我国两个地区儿童流感疫苗与肺炎疫苗接种现状与影响因素分析

目的 了解儿童流感疫苗和肺炎疫苗的接种行为与影响因素。方法 采用两阶段整群抽样,在北京市通州区和甘肃省白银市对适龄儿童家长开展横断面问卷调查,分析儿童流感疫苗和肺炎疫苗接种率及影响因素。结果 共纳入2 377名儿童,儿童流感疫苗接种率为35.93%,肺炎疫苗接种率为16.58%,两种疫苗均接种率为11.65%。接种两种疫苗的理由占比前三位分别为认为疾病严重（流感疫苗：36.02%;肺炎疫苗：49.61%）、学校、单位要求接种（流感疫苗：28.76%;肺炎疫苗：25.45%）和认为疾病易感（流感疫苗：26.41%;肺炎疫苗：13.88%）;未接种疫苗的理由前三位分别为个人方面、疫苗本身和疫苗供应。家庭居住地为农村是影响两类疫苗接种的重要因素。子女数量>1个的家庭、家庭居住地为农村和家庭人均年收入较低与两类疫苗的接种呈负相关。结论 调查地区儿童流感疫苗和肺炎疫苗接种率较低,农村家庭、多子女家庭是扩大疫苗接种的重点关注人群。加强疫苗相关知识宣教,引导家长正确认知疫苗安全性问题,协调疫苗供应与降低疫苗价格对提高流感疫苗和肺炎疫苗接种率具有促进作用。     

Effectiveness of influenza vaccination and its impact on health inequalities

BACKGROUND: Since 1998, annual publicly funded campaigns for mass vaccination against influenza of the population aged 65 years or older have been performed in the city of S?o Paulo, Brazil. The effectiveness of the intervention was not assessed for its contribution to the reduction of influenza-attributable mortality. This study sought to compare the age-specific mortality (65 years or older) before and after the onset of yearly vaccination, and to assess the impact of the intervention on health inequalities in relation to inner-city areas. METHODS: Official information on deaths and population allowed assessment of overall pneumonia and influenza mortality. Monitoring of outbreaks and the estimation of mortality attributable to influenza peaks used Serfling and ARIMA models. Rates were compared between 1998 and 2002, when vaccination coverage ranked higher than 60% among individuals aged 65 years or older, and 1993-97 (prior to vaccination). RESULTS: Overall mortality due to pneumonia and influenza fell by 26.3% after vaccination. An even higher reduction was observed for mortality specifically attributable to influenza epidemics; the number of peaks of influenza mortality also decreased. Deprived areas of the city had a higher decrease of mortality by pneumonia and influenza during the vaccination period. CONCLUSIONS: Influenza vaccination contributed to reduce influenza-attributable mortality in this age group, and was associated with the reduction of inequalities in the burden of the disease among social groups. The concurrent promotion of health and social justice is feasible when there is political will and commitment to implement public health interventions with prompt and effective universal access.     

The impact of influenza-associated respiratory illnesses on hospitalizations,physician visits,emergency room visits,and mortality

OBJECTIVES: Although the increased risk of hospitalization and mortality during influenza seasons has been documented extensively, there is a relative paucity of research on the impact of influenza-related illnesses on other health care use indicators, such as physician use. The purpose of this study was to examine the impact of influenza-associated respiratory illnesses on the Winnipeg health care system, including hospitalizations, physician visits and emergency room visits. Their impact on mortality was also examined. METHODS: Administrative data were used to track health care use and mortality over four influenza seasons (1995-96 to 1998-99). Excess health care use and deaths were calculated by subtracting rates during influenza seasons from those during weeks when influenza viruses were not circulating. RESULTS: Significant excess hospitalization, physician visit, and emergency room visit rates emerged for influenza and pneumonia, acute respiratory diseases, and chronic lung disease, especially among children and adults aged 65 and over. Considerable excess mortality due to influenza and pneumonia and chronic lung disease among individuals aged 65 and over also emerged, particularly among nursing home residents. DISCUSSION: Influenza-associated respiratory illnesses have a substantial impact on the health care system. Given the burden of illness among children during influenza seasons, the study further suggests that influenza vaccination might be considered for this age group.     

