Poor uptake of highly active antiretroviral therapy (HAART) by HIV-positive patients and low levels of adherence are caused by patients’ underestimation of the need for drug therapy and concerns about side-effects, according to the results of a prospective study presented last week at the Eleventh Annual Conference of the British HIV Association (BHIVA) with the British Association for Sexual Health and HIV in Dublin
Since the latest draft BHIVA treatment guidelines suggest most adherence interventions are limited in effectiveness, understanding this may pave the way for the design of more effective interventions to improve uptake and adherence in the future.
Recent studies have suggested that reduced adherence to anti-HIV medication is driven by personal doubts about need for treatment as well as concerns about the adverse effects of medications. These originate from patients’ ‘common sense’ reasoning and general suspicion surrounding medicine, rather than biomedical evidence.
This has led experts to develop a ‘necessity-concern framework’ that may explain why some patients fail to start therapy or do not adhere to their drug protocols, unnecessarily increasing the risk of disease progression. Investigators from Brighton wished to test this model in order to establish a clearer link between personal beliefs and uptake or adherence behaviour and to improve prediction of non-adherent patients.
They recruited 153 patients attending an HIV clinic in Brighton, whose doctors had recommended they start HAART. The patients completed a range of validated questionnaires investigating personal beliefs about HIV, their personal need for HAART and concerns about side-effects.
“This study has identified the key factors influencing patients’ decisions about HAART,” write the investigators. “Patients’ perceptions of need and concerns about HAART derived from their interpretation of symptoms and personal beliefs about HIV that may conflict with the medical view.”
Uptake of HAART following recommendation was significantly associated with increased perceived necessity for anti-HIV treatment (odds ratio [OR]: 6.7; 95% confidence interval [CI]: 2.5 – 18.0).
Similarly, patients with fewer concerns about the adverse effects of the drugs were more likely to start taking HAART following their doctor’s recommendation (OR: 0.12; 95% CI: 0.03 – 0.42).
These two factors were independent of other significant influences on uptake, including the length of time since HIV diagnosis, lower CD4 cell counts and higher viral loads.
Over the first year of therapy, adherence fell significantly among the 121 patients who started HAART (p
The investigators found that the perceived necessity for HAART was often influenced by patients’ good state of health, increases in CD4 cell counts, increased time since their diagnosis and scepticism over the benefits of HAART.
Increased concerns over therapy included worring about the adverse effects of drugs caused by ‘harmful’ medicines, as well as concomitant depression or anxiety.
Rob Horne, presenting, acknowledged that their study was largely restricted to gay men, and may not be applicable to the population in general. However, the researchers concluded that it may “inform the design of evidence-based interventions to facilitate informed patient choice in relation to HAART, with implications for clinical care.”
Horne R et al. Identifying the key beliefs influencing uptake and adherence to HAART: final results of a 12-month prospective, follow-up study. Eleventh Annual Conference of the British HIV Association with the British Association for Sexual Health and HIV, Dublin, abstract O31, 2005.