**1. Introduction**

Recent findings from the *Lancet* series on early childhood development estimate that over 250 million children under five years of age in low-and middle-income countries are at risk of not achieving their full developmental potential [1]. Children in low- and middle-income countries may face a variety of adversities, including recurrent illness, malnutrition, and trauma, with long-term consequences for their health, productivity, and overall well-being [2]. It has been previously estimated that children not reaching their full developmental potential results in an average adult annual income deficit of 19.8% [3]. In addition to income loss, developmental delays have also been associated with considerable

**Citation:** Isquith-Dicker, L.N.; Kwist, A.; Black, D.; Hawes, S.E.; Slyker, J.; Bergquist, S.; Martin-Herz, S.P. Early Child Development Assessments and Their Associations with Long-Term Academic and Economic Outcomes: A Systematic Review. *Int. J. Environ. Res. Public Health* **2021**, *18*, 1538. https://doi.org/10.3390/ijerph18041538

Academic Editor: Verónica Schiariti Received: 25 December 2020 Accepted: 30 January 2021 Published: 5 February 2021

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academic underachievement [4–6]. These factors have led to increased interest in child development assessment tools that are adequately associated with long-term academic, economic, and human capital outcomes from a young age. However, existing child development assessment tools were generally designed to assess risk or developmental status at the time of testing [7–10]. Limited research focused on this topic suggests that available tools may not have strong predictive potential for later outcomes [1,4], highlighting the need for additional investigation to determine if specific tools or developmental domains may be useful for both prediction of outcome without intervention or in evaluation of intervention programs.

This systematic review was conducted to identify child development assessment tools that are associated with the long-term outcomes of educational attainment, academic achievement, and wealth. Given that an assessment of study quality is also included in this review, this synthesis provides information to aid researchers in the selection and prioritization of tools or domains for further research in this area.

#### **2. Materials and Methods**

#### *2.1. Data Sources*

A literature search was conducted in PubMed, PsycINFO, and Educational Resources Information Center (ERIC) on March 30, 2018. Publication date was restricted to manuscripts published in 1990 or later, due to differences in assessment tools and publication standards in comparison to more recent literature (Document S1). A search template was created that was applied to all 3 databases with minimal tailoring (Document S2). The search yielded 597 unique results that were exported into the Covidence (Melbourne, Australia) systematic review software [11]. This systematic review was conducted in accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines and preregistered at PROSPERO: CRD42018092292.

### *2.2. Development Tool Selection*

The search template contained a list of 104 child development assessment tools (Table S1). An initial list of 1398 tools was generated from a search of the PsycTEST database, a repository of assessment tools indexed from articles in peer-reviewed journals and books by experts at the American Psychological Association [12]. The PsycTEST search utilized the search terms, "child development, executive function, school, education, academic, readiness, reading, literacy" and excluded the terms "sexual behaviors and divorce." As many tools were not relevant to study objectives, one of the authors (SMH) manually filtered the list and added additional relevant assessment tools absent from PsycTEST database to assemble the final list. Tools were retained in the final list if they measured at least one of the five most common domains of development (gross motor, fine motor, language, cognitive, and social emotional), or examined reading/pre-reading skills or executive function. Tools were required to show some indication of psychometric properties, since it was felt that at least some evidence of reliability and validity were prerequisites to adequate association between the tools and future educational and economic outcomes, even if this was obtained from cross-sectional as opposed to longitudinal research. Tools were excluded if they examined only sublevels of developmental domains, were specific to second language learning, were designed explicitly to evaluate gender differences, were specific to health or mental health diagnoses, were specific to a particular study context, examined child or caregiver attitudes toward a developmental domain or skill set rather than the child's development (e.g., child reading attitude), or focused specifically on theory of the mind, math achievement, or home literacy environment.
