instruments in studies.
Identification of speech and language delay may be associated with benefits and adverse effects that would not be captured by studies of clinical or health outcomes. The process of screening alerts physicians and caretakers to developmental milestones and focuses attention on the child's development, potentially leading to increased surveillance, feelings of caregiver support, and improved child self esteem. Alternatively, caretakers and children may experience increased anxiety and stress during the screening and evaluation process. Detection of other conditions during the course of speech and language evaluation, such as hearing loss, is an unmeasured benefit if appropriate interventions can improve the child's status.
Future research should focus on determining optimal approaches of identifying preschool children with speech and language delay in primary care settings who would be appropriate candidates for further evaluations and possibly speech and language interventions. These approaches should be integrated into routine developmental surveillance practices of clinicians caring for children.97 Studies that evaluate the effectiveness of validated brief screening instruments that include child and caretaker components could lead to a more standardized approach. Studies of specific speech and language components of currently available broad developmental screening instruments, such as Ages and Stages, would be useful. Incorporation of risk factors and parent report in studies of screening approaches could provide information about their added value. Additional studies that compare screening instruments and methods in large primary care populations could lead to defining gold standards and acceptable referral criteria. Evaluating these criteria in different populations of children would minimize cultural and language biases.
Additional work about the effectiveness of interventions, including speech and language domain-specific results, may provide new insights. School-based efforts could be designed to complement strategies developed for young children improving long-term outcomes. Results of these studies may help determine optimal ages and intervals for screening. Functional long-term outcomes such as school performance, high school graduation rates, in-grade retention, special education placement/duration, and social adjustment need to be addressed more thoroughly. Cost-effectiveness evaluations of effective approaches that consider cost of treatment, the time that caregivers spend in transit to treatment locations, the time they spend participating in the program on site or in the home, and long-term outcomes, among other factors, would be useful.
Acknowledgments
The investigators thank Andrew Hamilton, M.L.S., M.S., for conducting the literature searches, expert reviewers for commenting on draft versions of this report, and members of the USPSTF who served as leads for this project including Alfred Berg, M.D., M.P.H.; Paul Frame, M.D.; Leon Gordis, M.D., Dr.P.H.; Jonathan Klein, M.D., M.P.H.; Virginia Moyer, M.D., M.P.H.; and Barbara Yawn, M.D., M.Sc.
This study was conducted by the Oregon Evidence-based Practice Center under contract to the Agency for Healthcare Research and Quality, Contract #290-02-0024, Task Order Number 2, Rockville, MD.
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Notes
Author Affiliations
All Oregon Health and Science University, Portland, Oregon.
[a] Department of Medical Informatics and Clinical Epidemiology.
[b] Department of Medicine.
[c] Department of Pediatrics.
[d] The Oregon Evidence-based Practice Center.
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Source: Nelson HD, Nygren P, Walker M, Panoscha R. Screening for Speech and Language Delay in Preschool Children: Systematic Evidence Review for the US Preventive Services Task Force. Pediatrics 2006;117:e298-e319.
Current as of February 2006
Internet Citation:
Nelson HD, Nygren P, Walker M, Panoscha R. Screening for Speech and Language Delay in Preschool Children: Systematic Evidence Review for the U.S. Preventive Services Task Force. Originally in Pediatrics 2006;117:e298-e319. February 2006. http://www.uspreventiveservicestaskforce.org/uspstf06/speech/speechrev.htm
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