National Institute for Medical Research, Mwanza, Tanzania.
PLoS One. 2010 Jan 14;5(1):e8707. doi: 10.1371/journal.pone.0008707.
Over diagnosis of malaria contributes to improper treatment, wastage of drugs and resistance to the few available drugs. This paper attempts to estimate the rates of over diagnosis of malaria among children attending dispensaries in rural Tanzania and examines the potential cost implications of improving the quality of diagnosis.
METHODOLOGY/PRINCIPAL FINDINGS: The magnitude of over diagnosis of malaria was estimated by comparing the proportion of outpatient attendees of all ages clinically diagnosed as malaria to the proportion of attendees having a positive malaria rapid diagnostic test over a two month period. Pattern of causes of illness observed in a <2 year old cohort of children over one year was compared to the pattern of causes of illness in <5 year old children recorded in the routine health care system during the same period. Drug and diagnostic costs were modelled using local and international prices. Over diagnosis of malaria by the routine outpatient care system compared to RDT confirmed cases of malaria was highest among <5 year old children in the low transmission site (RR 17.9, 95% CI 5.8-55.3) followed by the >or=5 year age group in the lower transmission site (RR 14.0 95%CI 8.2-24.2). In the low transmission site the proportion of morbidity attributable to malaria was substantially lower in <2 year old cohort compared to children seen at routine care system. (0.08% vs 28.2%; p<0.001). A higher proportion of children were diagnosed with ARI in the <2 year old cohort compared to children seen at the routine care system ( 42% vs 26%; p<0.001). Using a RDT reduced overall drug and diagnostic costs by 10% in the high transmission site and by 15% in the low transmission site compared to total diagnostic and drug costs of treatment based on clinical judgment in routine health care system.
The introduction of RDTs is likely to lead to financial savings. However, improving diagnosis to one disease may lead to over diagnosis of another illness. Quality improvement is complex but introducing RDTs for the diagnosis of malaria is a good start.
疟疾的过度诊断会导致治疗不当、药物浪费以及对现有少数几种药物产生耐药性。本文试图估计坦桑尼亚农村诊所就诊的儿童中疟疾过度诊断的比率，并探讨提高诊断质量所带来的潜在成本影响。
方法/主要发现：通过比较所有年龄段门诊就诊者中临床诊断为疟疾的比例与在两个月期间进行疟疾快速诊断检测呈阳性的就诊者比例，估算疟疾的过度诊断程度。在为期一年的时间里，对一岁以下儿童队列中观察到的疾病病因模式与同期常规医疗保健系统中记录的五岁以下儿童的疾病病因模式进行了比较。使用当地和国际价格对药物和诊断成本进行建模。与 RDT 确诊的疟疾病例相比，低传播地区常规门诊医疗系统对疟疾的过度诊断在五岁以下儿童中最高（RR17.9，95%CI5.8-55.3），其次是低传播地区年龄大于等于五岁的儿童（RR14.0，95%CI8.2-24.2）。在低传播地区，与常规医疗保健系统就诊的儿童相比，两岁以下儿童队列中与疟疾相关的发病率比例明显较低（0.08%对 28.2%；p<0.001）。与常规医疗保健系统就诊的儿童相比，两岁以下儿童队列中更多的儿童被诊断为急性呼吸道感染（ARI）（42%对 26%；p<0.001）。与基于常规医疗保健系统临床判断的总诊断和药物治疗费用相比，在高传播地区使用 RDT 可使药物和诊断总费用降低 10%，在低传播地区降低 15%。
引入 RDT 可能会带来财务节省。然而，改善对一种疾病的诊断可能会导致对另一种疾病的过度诊断。质量改进很复杂，但引入 RDT 来诊断疟疾是一个良好的开端。
