The monitoring of ART site and program factors potentially associated with the emergence of HIVDR is essential, especially in settings where viral load and HIVDR testing are not widely implemented.
In 2009, Namibia piloted WHO-recommended EWIs which lead to direct public health action. ART record-keeping systems were strengthened which will lead to better patient management as well as enabling the monitoring of all five nationally chosen EWIs in future years. Moreover, EWI data identified populations vulnerable to the development of HIVDR and lead to the development of operational research proposals and interventions targeted at these most-at-risk populations.
Monitoring of ART prescribing practices
is important because inappropriate prescribing of mono- or dual-therapy or inappropriate drug combinations and/or dosing has been well substantiated to lead to the development of HIVDR in individual patients and at the population level.4,20,21,22,23
Importantly, no inappropriate prescribing was observed at any of the nine pilot sites in Namibia, suggesting strong leadership in the public health sector.
Poor retention in treatment programs, like poor adherence to ART, is an important reason for undesirable treatment outcomes among patients receiving ART.24,25,26
When patients previously LTFU reinitiate ART, they may not achieve the same rates of viral suppression compared to those never LTFU due to previous selection of drug resistant virus; thus they are at increased risk of morbidity and mortality.27
Furthermore, because patients LTFU are at risk of having acquired HIVDR due to treatment interruptions5,6
, they may transmit drug resistant HIV to others.28
Although the proportion of Patients LTFU at 12 months in Namibia was low and met the WHO target, a large number of ART starters were noted to have had a mean 2.3 month period of absence from their ART site during the first year of treatment. The MoHSS hypothesizes that many of these individuals may be “in transits”, a term used to denote patients who migrate seasonally to other areas of the country for work, possibly continuing ART at a different site, only to return to the site of ART initiation at some point in the future. However, existing record-keeping systems do not permit the tracing of this mobile population at risk for the development of HIVDR. As a result of this pilot, the MoHSS has planned an intensification of existing ART defaulter tracing mechanisms through improvements in EDT, the establishment of a national patient database with unique patient identifiers, and increased mobilization and redistribution of human resources.
Namibia’s results for Patient retention on first-line ART at 12 months suggest success in managing ARV toxicity and side-effects through in-class substitutions rather than switches to regimens using drugs from a different class. These results also highlight general success in maintaining the efficacy of available first-line regimens during the first 12 months of treatment and suggest appropriate identification and management of patients with virological failure.
With the exception of one site, data were not able to assess On-time ARV drug pick-up
. In Namibia, routine pharmacy dispensing practice is meant to include the routine counting of remnant pills (number of pills left over from the previous prescription) and the dispensing of a specified number of days of pills. However, the number of remnant pills was not routinely recorded, thus it was not possible to calculate the actual pill run-out date, necessary to monitor this indicator. At the single site where assessment was feasible, the proportion of patients picking up pills on time fell short of the ≥90% target. Because pharmacy refill adherence has been shown to predict virological failure,29,30
it is reasonable to hypothesize that patients not picking up pills on time may be experiencing intermittent treatment interruptions and may be predisposed developing drug resistant virus.5,6
ARV drug stock-outs are an important cause of treatment interruptions and HIVDR in RLS.6,7,8,10
It was not possible to assess ARV drug-supply continuity
because existing pharmacy records did not capture stock at the level of the site dispensary, but rather at a more central level.
EWI monitoring results were extensively discussed with individual sites during interactive feedback sessions. These sessions emphasized how sites can make use of well-maintained medical and pharmacy records to conduct their own quality of care assessments and make meaningful local adjustments in practice.
As a result of this EWI pilot, changes have been made in EDT which will not only improve the quality of patient care but will also permit abstraction of all five selected EWIs in the future. Specifically, EDT was modified to include a pill-count field into which pharmacists will record number of remnant pills at each visit. Because drug-supply continuity at the level of the dispensary was not possible to assess, EDT will be adjusted to capture this information.
One important limitation of this pilot is that data are derived only from patients receiving ART in the public sector. Acknowledging that over 23% of patients receive ART in the private sector, the MoHSS in collaboration with the private sector are assessing ART prescribing practices and On-time ARV drug pick-up in the private sector using insurance company claims databases. An additional limitation of this report is that pediatric patients were not included; however, pediatric EWI monitoring assessing the use and availability of pediatric formulations and weight-based dosing will be implemented. The fact that the ART sites chosen for this pilot may not have been representative of all ART sites in Namibia does not diminish the important public health significance of these results. Over the next five years, Namibia plans to scale up monitoring of EWIs to all of its ART sites. Steps have been taken to ensure the long-term sustainability of EWI monitoring by integrating it into the existing national monitoring and evaluation system and by securing funds from the Global Fund to fight AIDS, TB, and Malaria.
In conclusion, this EWI pilot has given Namibia data which allowed it to identify areas within its national ART program which could be strengthened to minimize the emergence of preventable HIVDR. As Namibia’s HIVDR evidence base grows and is augmented by data generated from WHO-recommended population-based surveys to assess transmitted and acquired HIVDR,12,13
the quality of care for HIV-infected patients in Namibia will be further maximized and the emergence of preventable HIVDR minimized.