A socially neutral disease? Individual social class, household wealth and mortality from Spanish influenza in two socially contrasting parishes in Kristiania 1918-19

The Spanish influenza pandemic of 1918-19 was one of the most devastating diseases in history, killing perhaps as many as 50-100 million people worldwide. Much of the literature since 1918 has favored the view that mortality from Spanish influenza was class neutral. This view has prevailed, even though several contemporary surveys showed that there indeed were clear differences between the classes in disease incidence and that case fatality rates from influenza and pneumonia also varied according to socioeconomic status. Furthermore, studies of more recent influenza epidemics have also shown that there can be clear class differentials in mortality in this type of illness--is there any reason to believe that Spanish influenza was different? This paper is the first study in which individual- and household-level data which are unique for the period are utilized to test the conservative hypothesis that Spanish influenza was a socially neutral disease with respect to mortality. Through the use of Cox regressions in an analysis of two socially contrasting parishes in the Norwegian capital city of Kristiania, it is shown that apartment size as an indicator of wealth of a household, in addition to social status of place of residence, were the only socioeconomic variables that had an independent and significant effect on mortality after controlling for age, sex and marital status.     

The association between influenza immunization coverage rates and hospitalization for community-acquired pneumonia in Alberta

BACKGROUND: We compared regional coverage rates of influenza vaccination (composition in 1999/00 was A/Sydney-like A/Beijing-like B/Yamanashi-like and in 2000/01 was A/Moscow A/New Caledonia B/Beijing) to the rates, cost, and mortality for community-acquired pneumonia. METHODS: We used the Pearson's correlation coefficient to establish linear associations between variables derived from Alberta administrative data during the period April 1, 1999 to March 31, 2001. RESULTS: The influenza vaccination coverage rate for the 17 health regions varied between 30% to 80% (mean 70%) in Alberta seniors (n=298,473). The annual hospitalization and ambulatory community-acquired pneumonia attack rates were 2% and 6.5% per year respectively. There were strongly negative correlations between vaccination coverage rates and pneumonia rates requiring hospitalization (r1999=-0.59 and r2000=-0.79 with both p<0.05), total per capita physician and hospital costs for pneumonia (r1999=-0.57 and r2000=-0.79 with both p<0.01), community-diagnosed pneumonia rate (r1999=-0.39, p=0.12 and r2000=-0.70, p<0.01) and per capita in-hospital mortality for pneumonia (r1999=-0.30, p=0.24 and r2000=-0.57, p<0.05). Per capita costs, rates, and mortality were highest and influenza vaccinations rate lowest in the northern, remote health regions. The per capita vaccination cost (about 10 dollars) was small in relationship to the per capita cost of hospital care for pneumonia (about 100 dollars). CONCLUSION: Regional under-utilization of preventive influenza vaccination in Alberta seniors is associated with increased utilization of health services for community-acquired pneumonia.     

Influenza-related mortality in the Italian elderly: no decline associated with increasing vaccination coverage

We investigated trends in influenza-related mortality among the elderly population in Italy associated with increased vaccination coverage. Using Italian vital statistics data, we studied monthly death rates for pneumonia and influenza and all-cause for persons >/=65 years of age by 5-year age groups for 1970-2001. Using a classic seasonal regression modelling approach, we estimated the age-specific seasonal excess mortality rates among Italian elderly as a measure of influenza-related deaths. We studied trends in excess mortality after adjusting for population aging and analyzing separately seasons dominated by the severe A/H3N2 subtype and those dominated by other circulating influenza subtypes. After the late 1980s, no decline in age-adjusted excess mortality was associated with increasing influenza vaccination distribution primarily targeted for the elderly. These findings suggest that either the vaccine failed to protect the elderly against mortality (possibly due to immune senescence), and/or the vaccination efforts did not adequately target the frailest elderly. As in the US, our study challenges current strategies to best protect the elderly against mortality, warranting the need for better controlled trials with alternative vaccination strategies.     

