Ortqvist A, Granath F, Askling J, Hedlund J
Department of Communicable Diseases Control and Prevention (Smittskyddsenheten), Norrbacka, Karolinska University Hospital, SE-171 76 Stockholm, Sweden.
Eur Respir J. 2007 Sep;30(3):414-22. doi: 10.1183/09031936.00135306. Epub 2007 May 30.
The 50% reduced overall mortality previously associated with influenza vaccination among the elderly was based on studies neither fully taking into account systematic differences between individuals who accept or decline vaccination nor encompassing the entire general population. A population-based prospective cohort study was performed in Stockholm County (Sweden), including all persons aged > or =65 yrs (n = approximately 260,000), over three influenza seasons: 1998/1999, 1999/2000 and 2000/2001. The relative risks of mortality among vaccinated versus unvaccinated individuals were estimated using Cox's proportional hazards regression adjusted for, and stratified by, demographic factors and comorbid conditions during the three seasons and the respective following off-seasons. Influenza vaccination was associated with an unadjusted reduction in all-cause mortality during the three seasons of 50, 46 and 42%, respectively, which decreased to 14, 19 and 1%, respectively, following adjustment for confounders and differences in mortality between vaccinated and unvaccinated individuals following the influenza season. The numbers needed to treat to prevent one death, during the three seasons, were 297, 158 and 743, respectively. Vaccination remains the most important measure for prevention of influenza complications in elderly people, although the effectiveness in reducing all-cause mortality in elderly persons is lower than previously thought.
先前认为流感疫苗接种可使老年人总体死亡率降低50%，但这些研究既未充分考虑接受或拒绝接种疫苗的个体之间的系统差异，也未涵盖全体普通人群。在瑞典斯德哥尔摩县开展了一项基于人群的前瞻性队列研究，纳入了1998/1999、1999/2000和2000/2001三个流感季节中所有年龄≥65岁的人群（约260,000人）。使用Cox比例风险回归模型估计接种疫苗与未接种疫苗个体的死亡相对风险，并根据三个季节及随后相应非流行季节的人口统计学因素和合并症进行调整和分层。在三个季节中，流感疫苗接种与全因死亡率未经调整的降低分别为50%、46%和42%，在对混杂因素以及流感季节后接种疫苗和未接种疫苗个体之间的死亡率差异进行调整后，分别降至14%、19%和1%。在这三个季节中，预防一例死亡所需治疗的人数分别为297、158和743。接种疫苗仍然是预防老年人流感并发症的最重要措施，尽管其降低老年人全因死亡率的有效性低于先前的认识。
