Comparison of phenotypic characteristics for the four sets of samples used in this study.

Note: For the differential white blood cell counts, we present absolute values, obtained by multiplying the differential counts (expressed as a percentage of total WBC) by the total WBC. The Health ABC study did not obtain band counts.*For the JHS-ARIC overlap samples, the values of all phenotypes (age, BMI, and differential white blood cell counts) are averaged between the JHS and ARIC baseline measurements, taken an average of 14 years apart. Analyses in all other groups use a single measurement at the cohort baseline.§Average percentage of European ancestry was estimated using the ANCESTRYMAP software. European ancestry “carrier status” was defined by rs2814778 genotype.†Neutrophil count is used to assess the genetic association, since it accounts for essentially all the correlation to the chromosome 1 locus and thus provides the best measure of association (text and Table 2). Association analyses are carried out on the normally transformed rank-ordered values of the absolute neutrophil count. Standard errors on the correlation coefficients are obtained by a leave-1-out jackknife analysis.