Cost-effectiveness of influenza vaccination in prior pneumonia patients in Israel

Pneumonia is a common complication of influenza infection, and accounts for the majority of influenza mortality. Both the WHO and the Ministry of Health in Israel prioritize seasonal influenza vaccination primarily on the basis of age and specific co-morbidities. Here we consider whether the targeting of individuals previously infected with pneumonia for influenza vaccination would be a cost-effective addition to the current policy. We performed a retrospective cohort data analysis of 163,990 cases of pneumonia hospitalizations and 1,305,223 cases of outpatient pneumonia from 2004 to 2012, capturing more than 54% of the Israeli population. Our findings demonstrate that patients infected with pneumonia in the year prior had a substantially higher risk of becoming infected with pneumonia in subsequent years (relative risk >2.34, p < 0.01). Results indicated that the benefit of targeting for influenza vaccination patients hospitalized with pneumonia in prior year would be cost-saving regardless of age. Complementing the current policy with the targeting of prior pneumonia patients would require vaccination of only a further 2.3% of the Israeli population to save additional 204–407 quality-adjusted life years (QALYs) annually at a mean price of 58–1056 USD/QALY saved. Global uncertainty analysis demonstrates that the cost-effectiveness of adding this policy is robust over a vast range of conditions. As prior pneumonia patients are currently not prioritized for influenza vaccination in Israel, nor elsewhere, this study suggests a novel supplement of current policies to improve cost-effectiveness of influenza vaccination. Future studies should use case–control study to further evaluate the effectiveness of vaccination in prior pneumonia patients.     

Estimation of excess mortality associated with influenza-epidemics by age and cause specific death in Japan, 1975-1999

OBJECTIVES: The purpose of this study was to assess the effects of recent influenza epidemics on mortality in Japan. METHODS: We applied a new definition of excess mortality associated with influenza epidemics and a new estimation method (new method) proposed in our previous paper to the national vital statistics for 1975-1999 (ICD8-ICD10 had been adopted) in Japan. This new method has the advantages of removing a source of random variations in excess mortality and of being applicable to shifting trends in mortality rates from different causes of death in response to the revision of ICD. The monthly rates of death from all causes other than accidents (all causes) and some cause-specific deaths such as pneumonia, malignant neoplasm, heart disease, cerebrovascular disease(C.V.D) and diabetes(D.M.) were analyzed by total and by five age groups: 0-4 years, 5-24 years, 25-44 years, 45-64 years, and 65 years old or older. RESULTS: The following findings were noted: 1. For each epidemic in every other year since 1993, large-scale excess mortality of over 10,000 deaths was observed and the effect of those epidemics could be frequently detected in mortality even among young persons, i.e., 0-4 years or 5-25 years. 2. Excess mortality associated with influenza epidemics influenced mortality by some chronic diseases such as pneumonia, heart disease, C.V.D., D.M., etc. For some epidemic years since 1978, excess mortality rates were detected even in mortality by malignant neoplasm. CONCLUSIONS: It has been definitely shown by applying the new method to the national vital statistics for 1975-1999 in Japan that influenza epidemics in recent years exerted an influence on overall mortality, increasing the number of deaths among the elderly and the younger generation. Monitoring of the trends in excess mortality associated with influenza epidemics should be continued.     

