Table 1 Characteristics of 31,168 participants by social isolation
|  | Social isolation No. (%) (n = 5138) | Non-social isolation, No. (%) (n = 26030) | Overall, No. (%) (n = 31168) | P-value |
|---|---|---|---|---|
Age, mean (SD), years | 89.9 (9.8) | 87.7 (11.3) | 88.1 (11.1) | < 0.001 |
Sex |  |  |  | < 0.001 |
 Male | 1805 (35.1) | 11,205 (43.0) | 13,010 (41.7) |  |
 Female | 3333 (64.9) | 14,825 (57.0) | 18,158 (58.3) |  |
Residence |  |  |  | < 0.001 |
 Rural | 3269 (63.6) | 15,598 (59.9) | 18,867 (60.5) |  |
 Urban | 1869 (36.4) | 10,432 (40.1) | 12,301 (39.5) |  |
Education |  |  |  | < 0.001 |
 Illiterate | 3818 (74.3) | 16,577 (63.7) | 20,395 (65.4) |  |
 Literate | 1320 (25.7) | 9453 (36.3) | 10,773 (34.6) |  |
 Missing | 16 | 70 | 86 |  |
Household income |  |  |  | < 0.001 |
 Stable | 506 (9.8) | 4435 (17.0) | 4941 (15.9) |  |
 Unstable | 4632 (90.2) | 21,595 (83.0) | 26,227 (84.1) |  |
 Missing | 0 | 1 | 1 |  |
Childhood socioeconomic status |  |  |  | < 0.001 |
 Poor | 3613 (70.3) | 17,465 (67.1) | 21,078 (67.6) |  |
 Great | 1525 (29.7) | 8565 (32.9) | 10,090 (32.4) |  |
 Missing | 157 | 662 | 819 |  |
Intake of vegetables |  |  |  | < 0.001 |
 Yes | 2845 (55.4) | 16,307 (62.6) | 19,152 (61.4) |  |
 No | 2293 (44.6) | 9723 (37.4) | 12,016 (38.6) |  |
 Missing | 0 | 13 | 13 |  |
Intake of fruits |  |  |  | < 0.001 |
 Yes | 453 (8.8) | 3516 (13.5) | 3969 (12.7) |  |
 No | 4685 (91.2) | 22,514 (86.5) | 27,199 (87.3) |  |
 Missing | 0 | 10 | 10 |  |
Smoking |  |  |  | < 0.001 |
 Yes | 1416 (27.6) | 8790 (33.8) | 10,206 (32.7) |  |
 No | 3722 (72.4) | 17,240 (66.2) | 20,962 (67.3) |  |
 Missing | 1 | 17 | 18 |  |
Drinking |  |  |  | < 0.001 |
 Yes | 1421 (27.7) | 8307 (31.9) | 9728 (31.2) |  |
 No | 3717 (72.3) | 17,723 (68.1) | 21,440 (68.8) |  |
 Missing | 3 | 17 | 20 |  |
Regular physical exercise |  |  |  | < 0.001 |
 Yes | 1172 (22.8) | 7476 (28.7) | 8648 (27.7) |  |
 No | 5138 (77.2) | 18,554 (71.3) | 22,520 (72.3) |  |
 Missing | 1 | 18 | 19 |  |
Frailty index, mean (SD) | 0.182 (0.102) | 0.178 (0.104) | 0.179 (0.104) | < 0.001 |
Frailty status |  |  |  | < 0.001 |
 Non-frailty | 524 (10.2) | 3210 (12.3) | 3734 (12.0) |  |
 Prefrailty | 3619 (70.4) | 17,720 (68.1) | 21,339 (68.5) |  |
 Frailty | 995 (19.4) | 5100 (19.6) | 6095 (19.6) |  |