Map of life expectancy at birth from Global Education Project.

Friday, March 05, 2010

Adherence

No, that's not about glue or sticky tape, it's what we called "compliance" back when I was a grad student, a term which is no longer politically correct. It means, is the patient following the therapeutic "regimen" -- itself an interesting term -- as prescribed by the physician. In the vernacular "regimen" usually means some strict and probably painful discipline, such as running 100 miles a week and eating precisely 3,500 calories per day in order to train for the marathon, but in medical practice, it usually just means taking pills. People given other regimens, such as exercise and diet, very rarely follow them anyway.

Readers ask if doctors inquire about what we call adherence and if so, how they talk about it with their patients. The answers are sometimes; and usually not very effectively.

It's hard to measure people's pill-taking behavior accurately because their self-reports tend to overstate their adherence, and other methods are intrusive, expensive, and/or imprecise. But, generally speaking, people follow their dosage schedules to a clinically acceptable degree something like half the time. It's relatively unlikely, obviously, that people will follow very complicated regimens to the letter. Nowadays as people get older they tend to have more and more prescriptions. People with chronic conditions like diabetes and kidney disease can easily get up to a dozen or even two dozen prescriptions. I kid you not. But even people who have just been prescribed one or two pills for asymptomatic conditions like hypertension just stop taking them about half the time.

Often people are afraid that if they tell their doctors they aren't taking the pills, the doctor will give them a hard time, so when the doctor asks, "Are you taking the pills?" they just say, "Yeah, yeah" and that's the end of it. But, their fears may well be justified and may in fact stem from experience. Doctors often don't know what to do when their patients don't take the pills except lecture them, scold them, and basically threaten them with death. It seldom works.

The problem is that when it comes to taking pills, doctors and patients are often in different worlds. To the doctor, the pill is characterized by a statistical prediction: the probability of averting some adverse event, weighed against the probability of causing one or more others. Many of the possible side effects, to the physician, won't really count for anything because they're just inconvenient -- odd feelings, constipation, itching, that sort of thing. Others, that aren't direct biological consequences of the chemical, such as being reminded that you have a diagnosis or a $15 copay, don't even exist in the physician's world.

For us patients, i.e. people, however, the stories are far more complicated, and they often aren't the sorts of stories we feel comfortable sharing with our doctors. This is a huge problem because it does absolutely no good to make progress in biomedicine and to discover terrific new ways of preventing and treating disease if people ultimately don't take the pills. We're talking tens of billions in investment every year that just isn't paying off half as well as it could, and tens of millions of physician visits that are pretty much a waste of everybody's time.

Of course there is overprescribing as well and there are undoubtedly cases in which the patient makes a correct decision not to take the pills. I have personal knowledge of more than a few. Those represent a different kind of failure, but it often comes down to communication as well. I'll get into these stories more specifically in coming days. Maybe some of them will even be interesting.

2 comments:

distracted by shiny objects said...

I find more recently an embarrassment of formerly employed individuals choosing between their prescriptions and other expenses--one a grandma choosing to pay for her granddaughter's school photos as she always had done. It can be humiliating.

C. Corax said...

Old folks with many prescriptions can become very, very confused. They can get those handy dandy pill minders of varying sizes and complexity, but with their cognitive abilities in decline, keeping track of many pills, each on its own schedule, is well nigh impossible. I recall trying to sort out my stepfather's pills. Yikes!

So, yeah, those are folks who are going to tell their docs that they are complying. If they're anything like my stepfather or my mother, they won't want to admit that they're confused.