Prescription Drugs on the Rise: Estimates Suggest 60 Percent of Americans Take at Least One Medication

A new study estimates that 15 percent of Americans regularly take five or more medications. REUTERS/Gary Cameron

Use of prescription medications—for chronic diseases such as hypertension, diabetes, acid reflux and depression—has surged in the U.S. in the past decade, according to a paper published Tuesday in JAMA.

Researchers looked at data on nearly 38,000 adults aged 20 and older and estimated that overall prescription drug use in the U.S. rose from approximately 51 percent to 59 percent between 1999 and 2012. In particular, the number of Americans who are on five or more maintenance medications at once—called poly-pharmacy use—increased from 8 percent to 15 percent in the same period.

To conduct the study, the researchers used data from the National Health and Nutrition Examination Survey that included seven different cycles from 1999 to 2000 and 2011 to 2012. Information was collected through in-home interviews; for 84 percent of the interviews, patients showed the surveyor bottles of their medications.

In the group, 27 percent of people were on medications to treat high blood pressure in 2011 to 2012, compared with 20 percent in 1999 to 2000. The use of antidepressants nearly doubled, going from 7 percent to 13 percent. Perhaps most startling was the rising prevalence of statins, usually prescribed to lower cholesterol. Simvastatin use increased the most: from 2 percent in 1999 to 2000 to 7.9 percent in 2011 to 2012.

On the other hand, use rates did decline for some medications. For example, despite ongoing reports that Americans are overusing antibiotics to the point of building up resistance, this study noted a small decrease in use among this class of drugs over the past decade: from 5.7 percent to 4.2 percent.

The study also found fewer women are using hormone drugs. This decrease—from 19 percent to 11 percent—was primarily driven by the diminishing use of menopausal hormone therapy. Fewer women are now taking hormone replacement therapy, a result of a large-scale study by the Women's Health Initiative that found hormone replacement therapy significantly increased the risk for heart disease and certain types of cancer. In 2002, the study's advisory board recommended researchers end the trial on combination hormone therapy versus a placebo, since higher rates of breast cancer and heart disease appeared to directly correlate with use of the hormones. This prompted the U.S. Food and Drug Administration to caution women who choose hormone replacement therapy to use the drugs at lower doses and for a shorter duration, and so the drugs became less popular.

But overall drug use is up, and that finding raises an important question: Are adults in the U.S. getting sicker or are doctors simply over-prescribing drugs to patients?

The 65 and over population is growing, and that certainly is contributing to overall rising rates of prescription drug use; nearly 40 percent of adults 65 and older reported use of five or more medications. But this doesn't explain the fact that the rates of poly-pharmacy rose for all age populations, not just seniors. Other factors, such as better screening and diagnosis, may also account for that particular change. For example, the paper's authors write that the increase in antidepressant use could "reflect shifting attitudes regarding depression."

But the researchers also point out one overarching theme: The drugs that are most commonly prescribed right now are used for medical conditions that tend to afflict people who are overweight or obese. The study found that 8 of the 10 most commonly used drugs are used to manage heart disease, high blood pressure, diabetes and high cholesterol, all conditions and health complications that may develop as a person gains weight.