Table 3

Results of mixed model statistical analysis

 Percentage change in BFM scores (negative indicates improvement)
Severity scoreDisability score
Estimatep valueEstimatep value
Reference group:
Childhood-onset primary generalised dystonia of torsional phenotype and less than 10 years duration, at 6 months follow-up−40.3<0.001−28.00.003
Additional effect of changes in fixed variables, relative to reference group above (negative indicates improvement):
Later time points
 1 year−1.00.81−6.10.39
 2 years−5.50.31+5.30.65
 5 years−8.30.17−3.60.75
Different aetiology
 DYT mutation−14.80.025−20.70.031
 Secondary (tardive dystonia excluded)+16.10.013+7.30.48
Myoclonic phenotype−11.10.11−18.60.11
Adult onset+4.40.46−8.30.38
Increased duration
 10–20 years−6.10.36+8.20.36
 20+ years+4.40.48+15.90.091
  • BFM, Burke-Fahn-Marsden.