The physician office data included information on 17,318 office visits for treatment of hypertension in 1990 and 21,885 hypertension visits in 2002. The pharmacy survey included information supplied by 20,000 retail pharmacies.
In 2002, Americans spent about $12 billion on prescribed drugs to treat high blood pressure. In 2002, more patients took more than one drug to control high blood pressure. Stafford said hypertension experts recommend this combination approach, which accounts for about 8 percent of the increase in treatment costs. And, of course, there are more patients with high blood pressure, both because of the growth and aging of the population, and because of the epidemicof obesity. Higher prices for the drugs caused 29 percent of the increase, and population growth is responsible for 17 percent. "More people were being treated for high blood pressure in 2002 than in 1990," Stafford said. But about a third of the cost increase in the past decade was due to physicians prescribing high-priced drugs over cheaper alternatives. "While a number of factors drive up the bill for high blood pressure drugs, physician-prescribing practices accounted for 32 percent of the cost increase," said Stafford.
He said the two types of "expensive drugs" that contribute most significantly to the cost increase are angiotensin converting enzyme inhibitors, called ACE-inhibitors and angiotensin receptor blockers (ARBs). Diuretics are inexpensive medications that seem not to be used as often as they might be, although they may not lower the blood pressure enough in many patients when used alone. A month's supply of ACE-inhibitors costs about $44, and ARBs costs about $56 -- both significantly more than the $9 cost for a diuretic. While ACE inhibitor and ARB use increased from 1990 to 2002, "the prescription of diuretics declined by about 50 percent during the same period," he said.
Daniel Jones, M.D., a spokesperson for the American Heart Association, agrees that diuretics are underused. "However, the selection of antihypertensive agents by health providers is based on many factors. Price should be one of those factors, but, for most patients, the type of drug selected is not as important as getting the blood pressure lowered to the right level."
Jones added that there is scientific evidence to support the selection of specific types of drugs for some patients, and that these options are clearly outlined for physicians in high blood pressure treatment guidelines issued in December 2003 by the National Heart, Lung, and Blood Institute and endorsed by the American Heart Association.
"While it is convenient to blame the pharmaceutical industry for price increases, it is likely that physician decisions also drive prescription drug expenses," Stafford said. "The bottom line is that both physicians and patients need to be more aware of real data regarding the best use of both new and old drugs."
Pharmaceutical companies' marketing to physicians, and television and print advertising aimed directly at patients, might influence physicians to prescribe the newer drugs.
Another factor is the effect of clinical trial data published in medical journals. "Most of these studies are conducted with newer, brand-name drugs rather than older, generic drugs," Stafford said. Stafford's co-author is Tseday Alehegn.