Skepticism toward Emerging Infectious Diseases and Influenza Vaccination Intentions in Nurses

Nurses generally show low compliance with vaccination recommendations. We assessed whether low vaccine acceptance is due to skeptical attitudes toward emerging infectious diseases (EIDs). Skepticism toward EIDs manifests as doubts about the real threat of emerging diseases and as distrust in the motives and the competence of institutions that fight these diseases. We performed a cross-sectional questionnaire study in 293 Swiss nurses using a newly developed scale to assess skepticism toward EIDs. Skepticism affected nurses’ intentions to vaccinate themselves against seasonal influenza and against possible future pandemic influenza. The influence of skepticism persisted after controlling for other factors that are known to determine nurses’ vaccination behavior, namely vaccination habits, feeling at risk of catching influenza, and perceiving vaccination as a professional duty. Skeptical attitudes toward EIDs seem to have a unique and hitherto ignored impact on vaccination intentions. Nurses’ vaccine acceptance could be increased if vaccination campaigns specifically target skeptical attitudes toward EIDs. These campaigns should address nurses’ doubts about the real threat of EIDs and should rebuild their trust in institutions which fight these diseases.     

Instrumental Variables in Influenza Vaccination Studies: Mission Impossible?!

Objectives:  Unobserved confounding has been suggested to explain the effect of influenza vaccination on mortality reported in several observational studies. An instrumental variable (IV) is strongly related to the exposure under study, but not directly or indirectly (through other variables) with the outcome. Theoretically, analyses using IVs to control for both observed and unobserved confounding may provide unbiased estimates of influenza vaccine effects. We assessed the usefulness of IV analysis in influenza vaccination studies.
Methods:  Information on patients aged 65 years and older from the computerized Utrecht General Practitioner (GP) research database over seven influenza epidemic periods was pooled to estimate the association between influenza vaccination and all-cause mortality among community-dwelling elderly. Potential IVs included in the analysis were a history of gout, a history of orthopaedic morbidity, a history of antacid medication use, and GP-specific vaccination rates.
Results:  Using linear regression analyses, all possible IVs were associated with vaccination status: risk difference (RD) 7.8% (95% confidence interval [CI] 3.6%; 12.0%), RD 2.8% (95% CI 1.7%; 3.9%), RD 8.1% (95% CI 6.1%; 10.1%), and RD 100.0% (95% CI 89.0%; 111.0%) for gout, orthopaedic morbidity, antacid medication use, and GP-specific vaccination rates, respectively. Each potential IV, however, also appeared to be related to mortality through other observed confounding variables (notably age, sex, and comorbidity).
Conclusions:  The potential IVs studied did not meet the necessary criteria, because they were (indirectly) associated with the outcome. These variables may, therefore, not be suited to assess unconfounded influenza vaccine effects through IV analysis.     

Socioeconomic determinants of influenza vaccination among older adults in Italy

ObjectivesSeasonal influenza represents a major threat to public health but vaccination campaigns are strongly recommended to reduce the risks of serious complications and mortality among community-dwelling elderly persons. We investigated on potential social predictors of influenza vaccination among older adults in Italy.MethodsData analysis was based on the national survey “Health and use of health care,” which was carried out in 2004/2005 and reached a sample of 25,183 elderly persons. After initial univariate and bivariate statistics, we used multivariate logistic regression to evaluate potential independent predictors of influenza immunization.Results62.6% of the recruited subjects declared to be vaccinated against influenza. At bivariate analysis, significative differences in immunization rates arose by each socioeconomic variable investigated. Logistic regressions confirmed that individuals in lower social classes have higher chances of being vaccinated. Moreover, older age and chronic disease were associated with higher likelihood of immunization. Conversely, reporting good health predicted a lower uptake.ConclusionIn our analysis we found several independent predictors of influenza vaccination. Surprisingly, individuals belonging to lower social classes have higher chances of being vaccinated. These results suggest that vaccination policies have a positive effect in preventing socioeconomic inequalities in access to this service in Italy.     

