Perfect adherence – taking medications as prescribed without missing doses – is considered to be one of the most important factors in terms of reducing the risk of HIV drug resistance and maximizing the life-saving benefits of treatment. But for many HIV-positive people taking daily doses, adherence can be a major challenge. To meet this challenge head on, researchers first needed to figure out the most common reasons for missed doses. And according to the results of one recent study, the answer was clear enough – “simply forgot” was the most frequently stated mea culpa for missed doses.

The study, conducted in Denmark and reported in the July issue of HIV Medicine, compared self-reported reasons for missed doses between two groups of HIV-positive patients. The first group involved patients who were frequently missing doses; the second group involved patients who had good treatment adherence and were only missing medication doses on occasion.

Adherence questionnaires were given to 1,126 people participating in the Danish HIV Cohort Study and had been on anti-HIV treatment for at least six months. During the year (July 2002 to June 2003) in which the study was conducted, the researchers received completed questionnaires from a total of 840 patients. Lower adherence, according to the questionnaire designed by the U.S.-based AIDS Clinical Trials Group (ACTG), was defined as reporting a missed dose within the four days preceding the completion of the survey.

In both groups of patients the three most frequently reported reasons for missed doses were “simply forgot,” “were away from home,” and “had a change in daily routines.”

Based on the results of this study, the researchers concluded that while HIV-positive patients may vary in their levels of adherence – some are better at taking their medications as prescribed compared to others – the reasons behind reduced adherence are similar in all patients studied. In turn, the authors suggest, developing strategies to remind patients when their dose is due should help with the challenges associated with long-term daily treatment.