4.6. Statistical Analysis for Clinical Variables

Characteristics of the study population were presented using descriptive statistics. The mean and SD values were calculated for continuous variables, while frequencies were reported for categorical variables. Patients were classified as having a higher severity score (if moderate/severe or very severe score) or lower severity score (if mild or very mild score). Pearson correlation was used to explore the relationship between the severity score and clinical variables. A non-parametric test for independent samples (Mann–Whitney U) was used to compare the quantitative clinical variables (age, AAO, MMT-MRC, 6MWT, FVC, ΔFVC, BMI, VDD, BMD total body, BMD femoral neck, BMD lumbar-sacral and GSGC) in the two populations. Chi-squared tests were used to compare the qualitative variables (sex, BF, BAD, MVP, IgG-rhGAA and ERT-AE) between the two subgroups. A p value < 0.05 was considered statistically significant.