title: Combined impact of health risk factors on mortality of a petroleum industry population.
abstract: OBJECTIVE
  To assess the combined impact of health risk factors on mortality.
  
  
  METHODS
  A 21-year mortality follow-up of 12,896 Shell Oil Company employees was conducted. Relative risks of mortality, expressed as hazard ratios, in relation to the six risk factors, including cigarette smoking, obesity, high blood pressure, total cholesterol, serum glucose, and triglycerides, were calculated using a Cox proportional hazards model.
  
  
  RESULTS
  Employees with health risk factors had higher mortality rates for all-causes combined and for cardiovascular diseases compared to employees without such risk factors. Smoking, obesity, hypercholesterolemia, and hyperglycemia independently and significantly predicted cardiovascular disease mortality. Mortality risks from all causes and from cardiovascular disease increased with the number of risk factors present.
  
  
  CONCLUSIONS
  This study found a positive association between several health risk factors and mortality. A greater number of risk factors corresponded to a higher rate of death. Reductions of employee health risk factors may be an effective means of improving employees' long-term health.
authors.affiliation: Shell Oil Company, Houston, TX 77252-2463, USA. shan.tsai@shell.com
authors.forename: Shan P
authors.initials: SP
authors.lastname: Tsai
authors.forename: Faiyaz A
authors.initials: FA
authors.lastname: Bhojani
authors.forename: Judy K
authors.initials: JK
authors.lastname: Wendt
mesh_terms: D000328:Adult; D000368:Aged; D002318:Cardiovascular Diseases / Q000401:mortality*; D003327:Coronary Disease / Q000401:mortality; D005260:Female; D006305:Health Status Indicators; D006801:Humans; D007221:Industry; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure; D010578:Petroleum / Q000009:adverse effects*; D016016:Proportional Hazards Models; D012307:Risk Factors; D013781:Texas / Q000453:epidemiology
chemical_list: D010578:Petroleum