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Funnel plot of comparison: 1 Treatment versus control random‐effects model, outcome: 1.1 Word reading accuracy
Figures and Tables -
Figure 1

Funnel plot of comparison: 1 Treatment versus control random‐effects model, outcome: 1.1 Word reading accuracy

Study flow diagram
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Figure 2

Study flow diagram

Risk of bias summary: review authors' judgements about each risk of bias item for each included study
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Figure 3

Risk of bias summary: review authors' judgements about each risk of bias item for each included study

Forest plot of comparison: 1 Treatment versus control random‐effects model, outcome: 1.1 Word reading accuracy
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Figure 4

Forest plot of comparison: 1 Treatment versus control random‐effects model, outcome: 1.1 Word reading accuracy

Forest plot of comparison: 1 Treatment versus control random‐effects model, outcome: 1.2 Nonword reading accuracy
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Figure 5

Forest plot of comparison: 1 Treatment versus control random‐effects model, outcome: 1.2 Nonword reading accuracy

Forest plot of comparison: 1 Treatment versus control random‐effects model, outcome: 1.3 Word reading fluency
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Figure 6

Forest plot of comparison: 1 Treatment versus control random‐effects model, outcome: 1.3 Word reading fluency

Forest plot of comparison: 1 Treatment versus control random‐effects model, outcome: 1.4 Nonword reading fluency
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Figure 7

Forest plot of comparison: 1 Treatment versus control random‐effects model, outcome: 1.4 Nonword reading fluency

Forest plot of comparison: 1 Treatment versus control random‐effects model, outcome: 1.5 Reading comprehension
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Figure 8

Forest plot of comparison: 1 Treatment versus control random‐effects model, outcome: 1.5 Reading comprehension

Forest plot of comparison: 1 Treatment versus control random‐effects model, outcome: 1.6 Spelling
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Figure 9

Forest plot of comparison: 1 Treatment versus control random‐effects model, outcome: 1.6 Spelling

Forest plot of comparison: 1 Treatment versus control random‐effects model, outcome: 1.7 Letter‐sound knowledge
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Figure 10

Forest plot of comparison: 1 Treatment versus control random‐effects model, outcome: 1.7 Letter‐sound knowledge

Forest plot of comparison: 1 Treatment versus control random‐effects model, outcome: 1.8 Phonological output
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Figure 11

Forest plot of comparison: 1 Treatment versus control random‐effects model, outcome: 1.8 Phonological output

Comparison 1 Phonics training versus control (random‐effects), Outcome 1 Word reading accuracy.
Figures and Tables -
Analysis 1.1

Comparison 1 Phonics training versus control (random‐effects), Outcome 1 Word reading accuracy.

Comparison 1 Phonics training versus control (random‐effects), Outcome 2 Nonword reading accuracy.
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Analysis 1.2

Comparison 1 Phonics training versus control (random‐effects), Outcome 2 Nonword reading accuracy.

Comparison 1 Phonics training versus control (random‐effects), Outcome 3 Word reading fluency.
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Analysis 1.3

Comparison 1 Phonics training versus control (random‐effects), Outcome 3 Word reading fluency.

Comparison 1 Phonics training versus control (random‐effects), Outcome 4 Nonword reading fluency.
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Analysis 1.4

Comparison 1 Phonics training versus control (random‐effects), Outcome 4 Nonword reading fluency.

Comparison 1 Phonics training versus control (random‐effects), Outcome 5 Reading comprehension.
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Analysis 1.5

Comparison 1 Phonics training versus control (random‐effects), Outcome 5 Reading comprehension.

Comparison 1 Phonics training versus control (random‐effects), Outcome 6 Spelling.
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Analysis 1.6

Comparison 1 Phonics training versus control (random‐effects), Outcome 6 Spelling.

Comparison 1 Phonics training versus control (random‐effects), Outcome 7 Letter‐sound knowledge.
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Analysis 1.7

Comparison 1 Phonics training versus control (random‐effects), Outcome 7 Letter‐sound knowledge.

