BackgroundOlder patients experience increased loss of mobility after hospitalization, largely because of physical disabilities and inactivity. There are, however, no current recommendations for prescribing physical activity (PA) at hospital discharge. ObjectivesDevelop a decisional tree for the systematic prescription of an individualized, adapted, nonsupervised home-based PA program for older adults after hospital discharge; investigate its feasibility, acceptability, and safety; and estimate its efficacy at improving physical function and mobility. DesignPragmatic prospective single-arm pilot study. Setting and participantsGeriatric assessment unit (GAU). Participants: Age ≥65 years, Mini-Mental State Examination score ≥18, hospitalization >7 days, discharge to home, no PA contraindications, understand French or English. MethodsDevelopment of a decisional tree for prescription of home-based exercise programs (Preventing loss of Autonomy by Treatment Post-Hospitalization: PATH tool) through meetings with a group of experts. The PATH tool was implemented in a short-term geriatric hospital. Feasibility, acceptability, and safety outcomes were measured and potential efficacy estimated after a 12-week period. ResultsThe decisional tree has 3 main components (cognitive, cardio strength, and balance) and comprises 27 different mobility profiles and PA programs. Fifty-six of the first 100 successively admitted GAU patients were found eligible, of whom 29 agreed to participate and 17 completed the protocol. Most were satisfied (14/17) and enjoyed (13/17) the program, and most health professionals found it relevant to patients (7/8) without extra burden (6/8) to patient care. Adherence to the PA program was 5 sessions/wk, and a medium to large effect size on walking speed (P < .01, d = 1.04), chair stand performance (P = .04, d = 0.75), and PA level (P = .07, d = 0.56) was observed after a 12-week period. Conclusions and implicationsThis study suggests that implementing the PATH tool might be feasible across GAUs, as well as safe and acceptable for patients and health care professionals. If this intervention proves beneficial after conducting a randomized controlled trial, this hospital-initiated care transition strategy should be implemented in short-term geriatric hospitals to prevent long-term mobility disability.