title: A population-based study of mortality in essential tremor.
abstract: BACKGROUND
  Although data are sparse, people with essential tremor (ET) are usually assumed to have mortality rates similar to those in the general population. Because ET is common, particularly among older adults, an influence of ET on the life span would have important public health implications. The authors compared the risks of mortality in patients with ET and control subjects without ET.
  
  
  METHODS
  A prospective, population-based design was used to compare the risk of mortality in participants with ET vs controls in three communities in central Spain. Participants were evaluated at baseline (1994 to 1995) and at follow-up 3 years later (1997 to 1998). The relative risk (RR) of mortality (ET vs controls) was estimated using Cox proportional hazards models that excluded participants with Parkinson disease or dementia.
  
  
  RESULTS
  Mean baseline age was 73.5 +/- 6.4 years. There were 33 (16.4%) deaths among 201 ET cases and 465 (13.9%) among 3,337 controls. In an unadjusted Cox model, risk of mortality was increased in ET (RR = 1.59, 95% CI = 1.11 to 2.27, p = 0.01). In a Cox model that adjusted for baseline age, gender, educational category, current ethanol drinking, use of antidepressant medication, and community, RR = 1.45, 95% CI = 1.01 to 2.08, p = 0.04. In an adjusted Cox model restricted to persons with longer (>3 years) follow-up, RR = 4.69 (95% CI = 2.18 to 10.07, p = 0.001).
  
  
  CONCLUSIONS
  In this longitudinal, prospective study, the risk of mortality was increased in essential tremor. Additional studies of incident cases are needed to confirm these results.
authors.affiliation: G.H. Sergievsky Center and Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, USA. EDL2@columbia.edu
authors.forename: Elan D
authors.initials: ED
authors.lastname: Louis
authors.forename: Julián
authors.initials: J
authors.lastname: Benito-León
authors.forename: Ruth
authors.initials: R
authors.lastname: Ottman
authors.forename: Félix
authors.initials: F
authors.lastname: Bermejo-Pareja
mesh_terms: D000368:Aged; D020329:Essential Tremor / Q000401:mortality*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D016016:Proportional Hazards Models; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D013030:Spain / Q000453:epidemiology; D016019:Survival Analysis; D015996:Survival Rate