Comparison 1 Phonics training versus control (random‐effects), Outcome 8 Phonological output.
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Analysis 1.8

Comparison 1 Phonics training versus control (random‐effects), Outcome 8 Phonological output.

Comparison 2 Phonics training versus control ‐ subgroups (random‐effects), Outcome 1 Word reading accuracy.
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Analysis 2.1

Comparison 2 Phonics training versus control ‐ subgroups (random‐effects), Outcome 1 Word reading accuracy.

Comparison 2 Phonics training versus control ‐ subgroups (random‐effects), Outcome 2 Nonword reading accuracy.
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Analysis 2.2

Comparison 2 Phonics training versus control ‐ subgroups (random‐effects), Outcome 2 Nonword reading accuracy.

Comparison 3 Phonics training versus control (fixed‐effect), Outcome 1 Word reading accuracy.
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Analysis 3.1

Comparison 3 Phonics training versus control (fixed‐effect), Outcome 1 Word reading accuracy.

Comparison 3 Phonics training versus control (fixed‐effect), Outcome 2 Nonword reading accuracy.
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Analysis 3.2

Comparison 3 Phonics training versus control (fixed‐effect), Outcome 2 Nonword reading accuracy.

Comparison 3 Phonics training versus control (fixed‐effect), Outcome 3 Word reading fluency.
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Analysis 3.3

Comparison 3 Phonics training versus control (fixed‐effect), Outcome 3 Word reading fluency.

Comparison 3 Phonics training versus control (fixed‐effect), Outcome 4 Nonword reading fluency.
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Analysis 3.4

Comparison 3 Phonics training versus control (fixed‐effect), Outcome 4 Nonword reading fluency.

Comparison 3 Phonics training versus control (fixed‐effect), Outcome 5 Reading comprehension.
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Analysis 3.5

Comparison 3 Phonics training versus control (fixed‐effect), Outcome 5 Reading comprehension.

Comparison 3 Phonics training versus control (fixed‐effect), Outcome 6 Spelling.
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Analysis 3.6

Comparison 3 Phonics training versus control (fixed‐effect), Outcome 6 Spelling.

Comparison 3 Phonics training versus control (fixed‐effect), Outcome 7 Letter‐sound knowledge.
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Analysis 3.7

Comparison 3 Phonics training versus control (fixed‐effect), Outcome 7 Letter‐sound knowledge.

Comparison 3 Phonics training versus control (fixed‐effect), Outcome 8 Phonological output.
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Analysis 3.8

Comparison 3 Phonics training versus control (fixed‐effect), Outcome 8 Phonological output.

Comparison 4 Phonics training versus control sensitivity analysis with Hurford 1994 removed (random‐effects), Outcome 1 Word reading accuracy.
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Analysis 4.1

Comparison 4 Phonics training versus control sensitivity analysis with Hurford 1994 removed (random‐effects), Outcome 1 Word reading accuracy.

Comparison 4 Phonics training versus control sensitivity analysis with Hurford 1994 removed (random‐effects), Outcome 2 Nonword reading accuracy.
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Analysis 4.2

Comparison 4 Phonics training versus control sensitivity analysis with Hurford 1994 removed (random‐effects), Outcome 2 Nonword reading accuracy.

Summary of findings for the main comparison. Phonics training compared with control (no training or alternative training) for English‐speaking poor readers

Phonics training compared with control (no training or alternative training) for English‐speaking poor readers

Patient or population: English‐speaking poor readers

Setting: English‐speaking countries

Intervention: phonics

Comparison: no training or alternative training

Outcomes

Illustrative comparative risks* (95% CI)

Relative effect
(95% CI)

No of participants
(studies)

Quality of the evidence
(GRADE) **

Comments *

Assumed risk

Corresponding risk

No training or alternative training

English‐speaking poor readers

Word reading accuracy

Immediate follow‐up

The mean score in the intervention groups was on average

0.47 SD better1

(95% CI 0.06 to 0.88)

683 (10 studies)

High

Nonword reading accuracy

Immediate follow‐up

The mean score in the intervention groups was on average

0.76 SD better1

(95% CI 0.25 to 1.27)

512 (8 studies)

