Loss to follow-up high in South African public sector ARV programmes

Almost thirty per cent of patients who started antiretroviral treatment in eight South African public sector programmes were lost to follow-up within three years, according to a cohort analysis published in the online edition of the journal AIDS.

LTFU accounted for an increasing proportion of overall programme attrition: from 9% at six months to 29% at 3 years on antiretroviral treatment.

The study was conducted by researchers from the International Epidemiologic Databases to Evaluate AIDS collaboration of South Africa (IeDEA-SA).

South Africa has the largest antiretroviral programme in the world. From 2004 when the public programme began until 2007 an estimated 370,000 people started treatment. Yet no data on programme outcomes exist at the national level. As in other resource-poor setting there is little evidence about trends over time – mortality, loss-to-follow-up and retention. 

Recently revised WHO treatment guidelines as well as South African national guidelines raise the concern of how the anticipated expansion of services will be met while keeping large numbers of patients in care. The time trend reported by the IeDEA-SA researchers suggests that increasing loss to follow-up will come with further expansion.

The increased demands will require a strengthened health care system capable of dealing with chronic disease, the researchers note. In most resource-poor countries the system is set up to deal with acute care and episodic illnesses. Keeping patients in care is a measure of a programme’s success.

LTFU is not a new phenomenon. However, a better understanding of LTFU at the national as well as at the programme level is key to successfully re-directing health  systems toward long-term chronic care management, they add.

The IeDEA researchers reported a declining trend in mortality rates over time. This may be a true decline, but the possibility of an association between programme expansion and an increasing inability to determine mortality correctly is likely, they note. Increasing numbers of LTFU may lead to an underestimate of mortality.

The researchers stress the urgent need for linkage to death registries and where they do not exist, their establishment in low- and middle-income countries.

However, they note it is the size and pace of scale-up in South Africa that is responsible for high rate of loss to follow-up (LTFU).

Enrolment has increased 12-fold over a five year period with a cumulative total of 44,000; 63% of whom enrolled in the last two years. The twelve month LTFU rate increased annually from 1% in 2002/2003 to 13% in 2006.

The longer the time on antiretroviral treatment, the greater the proportion of the overall programme loss was due to LTFU: from 9% at six months to 29% at 36 months on antiretroviral treatment.

Such rapid increases in numbers placed additional burdens on an already overburdened system.

Monitoring and retention of patients in care was severely handicapped; capturing and accurately reporting data was problematic. Increasing numbers of LTFU could be because of death, lost to care, administrative error or inadequate patient monitoring systems, the researchers note.

The distinction between those LTFU due to administrative error and those truly lost to care needs to be made. Those truly lost to care, the authors note, are more likely to be non-adherent and at higher risk of death. A further consequence is the development of drug resistance, which then hinders programme success.

The researchers conclude that there is a need for further research at both the programme and national levels to understand LTFU adding that “Innovative, effective strategies are needed to follow and retain patients in large HIV treatment programmes while rapidly expanding access to antiretroviral services (in low- and middle-income countries).”

At the programme level, in spite of good early outcomes, adherence levels are also declining along with an increase in poorer treatment outcomes.

In an observational cohort study, of two well-established antiretroviral programmes in South Africa, one in the community and the other in the workplace, Mison Dahab and colleagues found that poor treatment outcomes (viral load above 400 copies/ml or having stopped treatment within the first six months) were more common in the well-resourced workplace programme (40% compared to 17%).

The study was designed to identify baseline factors predictive of poor treatment outcomes. Knowledge of these factors would help providers address these issues before starting patients on antiretroviral treatment, so improving adherence and retention in care and treatment outcomes. Yet little evidence exists about which baseline factors might be predictive of poor outcomes.

The researchers found that baseline predictive factors were unique to each programme. While excessive drinking and having seen a traditional healer was associated with poorer outcomes in the community, being male and knowing someone on antiretroviral treatment showed better outcomes. Poorer outcomes in the workplace were associated with being uncertain about the benefits of ART and a traditional healer’s ability to treat HIV (aOR 7.53, 95% CI: 2.02-27.98; aOR 4.40, 95% CI: 1.41-13.75, respectively).

Barriers to remaining on treatment and in care were primarily structural in the community setting. Testing and getting into care were more likely to be self-motivated compared to the workplace setting where provider-initiated testing and counselling (PITC) was the entry point. This would suggest, according to the researchers, that where PITC is available there is a need for additional adherence support. 

Additionally in the workplace a longer time between diagnosis and starting antiretroviral treatment was associated with better outcomes (2-12 weeks compared to under two weeks (aOR 0.13, 95% CI:0.03-0.56)). This highlights, they note, the challenges of providing adequate antiretroviral counselling support before starting treatment when the need to start ART is immediate.

References

Cornell M et al. Temporal changes in programme outcomes among adult patients initiating antiretroviral therapy across South Africa, 2002-2007. Advance online edition AIDS, August 19, 2010. doi:10.1097/QAD.0b013e32833d45c5

Dahab M et al. Contrasting predictors of poor antiretroviral therapy outcomes in South African HIV programmes: a cohort study. BMC Public Health 10:430, 2010. doi: 10.1186/1471-2458-10-430

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