Reducing medical service utilization by encouraging vaccines: randomized controlled trial

BACKGROUND: Vaccination against influenza is associated with reductions in hospitalizations for heart disease, cerebrovascular disease, pneumonia, or influenza, and the risk of death from all causes during the influenza season. DESIGN: Randomized controlled trial. PARTICIPANTS: All members enrolled in the Blue Cross Blue Shield Association's Government Wide Service Benefit Program in the states of Oklahoma, Rhode Island, Kentucky, California, Arizona, Utah, and Colorado in October 2002. The sample size was 339,220 members. INTERVENTION: Two identical influenza/pneumonia direct mail marketing pieces that encouraged members to receive influenza and pneumococcal vaccinations. The study period was October 15, 2002 through March 15, 2003 when most influenza cases occur. Data were collected in July 2003 and analyzed during August 2003. MAIN OUTCOME MEASURES: Administrative claims based on influenza/pneumonia inpatient admissions and emergency department (ED) visits. RESULTS: The intervention group experienced a 2.62% (p=0.010) higher rate of influenza vaccinations; 4.61% (p=0.080) higher rate of pneumonia vaccinations; 9.67% (p=0.136) lower rate of influenza/pneumonia inpatient admissions; and 22.64% (p=0.002) lower rate of influenza/pneumonia ED visits compared to the control group. The benefit-cost ratio (return on investment) from this intervention was estimated to be US dollar 2.21 per dollar spent. CONCLUSIONS: Administrative claims data suggest that members respond to health plan mailings with an increase in influenza vaccination rates. Health plans can cost-effectively impact medical service utilization and vaccination rates by mailing information to their members.     

Assessing predictors of influenza and pneumonia vaccination in rural senior adults

The overall purpose of this study was to identify predictors of influenza and pneumonia vaccination among rural senior adults. A mail survey was conducted in eight rural counties. Reported immunization rate for influenza (81.5%) among respondents was higher as compared to pneumonia (74.7%). Knowing someone with influenza was the strongest predictor of influenza vaccination and knowing someone with pneumonia was the strongest predictor of pneumonia vaccination. Belief that vaccinations are always beneficial was also a significant predictor. While several of the findings of this study are consistent with factors reported in literature to be significant predictors of immunization behavior for this age group, surprisingly, access was not a significant predictor for this rural sample.     

1951 influenza epidemic, England and Wales, Canada, and the United States

Influenza poses a continuing public health threat in epidemic and pandemic seasons. The 1951 influenza epidemic (A/H1N1) caused an unusually high death toll in England; in particular, weekly deaths in Liverpool even surpassed those of the 1918 pandemic. We further quantified the death rate of the 1951 epidemic in 3 countries. In England and Canada, we found that excess death rates from pneumonia and influenza and all causes were substantially higher for the 1951 epidemic than for the 1957 and 1968 pandemics (by > or =50%). The age-specific pattern of deaths in 1951 was consistent with that of other interpandemic seasons; no age shift to younger age groups, reminiscent of pandemics, occurred in the death rate. In contrast to England and Canada, the 1951 epidemic was not particularly severe in the United States. Why this epidemic was so severe in some areas but not others remains unknown and highlights major gaps in our understanding of interpandemic influenza.     

Influenza-associated deaths in tropical Singapore

We used a regression model to examine the impact of influenza on death rates in tropical Singapore for the period 1996-2003. Influenza A (H3N2) was the predominant circulating influenza virus subtype, with consistently significant and robust effect on mortality rates. Influenza was associated with an annual death rate from all causes, from underlying pneumonia and influenza, and from underlying circulatory and respiratory conditions of 14.8 (95% confidence interval 9.8-19.8), 2.9 (1.0-5.0), and 11.9 (8.3-15.7) per 100,000 person-years, respectively. These results are comparable with observations in the United States and subtropical Hong Kong. An estimated 6.5% of underlying pneumonia and influenza deaths were attributable to influenza. The proportion of influenza-associated deaths was 11.3 times higher in persons age >65 years than in the general population. Our findings support the need for influenza surveillance and annual influenza vaccination for at-risk populations in tropical countries.     

