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Prevalence and factors associated with influenza vaccination of persons over 65 years old in Spain (2009–2014)
Vaccine xxx (2017) xxx–xxx
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Vaccine journal homepage: www.elsevier.com/locate/vaccine
Prevalence and factors associated with influenza vaccination of persons over 65 years old in Spain (2009–2014) Caridad Dios-Guerra a,b,c, Juan Manuel Carmona-Torres a,d,⇑, Pablo Jesús López-Soto a,b,e, Ignacio Morales-Cané a,b,e, María Aurora Rodríguez-Borrego a,b,e a
Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Córdoba, Spain Departamento de Enfermería, Universidad de Córdoba, Córdoba, Spain UGC Occidente, Distrito Sanitario Córdoba y Guadalquivir, Córdoba, Spain d Universidad de Castilla-La Mancha (UCLM), E. U. Enfermería y Fisioterapia de Toledo, Toledo, Spain e Hospital Universitario Reina Sofía, Córdoba, Spain b c
a r t i c l e
i n f o
Article history: Received 24 September 2017 Received in revised form 27 October 2017 Accepted 30 October 2017 Available online xxxx Keywords: Influenza Vaccines Vaccination coverage Elderly Attitude Associated factors
a b s t r a c t Background: Influenza is a major public health problem. Achieving 65% coverage in people over 65 years old is a health policy priority in Spain. Objective: To determine the coverage of influenza vaccination in Spain in 2014 for people over 65 years and to analyze the factors associated with coverage and its progression between 2009 and 2014. Methods: A descriptive cross-sectional study was conducted that included 18,442 non-institutionalized individuals over 65 years who had participated in the National Health Survey in Spain in 2011 and in the European Health Survey in Spain in 2009 and 2014. Socio-demographic variables, health variables, and influenza vaccination data were used. A logistic regression analysis was performed to determine the variables associated with anti-influenza vaccination. Results: Influenza vaccination coverage has declined from 2009 (74.5%) to 2014 (57.4%). There are significant differences in the vaccination coverage among the different Spanish autonomous communities in the different years studied. Influenza vaccination was associated with males, low social class, and low level of education. There is greater participation in other preventive measures, such as assessing blood pressure, blood glucose, and cholesterol, than in influenza vaccination. Conclusions: Fewer people over 65 years old than recommended by the WHO participated in the influenza vaccination campaign in Spain in 2014. This coverage declined progressively from 2009 to 2014. Ó 2017 Elsevier Ltd. All rights reserved.
1. Introduction Influenza is a major public health problem that can lead to mortality (directly or indirectly), high economic and social costs, and numerous repercussions and complications. Globally, influenza epidemics cause 3–5 million cases of serious illness and 250,000 to 500,000 deaths annually [1]. In industrialized countries, most influenza-related deaths occur in those older than 65 years old [2]. Each year in the USA, influenza is associated with approximately 30,000 deaths, 1250,000 hospitalizations, and billions of dollars in healthcare costs [3].
⇑ Corresponding author at: Edificio Sabatini, Despacho 1.14, Escuela Universitaria de Enfermería y Fisioterapia de Toledo, Campus Tecnológico Fábrica de Armas, Avd. Carlos III s/n, C.P, 45071 Toledo, Spain. E-mail address: [email protected] (J.M. Carmona-Torres).
In a study estimating the worldwide mortality associated with the influenza pandemic in 2009, there were reported 201,000 deaths from respiratory causes and 83,330 cardiovascular deaths. 80% of these deaths, both respiratory and cardiovascular, occurred in people over 65 years old [4]. In Spain, according to the Influenza Surveillance Report [5] of the 2015/16 season, 3101 confirmed severe hospitalizations for influenza were reported, of which 1071 (35%) were admitted to the ICU and 352 (11.4%) died. The highest proportion of hospitalized cases were concentrated in people over 65 years old (40%), as were cases of death (59%). Notably, more than half (59%) of the patients recommended for vaccination had not received the influenza vaccine that season. The most effective way to prevent influenza and its serious consequences is through vaccination [6]. In fact, safe and effective vaccines have been used to combat influenza for more than 60 years. The main objective of this immunization is to reduce the mortality
https://doi.org/10.1016/j.vaccine.2017.10.086 0264-410X/Ó 2017 Elsevier Ltd. All rights reserved.