High

Word reading fluency

Immediate follow‐up

The mean score in the intervention groups was on average

0.51 SD better1

(95% CI ‐1.14 to 0.13)

54 (2 studies)

Moderate

Nonword reading fluency

Immediate follow‐up

The mean score in the intervention groups was on average

0.38 SD worse1

(95% CI ‐0.55 to 1.32 )

18 (1 study)

Moderate

Reading comprehension

Immediate follow‐up

The mean score in the intervention groups was on average

0.14 SD better1

(95% CI ‐0.46 to 0.74)

173 (3 studies)

Moderate

Spelling

Immediate follow‐up

The mean score in the intervention groups was on average

0.36 SD better1

(95% CI ‐0.27 to 1.00)

140 (2 studies)

Moderate

CI: confidence interval

**GRADE Working Group grades of evidence
High quality: Further research is very unlikely to change our confidence in the estimate of effect
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate
Very low quality: We are very uncertain about the estimate

1. Different studies used different continuous measures. Thus, comparative risk is reflected by size of the phonics training effect which was indexed with standardised mean differences (SMDs). The results are expressed as SD (standard deviation) units. As a rule of thumb, 0.2 SD represents a small difference, 0.5 a moderate difference, and 0.8 a large difference

2. Downgraded for imprecision. The confidence intervals are compatible with no effect at all as well as important improvement or deterioration

Figures and Tables -
Summary of findings for the main comparison. Phonics training compared with control (no training or alternative training) for English‐speaking poor readers
Table 1. Additional methods for future updates

Issue

Method

Primary outcome measures

In the current review, we have combined measures for regular and irregular word reading (that is, word reading) to improve the power of the meta‐analyses of the reading measures. However, from a theoretical point of view, it would be preferable to have separate estimates for these 2 types of reading. If relevant data are available, future updates will index the effect of phonics on (1) irregular and regular word reading separately, and (2) irregular and regular spelling separately.

Secondary outcome measures

If relevant data are available, future updates will include letter identification, parsing, and blending as outcomes in this review.

Training type

In future updates, we will include additional phonics training if the data are available (for example, phonics and letter identification training, phonics, and spoken vocabulary training).

Subgroups

If relevant data are available, future updates will include 4 additional subgroups to the analyses that were not possible in the current review owing to lack of data: (1) Age (children (below 12 years); adolescents (13 to 17 years); adults (18 years and above); (2) poor reading type (poor letter‐sound reading; poor sight word reading; a combination of both); (3) spoken language ability (impaired unimpaired); and (4) timing of outcome assessment (immediately after training, 1 to 6 months after training, 7 to 18 months after training, more than 18 months). In addition, data allowing, we will reinstated a third categeory in the training type subgroup: phonics and sight words.

Timing of outcome assessment

If relevant data are available, future updates will index 4 periods of assessment: (1) immediately after training, (2) 1 to 6 months after training, (3) 7 to 18 months after training, and (4) more than 18 months after training.

Multiple measures

If a study includes multiple measures of a single outcome (for example, word reading accuracy), and those measures are directly comparable in type and scale, an average of the 2 scores will be taken. If a study includes multiple measures of a single outcome that are not directly comparable, both measures will be used in the analysis

Multiple arms

If a study includes 2 or more comparable invention groups (for example, both 'phonics only' or both 'phonics and phoneme awareness'), the data of the 2 groups will be combined. If a study includes a 'phonics only' and 'phonics plus phoneme awareness' group (for example), the phonics only group will be used since this is a purer measure of phonics training. If a study includes more than 1 control group, the control group that does the least training of any type will be included in the review. For example, a control group that does 'school as usual' will be used over a control groups who does 'maths training'.

Cross‐over and cluster trials

If a cluster‐randomised trial analyses the data as if individuals were randomised, we will adjust the calculations using 1 + (M‐1) ICC, where M is the average cluster size, and ICC is an estimate of the relative variability between and within clusters (Higgins 2008b). If a cross‐over trial does not appear to suffer carry‐over or period effects, then a paired t‐test will be used to measure the effect, or we will approximate a paired analysis by imputing standard deviations. If carry‐over effects are a problem, we will use data from the first period (Higgins 2008b).

