Table 1.
Descriptive characteristics of the participants with different numbers of occasions in three age groups
| Number of occasions | d | |||||
|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 1–2 | 1–3 | 2–3 | |
| Number | ||||||
| 18–39 | 876 | 254 | 182 | NA | NA | NA |
| 40–64 | 1115 | 557 | 659 | NA | NA | NA |
| 65–99 | 546 | 326 | 287 | NA | NA | NA |
| Age | ||||||
| 18–39 | 26.6 (5.7) | 27.4 (6.7) | 28.8 (7.0) | .10 | .64^ | .23 |
| 40–64 | 53.2 (6.8) | 52.9 (6.4) | 52.9 (6.7) | .01 | .02 | .00 |
| 65–99 | 75.1 (7.2) | 74.4 (6.8) | 72.3 (5.7) | −.05 | −1.09^ | −.74^ |
| Proportion Females | ||||||
| 18–39 | .61 | .66 | .68 | NA | NA | NA |
| 40–64 | .69 | .68 | .73 | NA | NA | NA |
| 65–99 | .59 | .60 | .56 | NA | NA | NA |
| Self-Rated Health | ||||||
| 18–39 | 2.0 (0.8) | 2.0 (0.8) | 2.2 (0.9) | .01 | .25^ | .21 |
| 40–64 | 2.2 (0.9) | 2.1 (0.9) | 2.1 (0.9) | −.02 | −.06 | .01 |
| 65–99 | 2.4 (0.9) | 2.3 (0.9) | 2.3 (0.9) | −.05 | −.08 | .01 |
| Age correlation | .16* | .15* | .06 | |||
| Health-Related Limitations | ||||||
| 18–39 | 1.4 (0.7) | 1.4 (0.7) | 1.5 (0.8) | .05 | .13 | .03 |
| 40–64 | 1.7 (0.9) | 1.7 (1.0) | 1.7 (0.9) | .03 | .00 | .03 |
| 65–99 | 2.0 (1.0) | 2.0 (1.0) | 2.0 (1.0) | .00 | .01 | .00 |
| Age correlation | .27* | .23* | .18* | |||
| Education | ||||||
| 18–39 | 15.2 (2.4) | 14.8 (2.4) | 14.6 (2.2) | −.13 | −.30^ | −.06 |
| 40–64 | 15.7 (2.8) | 15.7 (2.6) | 16.0 (2.6) | .00 | .15 | .17^ |
| 65–99 | 15.9 (2.9) | 16.1 (2.8) | 16.2 (3.0) | .03 | .04 | .00 |
| Age correlation | .14* | .21* | .22* | |||
| Est. IQ | ||||||
| 18–39 | 109.1 (12.9) | 108.6 (12.4) | 105.4 (15.4) | .01 | −.32^ | −.24 |
| 40–64 | 107.9 (14.8) | 110.3 (14.6) | 112.0 (15.1) | .22^ | .62^ | .10 |
| 65–99 | 106.9 (13.8) | 109.1 (13.1) | 112.5 (13.0) | .17^ | .99^ | .36^ |
| Age correlation | −.06* | .01 | .17* | |||
| T1–T2 Interval (years) | ||||||
| 18–39 | 3.5 (2.2) | 2.5 (1.1) | NA | NA | −1.38^ | |
| 40–64 | 3.6 (2.0) | 2.7 (1.2) | NA | NA | −2.84^ | |
| 65–99 | 2.9 (1.4) | 2.4 (1.0) | NA | NA | −1.10^ | |
| Age correlation | −.11* | −.05 | ||||
| T2–T3 Interval (years) | ||||||
| 18–39 | 3.3 (1.5) | NA | NA | NA | ||
| 40–64 | 3.2 (1.4) | NA | NA | NA | ||
| 65–99 | 3.0 (1.3) | NA | NA | NA | ||
| Age correlation | −.08 | |||||
| Memory | ||||||
| 18–39 | .44 (.75) | .39 (.73) | .33 (.77) | −.02 | −.08 | −.03 |
| 40–64 | −.10 (.79) | .02 (.77) | .17 (.73) | .21^ | 1.13^ | .33^ |
| 65–99 | −.68 (.81) | −.46 (.76) | −.20 (.73) | .49^ | 2.26^ | .71^ |
| Age correlation | −.49* | −.41* | −.26* | |||
| Speed | ||||||
| 18–39 | .67 (.74) | .62 (.70) | .62 (.73) | −.03 | −.02 | .00 |
| 40–64 | −.07 (.71) | −.03 (.69) | .18 (.68) | .03 | 1.20^ | .79^ |
| 65–99 | −.87 (.76) | −.78 (.70) | −.52 (.60) | .09 | 1.53^ | .96^ |
| Age correlation | −.65* | −.61* | −.51* | |||
| Vocabulary | ||||||
| 18–39 | −.31 (.87) | −.31 (.88) | −.49 (.86) | .00 | .18^ | −.21 |
| 40–64 | −.03 (.92) | .12 (.87) | .29 (.84) | .25^ | 1.26^ | .34^ |
| 65–99 | .12 (.77) | .24 (.73) | .41 (.65) | .18 | 1.06^ | .57^ |
| Age correlation | .20* | .24* | .35* | |||
| Reasoning | ||||||
| 18–39 | .50 (.75) | .46 (.75) | .25 (.89) | −.01 | −.44^ | −.32^ |
| 40–64 | −.08 (.83) | .07 (.81) | .14 (.79) | .29^ | .62^ | .06 |
| 65–99 | −.62 (.81) | −.50 (.74) | −.26 (.73) | .15 | 1.24^ | .57^ |
| Age correlation | −.48* | −.43* | −.24* | |||
| Space | ||||||
| 18–39 | .57 (.91) | .45 (.90) | .30 (1.0) | −.11 | −.41^ | −.12 |
| 40–64 | −.15 (.77) | −.03 (.76) | .08 (.79) | .23^ | .83^ | .16 |
| 65–99 | −.54 (.61) | −.49 (.60) | −.33 (.68) | .05 | .71^ | .37^ |
| Age correlation | −.51* | −.43* | −.27* | |||
Note: NA indicates that the value is not applicable. Health was a self-rating on a scale from 1 for excellent to 5 for poor, and Health Limitations was a rating of health-related activity limitations on a scale from 1 for none to 5 for a great deal. MMSE is the Mini Mental State Exam (Folstein, Folstein & McHugh, 1975). Est. IQ is estimated IQ (see text for details).
^
indicates that the mean difference was significant at p<.01.