title: Comparison of cardiovascular disease risk calculators.
abstract: OBJECTIVE
  The cardiovascular benefit of many preventive interventions (like statins) is strongly dependent on the baseline cardiovascular risk of the patient. Many lipid and vascular primary prevention guidelines advocate for the use of cardiovascular risk calculators.
  
  
  RESULTS
  There are over 100 cardiovascular risk prediction models, and some of these models have spawned scores of calculators. Only about 25 of these models/calculators have been externally validated. The ability to identify who will have events frequently varies little (<5%) between models. However, disagreement between risk calculators is common with one in three paired comparisons disagreeing on risk category. In part, this disagreement is because calculators vary according to the database they are derived from, choice of clinical endpoints and risk interval duration upon which the estimate is based. Additional risk factors do little to improve the basic risk predictions performance, except perhaps coronary artery calcium which still requires further study before regular use.
  
  
  CONCLUSIONS
  The estimates provided by cardiovascular risk calculators are ballpark approximations and have a margin of error. Physicians should use models derived from, or calibrated for, populations similar to theirs and understand the endpoints, duration, and special features of their selected calculator.
authors: aEvidence-Based Medicine, Department of Family Medicine, University of Alberta, Alberta bFaculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada.
authors: G Michael
authors: GM
authors: Allan
authors: Scott
authors: S
authors: Garrison
authors: James
authors: J
authors: McCormack
mesh_terms: D002318:Cardiovascular Diseases / Q000453:epidemiology; D006801:Humans; D015233:Models, Statistical; D018570:Risk Assessment / Q000379:methods*; D013997:Time Factors