Figures and Tables -
Table 1. Additional methods for future updates
Table 2. Tests used by studies to measure outcomes

Outcomes

Tests

References

Studies

Word reading accuracy

1 experimental test

 

Barker 1995

Woodcock Johnson Reading Mastery Test Third Edition: Word Identification

Woodcock 1987

Barker 1995

Wechsler Individual Achievement Test 2nd Edition

Wechsler 2002

Blythe 2006

Woodcock Johnson Reading Mastery Test Third Edition: Word Identification

Woodcock 2001

Ford 2009

Woodcock Johnson Reading Mastery Test Revised: Word Identification

Woodcock 1987

Hurford 1994

British Ability Scale: Word Reading

Elliot, Murray & Pearson, 1984

Hurry 2007

1 experimental test

 

Levy 1997

1 experimental test

 

Levy 1999

2 experimental tests

 

Lovett 2000

2 experimental tests

 

Lovett 1990

1 experimental test

 

Savage 2003

Nonword reading accuracy

Woodcock Johnson Reading Mastery Test: Word Analysis

Woodcock 1987

Barker 1995

Wechsler Individual Achievement Test 2nd Edition

Wechsler 2002

Blythe 2006

Woodcock‐Johnson Tests of Achievement Third Edition: Word Attack

Woodcock 2001

Ford 2009

Woodcock Johnson Reading Mastery Test Revised: Word Attack

Woodcock 1987

Hurford 1994

1 experimental test

 

Levy 1997

1 experimental test

 

Levy 1999

Woodcock Johnson Reading Mastery Test Revised: Word Attack

Woodcock 1987

Lovett 2000

1 experimental test

 

Savage 2003

Word reading fluency

Test of Word Reading Efficiency: Phonemic Decoding Efficiency

Torgesen 1999

Ford 2009

2 experimental tests

 

Lovett 1990

Nonword reading fluency

Test of Word Reading Efficiency: Sight Word Efficiency

Torgesen 1999

Ford 2009

Reading comprehension

Wechsler Individual Achievement Test 2nd Edition

Wechsler 2002

Blythe 2006

Gates‐MacGinitie Reading Test: Comprehension

MacGinitie 2002

Ford 2009

Neale Analysis of Reading Ability

Neale 1988

Hurry 2007

Spelling

2 experimental tests

 

Lovett 1990

1 experimental test

 

Savage 2003

Letter‐sound knowledge

1 experimental test

 

Lovett 1990

1 experimental test

 

Savage 2003

1 experimental test

 

Savage 2005

Phonological output (measured with phoneme awareness tasks)

1 experimental test

 

Barker 1995

Goldman Fristoe Woodcock Test of Auditory Discrimination: Sound analysis

Goldman 1974

Lovett 2000

1 experimental test

 

Savage 2003

1 experimental test

 

Savage 2005

Figures and Tables -
Table 2. Tests used by studies to measure outcomes
Table 3. Effect sizes for random‐ and fixed‐effect model analyses, and heterogeneity for random‐effects analyses

 

 

 

Random‐effects model

Heterogeneity

Fixed‐effect model

Outcome measure

N studies

N Participants

SMD [95% CI]

Z

P

Chi2

P

I2%

SMD [95% CI]

Z

P

Word reading accuracy

10

683

0.47 [0.06, 0.88]

2.22

0.03

52.26

< 0.01

83

0.46 [0.29, 0.62]

5.44

< 0.01

Nonword reading accuracy

8

512

0.76 [0.25, 1.27]

2.91

< 0.01

44.04

< 0.01

84

0.82 [0.62, 1.01]

8.14

< 0.01

Word reading fluency

2

54

‐0.51 [‐1.14, 0.13]

1.56

0.12

1.30

0.25

23

‐0.53 [‐1.08, 0.02]

1.89

0.06

Nonword reading fluency

1

18

0.38 [‐0.55, 1.32]

0.81

0.42

NA

 NA

 NA

0.38 [‐0.55, 1.32]

0.81

0.42

Reading comprehension

3

173

0.14 [‐0.46, 0.74]

