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Table 2 Seven-year trajectories of global cognition (0–32) by cognitive reserve in urban residents (N = 2701)

From: Cognitive reserve over life course and 7-year trajectories of cognitive decline: results from China health and retirement longitudinal study

  Model 1a Model 2b Model 3c
Intercept Slope Intercept Slope Intercept Slope
b (95% CI) b (95% CI) b (95% CI) b (95% CI) b (95% CI) b (95% CI)
Mean 15.362 (14.972, 15.751) −0.293 (− 0.429, − 0.156) 14.562 (13.858, 15.266) − 0.233 (− 0.432, − 0.035) 15.140 (14.429, 15.851) − 0.287 (− 0.489, − 0.085)
Variance 8.462 (7.211, 9.714) 0.136 (0.062, 0.211) 8.269 (7.026, 9.512) 0.131 (0.057, 0.205) 7.912 (6.697, 9.127) 0.131 (0.057, 0.205)
Cognitive reserve 1.742 (1.652, 1.833)* 0.048 (0.026, 0.071)* 1.714 (1.623, 1.805)* 0.047 (0.024, 0.069)* 1.615 (1.521, 1.709)* 0.054 (0.031, 0.077)*
Baseline age, centred −0.157 (− 0.228, − 0.086)* −0.021 (− 0.040, − 0.002)* −0.146 (− 0.217, − 0.074)* −0.020 (− 0.039, 0.000) −0.148 (− 0.219, − 0.078)* −0.019 (− 0.038, 0.000)
Baseline age, squared − 0.002 (− 0.005, 0.002) 0.000 (− 0.001, 0.001) −0.001 (− 0.005, 0.002) 0.000 (− 0.001, 0.001) − 0.001 (− 0.004, 0.002) 0.000 (− 0.001, 0.001)
Gender
 Men Ref
 Women −0.543 (− 0.881, − 0.204)* 0.092 (0.011, 0.172)* −0.455 (− 0.898, − 0.013)* 0.021 (− 0.086, 0.127) −0.364 (− 0.804, 0.077) 0.003 (− 0.103, 0.110)
Marital status
 Unmarried    Ref
 Married    0.352 (−0.092, 0.797) 0.039 (−0.074, 0.151) 0.272 (− 0.167, 0.711) 0.042 (− 0.071, 0.154)
Alcohol drinking
 Never    Ref
 1/month    1.373 (−0.589, 3.334) −0.199 (− 0.686, 0.289) 1.125 (− 0.809, 3.060) −0.177 (− 0.664, 0.310)
 2–3/month    0.541 (−0.728, 1.810) 0.051 (− 0.250, 0.353) 0.415 (− 0.837, 1.667) 0.075 (− 0.227, 0.376)
 1–6/week    0.112 (− 0.827, 1.051) −0.163 (− 0.390, 0.064) 0.126 (− 0.801, 1.052) −0.176 (− 0.403, 0.051)
 ≥1/day    0.078 (−0.507, 0.663) 0.027 (−0.110, 0.164) 0.027 (− 0.551, 0.606) 0.029 (− 0.108, 0.166)
Smoking status
 Never    Ref
 Former    0.427 (−0.124, 0.979) −0.141 (− 0.276, − 0.007)* 0.505 (− 0.040, 1.050) −0.150 (− 0.284, − 0.015)*
 Current    − 0.069 (− 0.528, 0.391) − 0.122 (− 0.231, − 0.012)* −0.035 (− 0.489, 0.418) −0.123 (− 0.232, − 0.014)*
BMI
 Underweight    −0.324 (−1.122, 0.474) 0.034 (− 0.169, 0.238) −0.266 (− 1.059, 0.526) 0.031 (− 0.173, 0.235)
 Normal    Ref
 Overweight    0.791 (0.370, 1.212)* 0.017 (−0.082, 0.116) 0.738 (0.314, 1.161)* 0.018 (− 0.082, 0.119)
 Obesity    0.553 (−0.007, 1.112) − 0.057 (− 0.188, 0.075) 0.457 (− 0.116, 1.030) − 0.059 (− 0.196, 0.077)
Hearing loss
 No      Ref
 Yes      −0.428 (− 0.975, 0.119) −0.011 (− 0.155, 0.133)
Hypertension
 No      Ref
 Yes      −0.183 (− 0.544, 0.177) 0.006 (−0.082, 0.094)
Diabetes
 No      Ref
 Yes      0.035 (−0.485, 0.556) − 0.054 (− 0.181, 0.073)
Heart diseases
 No      Ref
 Yes      0.194 (−0.207, 0.595) −0.004 (− 0.102, 0.095)
Stroke
 No      Ref
 Yes      −0.243 (−1.084, 0.599) − 0.191 (− 0.428, 0.047)
Dyslipidaemia
 No      Ref
 Yes      0.166 (−0.304, 0.637) 0.088 (− 0.026, 0.202)
Probable depression§
 No      Ref
 Yes      −1.059 (−1.468, − 0.649)* 0.094 (− 0.009, 0.197)
ADLs (0–6)      −0.487 (− 0.668, − 0.306)* 0.064 (0.012, 0.117)*
  1. Notes: ADLs activities of daily life, BMI body mass index, Ref reference category. Quadratic slope was not regressed on CR or covariates because the magnitude of the slope is too small (b = 0.012). a Adjusted for age, age squared, gender, and urban/rural residence. b Adjusted for Model 1 covariates plus smoking status, alcohol drinking frequency and BMI. c Adjusted for Model 2 covariates plus number of limitations in ADLs, self-rated hearing, probable depression, and self-reported doctor-diagnosis of cardiovascular disease, hypertension, diabetes, stroke and dyslipidaemia. §Probable depression was defined as having CES-D-10 score ≥ 12. * p < 0.05