First, are there certain people that are more prone to poor drug compliance?
Historically, there have been a lot of adherence studies done with tuberculosis patients that are relevant to look at in considering that question. It has particular relevance for the HIV-infected population who are taking antiretrovirals. Treatment to cure tuberculosis requires taking medication for about six to nine months and in some cases longer. It usually requires taking medication on a daily basis, or in some programs, medications several times a week. The studies that were done were looking at who failed treatment, and why.
They had populations of people with TB from all kinds of socioeconomic backgrounds, races, and both genders. The results were interesting. There were no distinctive personality traits that could predict who would succeed and who would fail with a drug regimen. It wasn't necessarily the IV drug user that couldn't or the person on Park Avenue that could maintain a good regimen. I find in my practice that some patients who I imagine are not organized enough to brush their teeth in the morning are absolutely diligent with their HIV medicines and have really good results for a sustained period of time. And some of the patients who are very organized, are working, have children, or have really very structured lives, can't. Adherence studies among HIV-infected individuals yield similar results. There is really no personality profile that you could point to as a predictor.
What are some of the reasons why people find it difficult to comply?
There are many barriers. One barrier is the number of times that pills must be taken each day. Patients who are taking medications that require three-times-a-day dosing, for example, may have difficulty remembering that middle dose. How many times a day is a very important factor.
