Table 1.
Descriptive statistics for the observed distribution of demographic variables and continuous proxies for CR and frequency of categorical proxies for CR (WAIS III = Wechsler Adult Intelligence scale) (n = 266).
| Mean | Standard deviation |
Range | |
|---|---|---|---|
| Time of Follow-up (months) | 18.67 | 2.73 | 15–25 |
| Age (years) | 66.68 | 9.05 | 50–87 |
| Years of education | 9.63 | 4.45 | 1–22 |
| WAIS III vocabulary test | 48.53 | 13.71 | 15–75 |
| Peabody picture-vocabulary test | 61.63 | 17.41 | 7–94 |
| Categorical variables | |||
| Category | Frequency | ||
| Occupational attainment | No occupation | 0.4 | |
| Unqualified worker | 40.6 | ||
| Housewife | 20.7 | ||
| Qualified worker | 29.7 | ||
| Other | 8.6 | ||
| Reading habits | Never | 15.0 | |
| Occasionally | 12.4 | ||
| Once or twice a week | 18.8 | ||
| Everyday | 53.8 | ||
| Social activities | Never | 30.5 | |
| Occasionally | 28.6 | ||
| Often | 22.2 | ||
| Always | 18.8 | ||
| Cultural activities | Never | 66.5 | |
| Occasionally | 9.8 | ||
| Often | 10.5 | ||
| Always | 13.2 | ||