Antiretroviral treatment has given millions of people around the world - six million at last count - a new lease on life. However, less-than-strict adherence undermines the efficacy of the drugs.
Some common reasons for failing to stick to ARV regimens include: side-effects; insufficient food; long distances and high transport costs to and from drug collection points; forgetting to take them; stigma and fear of disclosure of one's status and spending time away from home.
Adherence is crucial to preventing the huge expense of putting patients on second- and third-line HIV treatment. Here are some ways HIV programmes can improve adherence:
Continuous counselling - Crucial to ensure patients understand the importance of strictly adhering to their medication and make healthy lifestyle choices. Many HIV programmes offer counselling at the initiation of ART, after which patients merely collect their drugs from the pharmacy monthly, being seen a few times a year or only when they have other health conditions.
However, experts recommend sustained ART adherence counselling to achieve the best results. A randomised controlled study published in 2011 and conducted in the Kenyan capital, Nairobi, found that patients who received intensive counselling at the start of ART were 29% less likely to have poor adherence and 59% less likely to have virological failure compared with those who did not.
Additional lifestyle counselling, such as alcohol counselling for heavy drinkers, can also improve adherence.
Community support - Visits by community members to encourage patients to adhere to their medication, home-based care by community health workers or people visiting the clinic with the patient and keeping tabs on them between visits, can all help.
Some programmes are using community drug distribution to bring health services closer to remote villages. One Tanzanian project uses community-based volunteers - many of them HIV-positive - and trained medical workers to drive around villages refilling prescriptions and providing counselling and support to patients.
A 2011 South African study found community-based adherence to be crucial in ensuring that patients remained in care, regularly picked up their treatment and retained low viral loads.
Task-shifting - Patients do not waste precious working hours and lose money waiting for medical care. Many African countries lack medical staff; overburdened health workers are unable to provide the proper attention to patients. Task-shifting - the use of mid- to low-level health workers rather than doctors to prescribe ART - helps ease the burden on doctors and saves patients' time.
As more HIV programmes take on task-shifting, experts warn that ongoing training and monitoring are necessary to ensure the quality of care is not compromised.
Technology - Many health centres provide patients with devices such as pill boxes, medical calendars and alarms to help them to remember to take their drugs at the appropriate time.
The use of text messages to remind patients to take their medicines and to report health issues to medical personnel is proving popular and effective. A 2011 study of 431 patients at a rural Kenyan clinic found that 53% receiving weekly SMS reminders achieved adherence of at least 90% during the 48 weeks of the study, compared with 40%of participants who did not.
Social assistance - Patients often abandon their HIV medication due to hunger; for others, the costs associated with travelling long distances to seek treatment are simply too high.
According to a 2010 study in Haiti, food assistance was associated with improved clinic attendance and adherence to ART, while a 2010 Ugandan study found that cash transfers of between US$5 and $8 for transport costs resulted in improved ART adherence and retention in care.
Researchers argue that the cost of food assistance and transportation is dwarfed by the potential costs - including hospitalisation and additional medication - associated with failure to adhere. - (Plusnews, April 2011)