Table 5

Annual Literacy Scores by group

(raw score)
Comparison groupsEffect size
(Cohen’s d)*
1Comparison25Comparison versus adherent0.06
Adherent24.3Comparison versus non-adherent0.06
Non-adherent24.3Adherent versus non-Adherent0.00†
2Comparison34.7Comparison versus adherent0.05
Adherent34.4Comparison versus non-adherent0.13
Non-adherent34.0Adherent versus non-Adherent0.07
3Comparison39.1Comparison versus adherent0.08
Adherent38.8Comparison versus non-adherent0.18
Non-adherent38.4Adherent versus non-Adherent0.11
  • SD 10.9 at year 1, 5.6 at year 2 and 3.8 at year 3.

  • *Based on group difference divided by the pooled SD of letter-ID score.

  • †In year 1, there is no difference as spectacle wear has not commenced.

  • ID, identification.