0.45

0.65

4.27

0.12

53

0.01 [‐0.31, 0.32]

0.04

097

Spelling

2

140

0.36 [‐0.27, 1.00]

1.12

0.26

2.53

0.11

60

0.28 [‐0.09, 0.65]

1.49

0.14

Letter‐sound knowledge

3

192

0.35 [0.04, 0.65]

2.22

0.03

0.11

0.95

0

0.35 [0.04, 0.65]

2.22

0.03

Phonological output

4

280

0.38 [‐0.04, 0.80]

1.77

0.08

7.97

0.05

62

0.44 [0.19, 0.70]

3.45

< 0.01

CI: confidence interval; SMD: standardised mean difference

Figures and Tables -
Table 3. Effect sizes for random‐ and fixed‐effect model analyses, and heterogeneity for random‐effects analyses
Table 4. Characteristics of participants in each study

Study

Location

Age

Gender

IQ

Ethnicity

SES

Inclusion criteria

Exclusion Criteria

Population

Barker 1995

USA

Range 6.2 to 7.8 years

Not reported

Verbal

Mean = 16.5

SD = 2.36

Not reported

Not reported

Students nominated by teachers from 2 elementary schools who were given a short series of pre‐tests assessing phonological awareness skills and basic word recognition skills. These children were then given further 2 tests and those scoring below the 40th percentile and the 50th percentile on the subsequent test were selected

None stated

First‐grade students

Blythe 2006

Australia

Mean 101.5 months

Male 75%

Female 25%

FSIQ‐2

Mean 100.15

SD 9.38

Not reported

Not reported

Children who received group‐based remedial reading instruction at school and were referred by a support teacher

After referral children completed the WISC‐III FSIQ. Those who scored below the 20th percentile were excluded

Dyslexic primary school students

Ford 2009

USA

Mean 16.18 years

Male 55%

Female 45%

Not reported

African‐American 22%,

Hispanic 67%,

white 11%

Lower

Students who were enrolled in the remedial reading programme were invited to participate. Below average reading skills were based on the ISAT

None stated

Teenagers enrolled at an alternative high school, that is, a high school for non‐special education students or students at risk of dropping out

Hurford 1994

USA

Mean 80.35

months

Male 48%

Female 52%

Mean 90.37

White 92.8,

African‐American 6%,

Hispanic 5%,

Asian‐American 0.7%

Middle

Classification data from Hurford, Darrow, Edwards, Howerton, Mote, Schauf and Coffey (1993) was used with more relaxed criteria for eligibility, that is standard scores in reading of less than 91 were included rather than less than 86

None stated

Children at risk of reading disability

Hurry 2007

UK

Range 6 to 6.6 years

Male 61%

Female 39%

Range 92 to 96

16% spoke English as a second language

42% of the sample were eligible for free school meals

In 63 schools the 6 poorest Year 2 readers were selected on the basis of their Diagnostic Survey (Clay, 1985) performance. Of the 22 schools using Reading Recovery, the poorest scorers were offered intervention

The remaining children, that is, those less poor at reading then those that were selected for the experimental condition, were assigned to a within school condition

Children with reading difficulties

Levy 1997

Canada

Range 5.9 to 7.2 years

Male 48%

Female 52%

Not reported

Not reported

Not reported

Children were given word reading tests, children that read fewer than 7 words on any of the screening tests were selected

None stated

All children from Grade 1 and senior kindergarten from 2 schools, whose parents consented to their participation

Levy 1999

Canada

Mean age 7.7 years

Male 56%

Female 44%

Non‐verbal (picture assembly)

Experimental group mean 10.88

Control group mean 10.65

Mixed racial distribution

Covers all SES

Children were given a word identification test (WRAT‐3), if they scored below 90 they were given another word identification test (WRMT) and if they read below half a grade below their grade level and read no more than 15 of the training words then they were included in the sample

None stated

17 schools participated in the screening process with permission for participation obtained from the board, schools and a parent or guardian

