Court Richard, Leisegang Rory, Stewart Annemie, Sunpath Henry, Murphy Richard, Winternheimer Philip, Ally Mashuda, Maartens Gary
Department of Medicine, University of Cape Town, Cape Town, South Africa.
Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa.
BMC Infect Dis. 2014 Dec 4;14:664. doi: 10.1186/s12879-014-0664-3.
Most patients who experience virologic failure (VF) on second line antiretroviral therapy (ART) in low-middle income countries fail due to poor adherence rather than antiretroviral resistance. A simple adherence tool designed to detect VF would conserve resources by rationally limiting need for viral load (VL) testing and, in those countries with access to third line ART, the need for resistance testing.
We conducted an observational cohort study of patients who initiated second line ART at a clinic in Kwazulu-Natal, South Africa. Using clinical and pharmacy refill data extracted from the clinic's electronic database, we determined risk factors for VF. Three different methods of calculating short term pharmacy refill adherence were evaluated and compared with long term adherence since second line initiation. We also explored the ability of differing durations of short term pharmacy refill to predict VF on second line ART.
We included 274 patients with a median follow up of 27 months on second line ART. VF ranged between 3% and 16% within each six month interval after initiating second line ART. 243 patients with at least one VL after 4 months on second line were analysed in the statistical analysis. Pharmacy refill adherence assessed over shorter periods (4 to 6 months) predicted virologic suppression as well as pharmacy refill assessed over longer periods. The risk of VF fell 73% with each 10% increase in adherence measured from pharmacy refills over a 4 month period. Low CD4 count at second line ART initiation was a significant independent risk factor for VF.
Patients identified as poorly adherent by short term pharmacy refill are at risk for VF on second line ART. This pragmatic adherence tool could assist in identifying patients who require adherence interventions, and help rationalize use of VL monitoring and resistance testing among patients on second line ART.
在低收入和中等收入国家，大多数接受二线抗逆转录病毒治疗（ART）出现病毒学失败（VF）的患者是由于依从性差而非抗逆转录病毒耐药性导致治疗失败。一种旨在检测VF的简单依从性工具，通过合理限制病毒载量（VL）检测需求以及在有三线ART可用的国家减少耐药性检测需求，从而节省资源。
我们对在南非夸祖鲁 - 纳塔尔省一家诊所开始二线ART治疗的患者进行了一项观察性队列研究。利用从诊所电子数据库中提取的临床和药房配药数据，我们确定了VF的危险因素。评估了三种计算短期药房配药依从性的不同方法，并将其与二线治疗开始后的长期依从性进行比较。我们还探讨了不同时长的短期药房配药预测二线ART治疗VF的能力。
我们纳入了274例接受二线ART治疗且中位随访时间为27个月的患者。在开始二线ART治疗后的每个六个月间隔内，VF发生率在3%至16%之间。对二线治疗4个月后至少进行过一次VL检测的243例患者进行了统计分析。较短时间段（4至6个月）评估的药房配药依从性对病毒学抑制的预测效果与较长时间段评估的药房配药依从性相同。在4个月期间，药房配药依从性每增加10%，VF风险下降73%。二线ART治疗开始时CD4细胞计数低是VF的一个显著独立危险因素。
通过短期药房配药被确定为依从性差的患者在二线ART治疗时有VF风险。这种实用的依从性工具可帮助识别需要进行依从性干预的患者，并有助于合理安排二线ART治疗患者的VL监测和耐药性检测。
