While conducting probabilistic surveys is the gold standard for assessing vaccine coverage, implementing these surveys poses challenges for global health. There is a need for more convenient option that is more affordable and practical. Motivated by childhood vaccine monitoring programs in rural areas of Chad and Niger, we conducted a simulation study to evaluate calibration-weighted design-based and logistic regression-based imputation estimators of the finite-population proportion of MCV1 coverage. These estimators use a hybrid approach that anchors non-probabilistic follow-up survey to probabilistic baseline census to account for selection bias. We explored varying degrees of non-ignorable selection bias (odds ratios from 1.0-1.5), percentage of villages sampled (25-75%), and village-level survey response rate to the follow-up survey (50-80%). Our performance metrics included bias, coverage, and proportion of simulated 95% confidence intervals falling within equivalence margins of 5% and 7.5% (equivalence tolerance). For both adjustment methods, the performance worsened with higher selection bias and lower response rate and generally improved as a larger proportion of villages was sampled. Under the worst scenario with 1.5 OR, 25% village sampled, and 50% survey response rate, both methods showed empirical biases of 2.1% or less, below 95% coverage, and low equivalence tolerances. In more realistic scenarios, the performance of our estimators showed lower biases and close to 95% coverage. For example, at OR$\leq$1.2, both methods showed high performance, except at the lowest village sampling and participation rates. Our simulations show that a hybrid anchoring survey approach is a feasible survey option for vaccine monitoring.

翻译：尽管开展概率抽样调查是评估疫苗覆盖率的黄金标准，但在全球健康领域实施此类调查仍面临挑战。因此，需要一种更经济、更实用的便利性替代方案。基于乍得和尼日尔农村地区儿童疫苗监测项目的实践，我们进行了一项模拟研究，以评估基于校准加权的设计型估计量和基于逻辑回归的插补估计量在有限总体中MCV1覆盖率比例的表现。这些估计量采用混合方法，将非概率性随访调查锚定于概率性基线人口普查，以校正选择偏倚。我们探讨了不同程度的不可忽略选择偏倚（优势比范围1.0-1.5）、村庄抽样比例（25%-75%）以及村庄层面随访调查的响应率（50%-80%）。性能指标包括偏倚、覆盖度以及模拟95%置信区间落在5%和7.5%等效界值（等效容忍度）内的比例。两种调整方法的性能均随选择偏倚增大和响应率降低而恶化，并随村庄抽样比例增加而普遍改善。在最差情景下（优势比1.5、村庄抽样25%、调查响应率50%），两种方法均表现出2.1%或更低的经验偏倚，覆盖度低于95%，且等效容忍度较低。在更现实的场景中，估计量表现出更低的偏倚和接近95%的覆盖度。例如，当优势比≤1.2时，除最低村庄抽样率和参与率外，两种方法均表现出高性能。我们的模拟研究表明，混合锚定调查方法是疫苗监测中一种可行的调查方案。