The study has the advantage of a relatively large sample size, and the fact that the I-MOVE score was assessed before discharge eliminates the possibility of assessor bias. However, it has some limitations. We used a convenience sample, which may have introduced selection bias. Although we have no data on how providers selected patients for I-MOVE assessment, it would be reasonable to assume that patients were selected from among those whose activity level was, in terms of independence, doubtful or uncertain. That is, those who were not clearly vigorous (up and walking easily), nor clearly debilitated (in need of great assistance) may have been more likely to be assessed using I-MOVE. A more systematic selection of subjects might increase or decrease the predictive performance of the I-MOVE assessment. In addition, although we attempted to control for potential confounders, it is possible that additional confounders were left out of our analysis.
In summary, although the predictive performance of I-MOVE still needs to be confirmed by prospective studies with a comprehensive selection of subjects, the I-MOVE score at discharge appears to be associated with 30-day post-discharge mortality.
Acknowledgments: We thank the Department of Medicine’s clinical research office for their help in study design, data acquisition, and statistical analysis.
Corresponding author: Santiago Romero-Brufau, MD, Mayo Clinic Center for Innovation, 200 First St. SW, Rochester, MN 55905, romerobrufau.santiago@mayo.edu.
Funding/support: This publication was supported by grant number UL1 TR000135 from the National Center for Advancing Translational Sciences (NCATS). Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the NIH.