Table 2.

Comparison of baseline refractive error between study eyes with active choroidal neovascularization (CNV) and fellow eyes without CNV in the Comparison of Age-related Macular Degeneration Treatments Trials

Analysis approaches	The mean difference between study eyes with CNV and fellow eyes without CNV (95% CI), in diopters	P-value
Unadjusted analysis
Independent-sample t-test	0.15 (−0.03, 0.33)	0.09
Standard linear regression model	0.15 (−0.03, 0.33)	0.09
Paired t-test	0.15 (0.02, 0.28)	0.02
Mixed model, compound symmetry or unstructured	0.15 (0.02, 0.28)	0.02
Marginal model, PROC MIXED using REPEATED, unstructured	0.15 (0.02, 0.28)	0.02
Marginal model, GEE, working independent	0.15 (0.02, 0.28)	0.02
Covariates-adjusted analysis§
Standard linear regression	0.15 (−0.03, 0.32)	0.10
Mixed model, compound symmetry or unstructured	0.15 (0.01, 0.28)	0.03
Marginal model, PROC MIXED using REPEATED, unstructured	0.15 (0.01, 0.28)	0.03
Marginal model, GEE, working independence	0.15 (0.01, 0.28)	0.03
Marginal model, GEE, compound symmetry	0.15 (0.01, 0.28)	0.03

^§Adjusted for age, sex, current smoking status, geographic atrophy and glaucoma.

CI, confidence interval; GEE generalized estimating equation