Table 1

Descriptive summary statistics and one-stage individual patient data meta-analysis mixed-effects linear regression model for age of symptom onset, with ‘tremor’ and ‘female’ as the reference categories

n (%)Age of onset
Mean (SD)
Gender
Women (%)
Coefficient
(95% CI)
Standardised effect size
(95% CI)
P value
Gender
 Women3558 (72.5)39.1 (15.9)
 Men1347 (27.5)41.0 (16.5)1.66 (0.71 to 2.62)0.10 (0.04 to 0.16)0.001*
Phenotype
 Mixed1127 (23.0)42.1 (16.3)848 (75.2)0.32 (−1.05 to 1.69)0.02 (−0.07 to 0.10)0.649
 Tremor1056 (21.6)40.7 (16.6)752 (71.2)
 Weakness887 (18.1)36.4 (13.4)647 (72.9)−3.74 (−5.35 to to 2.14)−0.23 (−0.33 to to 0.13)<0.001*
 Dystonia578 (11.8)34.5 (14.8)453 (78.4)−4.31 (−5.98 to to 2.65)−0.27 (−0.37 to to 0.16)<0.001*
 Gait405 (8.3)43.2 (18.4)284 (70.1)3.21 (1.39 to 5.03)0.20 (0.09 to 0.31)0.001*
 Jerks/myoclonus223 (4.5)39.8 (18.7)142 (63.7)1.03 (−1.19 to 3.25)0.06 (−0.07 to 0.20)0.363
 Parkinsonism†83 (1.7)44.6 (12.9)43 (51.8)
 Facial symptoms†67 (1.4)37.3 (12.6)56 (83.6)
 Other/unknown479 (9.8)40.3 (15.8)333 (69.5)−1.11 (−3.19 to 0.98)−0.07 (−0.20 to 0.06)0.298
Total sample4905 (100.0)39.7 (16.1)
  • Coefficients are to be interpreted in terms of age at onset in years; and standardised coefficients are interpreted in SD. Positive coefficient means that the variable was associated with a later age of onset and negative coefficient with an earlier age of onset.

  • *Statistically significant at the p<0.05 level.

  • †Not inputted into linear regression model.