2.3. Statistical analysis
Statistical analyses were performed with the SPSS statistical
package (version 11). Logarithmic transformation was applied to
some of the variables to achieve a normal distribution before
being subjected to data analysis. The relationships among measured
variables such urinary levels of Cd and renal biomarkers
in urine, subject’s age, and period of engagement in agriculture
were examined with analysis of variance (ANOVA). The post hoc
multiple comparisons were determined with the Dunnett’s test.
The generalized linear model (GLM) was used to determine the
relationships between urinary Cd levels and risk factors of Cd
exposure/renal markers after adjustment of age. Dose–response
relationships between age-adjusted urinary Cd and prevalence of
abnormal values for urinary 2-MG and NAG were analyzed using
the logistic regression model. The P-values of 0.05 or less were
considered to identify statistical significance.