Data for variables of which the histogram of observations
showed a normal distribution are reported as means ± SDs; those
with a non-normal distribution are reported as medians and
25th–75th percentiles. Changes in biochemical indicators were
calculated by subtracting the value before the intervention from
the value after the intervention. Those changes had a normal distribution;
therefore, data are presented as means and 95% CIs.
Changes within groups were examined with a paired t test. Differences
between groups were examined by analysis of variance
(ANOVA) or, for indexes with a non-normal distribution, by the
Kruskal-Wallis test. Multiple regression analysis was used to
compare changes in indicators between groups by using dummy
variables for treatment and controlling for variables such as
baseline level of the indicator, weight change, and parasitic
infestation.