Association of clusters with variables not used in the cluster analysis, along with a p value derived from a hypothesis test that the variable is equally distributed (ie, same mean or same proportion) among the four clusters
| Variable | Tracking Parkinson’s clusters | Discovery—clusters predicted from Tracking Parkinson’s model | ||||||||||
| P values | Total (N=1601) | Cluster 1 (N=493, 30.8%) | Cluster 2 (N=459, 28.7%) | Cluster 3 (N=336, 21.0%) | Cluster 4 (N=313, 19.6%) | P values | Total (N=944) | Cluster 1 (N=307, 32.5%) | Cluster 2 (N=167, 17.7%) | Cluster 3 (N=223, 23.6%) | Cluster 4 (N=247, 26.2%) | |
| Women* | <0.001 | 554 (34.6%) | 144 (29.2%) | 204 (44.4%) | 98 (29.2%) | 108 (34.5%) | <0.001 | 334 (35.4%) | 92 (30.0%) | 87 (52.1%) | 58 (26.0%) | 97 (39.3%) |
| Disease duration from diagnosis† | <0.001 | 1.3 (0.9) | 1.3 (0.9) | 1.2 (0.9) | 1.5 (0.9) | 1.4 (0.9) | 0.002 | 1.2 (0.9) | 1.2 (0.9) | 1.1 (0.9) | 1.4 (0.9) | 1.2 (0.9) |
| Age diagnosis† | <0.001 | 65.9 (9.3) | 68.1 (8.1) | 62.6 (9.3) | 66.5 (9.8) | 66.7 (9.2) | <0.001 | 65.9 (9.6) | 67.6 (8.8) | 62.7 (9.4) | 67.0 (9.5) | 65.1 (10.2) |
| Age diagnosis <50* | <0.001 | 98 (6.1%) | 16 (3.2%) | 51 (11.1%) | 19 (5.7%) | 12 (3.8%) | <0.001 | 60 (6.4%) | 8 (2.6%) | 18 (10.8%) | 12 (5.4%) | 22 (8.9%) |
| UPDRS motor phenotype*‡ | ||||||||||||
| Tremor dominant | <0.001 | 741 (48.0%) | 194 (40.8%) | 241 (54.9%) | 92 (28.3%) | 214 (70.6%) | <0.001 | 510 (54.7%) | 129 (43.0%) | 98 (59.0%) | 90 (40.7%) | 193 (78.5%) |
| Indeterminate | 196 (12.7%) | 61 (12.8%) | 54 (12.3%) | 41 (12.6%) | 40 (13.2%) | 115 (12.3%) | 44 (14.7%) | 22 (13.3%) | 28 (12.7%) | 21 (8.5%) | ||
| Postural instability gait difficulty | 606 (39.3%) | 221 (46.4%) | 144 (32.8%) | 192 (59.1%) | 49 (16.2%) | 308 (33.0%) | 127 (42.3%) | 46 (27.7%) | 103 (46.6%) | 32 (13.0%) | ||
| Hoehn and Yahr stage* | ||||||||||||
| 0–1.5 | <0.001 | 808 (51.4%) | 259 (53.6%) | 298 (66.2%) | 110 (33.4%) | 141 (45.5%) | <0.001 | 216 (23.0%) | 76 (24.9%) | 60 (35.9%) | 21 (9.5%) | 59 (24.0%) |
| 2–2.5 | 685 (43.6%) | 211 (43.7%) | 147 (32.7%) | 181 (55.0%) | 146 (47.1%) | 660 (70.2%) | 208 (68.2%) | 103 (61.7%) | 178 (80.2%) | 171 (69.5%) | ||
| 3 | 79 (5.0%) | 13 (2.7%) | 5 (1.1%) | 38 (11.6%) | 23 (7.4%) | 64 (6.8%) | 21 (6.9%) | 4 (2.4%) | 23 (10.4%) | 16 (6.5%) | ||
| Untreated* | <0.001 | 149 (9.3%) | 33 (6.7%) | 69 (15.0%) | 12 (3.6%) | 35 (11.2%) | 0.001 | 119 (12.6%) | 35 (11.4%) | 28 (16.8%) | 14 (6.3%) | 42 (17.0%) |
| LEDD total† | <0.001 | 293 (205) | 304 (195) | 245 (202) | 361 (204) | 272 (203) | <0.001 | 282 (212) | 292 (196) | 242 (206) | 345 (225) | 241 (209) |
| LEDD total on medication†§ | <0.001 | 324 (190) | 327 (183) | 289 (188) | 375 (195) | 309 (188) | <0.001 | 327 (194) | 333 (173) | 293 (191) | 368 (213) | 297 (193) |
| Levodopa challenge† | ||||||||||||
| Percentage change | 0.002 | 32.1 (22.8) | 30.6 (23.0) | 36.3 (24.0) | 31.9 (21.7) | 28.8 (20.9) | 0.06 | 23.6 (15.2) | 22.1 (15.5) | 29.4 (16.7) | 23.4 (16.0) | 22.5 (12.3) |
*χ2 test.
†Analysis of variance.
‡Changed denominator where 80% or more of questions were answered.
§The LEDD restricted to those who are taking dopaminergic medication.
Cluster 1 is fast motor progression; cluster 2 is mild motor and non-motor disease; cluster 3 is severe motor disease, poor psychological well-being and poor sleep; cluster 4 is slow motor progression.
LEDD, levodopa equivalent daily dose; UPDRS, Unified Parkinson’s Disease Rating Scale.