Table 1.
Baseline participants characteristics according to categories of social isolation and loneliness (N = 9,430)a.
| Characteristics | All participants, mean (SD) or N (%) | Not socially isolated, mean (SD) or N (%) | Socially isolated, mean (SD) or N (%) | P b | Not lonely, mean (SD) or N (%) | Lonely, mean (SD) or N (%) | P b |
|---|---|---|---|---|---|---|---|
| N | 9,430 | 6,728 (71.4) | 2,702 (28.6) | 7,471 (79.2) | 1,959 (20.8) | ||
| Age in years | 68.0 (10.2) | 66.9 (9.9) | 70.5 (10.5) | <.001 | 68.2 (10.2) | 67.1 (10.4) | <.001 |
| Women | 5,495 (58.3) | 4,026 (59.8) | 1,469 (54.4) | <.001 | 4,308 (57.7) | 1,187 (60.6) | .019 |
| Race/ethnicity | <.001 | <.001 | |||||
| Non-Hispanic white | 6,294 (66.8) | 4,643 (69.0) | 1,651 (61.2) | 5,003 (67.0) | 1,291 (65.9) | ||
| Non-Hispanic black | 1,633 (17.3) | 1,067 (15.8) | 566 (21.0) | 1,239 (16.6) | 394 (20.1) | ||
| Hispanics | 1,177 (12.5) | 784 (11.7) | 393 (14.5) | 990 (13.3) | 187 (9.6) | ||
| Other | 320 (3.4) | 232 (3.5) | 88 (3.3) | 234 (3.1) | 86 (4.4) | ||
| Education | <.001 | .009 | |||||
| <High school | 1,477 (15.7) | 784 (11.7) | 693 (25.6) | 1,147 (15.3) | 330 (16.8) | ||
| High school diploma | 2,901 (30.8) | 1,855 (27.5) | 1,046 (38.7) | 2,255 (30.2) | 646 (33.0) | ||
| Some/completed college | 3,711 (39.3) | 2,948 (43.8) | 763 (28.3) | 2,986 (40.0) | 725 (37.0) | ||
| Graduate degree | 1,341 (14.2) | 1,141 (17.0) | 200 (7.4) | 1,083 (14.5) | 258 (13.2) | ||
| Income levels ($) | <.001 | <.001 | |||||
| ≤49,999 | 4,855 (51.6) | 2,965 (44.2) | 1,890 (70.1) | 3,679 (49.4) | 1,176 (60.3) | ||
| 50,000–99,999 | 2,441 (26.0) | 1,905 (28.4) | 536 (19.9) | 2,005 (26.9) | 436 (22.3) | ||
| 100,000–200,000 | 1,489 (15.8) | 1,277 (19.0) | 212 (7.9) | 1,252 (16.8) | 237 (12.2) | ||
| >200,000 | 620 (6.6) | 563 (8.4) | 57 (2.1) | 518 (6.9) | 102 (5.2) | ||
| Smoking status | <.001 | <.001 | |||||
| Never | 4,406 (46.9) | 3,271 (48.8) | 1,125 (41.8) | 3,510 (47.2) | 886 (45.4) | ||
| Former | 3,974 (42.3) | 2,817 (42.1) | 1,157 (43.0) | 3,192 (42.9) | 782 (40.0) | ||
| Current | 1,020 (10.8) | 613 (9.1) | 407 (15.2) | 735 (9.9) | 285 (14.6) | ||
| Alcohol consumption | <.001 | <.001 | |||||
| Never | 5,532 (58.9) | 3,681 (54.9) | 1,851 (68.8) | 4,291 (57.6) | 1,241 (63.6) | ||
| Light | 2,818 (30.0) | 2,242 (33.4) | 576 (21.4) | 2,302 (30.9) | 516 (26.5) | ||
| Heavy | 1,048 (11.1) | 784 (11.7) | 264 (9.8) | 855 (11.5) | 193 (9.9) | ||
| Have regular physical exercise | 2,572 (27.4) | 2,046 (30.5) | 526 (19.5) | <.001 | 2,148 (28.9) | 424 (21.7) | <.001 |
| Obesity (BMI ≥30 kg/m 2 ) | 5,948 (63.1) | 4,250 (63.2) | 1,698 (62.8) | .766 | 4,766 (63.8) | 1,182 (60.3) | .005 |
| Depressive symptoms | .68 (1.24) | .57 (1.13) | .95 (1.44) | <.001 | .50 (1.01) | 1.35 (1.71) | <.001 |
| Cognitive function | 15.22 (4.50) | 15.84 (4.33) | 13.66 (4.55) | <.001 | 15.36 (4.44) | 14.68 (4.71) | <.001 |
| ADL disability | 452 (4.8) | 244 (3.6) | 208 (7.7) | <.001 | 316 (4.2) | 136 (6.9) | <.001 |
| Number of chronic conditions | 1.84 (1.27) | 1.73 (1.25) | 2.09 (1.27) | <.001 | 1.81 (1.26) | 1.93 (1.29) | <.001 |
Note:
Abbreviations: SD, standard deviation; BMI, body mass index (kilograms divided by height in meters squared), ADL, activities of daily living.
a
Unless indicated otherwise, data are expressed as N (%) of participants. Percentages have been rounded and may not total 100, and numbers may not total numbers in column headings owing to missing data.
b
Comparisons were performed using t-tests for continuous variables and the Chi-squared tests for categorical variables.