Associations between Literacy (letter identification score) and visual acuity, British Picture Vocabulary Scale (BPVS), socioeconomic and demographic (child and maternal) factors, n=2025 children, n=74 schools
| Factor | Unadjusted Mean difference in literacy scores (95% CI) | Adjusted BPVS Mean difference in literacy scores (95% CI) | Adjusted demographic Mean difference in literacy scores (95% CI)* | Adjusted socioeconomic Mean difference in literacy scores (95% CI)† | Fully adjusted model Mean difference in literacy scores (95% CI)‡ |
|---|---|---|---|---|---|
| Change in literacy score per one line (0.1log unit) of visual acuity | −2.42 (−2.98 to −1.87) p<0.001 | −1.79 (−2.32 to −1.26) p<0.001 | −1.72 (−2.24 to −1.19) p<0.001 | −1.72 (−2.25 to −1.19) p<0.001 | −1.65 (−2.17 to −1.13) p<0.001 |
| Change in literacy score per one unit change in BPVS | 0.27 (0.23 to 0.30) p<0.001 | 0.26 (0.22 to 0.30) p<0.001 | 0.25 (0.22 to 0.29) p<0.001 | 0.25 (0.21 to 0 0.28) p<0.001 | |
| Ethnicity | |||||
| White British | Reference | Reference | |||
| Pakistani | 0.83 (−0.82 to 2.47) p=0.325 | −0.14 (−1.86 to 1.58) p=0.872 | |||
| Other | 3.79 (1.86 to 5.73) p<0.001 | 2.85 (0.88 to 4.82) p=0.005 | |||
| Sex at birth | |||||
| Male | Reference | Reference | |||
| Female | 3.01 (2.03 to 3.99) p<0.001 | 3.06 (2.09 to 4.04) p<0.001 | |||
| Birth weight (g) | 0.001 (0.0001 to 0.002) p=0.028 | 0.001 (0.0001 to 0.002) p=0.036 | |||
| Gestational age (weeks) | 0.006 (−0.35 to 0.37) p=0.975 | −0.01 (−0.37 to 0.34) p=0.937 | |||
| Questionnaire language | |||||
| English | 1.78 (0.21 to 3.35) p=0.026 | 1.61 (3.18 to 0.04) p=0.045 | |||
| Other language | Reference | Reference | |||
| UK born | |||||
| Yes | −1.19 (−2.66 to 0.28) p=0.113 | −0.97(−0.49 to 2.43) p=0.192 | |||
| No | Reference | Reference | |||
| Receiving benefits | |||||
| Yes | −1.05 (−2.06 to −0.03) p=0.043 | −1.03 (−2.04 to −0.03) p=0.045 | |||
| No | Reference | Reference | |||
| Level of education | |||||
| Low (<5 GCSE equivalent and unknown) | Reference | Reference | |||
| Medium (5 GCSE and A level equivalent) | 1.14 (−0.024 to 2.3) p=0.055 | 1.13 (−0.04 to 2.3) p=0.059 | |||
| High (higher than A level) | 3.30 (1.8 to 4.8) p<0.001 | 3.20 (1.71 to 4.70) p<0.001 | |||
| Smoked in pregnancy | |||||
| Yes | −2.19 (−3.68 to −0.69) p=0.004 | −1.82 (−0.25 to −3.39) p=0.023 | |||
| No | Reference | Reference | |||
*Demographic adjustment includes visual acuity, BPVS, ethnicity, sex at birth, birth weight, gestational age, language of baseline questionnaire, mothers’ place of birth.
†Socioeconomic adjustment includes visual acuity, BPVS, receipt of benefits, level of mothers’ education, mother smoked during pregnancy.
‡Fully adjusted analysis includes all factors: visual acuity, BPVS, ethnicity, sex at birth, birth weight, gestational age, language of baseline questionnaire, mothers’ place of birth, receipt of benefits, level of mothers’ education, mother smoked during pregnancy.