(Last updated: March 5, 2015; last reviewed: March 5, 2015)
Rating of Recommendations: A = Strong; B = Moderate; C = Optional
Rating of Evidence: I = One or more randomized trials in children† with clinical outcomes and/or validated endpoints; I* = One or more randomized trials in adults with clinical outcomes and/or validated laboratory endpoints with accompanying data in children† from one or more well-designed, nonrandomized trials or observational cohort studies with long-term clinical outcomes; II = One or more well-designed, nonrandomized trials or observational cohort studies in children† with long-term outcomes; II* = One or more well-designed, nonrandomized trials or observational studies in adults with long-term clinical outcomes with accompanying data in children† from one or more similar nonrandomized trials or cohort studies with clinical outcome data; III = Expert opinion
† Studies that include children or children/adolescents, but not studies limited to post-pubertal adolescents
Adherence to combination antiretroviral therapy (cART) is a principal determinant of virologic suppression.1-3 Prospective adult and pediatric studies have established a direct correlation between risk of virologic failure and the proportion of missed doses of antiretroviral (ARV) drugs.4 Based on early work in HIV-infected adults treated with unboosted protease inhibitor-based regimens, ≥95% adherence has been the threshold associated with complete viral suppression. More recent studies from adult populations suggest that the relationship between ARV adherence and viral suppression may vary with individual drug, drug class, and pattern of adherence.5 Viral suppression may be achieved with lower levels of adherence to boosted PI and non-nucleoside reverse transcriptase inhibitor regimens.5,6 In patients who achieve virologic suppression, the degree of adherence needed to prevent viral rebound appears to decrease over time.7 Different patterns of inadequate adherence (e.g., intermittent missed doses, treatment interruptions) may have a differential impact on regimen efficacy, depending on the drug combination.8,9
Poor adherence will result in sub-therapeutic plasma ARV drug concentrations, facilitating development of drug resistance to one or more drugs in a given regimen, and possibly cross-resistance to other drugs in the same class. Multiple factors (including regimen potency, pharmacokinetics, drug interactions, viral fitness, and the genetic barrier to ARV resistance) influence the adherence-resistance relationship.10 In addition to compromising the efficacy of the current regimen, suboptimal adherence has implications for limiting future effective drug regimens in patients who develop multidrug-resistant HIV and for increasing the risk of secondary transmission.
Poor adherence to ARVs is commonly encountered in the treatment of HIV-infected children and adolescents. Multiple studies have reported that fewer than 50% of children and/or caretakers reported full adherence to prescribed regimens. Rates of adherence varied with method of ascertainment (e.g., parent/child report, pharmacy records), ARV regimens, and study characteristics.2,3,11,12 A variety of factors—including medication formulation, frequency of dosing, child’s age, and psychosocial and behavioral characteristics of children and parents—have been associated with adherence; however, no consistent predictors of either good or poor adherence in children have been consistently identified.13-15 Furthermore, several studies have demonstrated that adherence is not static and can vary with time on treatment.16 These findings illustrate the difficulty of maintaining high levels of adherence and underscore the need to work in partnership with families to ensure that adherence education, support, and assessment are integral components of care.
Specific Adherence Issues in Children
Adherence is a complex health behavior that is influenced by the regimen, patient and family factors, and characteristics of health care providers.14 The limited availability of palatable formulations for young children is especially problematic.4 Furthermore, infants and children are dependent on others for administration of medication; thus, assessment of the capacity for adherence to a complex, multidrug regimen requires evaluation of the caregivers and their environments, as well as the ability and willingness of a child to take the drug. Barriers faced by adult caregivers that can contribute to non-adherence in children include forgetting doses, changes in routine, being too busy, and child refusal.17,18 Some caregivers may place too much responsibility for managing medications on older children before they are developmentally able to undertake such tasks,19 whereas others themselves face health and adherence challenges related to HIV infection, substance use, or other medical conditions. Other barriers to adherence include caregivers’ unwillingness to disclose HIV infection status to the child and/or others, reluctance of caregivers to fill prescriptions locally, hiding or relabeling of medications to maintain secrecy within the household, avoidance of social support, and a tendency for doses to be missed if the parent is unavailable. Adherence may also be jeopardized by social issues within a family (e.g., substance abuse, unstable housing, and involvement with the criminal justice system).
Specific Adherence Issues in Adolescents
HIV-infected adolescents also face specific adherence challenges. Several studies have identified both pill burden and lifestyle issues (i.e., not having medications on hand when away from home, change in schedule) as significant barriers to effective adherence.20 Denial and fear of their HIV infection are common in adolescents, especially youth who have been recently diagnosed; this may lead to refusal to initiate or continue cART. Distrust of health care workers, misinformation about HIV, and lack of knowledge about the availability and effectiveness of ARV treatments can also be barriers to linking adolescents to care, retaining them in care, and maintaining them on successful cART.
