Statistical analysis
REGRESSION
Statistical analyses were performed using the R statistical package (version 4.1.3), with the α-value set to 0.05. Quantitative variables were compared between groups using the Mann–Whitney U-test or Student t-test for independent samples, as applicable. The normal distribution of the study variables was verified using the Shapiro–Wilk test, and the homogeneity of their variances was verified using Levene’s test. Mean differences (MDs) and odds ratios (ORs) were calculated, along with their 95% confidence intervals (CIs). The relationships between categorical variables were analyzed using the chi-square test. Univariate and multivariable logistic regression models were created using AMD as the outcome variable. The results were presented as ORs with 95% CIs. To verify the significance and goodness of fit of the models, the chi-square statistic and Nagelkerke pseudo-RThe study was conducted in accordance with the provisions of the Declaration of Helsinki, and all participants provided written informed consent prior to enrollment. The Bioethics Committee of the Medical University of Białystok approved the study protocol (approval number R-I-002/108/2016 of 31 March 2016).