2.5. Statistical analysis
In the present study to determine inadequate adherence level in our
institution, a sample size of at least 940 patients was calculated based
on an expected inadequate adherence level of 55% with a power of 80%
and a two-tailed 5% significance level, considering a 20% anticipated
patient dropout. Initially, a 24-month inclusion period was anticipated.
However, enrollment concluded in February 2020 when the calculated
sample size was reached.
Categorical variables are expressed as frequency and percentages,
whereas continuous variables are reported as mean and standard deviation
(SD), or median and quartiles 1 and 3 according to their distribution.
Continuous variable distribution was determined using the
Kolmogorov-Smirnoff test.
According to the results of the MMAS-4, patients were classified into
two groups: adequate and inadequate adherence to treatment for
statistical analysis. Bivariable analysis was initially performed using
the chi-squared test or Fisher’s exact test for categorical variables
and Student t or Mann Whitney U for continuous variables to generate
unadjusted 2-sided p values. Multivariable analysis was then conducted
using logistic regression, including all statistically significant
variables obtained from the bivariate analysis. A two-tailed p
<0.05 was considered significant. The IBM-SPSS Statistics
package v. 25 was used for statistical analysis.