Cost of care shown to be primary barrier to adherence in African study

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Financial constraints, including though not limited to the cost of antiretrovirals, were reported to be the most significant barrier to antiretroviral adherence in patients living with HIV infection and AIDS in Botswana prior to the introduction of free treatment. The study, published in the Nov. 1st issue of the Journal of Acquired Immune Deficiency Syndromes reported that though 54% of the patients reported that they took their drugs as prescribed, if cost were removed as a barrier, 74% would have been adherent, which is comparable to rates of adherence in the developed world.

The study highlights several problems that will affect decision making by governments, donors and public health officials throughout the developing world as antiretroviral treatment is introduced. Decisions about the balance of free treatment provision and cost recovery will need to be taken in the light of evidence suggesting that cost of treatment is the biggest single determinant of non-adherence in all studies so far carried out in Africa.

The findings also suggest that other economic issues apart from the cost of medication have an influence on adherence in resource-limited settings, and that these need to be taken into account when planning treatment programmes.

Glossary

pathogenesis

The origin and step-by-step development of disease.

stigma

Social attitudes that suggest that having a particular illness or being in a particular situation is something to be ashamed of. Stigma can be questioned and challenged.

drug resistance

A drug-resistant HIV strain is one which is less susceptible to the effects of one or more anti-HIV drugs because of an accumulation of HIV mutations in its genotype. Resistance can be the result of a poor adherence to treatment or of transmission of an already resistant virus.

regression

Improvement in a tumour. Also, a mathematical model that allows us to measure the degree to which one of more factors influence an outcome.

cross-sectional study

A ‘snapshot’ study in which information is collected on people at one point in time. See also ‘longitudinal’.

Lack of strict adherence to highly active antiretroviral (ARV) therapy is one of the key challenges to AIDS care worldwide. Treatment adherence has been closely correlated with viral suppression, while non-adherence has contributed to progression to AIDS, the development of multi-drug resistance and death. Adherence is often perceived to be a significant barrier to the delivery of ARV therapy in sub-Saharan Africa.

Currently Botswana has the highest estimated prevalence of HIV infection in the world — more than 330,000 people of a population of 1.5 million have been infected with HIV, and there were 26,000 estimated deaths due to AIDS in 2001 alone. Statistics from 2002 indicate that 38.8% of economically productive and sexually active adults (aged 15 to 49 years) have HIV/AIDS.

To evaluate the possible social, cultural, and structural barriers for adherence in the Botswana population, researchers conducted a cross-sectional study involving 109 adult patients (over 18 years) receiving at least three months of ARV therapy in 3 private clinics in Botswana (2 in Gaborone and 1 in Francistown), between January and July 2000. Patients’ report of their own adherence and their care providers estimate of adherence (taking at least 95% of their doses correctly) were the primary outcomes of the study.

Although the percentage of patients who were adherent 95% of the time was roughly the same by patient (54%) and doctor assessment (56%), these assessments were only in concurrence 68% of the time. According to the patients, the principal barriers to adherence included financial constraints (48%, including the cost of antiretrovirals 44% of the time), stigma (15%), travel/migration (10%), and side effects (9%).

Even though natural resources make Botswana one of the wealthiest countries in Africa, the cost of triple combination antiretroviral therapy remains far beyond what its citizens can afford on their own. At the time this study was conducted, the vast majority of patients on antiretroviral therapy were buying their own drugs with the help of medical insurance — but less than 1% of the HIV-infected patients in Botswana had such insurance. To make matters worse, medical insurance typically covers only one quarter or one third of the entire cost of triple drug therapy.

Consequently, most patients using antiretroviral therapy in this study were receiving suboptimal regimens — only 43 of the patients were receiving triple drug therapy. Sub-standard regimens are less effective and that, in and of itself, could have been expected to dampen the rates of adherence. But the study authors also reported that patients in this study often had no choice but to interrupt treatment because they could not afford to renew their prescriptions. Limited finances also made it difficult to travel to the clinic site, sometimes more than 1000 kilometres away, to renew their prescriptions; in addition, some simply couldn’t afford to take off work to travel to the clinic site.

Logistic regression analysis showed that if cost were removed as a variable, the expected rate of adherence to therapy would be 74%. The proof of this came shortly after this study was conducted, when Botswana began to supply free antiretroviral therapy to several thousand patients through a network of district hospitals and smaller sites throughout the country.

As the authors of the study had predicted, adherence levels were substantially better in patients receiving free medication. Preliminary data to this effect were presented at the Second International AIDS Society Conference in Paris in July. A study in a subset of patients in the programme receiving treatment at Maun General Hospital used a very strict definition of adherence in this study (100%). Even dosing late was treated as non-adherence.

Using this strict definition, the 176 patients were adherent 83.16% of the time (on average, patients took their medication in exactly the way prescribed on 24.9 days of each month). Once cost was removed, the leading barriers to adherence became forgetfulness (26.92%); access to the site/drug, 37 (20.33%); and lack of privacy, 33 (18.13%).

During a plenary during the same conference, Dr. Ernest Darkoh, the Operations Manager of the Botswana National Antiretroviral programme spoke about the challenges and lessons learned while implementing the programme. One of the challenges is “maintaining adherence. We’ve managed to maintain 90% rates, or, levels of adherence.”

He noted that there were other initiatives planned by the Botswana government to further improve adherence, including improvements in the distribution of antiretrovirals, increased availability of clinical and laboratory monitoring, and strengthened health infrastructures for delivering care.

As shown in the study in the Journal of Acquired Immune Deficiency Syndromes, the remainder of patients in Botswana and other resource-limited settings who are forced to pay for the medicines themselves will be at much greater risk of poor adherence and most will be on sub-optimal therapy.

Similar findings have been produced from an analysis of 159 adults who received antiretrovirals through the Senegalese government’s national treatment programme between 1999 and 2002. This study found that the probability of 95% adherence declined if individuals were required to contribute more than 15 euros per month towards the cost of treatment (Laniece 2003).

References

Weiser S et al. Barriers to antiretroviral adherence for patients living with HIV infection and AIDS in Botswana. J Acquir Immune Defic Syndr, 34:281–288, 2003.

Laniece I et al. Determinants of adherence among adults receiving antiretroviral drugs in Senegal (ANRS 1215 Cohort Study). Second International AIDS Society Conference on HIV Pathogenesis and Treatment, Paris, abstract 1118, 2003.

Nwokike JI. Baseline data and predictors of adherence to antiretroviral therapy in Maun General Hospital (MGH), Maun, Botswana. Second International AIDS Society Conference on HIV Pathogenesis and Treatment, Paris, abstract 759, 2003.