Gender bias exists in the diagnosis of chronic obstructive lung disease (COPD), according to the results of a random sampling of 96 American and 96 Canadian primary care physicians. The study is published in the June issue of CHEST.

COPD, a term used to describe chronic bronchitis and emphysema, is a serious airway disease characterized by gradual loss of lung function. In 1996, an estimated 16 million Americans had the illness, which is primarily caused by cigarette smoking. There is no known cure, but smoking cessation can slow disease progress. However, it is the fourth leading cause of death in the U.S., behind heart disease, cancer, and stroke.

Writing in the peer-reviewed journal of the American College of Chest Physicians, Kenneth R. Chapman, M.D., of the Division of Respiratory Medicine, Department of Medicine, University of Toronto, Canada, along with two associates, presented 154 male and 38 female physicians with a hypothetical COPD case presentation, followed by a structured questionnaire given by a trained interviewer. The case described cough and serious breathlessness (dyspnea) in a smoker in the context of six different versions varying only in the age and sex of the patient. In other words, the hypothetical male and female patients with COPD symptoms had identical clinical respiratory symptoms and identical smoking histories, but could differ in age and sex.

After the physicians were presented with the history and physical findings, they were asked to state the most probable diagnosis and to choose appropriate diagnostic studies for the patient. Next, the physicians were presented with results from a simple lung function test (spirometry) that demonstrated findings of moderate to severe airflow obstruction. In addition, they were told that the use of a bronchodilator had provided no relief from the symptoms. The physicians were then questioned again about the diagnosis. Finally, they were told that oral steroids were tried and again with no response shown. (Had the disease been asthma, then the patient would have been provided relief.)

After the physicians reviewed the history and physical exam information for the potential COPD case, the researchers discovered that the doctors gave 64 percent of the hypothetical male patients and 49 percent of the hypothetical female cases the correct diagnosis of COPD. After the lung function test results were provided, 76 percent of the males and 64 percent of the females were deemed to be suffering from the disease. Following the oral steroid trial results, over 85 percent of the male patients and 78 percent of the female patients were correctly pegged as COPD victims.

The researchers found that asthma was listed as the diagnosis for over 32 percent of the men and almost 44 percent of the women following presentation of the initial history and physical findings. But the asthma misdiagnosis dropped to 10 percent for the men, and almost 18 percent for the women when the primary care physicians learned of the final diagnostic clueÐ the negative oral steroid use results.

Although they are definitely different illnesses, asthma and COPD are frequently confused. According to Dr. Chapman, in a previous study he performed involving the inappropriate diagnosis of asthma, some patients had endured treatment with two or more anti-asthma medications for more than two years.

"Our data show that many primary care physicians in North America are reluctant to consider the diagnosis of COPD, even when confronted by a middle-aged former smoker with chronic cough, dyspnea, and wheezes on physical examination," said Dr. Chapman. "Moreover, they are less likely to make the diagnosis of COPD in women than in men, a diagnostic bias that is eliminated by the presentation of compatible spirometric data. Regrettably, only a minority of primary care physicians would consider requesting spirometry in the investigation of a dyspneic patient with wheezes and a substantial smoking history."

In this study, only 22% of the physicians requested the simple lung function test called spirometry following the initial presentation of facts about the hypothetical patient with the COPD symptoms. The doctors were much more likely to request a chest X-ray, then blood lab work, followed by an electrocardiogram.

According to the authors, there is growing evidence that women may be more susceptible to the adverse pulmonary consequences of tobacco smoking. They cited two Danish studies that involved 13,897 subjects who were followed for between 7 and 16 years. The investigators in those studies found that women who had smoked had a higher rate of lung function decline per amount smoked than men and were at greater risk of being hospitalized for the treatment of COPD.

"Although women are clearly at increasing risk of developing COPD, the diagnosis continues to be made much more commonly in men," said Dr. Chapman. "By contrast, in studies of emergency department and ambulatory clinical care for asthma, women present with doctor-diagnosed asthma more often than men."

He pointed out it was disturbing to him that some physicians in their survey were remarkably reluctant to use the diagnostic term COPD. Even after the description of persistent and unchanging airway obstruction following two weeks of oral steroid therapy, one in seven physicians continued to use the diagnostic label of "asthma."

Dr. Chapman speculates the physicians may prefer the term "asthma" because they regard it as a disease more amenable to therapy and more rewarding to treat than COPD.

CHEST is published by the American College of Chest Physicians, which represents more than 15,000 members who provide clinical, respiratory, and cardiothoracic patient care in the U.S. and throughout the world.

---American College of Chest Physicians

Back to The Science of Mental Health