Statistical analyses were performed using the SPSS statistical package 19.0 for Windows (SPSS Inc., Chicago, IL, USA). Differences between MDD status groups (no MDD history / single episode / recurrent episodes) were examined using ANOVA for continuous variables and Chi-squared tests (Fisher’s Exact Test) for categorical variables.
Univariate and multiple linear regression techniques were used to determine the association between exposure (i.e. history of MDD episodes or use of antidepressants) and outcome (i.e. BMD at the forearm, lumbar spine, total hip or total body). Age, weight, height, smoking, activity level, calcium intake, alcohol intake, socio-economic status, current use of bisphosphonates, corticosteroids, gonadal hormones, calcium or vitamin D supplements were each explored as effect modifiers with MDD episodes and antidepressant use regressed on BMD at each site and included in the final model if significant (p<0.05).
Univariate and multiple linear regression techniques were used to determine the association between exposure (i.e. history of MDD episodes or use of antidepressants) and outcome (i.e. BMD at the forearm, lumbar spine, total hip or total body). Age, weight, height, smoking, activity level, calcium intake, alcohol intake, socio-economic status, current use of bisphosphonates, corticosteroids, gonadal hormones, calcium or vitamin D supplements were each explored as effect modifiers with MDD episodes and antidepressant use regressed on BMD at each site and included in the final model if significant (p<0.05).