Perinatally infected youth are familiar with the challenges of taking complex drug regimens and with the routine of chronic medical care; nevertheless, they often have long histories of inadequate adherence. Regimen fatigue also has been identified as a barrier to adherence in adolescents.21 HIV-infected adolescents often have low self-esteem, unstructured and chaotic lifestyles, concomitant mental illnesses, and cope poorly with their illness. Depression, alcohol or substance abuse, poor school attendance, psychiatric disorders and advanced HIV disease have been associated with non-adherence.22 A review of published papers on adherence among HIV-infected youth suggests that depression and anxiety are consistently associated with poorer adherence.22 Adherence to complex regimens is particularly challenging at a time of life when adolescents do not want to be different from their peers. Further difficulties include adolescents who live with parents or partners to whom they have not yet disclosed their HIV status and youth who are homeless and have no place to store medicine. When recommending treatment regimens for adolescents, clinicians must balance the goal of prescribing a maximally potent ARV regimen with a realistic assessment of existing and potential support systems to facilitate adherence.
Adherence Assessment and Monitoring
The process of adherence preparation and assessment should begin before therapy is initiated or changed. A routine adherence assessment should be incorporated into every clinic visit. A comprehensive assessment should be instituted for all children in whom cART initiation or change is considered. Evaluations should include nursing, social, and behavioral assessments of factors that may influence adherence by children and their families and can be used to identify individual needs for intervention. Specific, open-ended questions should be used to elicit information about past experience as well as concerns and expectations about treatment. When assessing readiness and preparing to begin treatment, it is important to obtain a patient’s explicit agreement with the treatment plan, including strategies to support adherence. It is also important to alert patients to minor adverse effects of ARVs, such as nausea, headaches, and abdominal discomfort that may recede over time or respond to change in diet or timing of medication administration.
Adherence is difficult to assess accurately; different methods of assessment have yielded different results and each approach has limitations.12,23,24 Patients, caregivers, and health care providers often overestimate adherence although infected youth and caregivers report similar rates of adherence.25 Use of multiple methods to assess adherence is recommended.24,26 Viral load monitoring is useful in identifying patients who require enhanced adherence support.27 The viral load response to a new regimen is often the most accurate indication of adherence if the virus is susceptible to the regimen and the medication doses are appropriate. Other measures include quantitative self report of missed doses by caregivers and children or adolescents (i.e., focusing on missed doses during a recent 3-day or 1-week period), descriptions of the medication regimens, and reports of barriers to administration of medications. Caregivers may report number of doses taken more accurately than doses missed.28 Targeted questions about stress, pill burden, and daily routine are recommended. Pharmacy refill checks and pill counts can identify adherence problems not evident from self-reports.29 Electronic monitoring devices (e.g., Medication Event Monitoring System [MEMS] caps) which are equipped with a computer chip that records each opening of a medication bottle are primarily used in research studies, but have been shown to be useful tools to measure adherence in some settings. Mobile phone technologies (e.g., interactive voice response, SMS text messaging) are being evaluated to quantify missed doses and provide real-time feedback on adherence to caregivers, but studies in the pediatric population are in the pilot phase.30,31 Home visits can play an important role in assessing adherence. In some cases, suspected non-adherence is confirmed only when dramatic clinical responses to cART occur during hospitalizations or in other supervised settings. Preliminary studies suggest that monitoring plasma ARV concentrations or therapeutic drug monitoring may be useful measures in situations where non-adherence is suspected. Drug concentrations in hair are currently being studied as an alternative method to measure adherence.32,33
Adherence can change over time. An adolescent who was able to strictly adhere to treatment upon initiation of a regimen may not be able to maintain complete adherence over time. A nonjudgmental attitude and trusting relationship foster open communication and facilitate assessment. To obtain information on adherence in older children, it is often helpful to ask both HIV-infected children and their caregivers about missed doses and problems. Their reports may differ significantly; therefore, clinical judgment is required to best interpret adherence information obtained from the multiple sources.34
Strategies to Improve and Support Adherence
Intensive follow-up is required, particularly during the first few months after therapy is initiated. This is particularly important if treatment must be started urgently. If there are particular concerns about adherence, patients should be seen and/or contacted by phone (voice mail and text messaging) or email frequently—as often as weekly during the first month of treatment—to assess adherence and determine the need for strategies to improve and support adherence.
