"Take two tablets by mouth twice daily." This printed instruction, common on prescription pill bottles, might seem straightforward. Yet in a study, nearly half of patients misunderstood what it or other common label instructions meant.

Now, the nonprofit organization that sets quality and safety standards for drugs approved by the Food and Drug Administration is aiming to simplify, clarify and standardize the labels that are affixed to those drugs.

The U.S. Pharmacopeia proposal, developed in conjunction with a group of independent experts, was released early this year for public comment. If adopted by state pharmacy boards nationwide, its developers hope it will help remove one of the many barriers that discourage people from taking their prescription drugs.

Medication compliance - or "adherence," as it's called - is a big problem. Even though 87 percent of people in a recent survey said they thought prescription medicines were important to their health, only about half take their drugs as directed. People skip doses, take the wrong number of pills and take pills at the wrong time of day, among many other problems. Poor adherence results in up to $290 billion in medical expenses each year, according to NEHI, a health research organization.

In general, people are more compliant with drugs for acute conditions, such as bladder infections, than for chronic ills, such as diabetes. But both types of noncompliance are problematic, and the reasons people offer for not taking their drugs are as varied as the drugs they're not taking. In that patient survey, 59 percent said they stopped taking their medication because they were feeling better and didn't think it was necessary to continue, while 25 percent said they stopped because they weren't feeling any better. Thirty-seven percent were worried about side effects, while 24 percent said their drugs were too expensive.

With such varied reasons for noncompliance, experts agree that solutions must be varied, too. "There is no silver bullet," says Bob Nease, chief scientist at Express Scripts, a large pharmacy benefit manager for employers and insurers.

Simple forgetfulness may be the culprit in many cases of non-adherence, especially when a drug doesn't make people feel different. Drugs to treat high cholesterol or high blood pressure fall into this category. Many researchers and others involved in medication adherence issues are excited about the potential of technology to educate patients and provide a "tickler" system to remind them to take their drugs.

Researchers at the Center for Connected Health in Boston, for example, found that sending daily text messages to patients with a type of eczema increased drug adherence, as did the use of pill bottle "GlowCaps" that light up and beep when high blood pressure patients miss a dose.

The center, a division of Partners HealthCare, works to identify ways that technology can help change patient behavior and improve health outcomes. With medication adherence, "what we've found is that the power of simple reminders is enormous," says the center's director, Joseph Kvedar.

Even the most unlikely people need an assist now and then. Kvedar uses a GlowCap to remind him to take his cholesterol-lowering drug every night.

At 9 p.m., the pill cap lights up to remind him it's time to take his pill. If he's not near his pill bottle, a small plug-in unit in his kitchen that looks like a night light glows at the same time to remind him. When he takes his dose, the cap relays the information wirelessly to the company network. But if he hasn't taken his pill after an hour has passed, the cap emits a ring tone. If he fails again to take a dose after another hour, the system calls him on his cellphone to remind him.

Kvedar says he would have expected that his adherence would be 100 percent, but "I've discovered with the GlowCap that I would have forgotten some nights."

There are many lower-tech ways to improve adherence, say experts. Communication is key. If doctors and pharmacists make a point of explaining possible side effects and the importance of completing a course of treatment, for example, a patient may be less likely to discontinue taking a drug after experiencing a side effect.

As for costs, reducing or eliminating co-payments for drugs increases patients' adherence, says Niteesh Choudhry, an assistant professor of medicine at Harvard Medical School who has conducted research on the subject. Increasingly, companies are picking up the tab for medications to treat their employees' chronic conditions, with the expectation that they'll save money down the road through lower medical costs.

While no single strategy or technology will get everyone to take his medicine as directed, experts agree that clear instructions on the pill bottle are a basic requirement. Many of the U.S. Pharmacopeia recommendations seem commonsensical: Place patient information and instructions at the top of the label in bigger type than the doctor or pharmacy name or information on refills and expiration; use everyday words, such as "high blood pressure" instead of "hypertension"; keep auxiliary information, such as warnings, simple and straightforward.

And to avoid confusion over such things as dosages and when to take the medication, the recommendations say, keep those instructions separate and simple, using numbers instead of words when appropriate. With those guidelines in mind, perhaps fewer people would be confused by the instruction that started this column. The new and improved pill bottle would read, "Take 2 tablets by mouth in the morning and 2 tablets by mouth in the evening."

health-science@washpost.com

This column is produced through a collaboration between The Washington Post and Kaiser Health News. KHN, an editorially independent news service, is a program of the Kaiser Family Foundation, a nonpartisan health-care-policy organization that is not affiliated with Kaiser Permanente.