Optimizing viral load testing access for the last mile: Geospatial cost model for point of care instrument placement
Optimizing viral load testing access for the last mile: Geospatial cost model for point of care instrument placement
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DOI：
10.1371/journal.pone.0221586
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发表时间：
2019-08-26
期刊：
影响因子：
3.7
通讯作者：
Rosen, Sydney
中科院分区：
文献类型：
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作者：
Girdwood, Sarah J.;Nichols, Brooke E.;Rosen, Sydney
病毒载量（VL）监测项目已迅速扩大规模，但目前面临着向最偏远的设施（“最后一英里”）提供服务的挑战。对于赞比亚最难到达的设施，我们比较了在设施内或设施附近放置护理点（POC）病毒载量仪器的成本与将样本运送到集中实验室的扩展样本运输网络（STN）的成本。方法我们扩展了先前描述的赞比亚地理空间模型，该模型首先优化了集中式实验室的STN，用于估计病毒载量的90%。在剩余的10%的体积中，设施被确定为POC放置的候选设施，然后对仪器放置进行优化，以使通道和仪器利用率最大化。我们在三种情况下评估了每次测试的全部成本：1)在所有确定为POC的设施中放置POC；2)现场POC放置和作为POC中心的设施放置的优化组合；3)整合到集中式STN中，以允许使用集中式实验室。结果对于最难到达的设施，最佳POC安置覆盖了四分之一的艾滋病毒治疗设施。方案2的每次测试成本为39.58美元，比方案1的每次测试成本41.81美元低6%。这是由于场景2中设施可以充当POC集线器的POC仪器利用率增加。方案3的成本最高，为每次测试53.40美元，这是由于集中式模式下的高运输成本（每次测试36美元，而方案2为每次测试12美元）。结论尽管设备成本高，患者数量少，但spoc VL检测可以降低扩大难以接触人群的成本。现场放置和使用POC集线器的最佳组合可以通过降低运输成本和提高仪器利用率，将每次测试的成本降低6-35%。
IntroductionViral load (VL) monitoring programs have been scaled up rapidly, but are now facing the challenge of providing access to the most remote facilities (the "last mile"). For the hardestto- reach facilities in Zambia, we compared the cost of placing point of care (POC) viral load instruments at or near facilities to the cost of an expanded sample transportation network (STN) to deliver samples to centralized laboratories.MethodsWe extended a previously described geospatial model for Zambia that first optimized a STN for centralized laboratories for 90% of estimated viral load volumes. Amongst the remaining 10% of volumes, facilities were identified as candidates for POC placement, and then instrument placement was optimized such that access and instrument utilization is maximized. We evaluated the full cost per test under three scenarios: 1) POC placement at all facilities identified for POC; 2) an optimized combination of both on-site POC placement and placement at facilities acting as POC hubs; and 3) integration into the centralized STN to allow use of centralized laboratories.ResultsFor the hardest-to-reach facilities, optimal POC placement covered a quarter of HIV-treating facilities. Scenario 2 resulted in a cost per test of $39.58, 6% less than the cost per test of scenario 1, $41.81. This is due to increased POC instrument utilization in scenario 2 where facilities can act as POC hubs. Scenario 3 was the most costly at $53.40 per test, due to high transport costs under the centralized model ($36 per test compared to $12 per test in scenario 2).ConclusionsPOC VL testing may reduce the costs of expanding access to the hardest-to-reach populations, despite the cost of equipment and low patient volumes. An optimal combination of both on-site placement and the use of POC hubs can reduce the cost per test by 6-35% by reducing transport costs and increasing instrument utilization.