Statistical analyses
The analyses were conducted using the statistical software
Stata®, version 13.1 (StataCorp, College Station, TX, USA).
Descriptive statistics (means and standard deviations [SDs]
for continuous variables; frequencies and percentages for
categorical variables) were performed on the overall sample
(France and Spain together) and within each country.
Bivariate analyses were performed on the overall sample and
within each country. Patient satisfaction with, preference for,
and adherence to lanthanum carbonate powder at the time
of the survey versus the phosphate binder that the patient
was using prior to the survey (all classes of phosphate binder
apart from lanthanum carbonate powder) were compared.
Differences between categorical variables were examined
using McNemar’s χ2 tests, and differences between continuous
variables were examined using paired-sample t-tests. Singlesample
t-tests of chewing, swallowing, and meal-enjoyment
measures tested whether patients’ opinions of lanthanum
carbonate powder and a previous phosphate binder were
significantly different from the midpoint (a score of 3, which
represents indifference between past and current treatment).