November 2019: Long-Term Effects of Phonemic Awareness, Phonics, Fluency, and Reading Comprehension Interventions

Suggate, S. P. (2016). A meta-analysis of the long-term effects of phonemic awareness, phonics, fluency, and reading comprehension interventions. Journal of Learning Disabilities, 49(1), 77–96.

Summary by Johny Daniel and Dr. Jeremy Miciak

Study Background

Meta-analyses are considered evidence-based resources that combine the results of multiple scientific studies to determine the effectiveness of a particular intervention. Several past meta-analyses that have systematically combined the results of various reading intervention experimental studies have reported the positive effects of these interventions on students’ reading outcomes. Although a lot is known about the immediate effects of reading interventions, not much is known about the ways in which they affect students’ reading proficiency in the long-term. In other words, a majority of meta-analyses combine data of study results that are collected immediately at the end of the intervention, and rarely do they report how well intervention effects are sustained two or more weeks (i.e., long-term) after immediate posttest. Thus, the focus of Suggate’s (2016) meta-analysis was to evaluate the long-term effectiveness of reading interventions for students in kindergarten through grade­ 6.

The primary aim of the meta-analysis was to measure the long-term effects of phonological awareness, phonics, fluency, comprehension, and spelling interventions for students in K–6. Additionally, Suggate’s meta-analysis aimed to examine whether the long-term effectiveness of interventions were different for intervention features such as instructor, student ratio, intervention administrator, fidelity of implementation, study design, dosage, and intervention length. Furthermore, participant characteristics such as grade-level and reading risk-status were also examined.

Research Questions

It was expected that the interventions would result in positive short-term gains that would subside at follow-up. The following research questions were addressed:

  1. What are the effect sizes for normal, at-risk, and low readers, and reading disabled readers from posttest to follow-up?
  2. To what degree do phonemic awareness, phonics, fluency, comprehension, and mixed interventions result in different effect sizes on different outcome measures (i.e., transfer effects)?
  3. To what extent do sample characteristics, including grade, gender, and intervention language relate to follow-up effect size?
  4. How do the methodological quality indicators of sample attrition, experimental design, treatment fidelity, and sample size with respect to publication bias influence effect size?
  5. How do the intervention characteristics of intervention length and administrator (i.e., preschool teacher, trained intervener, computer, tutor, experimenter, class teacher), instructor-student ratio, months to follow-up, and the presence of a booster intervention relate to effect size?


Studies were included if they met the following criteria: (a) focused on phonetics, decoding, comprehension, or fluency, (b) included a follow-up assessment, (c) contained at least one control or comparison group, (d) included a sample of students up to grade 6, and (e) were published in English, French, or German.

Fifty-seven studies met inclusion criteria. The average time from posttest to follow-up testing was 11.17 months (SD = 7.18). The sample of students across included studies comprised 24% typical readers, 28% at-risk readers (students performing between the 26th and 50th percentiles), 27% low readers (students performing between the 11th and 25th percentiles), and 21% students who were reading disabled (students performing at or below the 10th percentile). Furthermore, the majority of the interventions included in the review targeted either a phonemic awareness component (64.8%) or a phonics component (53.5%), whereas only 26.8% and 29.6% included components targeting fluency and comprehension, respectively.

Key Findings

Results showed greater retention of intervention effects to follow-up for at-risk, low, and disabled readers in comparison to typical readers.

Overall, comprehension and phonemic awareness interventions showed good maintenance of effects that transferred to nontargeted reading skills, whereas phonics and fluency interventions did not demonstrate maintenance of effects.
Effects of reading interventions reduced for preschool to grade 2 students from posttest to follow-up testing time. However, treatment group students in grades 3 to 4 demonstrated increased reading proficiency compared to control group peers; the magnitude of difference increased from dw = 0.35 at posttest to dw = 0.43 at follow-up.


Many studies did not provide information on the kinds of reading experiences children received after the intervention. Thus, it was not possible for the investigators to reliably code whether intervention or control groups received a booster intervention between posttest and follow-up testing.

Implications for Practitioners

Based on the study’s findings, the author suggests that intervention type align with students’ age. For instance, the author recommends that preschool and kindergarten interventions target developing students’ phonemic awareness skills. In grades 1 and 2, teachers should implement mixed interventions that target multiple reading skills such as decoding, fluency, and comprehension. And from grade 3 onwards, the focus should shift to comprehension-focused interventions. However, these are general guidelines, and the author highlights the importance of tailoring interventions to suit individual student needs in reading.