Cost-utility of non-pharmacologic interventions aimed at improving cognitive outcomes after traumatic brain injury in older adulthood from the Ontario public healthcare payer perspective

Traumatic brain injury (TBI) can accelerate cognitive decline and increase dementia risk in older adults. Interventions including physical rehabilitation and cognitive training may preserve or improve their cognitive function. However, their cost-utility remains uncertain. Our objective was to identify the most economically attractive intervention for improving cognitive outcomes among older adults following TBI from a public healthcare payer perspective in Ontario, Canada. A cost-utility analysis was conducted using a discrete-time, individual-level Markov microsimulation model employing two-dimensional Monte Carlo simulation to compare four non-pharmacologic strategies for improving cognitive outcomes in older adults (≥ 65 years) following TBI: usual care, physical rehabilitation, cognitive training, and combination therapy (physical rehabilitation and cognitive training). The analysis adopted a public healthcare payer perspective in Ontario, Canada, over a lifetime horizon. Primary model outputs included incremental cost-effectiveness ratios (ICERs) as the main measure of cost-utility, along with quality-adjusted life years (QALYs), lifetime costs (QALYs and costs were discounted at 1.5% annually) and net monetary benefits (NMBs). Secondary outcomes included total life years, life expectancy, and incidence of mild cognitive impairment (MCI) and dementia. Costs are presented in 2024 Canadian dollars (CAD$), and a cost-effectiveness threshold of CAD$50,000 per QALY was applied. In the base-case analysis, combination therapy (physical rehabilitation and cognitive training) yielded the highest QALYs gained (3.04 QALYs) and NMB (CAD$102,653). The ICER of combination therapy compared to usual care was CAD$18,028 per QALY gained. All strategies were cost-effective, though cognitive training (ICER of 16,395; lifetime cost of CAD$13,027) was extendedly dominated by physical rehabilitation (ICER of 16,010; lifetime cost of CAD$14,310). Combination therapy was the optimal intervention in 92% of outer loop simulations. It was associated with the highest total life years and life expectancy, as well as lower incidence of MCI (64% [95% credible interval 63.9–64.1%]), mild dementia (1.7% [95% credible interval 1.6–1.8%]), and advanced dementia (0.7% [95% credible interval 0.6–0.7%]). Physical rehabilitation, cognitive training, and combination therapy were all cost-effective compared with usual care. Among these, combination therapy was the most economically attractive strategy. These findings support prioritizing multicomponent non-pharmacologic interventions to improve cognitive outcomes after TBI in older adults. Protocol registration: https://osf.io/z7xgj/