Odds ratios (ORs) and 95% confidence intervals (CIs) for the presence of any colorectal neoplasm for the 3 highest quartiles of insertion time compared to the first quartile were calculated using fixed effects logistic regression conditioned on colonoscopists.
Adjusted mean scores for each quartile were calculated, as well as the difference between the first quartile mean score and the other three quartiles' mean score.
Median and inter-quartile ranges for country sales were calculated using MS Excel.
P-values for linear trends were calculated using the quartile median values.
The first quartile, median, and third quartile of R were calculated using Microsoft Excel 2007 software.
Tests for trend were calculated using likelihood ratio tests, where the categorical medians of each quartile were modelled as ordinal covariates.
Analysis of variance, medians, and quartiles for box and whisker plots were calculated using StatGraphics (StatPoint Technologies, Warrenton, USA).
ORs for the prevalence of MS were calculated using the lowest quartile subgroup as the standard, and the effect of confounders was adjusted for by using logistic regression to investigate the degree of MS risk based on heavy metal concentration.
For total fluid and water intakes, ORs were calculated using quartile cutoff points in controls.
Odds ratios (ORs) and 95% confidence intervals (95% CIs) for quartiles of lipid-corrected metabolite levels were calculated using conditional logistic regression.
