Nichol K L, Margolis K L, Wouremna J, von Sternberg T
Medical Service (111), VA Medical Center, Minneapolis, MN 55417, USA.
Gerontology. 1996;42(5):274-9. doi: 10.1159/000213803.
Each year, influenza and its complications account for 10,000-40,000 excess deaths in the United States. Over 80% of these deaths occur among the elderly. The Advisory Committee on Immunization Practices for the US Public Health Service and others recommend that all persons 65 years of age and older as well as other persons with high-risk conditions receive annual influenza vaccination. Despite these recommendations, 40% or more of high-risk persons fail to receive influenza vaccine. Among the barriers to successful immunization efforts are persistent uncertainties regarding the effectiveness of the vaccine in preventing morbidity and mortality associated with influenza. The purpose of this study was to assess influenza vaccine effectiveness in reducing hospitalization rates for a broad range of influenza-associated complications, in reducing deaths from all causes, and in reducing hospitalization costs among all elderly enrollees of a large health maintenance organization.
A serial cohort study with internal controls was designed. All enrollees, 65 years of age and older, were identified for each of three consecutive vaccination and subsequent influenza seasons for 1990-1991 through 1992-1993. Baseline characteristics and outcome data were collected from computerized, linked, administrative data bases. Outcomes were adjusted for the presence of baseline characteristics including age, gender, high-risk diagnoses, medication refills in high-risk therapeutic classes, and previous health care resource utilization.
There were more than 25,000 seniors in each of the three study cohorts. Influenza vaccination rates ranged from 45 to 58%, and vaccinated subjects at baseline appeared to be 'sicker' than nonvaccinated subjects. Influenza vaccination was associated with significant reductions in all outcomes evaluated including outpatient visits (17% reduction in pneumonia and influenza visits, 6.4% reduction in all respiratory condition visits), hospitalizations (51.2% reduction in pneumonia and influenza hospitalizations, 32.5% reduction in all respiratory condition hospitalizations, 28.6% reduction in congestive heart failure hospitalizations), hospitalization costs (30.7% reduction in hospitalization costs for all respiratory conditions and congestive heart failure combined), and deaths from all causes (45% reduction in death from all causes).
Influenza vaccination of elderly persons living in the community is associated with reduced hospitalizations from complications from influenza, with fewer deaths during the influenza season, and with direct health care cost savings. Few, if any, other preventive or therapeutic interventions for adults match or exceed these benefits.
在美国，每年流感及其并发症导致10,000 - 40,000例额外死亡。其中超过80%的死亡发生在老年人中。美国公共卫生服务部免疫实践咨询委员会及其他机构建议，所有65岁及以上的人群以及其他患有高危疾病的人群每年接种流感疫苗。尽管有这些建议，但40%或更多的高危人群未能接种流感疫苗。成功开展免疫工作的障碍之一是，疫苗在预防与流感相关的发病和死亡方面的有效性一直存在不确定性。本研究的目的是评估流感疫苗在降低各类流感相关并发症的住院率、降低全因死亡率以及降低大型健康维护组织所有老年参保者的住院费用方面的有效性。
设计了一项带有内部对照的系列队列研究。在1990 - 1991年至1992 - 1993年的三个连续接种疫苗及随后的流感季节中，确定了所有65岁及以上的参保者。从计算机化的、相互关联的行政数据库中收集基线特征和结局数据。对结局进行了调整，以考虑基线特征的存在情况，这些特征包括年龄、性别、高危诊断、高危治疗类别中的药物 refill 情况以及先前的医疗资源利用情况。
三个研究队列中的每一个都有超过25,000名老年人。流感疫苗接种率在45%至58%之间，且基线时接种疫苗的受试者似乎比未接种疫苗的受试者“病情更重”。流感疫苗接种与所评估的所有结局的显著降低相关，包括门诊就诊（肺炎和流感就诊减少17%，所有呼吸道疾病就诊减少6.4%）、住院（肺炎和流感住院减少51.2%，所有呼吸道疾病住院减少32.5%，充血性心力衰竭住院减少28.6%）、住院费用（所有呼吸道疾病和充血性心力衰竭的住院费用合并减少30.7%）以及全因死亡（全因死亡减少45%）。
社区老年人接种流感疫苗与流感并发症导致的住院减少、流感季节死亡人数减少以及直接医疗保健费用节省相关。对于成年人而言，很少有其他预防或治疗干预措施能达到或超过这些益处。
