Better evidence for a better world

Campbell evidence and gap maps

Coming soon – Campbell EGMs are a new evidence synthesis product. Plain language summaries of our EGMs will be published on this website. The interactive EGMs and full EGM reports will be available in our journal on the Wiley Online Library platform: click here.

Learn more about Campbell EGMs

Other EGMs

Campbell has produced maps on other topics, sometimes in partnership with other organisations.

See our other EGMs
Preschool predictors of later reading comprehension ability

Additional Info

  • Authors: Hanne Næss Hjetland, Ellen Irén Brinchmann, Ronny Scherer, Monica Melby-Lervåg
  • Published date: 2017-12-15
  • Coordinating group(s): Education
  • Type of document: Title, Protocol, Review, Plain language summary
  • See the full review:

About this systematic review

A variety of language skills related to both language comprehension (e.g., vocabulary and grammar) and code-related skills (e.g., phonological awareness and letter knowledge) is important for developing decoding skills and, in turn, reading comprehension in school. Thus, reading comprehension instruction is more likely to be successful if it focuses on a broad set of language skills.

What are the main results?

Code-related skills in preschool (e.g., phoneme awareness and letter knowledge) are indirectly related to reading comprehension via word decoding. Linguistic comprehension is directly related to reading comprehension skills. Code-related skills and linguistic comprehension were strongly related. Moreover, language comprehension was more important for reading comprehension in older readers than in younger readers.


Knowledge about preschool predictors of later reading comprehension is valuable for several reasons. On a general level, longitudinal studies can aid in generating understanding and causal hypotheses about language and literacy development, both of which are crucial processes in child development. A better understanding of these developmental processes may guide the establishment of effective instruction and interventions to teach reading comprehension that can later be tested in randomized controlled trials. Knowledge about preschool precursors for reading comprehension skills can also aid in developing tools to identify children at risk of reading difficulties.


The primary objective for this systematic review is to summarize the available research on the correlation between reading-related preschool predictors and later reading comprehension skills.

Search methods

We developed a comprehensive search strategy in collaboration with a search information retrieval specialist at the university library. The electronic search was based on seven different databases. We also manually searched the table of contents of three key journals to find additional references. Finally, we checked the studies included in two previous systematic reviews.

Selection criteria

The included studies had to employ a longitudinal non-experimental/observational design. To avoid the overrepresentation of participants with special group affiliation (e.g., participants with learning disabilities or second language learner status), we chose studies that included either a sample of typically developing children or an unselected cohort.

Data collection and analysis

The search resulted in 3285 references. After the duplicates were removed, all remaining references were screened for inclusion and exclusion. A total of 64 studies met the eligibility criteria.

The analysis was conducted in two steps. First, the predictive relation between the abilities assessed in preschool and later reading comprehension skills was analyzed using Comprehensive Meta-analysis (CMA) software. Second, we used the correlation matrices in the included studies to further explore these relations by means of meta-analytic structural equation modeling.


First, analyses of bivariate correlations showed that all the included predictors, except for non-word repetition, were moderately to strongly correlated with later reading comprehension in the bivariate analyses. Non-word repetition had only a weak to moderate contribution to later reading comprehension ability. To explain the between-study variation, we conducted a series of meta-regression analyses. Age at time of reading assessment could predict variations between studies in correlations related to the code-related predictors.

Second, meta-analytic structural equation modeling showed a significant indirect effect of code-related skills on reading comprehension via consecutive word recognition. Third, there was a strong relationship in preschool between language comprehension and code-related skills. Language comprehension had a moderate direct impact on reading comprehension. As hypothesized, this impact increased with age, and linguistic comprehension becomes more important for reading comprehension when children master decoding. Moreover, the overall individual variance in reading comprehension explained by the model was 59.5%; that of consecutive word recognition was 47.6%.

Authors’ conclusions

Overall, our findings show that the foundation for reading comprehension is established in the preschool years through the development of language comprehension and code-related skills. Code-related skills and decoding are most important for reading comprehension in beginning readers, but linguistic comprehension gradually takes over as children become older. Taken together, these results suggest a need for a broad focus on language in preschool-age children.

See the full review

Contact us