Lovett 1990

Canada

Mean age 8.4 years

SD 1.6

Range 7 to 13 years

Male 70.4%

Female 29.6%

Verbal

Mean 98.4 SD 10.6

Performance

Mean 106.2

SD 12.6

Not reported

Middle

Children had to score below the 25th percentile on at least 4 of 5 reading measures used in the screening test and have at least low average intelligence

Children with English as a second language, history of extreme hyperactivity, hearing impairment, brain damage, a chronic medical condition, serious emotional disturbance, or attention deficits

Children referred to the Learning Disabilities Reading Program

Lovett 2000

Canada

Mean age 9.9 years

SD 1.6

Range 7 to 13 years

Male 68.1%

Female 31.9%

Verbal

Mean 92

SD 13.7

Range 58 to 133

Performance

Mean 98.7

SD 14.3

Range = 63 ‐ 136

Not reported

Not reported

Children needed to demonstrate a 'substantial underachievement' on 4 of the 5 reading based screening assessments

None stated

Children with severe reading disabilities that were referred to the Clinical Research Unit for remediation

Savage 2003

UK

Mean age 5.9 years

Range 5 to 6.3 years

Male 60%

Female 40%

Not reported

Not reported

Not reported

Over 2 sessions a series of reading‐ and spelling‐based assessments were used to find the poorest readers in Year 1 of the school. The lowest performers were recruited

A teacher identifying a child as being too immature to deal with working in small groups

Children with the lowest reading performance for their age within a Local Education Authority or School District

Savage 2005

UK

Not reported

 

Male 50%

Female 50%

Not reported

Not reported

Lower

Over 2 sessions a series of reading‐ and spelling‐based assessments were used to find the poorest readers in Year 1 of the school. The lowest performers were recruited

None stated

Children with the lowest reading performance for their age within a Local Education Authority or School District

FSIQ: Full Scale intelligence quotient; IQ: intelligence quotient; ISAT: Illinois State Achievement Test; SD: standard deviation; SES: socioeconomic status; WISC: Wechsler Intelligence Scale for Children; WRAT: Wide Range Achievement Test; WRMT: Woodcock Reading Mastery Test

Figures and Tables -
Table 4. Characteristics of participants in each study
Table 5. Allocation of studies to different subgroups (categories)

 Subgroups

 

Barker 1995

Blythe 2006

Ford 2009

Hurford 1994

Hurry 2007

Levy 1997

Levy 1999

Lovett 1990

Lovett 2000

Savage 2003

Savage 2005

Training type

Phonics only

X

X

X

 

Phonics + phoneme awareness

X

X

X

X

X

X

X

 

Phonics + irregular words

X

Training intensity

< 2 hours/week

X

X

X

X

X

X

X

X

X

 

≥ 2 hours/week

X

X

Training duration

< 3 months

X

X

X

X

X

X

X

X

X

 

≥ 3 months

X

X

Training group size

1

X

X

X

X

X

X

 

≤ 5

X

X

X

X

X

Training administrator

Human

X

X

X

X

X

X

X

 

Computer

X

X

X

X

Figures and Tables -
Table 5. Allocation of studies to different subgroups (categories)
Table 6. Results of subgroup analyses

 

 

Subgroups

 

 

Mean effect size

Heterogeneity

Subgroup analyses

N studies/

measures

N

participants

SMD [95% CI]

Z

P

Chi2

P

I2 %

Chi2

DF

P

I2 %

Word reading accuracy

Training type

Phonics only

3

232

0.91 [‐0.17, 1.98]

1.63

0.10

23.93

< 0.10

92

 

 

 

 

 

Phonics +

phoneme awareness

6

415

0.28 [0.00, 0.56]

1.96

0.05

8.12

0.15

38

1.23

1

0.27

18.8

Training intensity

< 2 hours/week

8

559

0.48 [‐0.04, 1.00]

1.80

0.07

50.65

< 0.10

86

 

 

 

 

 

≥ 2 hours/week

2

124

0.34 [‐0.03, 0.72]

1.79

0.07

1.06

0.30

6

0.17

1

0.68

0

Training duration

< 3 months

8

498

0.56 [0.07, 1.04]

2.25

0.02

39.20

< 0.10

82

 

