Table 1.
Baseline demographic and clinical characteristics of retrospective fallers and new fallers at 18 month intervals over 54 months
| Retrospective (baseline) fallers | Prospective fallers | Non-fallers | P | |||
|---|---|---|---|---|---|---|
| (n = 26) | 18 m (n = 30) | 36 m (n = 17) | 54 m (n = 6) | (n = 20) | ||
| Age (years) | 66.9 (13.2) | 71.9 (13.0) | 70.2 (15.9) | 70.9 (11.8) | 67.6 (16.9) | 0.863 |
| BMI | 25.5 (6.4) | 26.3 (6.1) | 25.5 (7.2) | 26.1 (5.4) | 26.8 (5.6) | 0.935 |
| Male, n (%) | 13 (50) | 23 (76.6) | 9 (52.9) | 5 (83.3) | 16 (80) | 0.078 |
| Levodopa prescribed, n (%) | 13 (50) | 7 (23.3) | 5 (29.4) | 1 (16.6) | 6 (30) | 0.216 |
| LEDD (mg day−1) | 180.0 (285.0) | 100.0 (57.5) | 137.5 (200.0) | 100.0 (255.5) | 135.0 (165.0) | 0.174 |
| Dopamine agonist, n (%) | 9 (34.6) | 9 (30) | 7 (41.1) | 1 (16.6) | 8 (40) | 0.660 |
| Disease severity | ||||||
| H&Y score, n (%) I, II, III | 2 (7.6), 18 (69.2), 6 (23.0) | 6 (20), 12(60), 12 (60) | 6 (35.2), 10(58.8), 1 (5.8) | 0 (0), 6 (100), 0 (0) | 8 (40), 11(55), 1(5) | 0.002 |
| Motor phenotype, n (%) (PIGD, ID, TD) | 14 (53.8), 3 (11.5), 9 (34.6) | 17 (56.6),4 (13.3), 9(30) | 9 (52.9), 1 (5.8), 7 (41.1) | 1(16.6), 1 (16.6), 4 (66.6) | 6 (30), 1 (5), 13 (65) | 0.015 |
| PIGD score (0–4) | 0.60 (0.8) | 0.60 (0.4) | 0.60 (0.5) | 0.40 (0.4) | 0.40 (0.4) | 0.022 |
| Tremor score (0–4) | 0.75 (0.50) | 0.55 (0.55) | 0.64 (0.60) | 0.77 (0.53) | 0.72 (0.53) | 0.233 |
| UPDRS II (0–52) | 12.0 (8) | 11.0 (5) | 11.0 (10) | 9.0 (10) | 7.0 (8) | 0.144 |
| UPDRS III (0–132) | 29.0 (15.7) | 27.0 (12.5) | 26.0 (15.5) | 23.0 (17.0) | 19.5 (11.7) | 0.058 |
| FOG, n (%) | 5 (19.2) | 1 (3.3) | 1 (5.8) | 0 (0) | 2 (10.0) | 0.370 |
| NFOG score (0–28; higher worse) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 0.726 |
| Orthostatic hypotension, n (%) | 6 (23.0) | 5 (16.6) | 1 (5.8) | 3 (50.0) | 2 (10.0) | 0.493 |
| GDS (0–15; higher worse) | 3.0 (3) | 3.0 (3) | 2.0 (2) | 2.0 (3) | 2.0 (1.0) | 0.140 |
| ABC score (0–100; higher better) | 69.0 (44.6) | 89.3 (26.3) | 93.5 (20.9) | 93.6 (17.1) | 96.2 (18.9) | <0.001 |
| Total fatigue (20–100; higher worse) | 64.0 (17) | 49.0 (19) | 46.0 (21) | 51.0 (19) | 37.5 (34) | 0.000 |
| Cognitive outcomes | ||||||
| Years of education | 12.0 (6) | 11.5 (4) | 11.0 (8) | 13.0 (4) | 11.5 (6) | |
| MoCA (0–30) | 24.5 (7.2) | 25.0 (5.2) | 26.0 (4.7) | 27.5 (3.5) | 27.0 (5.5) | 0.232 |
| MoCA visuospatial (Item 1) (0–5) | 4.0 (2.0) | 4.0 (2.0) | 5.0 (1.7) | 5.0 (0.25) | 5.0 (1.0) | 0.205 |
| Subjective cognitive complaint, n (%) | 24 (92.3) | 19 (63.3) | 10 (58.8) | 3 (50.0) | 8 (40) | <0.001 |
| PoA (mean SRT, CRT, digit vigilance) | 1362 (260) | 1357 (156) | 1246(336) | 1360(300) | 1287(154) | 0.227 |
| PRM (mean correct latency) | 2165 (1510) | 2072 (646) | 2180 (902) | 2023 (660) | 1987 (753) | 0.604 |
| SRM (mean correct latency) | 2024 (1434) | 2128 (892) | 2335 (525) | 2089 (924) | 1971 (758) | 0.965 |
