The study analyzed health-care costs for that year and ranked the 15 most expensive medical conditions.
The overall bill for treating heart disease in 1997 was $58 billion. More than 17 million people were diagnosed with heart disease that year.
The second most expensive medical condition was cancer, at $46 billion, followed by trauma at $44 billion and mental disorders at almost $30 billion.
Lung disorders, including asthma, ranked fifth at a cost of $29 billion in 1997. But lung disorders affected the most people -- 41 million -- in the United States that year.
There were 44 million people with trauma, 20 million with mental disorders, and 9 million people with cancer.
The next 10 most expensive medical conditions in 1997 were:
- Diabetes: $20 billion; 10 million people.
- Hypertension: $18 billion; 27 million people.
- Cerebrovascular disease: $16 billion; 2 million people.
- Osteoarthritis: $16 billion; 16 million people.
- Pneumonia: $16 billion; 4 million people.
- Back problems: $13 billion; 13 million people.
- Kidney disease: $10 billion; 18 million people.
- Endocrine disorders: $10 billion; 18 million people.
- Skin disorders: $9 billion; 20 million people.
- Infectious diseases: $6 billion; 16 million people.
The study found private insurance covered at least 35 percent of the expenses for the top five conditions. That included more than 50 percent of the costs associated with cancer.
Medicare covered almost 45 percent of the expenses for heart disease, 20 percent to 25 percent of the costs of cancer and trauma, 16 percent of the costs for mental disorders, and 30 percent of the expenses for pulmonary conditions.
Hypertension was the most expensive for out-of-pocket expenses, with patients paying 30 percent of the costs. Hypertension also had the largest proportion of costs in prescription drug expenses. The cheapest out-of-pocket condition was pneumonia, at 4.1 percent.
Here's where you can learn more about health-care costs.