USA Today on Thursday examined how multiple studies have shown that only about half of people with chronic conditions in the U.S. and other developed countries continue to take medication as directed.
For example, a study published in the January issue of Drugs & Aging found that 20% to 30% of patients taking daily or weekly osteoporosis medication quit six to 12 months after they began.
A similar study published in the January issue of Cancer found that 22% of breast cancer patients taking the drug tamoxifen to reduce the risk of recurrence stopped taking the medication by the end of one year.
The study also found that more than one-third of patients had stopped taking tamoxifen after three-and-a-half years.
According to USA Today, "Reasons for this lack of adherence ... are complex, and quick fixes are few."
Physicians say the "problem cuts across all socioeconomic groups" and often goes unrecognized, USA Today reports.
Authors of the tamoxifen study -- from Trinity College in Dublin, Ireland -- wrote that decreased social support and declining memories might be reasons why older patients stopped taking their medications.
Alexandra Papaioannou, a geriatrician at McMaster University and author of the osteoporosis medication study, said that side effects and fear of the drugs were the primary reasons patients stopped taking their medication.
In addition, memory problems, depression and a daily regimen of multiple pills might have deterred patients from sticking to their prescriptions, Papaioannou said.
She added that patients should be provided with written, as well as oral, instructions for medication and that doctors should inform family members of the prescribed regimen to ensure that patient follow it.
"Adherence is a huge problem, costing billions of dollars," Papaioannou said, adding, "Obviously, if you don't take the drug, you won't have the full benefit" (Rubin, USA Today, 3/29).