Nivel (Netherlands Institute for Health Services Research), Utrecht, The Netherlands.
National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands.
PLoS One. 2021 May 28;16(5):e0249883. doi: 10.1371/journal.pone.0249883. eCollection 2021.
We aimed to develop an innovative population-based method to estimate the health effect of influenza vaccination based on electronic medical records collected within a general practitioner (GP)-based influenza surveillance system in the Netherlands.
In each season between 2006/07 and 2015/16, we fitted multilevel Poisson regression models to compare GP consultation rates for clinically diagnosed influenza, acute respiratory infections (ARI), pneumonia, and lower back pain (as a control) between vaccinated vs. unvaccinated individuals. Season-specific relative risks and 95% confidence intervals (CI) were pooled into summary risk ratio (SRR) through random-effects meta-analysis models. Analyses were stratified by patient age (<45, 45-59, 60-74, ≥75 years) and medical indication for the vaccine (any vs. none, subjects aged ≤60 years only).
Overall, 12.6% and 21.4% of study subjects were vaccinated because of their age only or because of an underlying medical condition. Vaccine uptake declined over time, especially among subjects aged ≤74 years with medical indications for vaccination. Vaccinated individuals had significantly higher GP consultation rates for clinically diagnosed influenza (SRR 1.24, 95% CI 1.12-1.38, p-value <0.001), ARI (SRR 1.33, 95% CI 1.27-1.39, p-value <0.001), pneumonia (SRR 1.27, 95% CI 1.19-1.36, p-value <0.001), and lower back pain (SRR 1.21, 95% CI 1.14-1.28, p-value <0.001) compared to unvaccinated individuals.
Contrary to expectations, influenza vaccinees have GP consultation rates for clinically diagnosed influenza, ARI and pneumonia that are 24-33% higher compared to unvaccinated individuals. The lower back pain finding suggests that the increase in consultation rates is partially caused by confounding. Importantly, considering the data are not laboratory-confirmed, our results cannot be linked directly to influenza, but only to respiratory illnesses in general.
我们旨在开发一种创新的基于人群的方法，以根据荷兰基于全科医生的流感监测系统中收集的电子病历来估计流感疫苗接种的健康效果。
在 2006/07 年至 2015/16 年的每个季节，我们使用多水平泊松回归模型比较了接种组和未接种组之间临床诊断为流感、急性呼吸道感染（ARI）、肺炎和下背痛（作为对照）的全科医生就诊率。通过随机效应荟萃分析模型，将季节特异性相对风险和 95%置信区间（CI）汇总为汇总风险比（SRR）。分析按患者年龄（<45、45-59、60-74、≥75 岁）和疫苗接种医学指征（任何与无，仅年龄≤60 岁的受试者）分层。
总体而言，12.6%和 21.4%的研究对象仅因年龄或潜在医疗状况而接种疫苗。随着时间的推移，疫苗接种率下降，尤其是在有接种疫苗医学指征的年龄≤74 岁的受试者中。与未接种疫苗的个体相比，接种疫苗的个体临床诊断为流感（SRR 1.24，95%CI 1.12-1.38，p<0.001）、ARI（SRR 1.33，95%CI 1.27-1.39，p<0.001）、肺炎（SRR 1.27，95%CI 1.19-1.36，p<0.001）和下背痛（SRR 1.21，95%CI 1.14-1.28，p<0.001）的全科医生就诊率明显更高。
与预期相反，流感疫苗接种者的临床诊断为流感、ARI 和肺炎的全科医生就诊率比未接种疫苗的个体高 24-33%。下背痛的发现表明，就诊率的增加部分是由混杂因素引起的。重要的是，考虑到这些数据未经实验室证实，我们的结果不能直接与流感相关联，而只能与一般的呼吸道疾病相关联。
