Table 3.
Cognitive performance at the two waves of data collection (Wave 1 and Wave 2) for each telomere cohort
| Cognitive Test | Age Cohort | n at Wave1 | Wave 1 Mean ± SDa or Median [IQR]b | n at Wave 2 | Wave 2 Mean ± SDa or Median [IQR]b | P-valuec |
|---|---|---|---|---|---|---|
| Immediate recalld | 40+ | 350 | 8.21 ± 2.18a | 351 | 8.33 ± 2.24a | 0.694 |
| 40+ Men | 155 | 7.69 ± 1.97a | 155 | 7.74 ± 2.05a | 0.612 | |
| 40+ Women | 195 | 8.63 ± 2.26a | 196 | 8.80 ± 2.27a | 0.665 | |
| 60+ | 295 | 7.51 ± 2.13a | 293 | 7.16 ± 1.99a | 0.049* | |
| 60+ Men | 158 | 7.11 ± 2.05a | 157 | 6.86 ± 1.86a | 0.307 | |
| 60+ Women | 137 | 7.96 ± 2.14a | 136 | 7.51 ± 2. 08a | 0.102 | |
| SDMTe | 40+ | 349 | 61.30 ± 8.79a | 350 | 60.94 ± 8.59a | 0.966 |
| 40+ Men | 155 | 60.70 ± 8.65a | 155 | 60.45 ± 8.67a | 0.442 | |
| 40+ Women | 194 | 61.78 ± 8.89a | 195 | 61.32 ± 8.54a | 0.416 | |
| 60+ | 294 | 51.40 ± 8.00a | 293 | 50.58 ± 8.23a | 0.058 | |
| 60+ Men | 158 | 51.42 ± 7.65a | 156 | 50.93 ± 7.71a | 0.059 | |
| 60+ Women | 136 | 51.38 ± 8.41a | 137 | 50.19 ± 8.79a | 0.292 | |
| Simple RT | 40+ | 342 | 0.224 [0.206-0.245]b | 342 | 0.226 [0.210-0.250]b | 0.833 |
| 40+ Men | 150 | 0.216 [0.200-0.234]b | 150 | 0.223 [0.207-0.243]b | 0.553 | |
| 40+ Women | 192 | 0.228 [0.211-0.257]b | 192 | 0.232 [0.213-0.260]b | 0.390 | |
| 60+ | 285 | 0.238 [0.218-0.267] | 285 | 0.252 [0.228-0.290]b | 0..498 | |
| 60+ Men | 150 | 0.234 [0.213-0.254]b | 154 | 0.243 [0.223-0.285]b | 0.354 | |
| 60+ Women | 135 | 0.252 [0.221-0.281]b | 131 | 0.260 [0.235-0.302]b | 0.117 | |
| Choice RT | 40+ | 338 | 0.283 [0.266-0.306]b | 341 | 0.288 [0.263-0.310]b | 0.700 |
| 40+ Men | 150 | 0.278 [0.262-0.300]b | 149 | 0.278 [0.259-0.302]b | 0.784 | |
| 40+ Women | 188 | 0.287 [0.269-0.312]b | 192 | 0.295 [0.265-0.316]b | 0.615 | |
| 60+ | 283 | 0.314 [0.291-0.334]b | 285 | 0.318 [0.288-0.349]b | 0.068 | |
| 60+ Men | 149 | 0.315 [0.289-0.330]b | 154 | 0.317 [0.283-0.345]b | 0.989 | |
| 60+ Women | 134 | 0.313 [0.292-0.338]b | 131 | 0.318 [0.294-0.354]b | 0.029* |
IQR = interquartile range; SD = standard deviation; Immediate recall is from the California Verbal Learning Test; SDMT = Symbol Digit Modalities Test; RT = reaction time; Descriptive statistics are given using the raw data. * p < 0.05
a Mean ± standard deviation
b Median [interquartile range]
c Covariates were Wave1 performance on the relevant cognitive test, age, Spot-the-Word, systolic blood pressure, physical activity, alcohol consumption and where appropriate sex
d For the immediate recall descriptives, outliers (z-scores > +3.29 or < -3.29) were omitted
e For the SDMT descriptives, outliers (z-scores > +3.29 or < -3.29) were omitted