Adherence

Having a daily timetable for taking medication and taking all doses exactly as prescribed is the traditional definition of adherence, also known as compliance. This may sound simple, but in the case of highly active antiretroviral treatment (HAART), it is not. The challenge only increases as people who are infected and able to access therapy face life-long treatment and side-effect management.

If some medications are not taken at the correct time interval, the drug level can either be too high (causing unnecessary toxicities or side-effects) or too low (encouraging viral resistance). From a public health standpoint, suboptimal adherence also increases both the risk of transmission and the risk of transmitting drug-resistant virus to others.

For those who want an effective response to HAART, daily, near-perfect adherence (>95%) to a dosing schedule is required. This includes adhering to instructions as to whether a drug is taken on an empty stomach or with food, taking all drugs as prescribed, and taking each drug at the correct dosing time. This calls for a high level of precision, consistency, and commitment on the part of the patient.

The idea of ‘readiness’ for therapy is a major consideration before starting any treatment because of the high risk of developing drug resistance with incomplete adherence. The healthcare provider or team need to discuss the goals and demands of treatment, the potential side-effects, and the importance of adherence with each patient before therapy is started and repeatedly thereafter.

If treatment is still desired, then the optimal regimen for that patient needs to be chosen. This will depend on drug availability; the results of viral genotyping, if available; and the patient’s assessment of what regimen will be best for them (most effective? fewest pills? least number of side-effects?). Practical discussions on how to integrate pill-taking into a normal daily schedule should take place before any treatment is started. Providing a pillbox in which to organise a week's worth of medication is one of the simplest and most effective ways to help with adherence.

Patients should know in advance the treatment options available, the demands of a particular regimen, the potential side-effects that might be expected, and strategies for coping. It helps to problem solve in advance any changes in someone's normal schedule and ways to adapt.

Information and preparation may include discussion with doctors, nurses, pharmacists, peer educators, social workers, treatment supporters, community-based workers, members of support groups, and volunteers. Every treatment setting will vary in what it is able to offer patients in the way of support.

Actively monitoring adherence is one of the best ways to troubleshoot problems in advance of their arrival. It is quite important to identify other individuals who can provide support in maintaining adherence and know that the type of support needed will probably change over time.

Predictors of successful adherence include a level of trust between the patient and caregiver and a shared belief in the efficacy of the regimen selected. Clinician qualities found to encourage adherence were skill, knowledge, and experience as well as the willingness and ability to educate and support patients on an on-going basis.

The benefits of correct adherence to therapy include an improved quality of life through reduction in number of illnesses, hospitalisation events, rate of disease progression, and mortality. Because of these factors, adherence has been intensely studied since the advent of protease inhibitor therapy. Results of this research have altered, to some degree, how drugs are formulated and the scope of the patient/caregiver relationship. Pharmaceutical companies were urged to develop drugs with simpler dosing schedules (optimally, once-daily dosing with no food restrictions) and a longer half-life (referring to the amount of time the drug is active in the body).

Tracking pharmacy refills has turned out to be a quite accurate means of anticipating adherence problems. When this information is available, it gives clinicians the possibility to work proactively with someone to resolve adherence issues before virological failure occurs.

In resource-limited areas, adherence and therapeutic outcomes have proved to be similar or superior to results in developed countries, as long as there is consistent, available, affordable access to both care and medication.

Regardless of the setting, predictors of adherence success include the commitment, motivation, and preparation of the person starting on therapy and ongoing information, simplified dosing schedules, and support from the healthcare team.