marginally significantp = 0.051
Age stratification revealed younger-old (65–75) achieved 24% improvement (d = 1.38), middle-old (76–85) achieved 19% improvement (d = 1.12), and oldest-old (86+) achieved 14% improvement (d = 0.89), with age-by-time interaction marginally significant (F(2,297) = 3.02, p = 0.051) suggesting slightly attenuated but still substantial effects in oldest users.