Department of Non-Communicable Disease Epidemiology, Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom.
Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom.
PLoS Negl Trop Dis. 2018 Nov 19;12(11):e0006961. doi: 10.1371/journal.pntd.0006961. eCollection 2018 Nov.
Typhoid fever is a common cause of fever in Cambodian children but diagnosis and treatment are usually presumptive owing to the lack of quick and accurate tests at an initial consultation. This study aimed to evaluate the cost-effectiveness of using a rapid diagnostic test (RDT) for typhoid fever diagnosis, an immunoglobulin M lateral flow assay (IgMFA), in a remote health centre setting in Cambodia from a healthcare provider perspective. A cost-effectiveness analysis (CEA) with decision analytic modelling was conducted. We constructed a decision tree model comparing the IgMFA versus clinical diagnosis in a hypothetical cohort with 1000 children in each arm. The costs included direct medical costs only. The eligibility was children (≤14 years old) with fever. Time horizon was day seven from the initial consultation. The number of treatment success in typhoid fever cases was the primary health outcome. The number of correctly diagnosed typhoid fever cases (true-positives) was the intermediate health outcome. We obtained the incremental cost effectiveness ratio (ICER), expressed as the difference in costs divided by the difference in the number of treatment success between the two arms. Sensitivity analyses were conducted. The IgMFA detected 5.87 more true-positives than the clinical diagnosis (38.45 versus 32.59) per 1000 children and there were 3.61 more treatment successes (46.78 versus 43.17). The incremental cost of the IgMFA was estimated at $5700; therefore, the ICER to have one additional treatment success was estimated to be $1579. The key drivers for the ICER were the relative sensitivity of IgMFA versus clinical diagnosis, the cost of IgMFA, and the prevalence of typhoid fever or multi-drug resistant strains. The IgMFA was more costly but more effective than the clinical diagnosis in the base-case analysis. An IgMFA could be more cost-effective than the base-case if the sensitivity of IgMFA was higher or cost lower. Decision makers may use a willingness-to-pay threshold that considers the additional cost of hospitalisation for treatment failures.
伤寒在柬埔寨儿童中是一种常见的发热原因，但由于在初始就诊时缺乏快速准确的检测，诊断和治疗通常是推测性的。本研究旨在从医疗保健提供者的角度评估在柬埔寨偏远医疗中心使用伤寒快速诊断检测（RDT），即免疫球蛋白 M 侧流测定法（IgMFA）进行诊断的成本效益。采用决策分析模型进行了成本效益分析（CEA）。我们构建了一个决策树模型，在 1000 名儿童的每个臂中比较了 IgMFA 与临床诊断。成本仅包括直接医疗成本。合格条件为发热的儿童（≤14 岁）。时间范围是从初始就诊后的第七天。伤寒病例的治疗成功数量是主要健康结果。正确诊断的伤寒病例数量（真阳性）是中间健康结果。我们获得了增量成本效益比（ICER），表示为两个臂之间的成本差异除以治疗成功数量的差异。进行了敏感性分析。IgMFA 比临床诊断多检测到 5.87 个真阳性（38.45 比 32.59），每 1000 名儿童有 3.61 个更多的治疗成功（46.78 比 43.17）。IgMFA 的增量成本估计为 5700 美元；因此，每增加一次治疗成功的 ICER 估计为 1579 美元。ICER 的关键驱动因素是 IgMFA 与临床诊断的相对灵敏度、IgMFA 的成本以及伤寒或多药耐药菌株的流行率。在基本案例分析中，IgMFA 比临床诊断更昂贵但更有效。如果 IgMFA 的灵敏度更高或成本更低，IgMFA 可能比基本案例更具成本效益。决策者可以使用愿意支付的阈值，该阈值考虑到因治疗失败而住院的额外费用。