| OTS (mean correct latency) | 22,145 (18,658) | 22,452 (15,615) | 20,500 (11,122) | 12,802 (6144) | 19,039 (13,998) | 0.338 |
| OTS (mean choices correct) | 1.2 (0.21) | 1.2 (0.30) | 1.3 (0.37) | 1.5 (0.55) | 1.4 (0.50) | 0.328 |
| Motor outcomes | ||||||
| Single leg stance (s) (higher better) | 6.7 (20.5) | 9.9 (19.8) | 5.3 (15.6) | 18.5 (11.2) | 13.2 (23.4) | 0.092 |
| Timed chair stand (s) (higher worse) | 13.6 (4.9) | 14.6 (5.9) | 12.4 (4.7) | 14.6 (4.5) | 13.3 (5.4) | 0.595 |
| Gait outcomes | ||||||
| Pace domain | ||||||
| Step velocity (m/s) | 1.05 (0.27) | 1.03 (0.24) | 1.11 (0.36) | 1.12 (0.24) | 1.21 (0.14) | 0.021 |
| Step length (m) | 0.590 (0.11) | 0.615 (0.14) | 0.621 (0.12) | 0.658 (0.14) | 0.657 (0.10) | 0.044 |
| Swing time variability (ms) | 20.0 (11.6) | 16.9 (8.70 | 15.3 (6.3) | 15.4 (2.6) | 13.7 (7.2) | |
| Rhythm domain | ||||||
| Mean step time (ms) | 551.0 (63.8) | 579.6 (82.1) | 533.5 (59.0) | 569.5 (91.3) | 537.5 (42.4) | 0.215 |
| Mean swing time (ms) | 381.7 (32.3) | 391.4 (51.1) | 399.6 (49.1) | 395.1 (62.9) | 383.0 (40.8) | 0.421 |
| Mean stance time (ms) | 723.7 (98.5) | 749.1 (123.4) | 695.7 (100.1) | 752.0 (104.5) | 699.9 (50.0) | 0.074 |
| Variability domain | ||||||
| Step velocity variability (m s−1) | 0.057 (0.020 | 0.051 (0.01) | 0.047 (0.01) | 0.048 (0.01) | 0.048 (0.01) | 0.039 |
| Step length variability (m) | 0.024 (0.01) | 0.022 (0.00) | 0.018 (0.00) | 0.016 (0.00) | 0.020 (0.01) | 0.044 |
| Step time variability (ms) | 22.2 (11.5) | 19.0 (8.4) | 14.5 (8.5) | 15.8 (2.2) | 15.3 (8.0) | 0.016 |
| Stance time variability (ms) | 26.1 (16.9) | 23.3 (8.7) | 15.9 (10.3) | 16.6 (4.2) | 16.5 (7.3) | 0.002 |
| Asymmetry domain | ||||||
| Swing time asymmetry (ms) | 12.3 (8.3) | 11.8 (21.8) | 13.4 (26.0) | 19.0 (12.0) | 7.6 (10.1) | 0.082 |
| Step time asymmetry (ms) | 14.7 (20.1) | 13.3 (27.3) | 19.8 (20.4) | 20.0 (8.0) | 10.4 (15.2) | 0.460 |
| Stance time asymmetry (ms) | 12.6 (9.9) | 11.1 (20.4) | 11.1 (27.0) | 16.7 (9.7) | 10.1 (7.80 | 0.453 |
| Postural control domain | ||||||
| Step length asymmetry (m) | 0.022 (0.03) | 0.014 (0.02) | 0.020 (0.04) | 0.030 (0.02) | 0.019 (0.02) | 0.494 |
| Mean step width (m) | 0.105 (0.05) | 0.086 (0.05) | 0.086 (0.03) | 0.085 (0.03) | 0.080 (0.04) | 0.806 |
| Step width variability (m) | 0.018 (0.00) | .0.018 (0.00) | 0.019 (0.00) | .0.016 (0.00) | 0.017 (0.00) | 0.988 |
Significant values are indicated in bold
Data presented as the group median (IQR) unless otherwise stated
All comparisons using Kruskal–Wallis test apart from binary outcomes [Chi-square (χ 2) test]
LEDD levodopa equivalent daily dose, PIGD postural instability and gait disorder subscale UPDDRS, UPDRS III united Parkinson’s disease rating scale, NFOG new freezing of gait questionnaire, ABCs activities balance confidence-specific scale, GDS geriatric depression scale, MoCA Montreal cognitive assessment, MCR motor cognitive risk, PoA power of attention, PRM pattern recognition memory, SRM spatial recognition memory, OTS one touch stocking of Cambridge