Table 6 Wessex-controlled trial subgroup: effect of early confirmation of permanent childhood hearing impairment (PCHI) on reading and communication z scores in children with PCHI at primary school age

	Age at confirmation of PCHI
	No		Group mean* z score (SD)		Unadjusted* mean difference (95% CI)	p Value	Adjusted† mean difference (95% CI)	p Value
	⩽9 months	>9 months	⩽9 months	>9 months	Unadjusted* mean difference (95% CI)	p Value	Adjusted† mean difference (95% CI)	p Value
WORD aggregate reading	15	26	−0.62 (1.41)	−1.04 (1.13)	0.43 (−1.24 to 0.38)	0.29	−0.77 (−1.29 to −0.25)	0.004
VABS communication scale	15	25	−0.23 (1.46)	−0.78 (1.05)	−0.54 (−1.35 to 0.26)	0.18	−0.71 (−1.43 to 0.005)	0.052

*Adjusted only for age at assessment.
†Adjusted, in a linear regression model, for severity of PCHI, maternal educational qualifications and Ravens Coloured Progressive Matrices (non-verbal ability) score.
VABS, Vineland Adaptive Behaviour Scales; WORD, Weschler Objective Reading Dimensions.