Plotting the Path to Recovery: Group-Based Trajectory Modelling of Physical Activity After Major Oncological Surgery to Predict Postoperative Outcomes.

BACKGROUND AND METHODS: The role of early and increased activity on postoperative recovery is well established, yet the impact of its day-to-day variability remains unclear. This retrospective cohort study examined associations between early in-hospital postoperative physical activity trajectories and postoperative outcomes among 218 surgical oncology patients from the University Medical Center Utrecht. Group-based trajectory modelling identified subgroups based on daily activity patterns over the first five postoperative days. Primary analysis assessed associations between trajectory and length of stay (LOS), complications, and 30-day readmission. Secondary analysis explored sociodemographic and clinical predictors of trajectory. RESULTS: Three trajectories were identified: Minimal (n = 72), Moderate (n = 97), and Rapid Activity Recovery (n = 49). Compared with the Minimal group, Rapid Activity Recovery patients had a 38% shorter LOS (MR: 0.62, 95% CI: 0.50-0.77). Trajectory was not associated with complications or readmissions. Female sex and higher American Society of Anesthesiologists Physical Status Classification were associated with lower odds of belonging to the Rapid Activity Recovery group (OR: 0.33, 95% CI: 0.14-0.78 and OR: 0.38, 95% CI: 0.17-0.84, respectively). CONCLUSIONS: Favorable early postoperative activity trajectories were associated with shorter hospital stay. DISCUSSION: Further exploration of real-time trajectory-based assessment towards the improvement of postoperative care is needed.