BACKGROUND AND PURPOSE: Optimal timing of gastrostomy tube placement after stroke remains uncertain. Early gastrostomy tube placement may improve outcomes indirectly by facilitating earlier rehabilitation. We evaluated whether the effect of early gastrostomy tube placement on functional recovery and quality of life is mediated through rehabilitation. METHODS: We performed a literature-informed, model-based pathway-decomposition analysis using a prespecified framework. Modeling data was derived from approximately 6,100-7,100 patients, predominantly older adults aged ~70-80 years. Early gastrostomy tube placement (≤7 days) was defined as the exposure, rehabilitation timing, and intensity as mediators, and 90-day outcomes were measured by functional independence (modified Rankin Scale of 0-2) and EuroQol 5-Dimension (EQ-5D). Frequentist and Bayesian mediation models were applied. Posterior probabilities and 95% credible intervals (CrI) were estimated. RESULTS: Early gastrostomy tube placement was associated with earlier rehabilitation (-2.1 days; 95% CrI, -2.8 to -1.4). Each day, earlier rehabilitation is associated with higher functional independence (+0.7% absolute per day; 95% CrI, 0.3% to 1.1%) and EQ-5D (+0.012 per day; 95% CrI, 0.005 to 0.019). The total effect of early gastrostomy tube placement was +2.4% (95% CrI, 0.5% to 4.3%), with 63% mediated through earlier rehabilitation. The indirect effect was +1.5% (95% CrI, 0.6% to 2.6%; posterior probability > 0.99). For quality-of-life outcomes, early gastrostomy tube placement was associated with an EQ-5D increase of 0.021 (95% CrI, 0.004 to 0.038), of which approximately 70% was mediated through earlier rehabilitation. CONCLUSIONS: Early gastrostomy tube placement was associated with better 90-day functional and quality-of-life outcomes in this model-based pathway-decomposition analysis. The estimated association was primarily attributable to a rehabilitation-associated component rather than a residual direct component.
Qureshi et al. (Wed,) studied this question.