2.5 | Statistical analysis
We conducted all of the statistical analyses using complex sample
procedures of the Statistical Package for the Social Sciences (SPSS)
software program version 21.0 (IBM Corp., Armonk, NY, USA). Because the
KYRBS data were collected through a representative, stratified, and
clustered sampling method (as a statistical representative of the
general population), data from the survey were weighed based on the
sample design. Descriptive statistics were used to depict the basic
characteristics of the study population. The chi-square test for
categorical variables and independent t-test for continuous variables
were used appropriately to compare the general characteristics between
subjects with and without asthma. Following the selection of significant
covariates using univariable logistic regression analysis, multivariate
logistic regression analysis was carried out to determine which
sleep-related factors (e.g., sleep satisfaction, sleep duration, and
WCUS) were independently contributing to the risk of suicidal ideation
in adolescent asthmatics: Model 1 adjusted for sex and grade; Model 2
adjusted for Model 1 variables + socioeconomic variables (residential
type, SES, and academic achievement) and health-related behavioral
variables (breakfast skipping, smoking, alcohol drinking, and vigorous
exercise); and Model 3 adjusted for Model 2 variables + psychological
variables (perceived status of health, perceived level of happiness,
perceived frequency of stress, and experience of depressive symptoms).
The results were expressed using adjusted odds ratios (OR) and 95%
confidence intervals (CI). Statistical significance was indicated byp- values < 0.05 in all tests.