Of the 143 with discrepant classifications, 131 (91.6%) differed by a single quartile (when applying the published Boyd categories [ 10], results were similar with 66% of the patients classified in the same category and 32.5% within one category shift, see Additional file 1).
(15) Of three studies examining travel time to centre and receipt of chemotherapy, one study found no evidence of an association for colorectal cancer chemotherapy [ 40], but the remaining two studies had limited single quartile associations, which conflicted in the direction of their association [ 31, 36].
Associations shown are based on a single model where quartile terms for all PCBs are entered.
A strength of this study is that the finding of a social association in breast cancer survival was not affected by choice of data source (17 or 13 SEER registries) or categories of SES (quintile or quartile, single or composite).
The median length of Refseq cDNAs observed were around 900 1100 base pairs ranging from approximately 450 to 2000 base pairs (lower and upper quartile) with single cDNAs longer than 10 kb (Fig. 2b).
Low family income at birth was associated with higher Sat2 methylation (β = 19.7, 95% CI: 0.4, 39.0 for lowest vs. highest income quartile) and single parent family was associated with higher Alu methylation (β = 23.5, 95% CI: 2.6, 44.4), after adjusting for other early life factors.
This conclusion is further reinforced by the data in Table 3, where we look at the tenths and quartiles for single nucleotide content and AT and GC content at the 4-fold levels, as there is no significance at the 2-fold level.
For instance, Vance et al. divided the percentage of cancer in single biopsies into four quartiles (<2.5%, <10%, <25%, and ≥25%) [ 38], while Nelson et al. categorized it in to 0 10%, 11 59%, and 60 100% [ 36].
Results from marginal models controlling for blood pressure group assignment and waist-to-height quartile fit a single linear covariate (Table 3).
In their study published in 2009, Martini et al 7 reported a positive association between osteoporosis and age >45 years, not being single, height in the third quartile, and being a former smoker.
The median percentage of channels involved in a single burst was only 76% (quartiles: 52 94%, Fig. 2B), demonstrating that local bursts made up a substantial portion of total bursting.
