Table 1. Study characteristics of GWAS and validation sample.

	Cases *	Controls *
Pooled GWAS sample
Age (years)	69.9 (s.d.=11.7)	70.0 (s.d.=11.7)
% Ashkenazi	100%	100%
% Male	51%	50%
Validation sample
Age (years)	70.1 (s.d.=11.5)	71.1 (s.d.=11.5)
% Ashkenazi	90%	90%
% Male	51%	52%

Abbreviation: GWAS=genome-wide association study.

^*The participation rate was 67.5% among eligible cases and 52.1% of eligible controls. Participating cases were slightly younger (mean 70.1 years) than cases who declined (mean 70.4 years), whereas those who could not participate because they were too ill or died were significantly older (mean 78.9 years).