Making better use of numbers

Making better use of numbers


The Minister of Health and other senior health officials are rightly proud of the recent good news about HIV in South Africa: the rate of new infections is dropping, the number of people tested for HIV is close to 20-million (since 2010) , and around 2.1 million people are now on antiretroviral therapy (ART).

But how can we build upon these achievements and how can we measure the success of our existing programmes? We need to use existing markers to monitor progress more effectively. To do this, independent monitoring of clinic and district information systems must be implemented so that programme performance can be objectively verified. At the Wits Reproductive Health & HIV Institute (Wits RHI), we feel that the National Health Laboratory Services (NHLS) is well-placed to perform a key oversight role in the health sector. The NHLS has an extensive national footprint and relatively sophisticated data systems and is therefore ideally placed to provide more accurate sources of data.

With the National Department of Health’s (DoH’s) decision to implement a ‘single patient identifier’ across the health system, it will be possible to track individual level data through the health system. The NHLS is able to track laboratory requests right down to a facility level, and could therefore provide invaluable reporting at all levels of the health system. Certainly, these data will be more reliable than information collated in poorly-design registers and filled in by busy and distracted staff.

One measure we can use to assess the success of HIV programmes is the CD4 count threshold at which patients are started on antiretroviral treatment (ART). In line with the World Health Organisation’s recommendations, South Africa raised the official starting point for antiretroviral (ART) treatment for all patients in 2011 from 200 to 350 cells per cubic millimetre of blood, and is now considering whether to raise this further to 500, as there may be some benefits to starting earlier.

Starting treatment as close to 350 as possible means that patients are less likely to be prone to illness and hospitalisation, and less at risk of contracting TB. They are also less likely to experience side-effects. For many years, the baseline level at treatment initiation in South Africa was as low as 80-100, as people tended to test late in their illness. However, once the DoH initiated its HIV testing campaign in 2010, the average CD4 count at initiation of treatment began rising. This change has been a huge and often unrecognised victory because it indicates that our HIV programmes are getting people with higher CD4 counts onto ART. Doing so means that our patients are less likely to get ill.

We believe that the National Minister of Health should use the CD4 data available from the NHLS to gain a better understanding of the progress of HIV programmes in South Africa. Mapping the data onto district maps and charting the number of CD4s tests done would provide useful information: new patients who have received a CD4 count would probably have been recently tested, and this therefore will give us a rough idea of the amount of testing being done. The levels of immunosuppression, that is the average CD4 count at initiation,  recorded allow us to determine how effective the testing processes are, and whether linkage to care is being done. Any district with an initiation CD4 threshold level of over 200, for example, is probably doing sufficient testing, and is effectively linking their patients to care. But clinics reporting low CD4 counts, could either be assumed to not be testing enough people or not linking them to care.

Viral load data from the NHLS could be used in a similar way. The testing of viral loads is only undertaken when a patient is on ART and, according to the new guidelines, this is done annually after the first 6 months. Mapping how many viral loads have been measured in an area can provide us with a rough idea of the number of people on ART, the level of adherence (people taking their medication will be ‘undetectable’, so the overall proportion will be a quality measure), and the level of retention in an HIV programme. This again should correlate roughly with the number of patients on treatment. When triangulating these data with health registries and pharmaceutical deliveries, this data could help at a provincial, district and sub-district level, with issues such as M&E improvements, and identifying misreporting and procurement corruption.

The NHLS is a national asset. Few other countries have such well-integrated laboratory services in the state sector. We really should be making better use of this capacity and the data we have available.