Table 3 Influence of potentially confounding factors on the relative risk of spread in patients who started with blepharospasm compared with patients who started with onset in the neck or upper limb combined.
AdjustmentHazard ratio95% CIp Value
None2.51.5 to 4.1<0.001
Age2.31.3 to 4.10.003
Sex2.51.5 to 4.1<0.001
Referral2.41.5 to 4.1<0.001
Disease duration2.41.4 to 3.90.001
Age at dystonia onset1.81.1 to 3.30.03