estimated. Factor analyses were conducted separately for the OZALC-NAG and Cohorts 1 and 2 datasets; for the former, factor scoring coeffiecients were generated using the BIGSIB sample, by gender, and then applied to the combined OZALC-NAG data-set. Factor loadings were in the range 0.69–0.86 for women, 0.63 to 0.92 for men, for the HOD factor, 0.41 to 0.64 and 0.43 to 0.66 for the AUD factor. Quantitative measures were adjusted for gender, age and its quadratic and cubic terms, gender, and age*gender interaction using linear regression. Adjusted scores were then rank-normalized, separately for the BIGSIB, OZALC-NAG EDAC and NAG, Cohort 1 only and Cohort 2 only subsamples and combined in a single genetic association analysis. Analysis by subsample, with results combined in a meta-analysis, yielded similar results, so only the former results are reported.
