Pulmonary embolism: women who were obese, who smoked or had hypertension were at increased risk.

Clinical bottom line (level 1b)

  1. Pulmonary embolism was more likely in women who:
    • were obese (NNF = 230 for 16 years)
    • smoked >25 cigarettes a day (25-34/ day: (NNF = 480 for 16 years) ; 35 days or more: (NNF = 350 for 16 years) )
    • were hypertensive (NNF = 870 for 16 years)
Goldhaber et al: Journal of the American Medical Association 1997; 277 (8): 642-645
Expires October 2003

The study

Prospective cohort study with objective outcomes, adjusted for confounding factors, not validated in an independent set of patients.

Setting: community, USA

112822 patients (aged range 30-55 years in 1976, 100% female) women

Excluded if
  • prior history of pulmonary embolism
  • cancer (except non-melanoma skin cancer)
  • angina, MI, stroke, other cardiovascular disease in 1976



    • Factors studied:
  • pulmonary embolism
  • body mass index >29.0 weight/ (height) ²
  • cigarettes 25-34/ day
  • 35 or more cigarettes/ day
  • hypertension




    • Multivariate analysis was used to adjust for confounding factors.

    100% followed for 16 years
    Outcomes studied:
  • all pulmonary embolism (confirmed by medical records indicating high probability ventilation-perfusion scan, positive pulmonary angiography or diagnosis at autopsy)
  • primary pulmonary embolism (excludes secondary to trauma, cancer, surgery or immobilisation)

    • Patients were followed by postal questionnaire every two years. Follow-up was terminated if pulmonary embolism was diagnosed, death, return of last questionnaire.

    The evidence

    outcome time to outcome number of patients/total number %
    (95% CI)
    all pulmonary embolism 16 years 280/112822 0.25%
    (0.22% to 0.28%)
    primary pulmonary embolism 16 years 125/112822 0.11%
    (0.091% to 0.13%)

    prognostic factor for
    all pulmonary embolism     		time to outcome adjusted RR
    (95% CI)    		 NNF+
    (95% CI)
    body mass index >29.0 16 years 3.0
    (2.0 to 4.7)     		230
    (120 to 460)
    cigarettes 25-34/ day 16 years 1.8
    (1.2 to 2.9)     		480
    (200 to 1900)
    35 or more cigarettes/ day 16 years 2.1
    (1.2 to 3.6)     		350
    (150 to 1900)
    hypertension 16 years 1.5
    (1.2 to 2.0)     		870
    (440 to 2200)

    Comments

    1. Are the results applicable to men? Probably; similar risk factors were described in the Framingham study (which included men).

    Citation

    1. Goldhaber SZ, Grodstein F, Stampfer MJ, et al: A prospective study of risk factors for pulmonary embolism in women. Journal of the American Medical Association 1997; 277 (8): 642-645
    Contributor: Chris Ball and Clare Wotton, October 2000
    Reviewer: Kev Hopayian

    Clinical Question.
    Patient women
    Intervention or Exposure risk factors
    Outcome pulmonary embolism