 

 

 

 

≥ 3 months

2

185

0.12 [‐0.43, 0.67]

0.42

0.67

2.8

0.09

64

1.36

1

0.24

26.3

Training group size

1

6

419

0.62 [‐0.06, 1.29]

1.78

0.07

44.35

< 0.10

89

 

 

 

 

 

≤ 5

4

264

0.25 [‐0.04, 0.54]

1.67

0.10

8.78

0.29

12

0.94

1

0.33

0

Training administrator

Human

6

559

0.66 [0.08, 1.23]

2.24

0.03

46.02

< 0.10

89

 

 

 

 

 

Computer

4

124

0.15 [‐0.20, 0.51]

0.85

0.40

2.63

0.45

0

2.13

1

0.14

53

Nonword reading accuracy

Training type

Phonics only

3

232

0.91 [‐0.45, 2.28]

1.32

0.19

36.92

< 0.10

95

 

 

 

 

 

Phonics + phoneme awareness

5

280

0.63 [0.38, 0.88]

4.86

< 0.10

1.84

0.88

0

 0.16

1

0.69 

Training group size

1

5

284

1.06 [0.39, 1.73]

3.09

< 0.10

21.92

< 0.10

82

 

 

 

 

 

≤ 5

3

228

0.32 [‐0.32, 0.96]

0.97

0.33

9.64

< 0.10

79

2.43

1

0.12

58.8

Training administrator

Human

4

388

1.12 [0.48, 1.76]

3.42

< 0.10

22.23

< 0.10

87

 

 

 

 

 

Computer

4

124

0.31 [‐0.33, 0.96]

0.96

0.34

8.65

0.03

65

3.02

1

0.08

66.8

Figures and Tables -
Table 6. Results of subgroup analyses
Comparison 1. Phonics training versus control (random‐effects)

Outcome or subgroup title

No. of studies

No. of participants

Statistical method

Effect size

1 Word reading accuracy Show forest plot

10

683

Std. Mean Difference (IV, Random, 95% CI)

0.47 [0.06, 0.88]

2 Nonword reading accuracy Show forest plot

8

512

Std. Mean Difference (IV, Random, 95% CI)

0.76 [0.25, 1.27]

3 Word reading fluency Show forest plot

2

54

Std. Mean Difference (IV, Random, 95% CI)

‐0.51 [‐1.14, 0.13]

4 Nonword reading fluency Show forest plot

1

18

Std. Mean Difference (IV, Random, 95% CI)

0.38 [‐0.55, 1.32]

5 Reading comprehension Show forest plot

3

173

Std. Mean Difference (IV, Random, 95% CI)

0.14 [‐0.46, 0.74]

6 Spelling Show forest plot

2

140

Std. Mean Difference (IV, Random, 95% CI)

0.36 [‐0.27, 1.00]

7 Letter‐sound knowledge Show forest plot

3

192

Std. Mean Difference (IV, Random, 95% CI)

0.35 [0.04, 0.65]

8 Phonological output Show forest plot

4

280

Std. Mean Difference (IV, Random, 95% CI)

0.38 [‐0.04, 0.80]

Figures and Tables -
Comparison 1. Phonics training versus control (random‐effects)
Comparison 2. Phonics training versus control ‐ subgroups (random‐effects)

Outcome or subgroup title

No. of studies

No. of participants

Statistical method

Effect size

1 Word reading accuracy Show forest plot

10

Std. Mean Difference (IV, Random, 95% CI)

Subtotals only

1.1 Training type: phonics only

3

232

Std. Mean Difference (IV, Random, 95% CI)

0.91 [‐0.17, 1.98]

1.2 Training type: phonics + phoneme awareness

6

415

Std. Mean Difference (IV, Random, 95% CI)

0.28 [0.00, 0.56]

1.3 Training intensity: < 2 hours/week

8

559

Std. Mean Difference (IV, Random, 95% CI)

0.48 [‐0.04, 1.00]

1.4 Training intensity: ≥ 2 hours/week

2

124

Std. Mean Difference (IV, Random, 95% CI)

0.34 [‐0.03, 0.72]

