Which of the following statements are true about the incidence of asthma?

1. The prevalence has increased significantly over the past 20 years in the United States.
2. The mortality has remained the same over the past 20 years in the United States.
3. Researchers have determined the causes of asthma and are working on a vaccine.
4. Diagnosis of asthma is done in a physician's office following an extensive clinical assessment.
a. 1 and 3 only
b. 1 only
c. 1 and 2 only
d. 1, 2, and 4 only

ANS: B
Asthma is a chronic illness that has been increasing in prevalence in the United States since 1980. In 2007, asthma accounted for 3447 deaths, approximately 456,000 hospitalizations, and ap-proximately 13.3 million emergency room or physician office visits among persons of all ages. Approximately 7.7% of U.S. adults, or 17.5 million Americans, have asthma currently.