Strategies include the development of patient-focused treatment plans to accommodate specific patient needs, integration of medication administration into the daily routines of life (e.g., associating medication administration with daily activities such as brushing teeth), and use of social and community support services. Multifaceted approaches that include regimen-related strategies; educational, behavioral, and supportive strategies focused on children and families; and strategies that focus on health care providers—rather than one specific intervention—may be most effective.19,35,36 Programs designed for administration of directly observed combination therapy to adults, in either the clinic or at home, have demonstrated successful results in both the United States and in international, resource-poor settings.37,38 Modified directly observed therapy (m-DOT), where one dose is administered in a supervised setting and the remaining doses are self-administered, appears to be both feasible and acceptable.35,39 However, a recent meta-analysis of 10 randomized clinical trials evaluating DOT to promote adherence in adults found that it was no more effective than self-administered treatment.40 In another meta-analysis of DOT studies, DOT was found to have a demonstrated effect on virologic, immunologic, and adherence outcomes, but efficacy of the strategy was not supported when the analysis was restricted to randomized controlled trials.41 Table 12 summarizes some of the strategies that can be used to support and improve adherence to ARV medications. The Centers for Disease Control and Prevention offers a web-based toolkit (consisting of four evidence-based HIV medication adherence strategies) to HIV care providers.42
ARV regimens for children often require the administration of large numbers of pills or unpalatable liquids, each with potential adverse effects and drug interactions, in multiple daily doses. To the extent possible, regimens should be simplified with respect to the number of pills or volume of liquid prescribed, as well as frequency of therapy, and chosen to minimize drug interactions and adverse effects.43 When non-adherence occurs, addressing medication-related issues (e.g., adverse effects) may result in improvement. If a regimen is overly complex, it can be simplified. For example, when the burden of pills is great, one or more drugs can be changed to a fixed-drug combination resulting in a regimen with fewer pills. A once-daily regimen should be considered, when feasible. Several studies in adults have demonstrated better adherence with once-daily versus twice-daily ARV regimens.44-46 In a meta-analysis of randomized, controlled trials in adults, a lower pill burden was associated with better adherence and viral suppression. Adherence was modestly better with once-daily regimens than with twice-daily regimens; however, rates of viral suppression did not differ.47 Once-daily dosing may be less forgiving of poor adherence for some medications but outcomes are likely to vary by specific drug regimen. When non-adherence is related to poor palatability of a liquid formulation or crushed pills and simultaneous administration of food is not contraindicated, the offending taste can sometimes be masked with a small amount of flavoring syrup or food (see Appendix A: Pediatric Antiretroviral Drug Information) in order to overcome medication aversion.48 Unfortunately, the taste of lopinavir/ritonavir cannot be masked with flavoring syrup. A small study of children aged 4 to 21 years found that training children to swallow pills has been associated with improved adherence at 6 months post-training.49
The primary approach taken by the clinical team to promote medication adherence in children is patient and caregiver education. Educating families about adherence should begin before ARV medications are initiated or changed and should include a discussion of the goals of therapy, the reasons for making adherence a priority, and the specific plans for supporting and maintaining a child’s medication adherence. Caregiver adherence education strategies should include the provision of both information and adherence tools, such as written and visual materials; a daily schedule illustrating times and doses of medications; and demonstration of the use of syringes, medication cups, and pillboxes.
A number of behavioral tools can be used to integrate taking medications into an HIV-infected child’s daily routine. The use of behavior modification techniques, especially the application of positive reinforcements and the use of small incentives (including financial incentives) for taking medications, can be effective tools to promote adherence.50 Availability of mental health services and the treatment of mental health disorders (such as depression) may facilitate adherence to complex ARV regimens.51 A gastrostomy tube should be considered for non-adherent children who are at risk of disease progression and who have severe and persistent aversion to taking medications.52 If adequate resources are available, home-nursing interventions may also be beneficial. Directly observed dosing of ARV medications has been implemented in adults, adolescents, and children, using home nursing services as well as daily medication administration in the clinic setting.
Other strategies to support adherence that have been employed in the clinical setting include setting patients’ cell phone alarms to go off at medication times; using beepers or pagers as an alarm; sending SMS text-message reminders; conducting motivational interviews; providing pill boxes and other adherence support tools, particularly for patients with complex regimens; and delivering medications to the home. Randomized clinical trials in adults have demonstrated that text-messaging is associated with improved adherence.53-56 In a pilot study evaluating peer support and pager messaging in an adult population, peer support was associated with greater self-reported adherence post-intervention; however, the effect was not sustained at follow-up. Although pager messaging was not associated with reported adherence, improved biologic outcomes were measured.57 Motivational interviews, including computer-based interventions, are currently being evaluated.50,58 A study evaluating the efficacy of a 4-session, individual, clinic-based, motivational, interviewing intervention targeting multiple risk behaviors in HIV-infected youth demonstrated an association with lower viral load at 6 months in youth taking cART. However, reduction in viral load was not maintained at 9 months.59 In adults, an intervention that taught managed problem solving resulted in improved adherence and viral suppression during 1 year of follow-up.60
Health Care Provider-Related Strategies
Providers have the ability to improve adherence through their relationships with patients’ families. This process begins early in a provider’s relationship with a family, when the clinician obtains explicit agreement about the medication and treatment plan and any further strategies to support adherence. Fostering a trusting relationship and engaging in open communication are particularly important.61 Provider characteristics that have been associated with improved patient adherence in adults include consistency, giving information, asking questions, technical expertise, and commitment to follow-up. Creating an environment in the health care setting that is child-centered and includes caregivers in adherence support also has been shown to improve treatment outcomes.62
|Initial Intervention Strategies|
|Follow-Up Intervention Strategies|