title: Does a birthday predispose to vascular events?
abstract: OBJECTIVE
  To examine the influence of birthdays on the onset and course of vascular events such as stroke, TIA, and acute myocardial infarction (AMI).
  
  
  METHODS
  This population-based study included all emergency department (ED) admissions due to ischemic stroke, TIA, or AMI from April 2002 to March 2004 in Ontario, Canada. All cases were identified through the National Ambulatory Care Reporting System. Calculations of daily and weekly numbers of events were centered on the patient's birthday and the week of the birthday. Statistical analyses include binomial tests and logistic regression.
  
  
  RESULTS
  During the study period, there were 24,315 ED admissions with acute stroke, 16,088 with TIAs, and 29,090 with AMI. The observed number of vascular events during the birthday was higher than the expected daily number of visits for stroke (87 vs 67; p = 0.009), TIA (58 vs 44; p = 0.02), and AMI (97 vs 80; p = 0.027) but not for selected control conditions (asthma, appendicitis, head trauma). Vascular events were more likely to occur on birthday (242 vs 191; odds ratio [OR] = 1.27). No significant differences were observed during the birthday week for any of the conditions. Multivariate logistic regression showed that birthday vascular events were more likely to occur in patients with a history of hypertension (OR = 1.88; 95% CI 1.09 to 3.24). Sensitivity analyses with alternative definitions of birthday week did not alter the results.
  
  
  CONCLUSIONS
  Stress associated with birthdays may trigger vascular events in patients with predisposing conditions.
authors.affiliation: Stroke Team, Department of Clinical Neurological Sciences, London Health Sciences Center, University of Western Ontario, Ontario, Canada. gsaposni@uwo.ca
authors.forename: Gustavo
authors.initials: G
authors.lastname: Saposnik
authors.forename: Akerke
authors.initials: A
authors.lastname: Baibergenova
authors.forename: Jason
authors.initials: J
authors.lastname: Dang
authors.forename: Vladimir
authors.initials: V
authors.lastname: Hachinski
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001719:Birth Certificates; D015984:Causality; D015897:Comorbidity; D005260:Female; D006333:Heart Failure / Q000453:epidemiology; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D002546:Ischemic Attack, Transient / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000453:epidemiology*; D009864:Ontario / Q000453:epidemiology; D018570:Risk Assessment / Q000379:methods*; D013315:Stress, Psychological / Q000453:epidemiology*; D020521:Stroke / Q000453:epidemiology*