Table 1.
Demographic and clinical characteristics of subjects
| Characteristics | Findings for Subjects |
|---|---|
| Total sample, n | 443 |
| Men, n (%) | 271 (61.2) |
| Women, n (%) | 172 (38.8) |
| Age at onset of PD, median year (range) | 61 (31 – 94) |
| Age at study, median year (range)a | 68 (33 – 96) |
| Time period between baseline and follow-up assessment (n = 417), median year (range) |
9.0 (4.7 – 12.6) |
| Percentage of subjects with family history of PDb | 20.5 |
| Region of origin of parentsc | |
| Both parents of European origin, n (%) | 381 (86.0) |
| Both parents Northern European, n (%) | 111 (29.1) |
| Both parents Central European, n (%) | 145 (38.1) |
| Both parents Southern European, n (%) | 3 (0.8) |
| Both parents European, mixed region, n (%) | 122 (32.0) |
| Only one parent of European origin, n (%)d | 39 (8.8) |
| One parent declared “American”, n (%)e | 2 (0.5) |
| Both parents declared “American”, n (%)e | 18 (4.1) |
| Both parents Asian, n (%) | - |
| Unknown, n (%) | 3 (0.7) |
a
Age at blood draw.
b
Family history was defined as having at least one affected first-degree relative; 90/439 cases had a family history of PD (information was missing for 4).
c
Self-reported by subjects. “Northern European” includes Scandinavian, Swedish, Norwegian, Finnish, Danish, Irish, or British origins. “Central European” includes French, Belgian, Dutch, Swiss, Luxemburgian, German, Austrian, Hungarian, Polish, Czechoslovakian, or Russian origins. “Southern European” includes Italian, Spanish, Portuguese, Greek, or Yugoslavian origins.
d
Includes subjects for whom origin of one parent is unknown.
e
These subjects were all Caucasians and not Native Americans.