Departamento de Epidemiologia. Instituto Nacional de Saúde Doutor Ricardo Jorge (INSA). Lisboa; Centro de investigação Saúde Pública. Escola Nacional de Saúde Pública. Universidade NOVA de Lisboa. Lisboa. Portugal.
Departamento de Epidemiologia. Instituto Nacional de Saúde Doutor Ricardo Jorge (INSA). Lisboa. Portugal.
Acta Med Port. 2021 Jan 4;34(1):20-27. doi: 10.20344/amp.13438. Epub 2020 Nov 19.
The project 'Integrated Monitoring of Vaccines in Europe' aimed to measure seasonal influenza vaccine effectiveness against hospitalised adults, aged 65 years and over, with influenza. We describe the protocol implementation in Portugal.
We implemented a test-negative design, targeting community-dwelling patients aged 65 years old and over hospitalised with severe acute respiratory illness. Patients were reverse transverse-polymerase chain reaction tested for influenza. Cases were those positive for influenza while others were controls. Most variables were collected using hospital medical records. Selection bias was evaluated by comparison with the laboratory influenza test requests database according to demographic characteristics. Crude, season-adjusted influenza vaccine effectiveness was estimated as = 1 - odds ratio, and 95% confidence intervals were obtained by conditional logistical regression, matched with the disease onset month.
The recruitment rate was 37.8%. Most participants (n = 368) were female (55.8%) and aged 80 years old and over (55.8%). This was similar to values for potentially eligible severe acute respiratory illness patients (80 years old and over: 56.8%, female: 56.2%). The proportion of missing values was below 2.5% for 20 variables and above 5% (maximum 11.6%) for six variables. Influenza vaccine effectiveness estimates were 62.1% against AH1pdm09 (95% confidence intervals: -28.1 to 88.8), 14.9% against A(H3N2) (95% confidence intervals: -69.6 to 57.3), 43.6% against B/Yam (95% confidence intervals: -66.2 to 80.8).
Given the non-existence of a coded admission database in either participating hospital the selection of severe acute respiratory illness due to clinical features was the feasible one. These results are only valid for the older adult population residing in the catchment area of the two participating hospitals who were admitted to a public hospital with severe influenza or SARI symptoms.
Despite the low participation rate, we observed comparable characteristics of participants and eligible severe acute respiratory illness patients. Data quality was high, and influenza vaccine effectiveness results were in accordance with the results of meta-analyses and European season-specific estimates. The final sample size was low, which inhibited obtaining estimates with good precision.
“疫苗在欧洲的综合监测”项目旨在针对因流感住院的 65 岁及以上老年人测量季节性流感疫苗的有效性。我们描述了在葡萄牙实施该方案的情况。
我们实施了一项病例对照研究，以确定社区居住的年龄在 65 岁及以上因严重急性呼吸道疾病住院的患者。对患者进行了流感的逆转录-聚合酶链反应检测。病例是指流感阳性的患者，而对照组是指流感阴性的患者。大多数变量是通过医院病历收集的。根据人口统计学特征，通过与实验室流感检测请求数据库进行比较，评估选择偏倚。原始、季节调整的流感疫苗效力估计值为 = 1 - 比值比，并通过条件逻辑回归获得 95%置信区间，与疾病发病月份相匹配。
我们的招募率为 37.8%。大多数参与者（n=368）为女性（55.8%），年龄在 80 岁及以上（55.8%）。这与有资格接受严重急性呼吸道疾病治疗的潜在患者相似（80 岁及以上：56.8%，女性：56.2%）。20 个变量的缺失值比例低于 2.5%，6 个变量的缺失值比例高于 5%（最高为 11.6%）。流感疫苗效力估计值分别为 62.1%（95%置信区间：-28.1 至 88.8）、14.9%（95%置信区间：-69.6 至 57.3）、43.6%（95%置信区间：-66.2 至 80.8）。
鉴于两个参与医院都没有编码的入院数据库，因此基于临床特征选择严重急性呼吸道疾病是可行的。这些结果仅适用于居住在两个参与医院所在地的老年人群，他们因流感或严重急性呼吸道疾病症状入住公立医院。
尽管参与率较低，但我们观察到参与者和有资格接受严重急性呼吸道疾病治疗的患者具有相似的特征。数据质量很高，流感疫苗效力结果与荟萃分析和欧洲特定季节的估计结果一致。最终样本量较小，无法获得具有良好精度的估计值。