Assessing predictors of influenza and pneumonia vaccination in rural senior adults

The overall purpose of this study was to identify predictors of influenza and pneumonia vaccination among rural senior adults. A mail survey was conducted in eight rural counties. Reported immunization rate for influenza (81.5%) among respondents was higher as compared to pneumonia (74.7%). Knowing someone with influenza was the strongest predictor of influenza vaccination, and knowing someone with pneumonia was the strongest predictor of pneumonia vaccination. Belief that vaccinations are always beneficial was also a significant predictor. While several of the findings of this study are consistent with factors reported in literature to be significant predictors of immunization behavior for this age group, surprisingly, access was not a significant predictor for this rural sample.     

“Influenza” versus “Flu”: Do Different Medical Terms Affect Vaccination Intention?

Confusion about disease terminology contributes to lower risk perceptions that may lead to lesser engagement in protective measures. Communication campaigns promoting influenza vaccination have become commonplace around the world. Such campaigns vary widely in their terminology used from depicting the disease and response formally as an “influenza vaccination” to more colloquial terms like “flu shot.” This study gathered responses from 896 Singapore residents through an online experiment and employed a Chi-square test to assess if different medical terms describing the same preventive measure (“influenza vaccine” and “flu shot”) influence vaccination intentions. Results indicate that the formal term “influenza vaccine” prompts significantly greater vaccination intention than the abbreviated colloquial term “flu shot,” even when no further information about the disease or vaccine is provided. This finding suggests that the proclivity to use the less formal term “flu shot” in widespread campaigns is less advantageous in prompting intentions to vaccinate against the disease. This may be the result of an activated availability bias brought on by the distinct semantic frames. We conclude that in this instance the medical terms should not be used interchangeably and that “influenza vaccine” may be more advantageous in future communication to encourage adoption of advised health behavior.     

Vaccinations in pneumonia (VIP): pneumococcal and influenza vaccination patterns among patients hospitalized for pneumonia

BACKGROUND: Although the CDC ACIP (Advisory Committee on Immunization Practices) recommends that appropriate inpatients receive pneumococcal and influenza vaccines, adult vaccination rates for these remain low. We therefore examined perihospitalization vaccination rates for high-risk pneumonia inpatients. METHODS: A retrospective chart review of all pneumonia patients admitted to one community hospital from 6/1/95 to 5/31/96. Vaccination history, co-morbidity, mortality, and prior and subsequent pneumonia admissions were recorded. Primary care providers and nursing homes were contacted to complete and verify vaccine histories. RESULTS: For 173 total admissions (160 subjects), vaccine histories were documented in the hospital chart in less than 0.5% of patients. While 97% had indications for both vaccines at the time of admission, no vaccines were given in the hospital and less than 5% had documented vaccinations during the subsequent 3 years. CONCLUSIONS: Despite clear indications, few patients had documented vaccination at any time. These data lend urgency to the recommendation that pneumococcal and influenza vaccines should be routinely administered to pneumonia inpatients at discharge. Furthermore, they illustrate the need for an improved method for tracking individual adult vaccinations.     

社区公卫医师对糖尿病患者免疫接种的认知

目的了解社区公卫医师对糖尿病患者免疫接种的认知,为完善糖尿病病人的社区健康管理服务提供参考。方法在广州市某中心城区所有的社区卫生服务中心预防接种门诊,各深入访谈1名公卫医师。对数据进行描述性分析,比较不同组别之间认知的差异。结果共访谈37人,24人（64.9%）认为慢性病人感染流感后常并发肺炎;23人（62.2%）认为慢性病人感染流感后病死率高;15人（40.5%）认为慢性病人是肺炎链球菌性疾病的高风险人群;9人（24.3%）认为慢性病人适合接种流感疫苗,对23价肺炎球菌多糖疫苗应用效果的评价不清楚。在糖尿病病人中推广免疫接种受群众认知度不高、无工作要求、担心发生异常反应的影响。结论社区公卫医师对流感、肺炎链球菌性疾病有一定的认知,应加强宣传教育和培训,加大投入,完善服务,提高糖尿病患者疫苗接种率。