The main findings of this study were that there are significant differences between men and women in China with COPD in terms of smoking habits, treatment of their disease, history of using biomass fuel, average potential longevity lost, and cost of COPD.
Risk factors that contribute to development of COPD include smoking, use of biofuels, lack of exercise, social support, work-related dust exposure, and a family history of respiratory disease.16
However, in China, there is a difference between men and women in the incidence of COPD.10
The risk factors for COPD are not the same in women as in men. Therefore, study of the risk factors that cause COPD according to geographical region and gender and of the differences between men and women with regard to indicators of vulnerability to dealing with COPD may provide a scientific basis for designing rational and effective control programs.
This is the first published study on the difference in vulnerability associated with COPD from a gender perspective. After matching 5650 patients (2825 male, 2825 female) with COPD by age (± one year), education level, number of family members (± 1 person), GOLD stage, and duration of disease, we investigated their indicators of vulnerability. We found that patients with COPD in the rural areas of Xuzhou are extremely vulnerable.
Although quitting smoking is the most cost-effective means of preventing further deterioration of lung function, 20.5% of study patients were current smokers. The rates of ever, current, and passive smoking were all significantly higher in male patients than in female patients. The smoking rate in male patients with COPD was 69.9%, which is significantly higher than that of the general population.18
The rate of smoking for men with COPD in our study was similar to that in Spanish men with COPD, whereas the rate for women was lower than that of Spanish women with COPD.19
These findings show that the characteristics of smoking behavior, a unique indicator of vulnerability, differ between men and women with COPD.
However, we found that smoking is not the main vulnerable behavior in women with COPD. A history of using biomass fuel and duration of its use was significantly higher in female than in male patients. This is consistent with the fact that women are typically the main family members using biomass in the study locality and shows that smoke generated by using biofuels is of particular relevance to women with COPD. The local kitchens mainly have cornstalk, reed, or earth walls and are not ventilated. The biomass fuel used is derived mainly from straw or charcoal and produces lampblack, which exacerbates any tendency of women to develop COPD. Lampblack is a risk factor that is unique to women with COPD. Family history is also an important risk factor for COPD,20
and we found that a family history of COPD was more frequent in female patients than in male patients.
Because lung function tests and health education programs have never been available in the locality of the study patients, none of them had previously heard the term “COPD” or had been diagnosed as having the condition. Therefore, they had no incentive to acquire knowledge about COPD. There was a significant difference between male and female patients in vulnerability involving knowledge about the causes of COPD. However, vulnerability related to this knowledge correlated with undesirable behavior. For example, because the rate of smoking was higher in male patients, they thought that smoking was an important cause of COPD. In contrast, female patients were more likely to use biomass fuel, so they thought that using biomass was an important cause of COPD.
Because they had not received standard treatment and had longstanding symptoms of COPD, almost 16% of patients thought that treatment was not capable of slowing the progression of their disease. Female patients were more anxious about this than were male patients. Male patients were more willing to adopt helpful measures, such as preventing colds, maintaining a regular vaccination schedule, or having globulin injections, than were female patients. This may account for the finding that female patients were more likely to be hospitalized than were male patients, and that average medical expenses were lower for men than for women.
Medication is an effective means of preventing and controlling the symptoms of COPD, reducing the frequency and severity of exacerbations, and improving both exercise tolerance and quality of life.21
Providing treatment for COPD patients, especially for those who are stable, can reduce the frequency of exacerbations.23
However, we found that patients in rural Xuzhou were highly vulnerable to poor disease management. None of the stable patients had received regular drug treatment, and their drug regimen compliance rate was significantly lower than that reported by Barr et al.24
During acute exacerbations of COPD, no patients had used inhalers or sprays. This is much lower than the appropriate rate for use of inhaled drugs, which is 10% according to Restrepo et al.25
Whether male or female, none of the patients knew how to perform rehabilitation exercises and none of them had undergone lung function testing. In the stable and exacerbation stages of COPD, the rate of treatment was higher for male than for female patients. This finding is related to the fact that the household income of female patients is higher than that of males. Because men’s earnings are the main income source for families in the study locality, men who are ill are more likely to have treatment to enable them to keep earning wages, whereas women who are ill are more likely to be hospitalized.
We found that the annual direct economic burden of patients with COPD was 1982 yuan, which is lower than in Spain and the US.19
Although there was no difference between male and female patients in average annual medical expenses, there were more men with medical expenses of less than 1500 yuan per year than there were women. These findings reflect the fact that male patients more often used daily treatment, whereas female patients were more frequently hospitalized. COPD causes loss of potential years of longevity, and these losses were higher than those reported by Fei et al27
for both male and female patients. This discrepancy may relate to the fact that our study included rural patients and the studies were performed in different years.
In the present study, the total scores for quality of life were higher for female patients than for male patients. This finding relates mainly to women scoring higher than men in the affect part of the questionnaire we used, which in turn relates to women being more prone to mental illness.28
The quality of life aspect of vulnerability reported in this study is higher than that reported by An et al.29
This may be because our subjects lived in a rural area.
The present study has a number of limitations. First, its cross-sectional nature predisposes to recall bias and resulting misclassification bias with regard to case status. Second, our estimates of vulnerability may not be applicable to patients with COPD living in other areas, because health care practice patterns may differ regionally. Third, we did not use multiple regression to analyze the reasons for the differences in vulnerability between male and female patients with COPD.