Internal Medicine Department, Dr. Balmis General University Hospital, Alicante Institute for Health and Biomedical Research (ISABIAL), Alicante, Spain.
Unit of Infectious Diseases, Dr. Balmis General University Hospital, Alicante Institute for Health and Biomedical Research (ISABIAL), Alicante, Spain.
Front Public Health. 2024 Apr 2;12:1360372. doi: 10.3389/fpubh.2024.1360372. eCollection 2024.
Estimating the global influenza burden in terms of hospitalization and death is important for optimizing prevention policies. Identifying risk factors for mortality allows for the design of strategies tailored to groups at the highest risk. This study aims to (a) describe the clinical characteristics of hospitalizations with a diagnosis of influenza over five flu seasons (2016-2017 to 2020-2021), (b) assess the associated morbidity (hospitalization rates and ICU admissions rate), mortality and cost of influenza hospitalizations in different age groups and (c) analyze the risk factors for mortality.
This retrospective study included all hospital admissions with a diagnosis of influenza in Spain for five influenza seasons. Data were extracted from the Spanish National Surveillance System for Hospital Data from 1 July 2016 to 30 June 2021. We identified cases coded as having influenza as a primary or secondary diagnosis (International Classification of Diseases, 10th revision, J09-J11). The hospitalization rate was calculated relative to the general population. Independent predictors of mortality were identified using multivariable logistic regression.
Over the five seasons, there were 127,160 hospitalizations with a diagnosis of influenza. The mean influenza hospitalization rate varied from 5/100,000 in 2020-2021 (COVID-19 pandemic) to 92.9/100,000 in 2017-2018. The proportion of influenza hospitalizations with ICU admission was 7.4% and was highest in people aged 40-59 years (13.9%). The case fatality rate was 5.8% overall and 9.4% in those aged 80 years or older. Median length of stay was 5 days (and 6 days in the oldest age group). In the multivariable analysis, independent risk factors for mortality were male sex (odds ratio [OR] 1.14, 95% confidence interval [95% CI] 1.08-1.20), age (<5 years: OR 1; 5-19 years: OR 2.02, 95%CI 1.17-3.49; 20-39 years: OR 4.11, 95% CI 2.67-6.32; 40-59 years: OR 8.15, 95% CI 5.60-11.87; 60-79 years: OR 15.10, 95% CI 10.44-21.84; ≥80 years: OR 33.41, 95% CI 23.10-48.34), neurological disorder (OR 1.97, 95% CI 1.83-2.11), heart failure (OR 1.85, 95% CI 1.74-1.96), chronic kidney disease (OR 1.33, 95% CI 1.25-1.41), chronic liver disease (OR 2.95, 95% CI 2.68-3.27), cancer (OR 1.85, 95% CI 1.48-2.24), coinfection with SARS-CoV2 (OR 3.17, 95% CI 2.34-4.28), influenza pneumonia (OR 1.76, 95% CI 1.66-1.86) and admission to intensive care (OR 7.81, 95% CI 7.31-8.36).
Influenza entails a major public health burden. People aged over 60-and especially those over 80-show the longest hospital stays. Age is also the most significant risk factor for mortality, along with certain associated comorbidities.
从住院和死亡的角度评估全球流感负担对于优化预防政策非常重要。确定死亡率的风险因素可以设计针对高风险人群的策略。本研究旨在：(a)描述五个流感季节（2016-2017 年至 2020-2021 年）期间因流感住院的临床特征，(b)评估不同年龄组流感住院的相关发病率（住院率和 ICU 入院率）、死亡率和成本，(c)分析死亡率的风险因素。
本回顾性研究纳入了西班牙五个流感季节因流感住院的所有病例。数据从 2016 年 7 月 1 日至 2021 年 6 月 30 日从西班牙国家医院数据监测系统中提取。我们将诊断编码为流感的原发性或继发性诊断（国际疾病分类，第 10 版，J09-J11）的病例确定为案例。住院率相对于总人口进行计算。使用多变量逻辑回归确定死亡率的独立预测因素。
在五个季节中，有 127160 例因流感住院。流感住院率的平均值从 2020-2021 年（COVID-19 大流行期间）的 5/100000 变化到 2017-2018 年的 92.9/100000。入住 ICU 的流感住院比例为 7.4%，年龄在 40-59 岁的人群中最高（13.9%）。总体病死率为 5.8%，80 岁及以上人群为 9.4%。中位住院时间为 5 天（年龄最大的组为 6 天）。在多变量分析中，死亡率的独立危险因素为男性（比值比[OR]1.14，95%置信区间[95%CI]1.08-1.20）、年龄（<5 岁：OR1；5-19 岁：OR2.02，95%CI 1.17-3.49；20-39 岁：OR4.11，95%CI 2.67-6.32；40-59 岁：OR8.15，95%CI 5.60-11.87；60-79 岁：OR15.10，95%CI 10.44-21.84；≥80 岁：OR33.41，95%CI 23.10-48.34）、神经系统疾病（OR1.97，95%CI 1.83-2.11）、心力衰竭（OR1.85，95%CI 1.74-1.96）、慢性肾脏病（OR1.33，95%CI 1.25-1.41）、慢性肝病（OR2.95，95%CI 2.68-3.27）、癌症（OR1.85，95%CI 1.48-2.24）、SARS-CoV2 合并感染（OR3.17，95%CI 2.34-4.28）、流感肺炎（OR1.76，95%CI 1.66-1.86）和入住 ICU（OR7.81，95%CI 7.31-8.36）。
流感带来了重大的公共卫生负担。60 岁以上的人群，尤其是 80 岁以上的人群，住院时间最长。年龄也是死亡率的最重要危险因素，与某些相关的合并症一起。