1.5 Training duration: < 3 months

8

498

Std. Mean Difference (IV, Random, 95% CI)

0.56 [0.07, 1.04]

1.6 Training duration: ≥ 3 months

2

185

Std. Mean Difference (IV, Random, 95% CI)

0.12 [‐0.43, 0.67]

1.7 Training group size: 1

6

419

Std. Mean Difference (IV, Random, 95% CI)

0.62 [‐0.06, 1.29]

1.8 Training group size: ≤ 5

4

264

Std. Mean Difference (IV, Random, 95% CI)

0.25 [‐0.04, 0.54]

1.9 Training administrator: human

6

559

Std. Mean Difference (IV, Random, 95% CI)

0.66 [0.08, 1.23]

1.10 Training administrator: computer

4

124

Std. Mean Difference (IV, Random, 95% CI)

0.15 [‐0.20, 0.51]

2 Nonword reading accuracy Show forest plot

8

1536

Std. Mean Difference (IV, Random, 95% CI)

0.76 [0.48, 1.04]

2.1 Training type: phonics only

3

232

Std. Mean Difference (IV, Random, 95% CI)

0.91 [‐0.45, 2.28]

2.2 Training type: phonics + phoneme awareness

5

280

Std. Mean Difference (IV, Random, 95% CI)

0.63 [0.38, 0.88]

2.3 Training group size: 1

5

284

Std. Mean Difference (IV, Random, 95% CI)

1.06 [0.39, 1.73]

2.4 Training group size: ≤ 5

3

228

Std. Mean Difference (IV, Random, 95% CI)

0.32 [‐0.32, 0.96]

2.5 Training administrator: human

4

388

Std. Mean Difference (IV, Random, 95% CI)

1.12 [0.48, 1.76]

2.6 Training administrator: computer

4

124

Std. Mean Difference (IV, Random, 95% CI)

0.31 [‐0.33, 0.96]

Figures and Tables -
Comparison 2. Phonics training versus control ‐ subgroups (random‐effects)
Comparison 3. Phonics training versus control (fixed‐effect)

Outcome or subgroup title

No. of studies

No. of participants

Statistical method

Effect size

1 Word reading accuracy Show forest plot

10

683

Std. Mean Difference (IV, Fixed, 95% CI)

0.46 [0.29, 0.62]

2 Nonword reading accuracy Show forest plot

8

512

Std. Mean Difference (IV, Fixed, 95% CI)

0.82 [0.62, 1.01]

3 Word reading fluency Show forest plot

2

54

Std. Mean Difference (IV, Fixed, 95% CI)

‐0.53 [‐1.08, 0.02]

4 Nonword reading fluency Show forest plot

1

18

Std. Mean Difference (IV, Fixed, 95% CI)

0.38 [‐0.55, 1.32]

5 Reading comprehension Show forest plot

3

173

Std. Mean Difference (IV, Fixed, 95% CI)

0.01 [‐0.31, 0.32]

6 Spelling Show forest plot

2

140

Std. Mean Difference (IV, Fixed, 95% CI)

0.28 [‐0.09, 0.65]

7 Letter‐sound knowledge Show forest plot

3

192

Std. Mean Difference (IV, Fixed, 95% CI)

0.35 [0.04, 0.65]

8 Phonological output Show forest plot

4

280

Std. Mean Difference (IV, Fixed, 95% CI)

0.44 [0.19, 0.70]

Figures and Tables -
Comparison 3. Phonics training versus control (fixed‐effect)
Comparison 4. Phonics training versus control sensitivity analysis with Hurford 1994 removed (random‐effects)

Outcome or subgroup title

No. of studies

No. of participants

Statistical method

Effect size

1 Word reading accuracy Show forest plot

9

633

Std. Mean Difference (IV, Random, 95% CI)

0.47 [0.01, 0.93]

2 Nonword reading accuracy Show forest plot

7

462

Std. Mean Difference (IV, Random, 95% CI)

0.80 [0.22, 1.38]

Figures and Tables -
Comparison 4. Phonics training versus control sensitivity analysis with Hurford 1994 removed (random‐effects)