Reply to: The Association Between Cognitive Decline and Bone Loss and Fracture Risk Is Not Affected by Medication With Anticholinergic Effect

Abstract

To the Editors: We are grateful to Dr. Naharci for the interest in our study reporting the association between cognitive decline and bone loss and fracture risk. (1) We agree that bisphosphonates (BPs) have a proven effect on reducing bone loss and fracture risk. (2) Medication with anticholinergic (ACH) side effects may also affect cogni-tive function as well as propensity to fall and fracture, although these effects have not been demonstrated in all studies. (3) We did not include these medication classes in our models because in observational studies the relationship between medication and outcomes is likely driven by factors associated with medication use. This bias by indication can only be avoided by specific study design (ie, propensity score matching), which was beyond the scope of our study. (4) However, we have conducted additional analyses to determine the prevalence of BP and ACH medication in our cohort, the association between these medication classes and our study outcomes and the impact of the addition of these medication classes to our findings. BP and ACH use were self-reported and obtained by questionnaire at baseline, and years 5 and 10. Bone mineral density (BMD) was assessed by dual-energy X-ray absorptiometry (DXA) and cognitive function using the Mini Mental State Examination (MMSE) test during all clinical visits. Follow-up time for BMD