PASPORT Study: Regimen characteristics and adherence to HIV drugs

People taking HAART expect there to be little difference between the way in which pill burden, dosing frequency, side-effects and dietary restrictions may impact on their ability to adhere to their treatment well. This is the finding of a GlaxoSmithKline-sponsored study presented to the 40th Annual Meeting of the Infectious Diseases Society of America.

The PASPORT (Perspectives on Adherence and Simplicity for HIV+ Patients on Antiretroviral Therapy) study questioned 299 people taking HAART in six large US cities about how ten different factors associated with taking anti-HIV drugs might affect adherence.

The data suggest that a range of regimen characteristics are perceived to be important. The total number of pills taken daily was identified as an important obstacle by 14% of study participants; dosing frequency by 13%; side-effects by 12%; food restrictions by 11%; pill size by 10%; need for repeat prescriptions and insurance issues by 9% each; the number of prescriptions and number of medicine bottles by 8% each; and the need to take a bedtime dose by 6%.

Participants were asked to predict their likely adherence to seven HAART regimens, chosen to allow comparison between different 'adherence factors'. Whilst once daily dosing had been established as a preferred dosing frequency, when participants were asked to score their anticipated adherence to the seven test regimens, those dosed once daily were no more likely to be selected as easier-to-adhere to than twice daily regimens.

Overall, the study found that participants' ideal regimen would consist of one or two small pills dosed once per day, an acceptable side-effect profile, and no dietary restrictions. Such a regimen does not currently exist.

The impact of regimen characteristics on adherence to HIV therapy is reviewed within new draft recommendations on adherence issued by the British HIV Association and the Medical Society for the Study of Venereal Diseases click here. Comments on the guidelines can be submitted via the online discussion group and a NAM booklet on Adherence in the Information for HIV-positive People series is being prepared.