A model to predict level of adherence to prehabilitation in older adults with frailty having cancer surgery.

Purpose: Preoperative exercise could improve postoperative outcomes for people with frailty; however, little is known about how to predict older people's adherence to exercise before surgery (i.e., prehabilitation) programs. Our objective was to derive and validate a model to predict prehabilitation adherence in older adults living with frailty before cancer surgery.

Methods: This was a nested prospective cohort study of older adults with frailty having cancer surgery who participated in a randomized controlled trial of home-based prehabilitation compared with standard perioperative care. We constructed a multivariable ordinary least squares linear regression model to predict adherence. Covariates were selected a priori based on clinical expertise and systematic review. Optimism was estimated through internal validation using bootstrap resampling.

Results: The derivation cohort consisted of 95 participants in the intervention arm of the trial. Percent adherence ranged from 0% to 100%, with a mean (standard deviation) of 61 (34)%. Previous physical activity and age were the only predictors significant at the 5% level.

Conclusion: A prespecified multivariable model may help to explain a modest degree of variation in prehabilitation adherence in older people with frailty. While this model is an important step toward personalizing prehabilitation support, this study was limited by a small sample size and future research is needed to better understand personalized prediction of prehabilitation adherence in older people with frailty.