So we categorize the distributions of images into symmetric and asymmetric.
Benzene, DPM, and PAH levels from ASPEN were categorized using the distribution of the residential HAP levels among the controls: low or reference exposure (<25th percentile), medium exposure 25th-74thhighrcexposure, high exposure (75th-89th percentiles), and very high exposure (≥90th percentile).
First, we categorized into quartiles the distributions of each individual compound across the census tracts in which controls were born.
These studies are limited, however, by the requirement to categorize the continuous distribution of data generated by qPCR assays into discrete CN 'bins' (21, 22, 24) or alternatively to compare the means (23).
They were also categorized into quartiles based on the distributions of each analyte among controls, with the lowest quartile used as the reference category in analyses.
CRP was categorized according to the distribution of the variables into tertiles (<0.2 mg/dL, 0.20 0.56 mg/dL, and ≥0.57 mg/dL).
Total alcohol intake was categorized according to the distribution of the variable in the WLH population as categories (0, 0.1 5.0, 5.1–15, and >15 g/day), and as a continuous variable.
In general, exposures were categorized based on the distribution of PCB levels among controls, and odds ratios (ORs) for NHL were calculated by comparing higher exposure quantiles to the lowest referent quantile.
In other 86 cattle samples which were not categorized by the above-mentioned method, the distributions of the samples with 100% similarity were also observed in adjacent geographic areas (data not shown).
IL6 and CRP were categorized into quartiles, and the cut-off points were based on the distributions of the controls.
