Background: COPD is thought to be more prevalent among
men than women, a finding usually attributed to higher smoking rates
and more frequent occupational exposures of significance for men.
However, smoking prevalence has increased among women and there is
evidence that women may be more susceptible to the adverse pulmonary
function effects of smoking than men. There may also be underdiagnosis
and misdiagnosis of COPD in both sexes because objective measures of
lung function are underused.
Objectives: We undertook
the present study to determine if there is gender bias in the diagnosis
of COPD, such that women are less likely than men to receive a
diagnosis of COPD. We also attempted to determine if underuse of lung
function measurements was a factor in any bias detected.
Methods: We surveyed a random sample of 192 primary-care
physicians (96 American and 96 Canadian; 154 men and 38 women) using a
hypothetical case presentation and a structured interview. The case of
cough and dyspnea in a smoker was presented in six versions differing
only in the age and sex of the patient. After presentation of the
history and physical findings, physicians were asked to state the most
probable diagnosis and to choose the diagnostic studies needed.
Physicians were then presented with spirometric findings of moderate or
severe obstruction without significant bronchodilator response, and the
questions repeated. Finally, the negative outcome of an oral steroid
trial was described.
Results: Initially, COPD was
given as the most probable diagnosis significantly more often for men
than women (58% vs 42%; p < 0.05). The likelihood of a COPD
diagnosis increased significantly and initial differences between sexes
decreased as objective information was provided. After spirometry, COPD
diagnosis rates for men and women were 74% vs 66% (p = not
significant); after the steroid trial 85% vs 79% (p = not
significant). Only 22% of physicians would have requested spirometry
after the initial presentation.
Conclusions: In North
America, primary-care physicians underdiagnose COPD, particularly in
women. Spirometry reduces the risk of underdiagnosis and gender bias
but is underused.