The Importance of Adherence

Factors Influencing Adherence

Measuring Adherence

HIV Therapy Adherence
- Adherence to Antiretroviral Combination Therapy

Adherence Issues

Coping Strategies

Adherence Taskforce



HIV Therapy Adherence


HIV Adherence Studies
Definitions of adherence in HIV studies have generally used a cut-off of more than 80% of the prescribed doses taken over the period being investigated14-17. Studies of zidovudine therapy have reported adherence rates of 60-88%14-17. However, in a study of attitudes and beliefs towards zidovudine therapy, adherence was estimated to be only 42%18. This level of adherence is consistent with studies in other chronic illnesses.

In HIV infected people taking zidovudine, factors that have been found to influence adherence include19,20:

  • substance abuse
  • drug toxicity
  • complexity and frequency of doses
  • education about treatment expectations of drug efficacy
  • individual’s perceptions about severity of HIV disease
  • ethnicity
  • social and economic circumstances

In one study, people taking more than 3 times daily dosing, or an average of more than 4.5 medications, were significantly less adherent than those on twice daily regimens and fewer medications. Knowledge about medication was associated with improved adherence17.

People with HIV may be symptom free in the early stages of the disease, so the results of non-adherence may not be evident until much later21. Non-adherence is more common among people with psychological distress, depression and poor adaptive and coping mechanisms. People with HIV who have had opportunistic infections are more likely to adhere to therapy20. Taken together, these findings underline the challenges of starting complex multi-drug regimens for people with asymptomatic disease who may still be coming to terms with their HIV positivity.

Adherence to Antiretroviral Combination Therapy