Drug Adherence Crucial for HIV Patients
HIV today is no longer a death sentence – it can be managed well through a combination of powerful medications. But health outcomes depend on patients’ adherence to their drug regimes, says James Habyarimana, assistant professor of public policy. The professor studies how the use of new technologies, such as text messages to patients about maintaining their drug schedule, work in Africa. If effective, the text messages are a cheap tool to help support a successful response to the HIV/AIDS epidemic. As we mark World AIDS Day on Dec. 1, Habyarimana discusses his surprising research results, the importance of limiting the emergence of drug resistant strains and the changing perceptions of HIV.
Q. What are the main factors that affect adherence to a medication schedule?
A. There are three main categories– physiological, psychological and socio-economic. Some people do not react well to particular medications. Sometimes people simply forget to take their medications. Some patients face large direct and indirect costs of getting to the clinic to receive the drugs. Particularly in Africa, treatment programs maximize attendance and retention in care by only disbursing doses for only 30 days. While that’s a good way to make sure resources are allocated efficiently, it creates a financial burden for patients, who may live 20 to 40 miles away from the clinic.
Q. Why is proper medication adherence so important in fighting HIV/AIDS?
A. For policymakers, poor adherence can produce mutations in the virus that are resistant to the treatments being given. This a very costly risk. The first line of treatments costs about $100 to $300 per patient in Africa. If that fails, you have to go the second line of treatment, which is considerably more expensive at $6,000 to $10,000 per year. While prices of these drugs have been falling steadily, drug resistance could shrink the scope or eliminate treatment programs in Africa.
There are benefits to the patients, of course. Good adherence means that you can keep viral loads at levels that will not cause opportunistic infections. Low viral loads also reduce the chances of transmission to uninfected individuals. But from a fiscal perspective, good adherence reduces the cost of providing treatment.
Q. How does your research study adherence issues?
A. I’m involved in separate cell phone intervention research projects in Kenya that address the psychological constraints of drug adherence. Groups of the study participants received different text messages reminding them about taking the medications.
Patients in the study receive medication in bottles with electronic caps that record how often the bottle is opened. The projects looked at adherence, measured by the bottle openings, over 15 months. As has been recorded elsewhere, patients are usually very enthusiastic and good about adherence in the first six months. They came to the clinic very sick and the medication has had a tremendous effect in restoring the health functioning and overall capacities. Then as the health response plateaus, complacency follows. As they get better, compliance to the medication regime falls over time.
The studies measure whether a reminder may can support good adherence.
Q. What variables did the research examine?
A. We looked at the effect of varying the frequency of the messages and varying the content. On the content side, the idea is that providing encouragement to people could improve adherence. In addition to a control group that received a phone call but no messages, we sent text messages with a reminder and an encouragement component to one of the study groups and a simple reminder text to the study group.
We also looked at the frequency of the messages – each of the message groups were divided into two – one that got a reminder once a day and the other got a weekly reminder.
Q. How did the two groups react?
A. Surprisingly, we found that the encouraging messages had no effect at all on adherence. In addition, daily messages, whether they were short reminders or encouraging messages, had no statistically significant effect either. We were particularly surprised by the daily result because you’d think if this is about forgetfulness or even social pressure to comply, daily reminders should work best.
The weekly messages did have a large effect. Sending a message once a week improves adherence. About 55 percent of people who get the weekly message are 90 percent adherent (a measure that medical experts consider adequate), compared with 40 percent in the control group that got no intervention.
Q. Why do you think weekly reminders worked better than daily ones?
A. Sending a message in high frequency could be conceived as patronizing, or it could be that a high frequency stimulus has a declining response. Message fatigue, a well known phenomenon in marketing, could also explain these results.
Q. Do you plan follow-up studies based on these findings?
A. Absolutely. We need to think both about content, frequency and how often you refresh the message. Information campaigns are very cheap, so if we can find the right combination of each of these things that generates the right outcomes, we can maintain treatment programs at much lower costs.
In terms of thinking about the design of treatment programs, we need to consider both the psychological and socio-economic factors going forward. Even with reminders, there are wealth constraints that make it harder for people to adhere to medication schedules. We must address that.
Q. We’ve moved past the days of celebrities wearing red ribbons at award shows. As we mark this World AIDS Day, do you think HIV/AIDS has dropped from the social conscience?
A. It depends on where you are – we’ve seen both positive and negative trends. In the industrialized world, the thinking has changed to HIV as a disease one can live with, thanks to the medications available. In some cases, we’ve seen a move back toward risky behavior because of this.
In developing countries, it’s more positive, as the stigma associated with having HIV is dropping. People are more willing to have open discussions about HIV/AIDS. That’s made it possible for increased testing and counseling and people seeking treatment. (December 1, 2010)