Department of Global Health and Social Medicine, Harvard Medical School, Boston, MA 02115, USA.
Epidemiology. 2012 Mar;23(2):293-300. doi: 10.1097/EDE.0b013e3182459455.
Current methodology for multidrug-resistant tuberculosis (MDR TB) surveys endorsed by the World Health Organization provides estimates of MDR TB prevalence among new cases at the national level. On the aggregate, local variation in the burden of MDR TB may be masked. This paper investigates the utility of applying lot quality-assurance sampling to identify geographic heterogeneity in the proportion of new cases with multidrug resistance.
We simulated the performance of lot quality-assurance sampling by applying these classification-based approaches to data collected in the most recent TB drug-resistance surveys in Ukraine, Vietnam, and Tanzania. We explored 3 classification systems- two-way static, three-way static, and three-way truncated sequential sampling-at 2 sets of thresholds: low MDR TB = 2%, high MDR TB = 10%, and low MDR TB = 5%, high MDR TB = 20%.
The lot quality-assurance sampling systems identified local variability in the prevalence of multidrug resistance in both high-resistance (Ukraine) and low-resistance settings (Vietnam). In Tanzania, prevalence was uniformly low, and the lot quality-assurance sampling approach did not reveal variability. The three-way classification systems provide additional information, but sample sizes may not be obtainable in some settings. New rapid drug-sensitivity testing methods may allow truncated sequential sampling designs and early stopping within static designs, producing even greater efficiency gains.
Lot quality-assurance sampling study designs may offer an efficient approach for collecting critical information on local variability in the burden of multidrug-resistant TB. Before this methodology is adopted, programs must determine appropriate classification thresholds, the most useful classification system, and appropriate weighting if unbiased national estimates are also desired.
目前，世界卫生组织（WHO）认可的耐多药结核病（MDR-TB）调查方法提供了国家一级新发病例中 MDR-TB 流行率的估计。总体而言，MDR-TB 负担的局部差异可能被掩盖。本文研究了应用批量质量保证抽样来确定新发病例中多重耐药比例的地理异质性的效用。
我们通过将这些基于分类的方法应用于乌克兰、越南和坦桑尼亚最近的结核病耐药性调查中收集的数据，模拟了批量质量保证抽样的性能。我们探索了 3 种分类系统-双向静态、三向静态和三向截断序贯抽样-在 2 组阈值下：低 MDR-TB = 2%，高 MDR-TB = 10%和低 MDR-TB = 5%，高 MDR-TB = 20%。
批量质量保证抽样系统在高耐药性（乌克兰）和低耐药性（越南）环境中都确定了多重耐药性流行率的局部变异性。在坦桑尼亚，流行率普遍较低，批量质量保证抽样方法没有发现变异性。三向分类系统提供了更多信息，但在某些情况下可能无法获得样本量。新的快速药物敏感性测试方法可能允许截断序贯抽样设计和静态设计中的早期停止，从而产生更大的效率增益。
批量质量保证抽样研究设计可能为收集关于多重耐药结核病负担的局部变异性的关键信息提供一种有效的方法。在采用这种方法之前，计划必须确定适当的分类阈值、最有用的分类系统以及如果还希望获得无偏的全国估计值，则需要适当的加权。
