Forty-four percent of U.S. adults are "extremely worried" or "very worried" about paying for rising health-care costs. And the top reasons cited for those rising costs are profits generated by drug companies and health insurance companies.

Those are just two of the findings in a just-released study of 2,389 adults surveyed online between March 11 and 15 by Harris Interactive, one of the world's leading custom market research firms, and HealthDay, a leading producer and syndicator of health news.

Experts debate whether it's fair to blame the insurers and drug makers for the bulk of the escalating health-care costs. Some health economists say insurance and pharmaceutical company profits amount to only about 2 percent of total health-care spending. The rising charges are more likely due to the greater use of expensive health-care technologies and increased physician/hospital fees, some economists contend.

"Forty-four percent is a huge number of worried citizens and underscores the biggest concern about our health-care system, which is, 'How will America pay for it?’” said Humphrey Taylor, chairman of The Harris Poll, a service of Harris Interactive.

What is indisputable is that health-care costs are rising much faster than inflation or wages, and are gobbling up an ever-growing proportion of the Gross Domestic Product (GDP). Total spending on health care hit about $2.3 trillion in 2008, which translates to $7,681 per person and 16.2 percent of the GDP, according to the U.S. Department of Health and Human Services.