Participant characteristics and frailty classification at baseline survey
| Items | All (n=4249) | Robust (n=2121) | Pre-frailty (n=1228) | Frailty (n=900) | P value | Between-group difference |
| Age, years (SD) | 78.5 (2.8) | 78.2 (2.7) | 78.9 (2.9) | 79.3 (2.9) | <0.001 | Frail>Pre-frail>Robust |
| Sex: female, n (%) | 2074 (48.8) | 1157 (45.2) | 599 (53.2) | 318 (56.6) | <0.001 | Frail>Pre-frail>Robust |
| Disease burden (SD) | 1.5 (0.7) | 1.4 (0.7) | 1.6 (0.8) | 1.8 (0.9) | <0.001 | Frail>Pre-frail>Robust |
| Living alone, n (%) | 632 (14.9) | 374 (14.6) | 166 (14.7) | 92 (16.4) | 0.561 | n.s. |
| IADL decline, n (%)* | 138 (3.2) | 104 (4.1) | 149 (13.4) | 141 (28.1) | <0.001 | Frail>Pre-frail>Robust |
| Motor dysfunction, n (%)* | 585 (13.8) | 44 (1.7) | 234 (20.8) | 307 (54.6) | <0.001 | Frail>Pre-frail>Robust |
| Malnutrition, n (%)* | 77 (1.8) | 15 (0.6) | 28 (2.5) | 34 (6.0) | <0.001 | Frail>Pre-frail>Robust |
| Oral dysfunction, n (%)* | 705 (16.6) | 106 (4.1) | 297 (26.4) | 302 (53.7) | <0.001 | Frail>Pre-frail>Robust |
| Homebound, n (%)* | 194 (4.6) | 32 (1.2) | 49 (4.4) | 113 (20.1) | <0.001 | Frail>Robust |
| Cognitive decline, n (%)* | 1222 (28.8) | 374 (14.6) | 465 (41.3) | 383 (61.8) | <0.001 | Frail>Pre-frail>Robust |
| Depressive mood, n (%)* | 882 (20.8) | 73 (2.9) | 360 (32.0) | 449 (79.9) | <0.001 | Frail>Pre-frail>Robust |
| History of falls, n (%)* | 669 (15.7) | 201 (7.9) | 261 (23.3) | 207 (37.0) | <0.001 | Frail>Pre-frail>Robust |
| Fear of falling, n (%)* | 1677 (39.5) | 565 (22.4) | 663 (59.5) | 449 (80.9) | <0.001 | Frail>Pre-frail>Robust |
| Self-rated health (SD) | 3.6 (1.0) | 3.8 (0.9) | 3.3 (0.8) | 2.8 (0.8) | <0.001 | Robust>Pre-frail>Frail |
| Number of social activity (SD) | 0.9 (1.0) | 1.0 (1.0) | 0.8 (0.9) | 0.5 (0.7) | <0.001 | Robust>Pre-frail>Frail |
| Interaction with neighbours (SD) | 1.9 (0.8) | 2.0 (0.7) | 1.8 (0.8) | 1.6 (0.8) | <0.001 | Robust>Pre-frail>Frail |
| Trust in the community (SD) | 3.1 (0.7) | 3.2 (0.6) | 3.0 (0.7) | 2.9 (0.7) | <0.001 | Robust>Pre-frail>Frail |
Categorical variables were analysed by χ2 test (with residual test), and continuous variables were analysed by one-way ANOVA (with post-hoc LSD test).
*Based on Kihon Checklist (KCL) subscore of each area.
†Frailty identification: out of KCL 25 items, 0–3 for robust, 4–7 for pre-frailty and >8 for frailty.
ANOVA, analysis of variance; IADL, instrumental activities of daily living; LSD, least significant difference; n.s., not significant.