HIV patients with severe side-effects more likely to deliberately miss HAART doses

Non-adherence to HAART may, in some cases, represent a deliberate attempt by people with HIV to manage severe side-effects, according to a Canadian study published in the Journal of Acquired Immune Deficiency Syndromes this month.

Investigators in British Columbia provided a questionnaire to people receiving HAART between January and November 2001. Detailed questions about HIV treatment-related side effects were included. Forty two separate adverse effects were identified, which were grouped into four categories according to whether they could be classified as "objective" (symptoms visible to others, such as fat loss) or "subjective" (symptoms only experienced by the individual, such as pain) and their action in response to the symptoms.

Trial participants were asked to grade the severity of each side effect (mild, moderate, severe.) The questionnaire also enquired about their doctor’s response, and the individual patient’s action and in particular if they missed doses with the aim of reducing the frequency or severity of side effects.

Questions were also asked about background characteristics including age, ethnicity and educational attainment. Information about CD4 and viral load was also obtained.

A total of 638 people returned questionnaires, of whom 70 (11%) reported intentional non-adherence. These people were more likely to have a viral load above 400 copies/mL, to have less than a high school education, be unemployed, and to report at least one symptom that they considered severe. In particular, people recording at least one severe side-effect were twice as likely to report deliberately not taking their medication properly. Furthermore, each additional side-effect severe enough to warrant action by the doctor increased the probability of intentional non-adherence by 25%.

The investigators suggest that their study is particularly useful as it uniquely “explores self-perceived symptoms associated with antiviral use among patients and their subsequent responses in terms of adverse effect management. Moreover this study describes purposeful alterations in antiviral therapy as a direct response to adverse drug-related symptoms specifically rather than broadly defined adherence rates, which can be affected by many factors.”

The 11% of patients reporting intentional non-adherence is considered by the investigators to be an underestimate as the sample returning the questionnaire was likely to be “a generally more compliant sub-group.” In addition, “the possibility of social desirability bias cannot be discounted and may have led to underreporting of intentional non-adherence.”

The study also found that doctors were paradoxically more likely to recommend treatment changes or treatment interruptions on the basis of "subjective" symptoms compared to "objective" symptoms. Patients reported that in 20% of cases, doctors took no action to investigate further or change treatment where symptoms were classified as objective, even though this group of symptoms included problems such as rash, blood in urine and jaundice. Treatment to relieve "objective" symptoms was offered in only 41% of cases.