Table I.
Descriptive statistics for study sample and the rest of the AHEAD cohort
| Study Sample* N=6,474 |
Rest of the AHEAD cohort † (N=973) |
p value for test of difference ‡ |
|
|---|---|---|---|
| Baseline (1993) Variables | |||
| Age (years): mean | 77.1 | 80.2 | < .001 |
| Gender | |||
| Male (%) | 38.7 | 49.5 | < .001 |
| Female (%) | 61.3 | 50.5 | |
| Marital status | |||
| Married (%) | 51.8 | 56.4 | < .01 |
| Widow/widower (%) | 39.9 | 38.3 | |
| Separated/divorced (%) | 5.0 | 2.3 | |
| Never married (%) | 3.3 | 3.0 | |
| Ethnicity | |||
| Non-Hispanic White (%) | 88.2 | 80.1 | < .001 |
| Non-Hispanic Black (%) | 7.6 | 10.4 | |
| Mexican American (%) | 1.7 | 4.4 | |
| Other Hispanics (%) | 1.4 | 2.1 | |
| Other (%) | 1.1 | 3.1 | |
| Educational level (years): mean | 11.3 | 9.3 | < .001 |
| Wealth ($): median | 96,000 | 50,200 | < .01 |
| Annual income ($): median | 17,532 | 13,068 | < .01 |
| Depressive Symptoms § | |||
| Low, <2 (%) | 62.3 | 39.6 | < .001 |
| Medium, >=2 but <4 (%) | 21.7 | 30.3 | |
| High, >=4 (%) | 16 | 28.8 | |
| Chronic Diseases | |||
| Heart disease (%) | 29.2 | 34.4 | < .05 |
| Diabetes (%) | 11.8 | 13.7 | |
| Stroke (%) | 6.7 | 18.0 | < .001 |
| Physical Disabilities | |||
| Basic ADL¶ Limitations (%) | 25.7 | 53.7 | < .001 |
| IADL# limitations (%) | 22.1 | 64.9 | < .001 |
*
Weighted to make AHEAD cohort representative of non-institutionalized persons 70 years and older living in the US in 1993
†
Remaining age-eligible AHEAD cohort with missing data (791 had proxy interviews, 4 were missing depression data, and 178 were missing 2 or more cognition subscales = 973)
‡
Tests of difference between groups: t-test for age, and education, chi-square for marital status and ethnicity, and rank sum test for wealth and income. All tests were 2-sided
§
76 (1.2%) had baseline CES-D scores imputed: 67 were missing 1 item, 7 were missing 2 items, and 2 were missing 3 items
¶
Activities of Daily Living
#
Instrumental Activities of Daily Living