In Reply Dr Safer and colleagues identify several variables (vitamin D, nutritional status, and sarcopenia) that were not part of the full baseline assessment in our study. We acknowledge that these are among a number of variables that could potentially be associated with function after hip fracture, and that this could result in confounding if these variables were unevenly distributed between the intervention and control groups.
To minimize the potential for confounding, we used concealed and stratified randomization in the trial, which resulted in the intervention and control groups being balanced in all measures of comorbid conditions, demographic characteristics, impairments, and functional performance. At baseline, no significant differences between the intervention and control group were detected for muscle strength, mobility, or other physical performance measures that are associated with sarcopenia and vitamin D levels in older adults.1
Latham NK, Bean JF, Jette AM. Home-Based Exercise and Hip Fracture Rehabilitation—Reply. JAMA. 2014;311(23):2440-2441. doi:10.1001/jama.2014.5173