Please cite this article in press as: Dios-Guerra C et al. Prevalence and factors associated with influenza vaccination of persons over 65 years old in Spain (2009–2014). Vaccine (2017), https://doi.org/10.1016/j.vaccine.2017.10.086
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and morbidity associated with influenza and the impact of its consequences on the community [7]. To achieve this objective, the persons at greatest risk should be protected. One of the priorities in the use of influenza vaccines is increased coverage in the population 65 years old or older. In Spain, the objective is to reach 65% coverage in this group and to become closer to the goal established by the World Health Organization (WHO) and the European Commission of achieving coverage of at least 75% in this elderly population [8]. Many countries have currently implemented vaccination programs, and the influenza vaccine is included in the Catalog of Benefits of the National Health System for Primary Care in Spain that guarantees free and open access at the point of service. Vaccination against influenza in the elderly prevents between 30 and 40% of all hospital admissions and deaths from diseases related to this viral infection in developed countries [9]. In the USA, the seasonal influenza vaccine prevented more than 40,000 influenza-related deaths over a 9-year period from 2005–2006 through 2013–2014 [10]. Therefore, it is essential to continue working on the awareness of citizens and health professionals regarding the importance of influenza vaccination. Despite the different studies on the benefits of influenza vaccine, a considerable proportion of people over 65 years old remain unvaccinated every year, with the negative consequences that this entails, as detailed in the previous sections. Furthermore, previous studies [11–13] that have assessed the beliefs and attitudes of populations older than 65 years old regarding influenza vaccination emphasized that the subjects reject influenza vaccination for the following reasons: they do not consider themselves susceptible to infection (22%), they fear adverse vaccination events (18%), or they believe that alternative treatments are more effective than vaccination for preventing the disease. Therefore, the objectives of the present study were to identify the coverage of influenza vaccination in Spain in 2014 for people over 65 years old, to analyze the factors associated with influenza vaccination, and to analyze its progression from 2009 to 2014.
2. Methods 2.1. Design Cross-sectional descriptive study
a total of 18,442 records; 6026, 5896, and 6520 for the years 2009, 2011, and 2014, respectively. 2.3. Variables The independent variables included in the study were year of the survey, sociodemographic variables (autonomous community, age, gender, marital status, educational level, current domestic situation, and social class), and health-related variables (chronic or long-term illness, perception of health status, degree of limitation, blood pressure (BP) taken by a healthcare professional in the last year, blood cholesterol level measurement in the last year, measurement of blood glucose level in the last year, body mass index (BMI), and who recommended influenza vaccination). The dependent variable was the response (‘‘yes” or ‘‘no”) to the question have you been vaccinated for influenza in the last year. 2.4. Procedure Anonymized microdata files were downloaded from the INE website, which is publicly accessible and does not require special permission for downloading. After the download, the database was debugged, transferred, and processed using the IBM SPSS Statistics 22 program for analysis. For the purpose of this study we only used the records from people over 65 years using the subpopulation command in SPSS. Regarding the inter-annual comparability of the surveys, the question of have you been vaccinated against influenza in the last year was identical (and therefore comparable) in the surveys of 2009, 2011/12, and 2014. 2.5. Data analysis For the statistical analysis, the coverage of influenza vaccination in the three periods studied was estimated by calculating counts (n) and percentages (%) for the qualitative variables and by calculating the mean (m) and standard deviation (SD) for the quantitative variables. We also compared proportions of categorical variables using chi-square tests for contingency tables. In addition, a multiple logistic regression was performed to identify how the independent variables influenced participation in vaccination campaigns. Participation was assessed using the Wald statistic, in which the variables with p .15 were eliminated one by one from the model. Significant values were those whose confidence level was 95% (p < .05); all contrasts of hypotheses were bilateral.
2.2. Source of information, scope of study, and sample 3. Results Data were obtained from the records of the National Health Survey in Spain (Encuesta Nacional de Salud en España – ENSE) of 2011/12 [14] and the European Health Survey in Spain (Encuesta Europea de Salud en España – EESE) of 2009 [15] and 2014 [16] (the institutional latest records published). The ENSE and EESE were performed in a representative manner (each participant was assigned a weighting coefficient to ensure representativeness) by the National Institute of Statistics (Instituto Nacional de Estadística – INE) and the Ministry of Health, Social Services and Equality (Ministerio de Sanidad, Servicios Sociales e Igualdad – MSSI). These surveys were conducted in a non-institutionalized population residing in Spain, with representation from all the autonomous communities to constitute representative samples of the population. The sampling design was multistage stratified cluster sampling with the proportional probability of selection of primary sampling units (municipalities), and the secondary (sections) and third (individuals) units by random routes and sex and age quotas. For the current study, all the records corresponding to people older than 65 years old were selected. The final sample constituted
A total of 18,442 records of people aged 65 and older who participated in the ENSE 2011 and EESE 2009 and 2014 (6026 in 2009, 5896 in 2011, and 6520 in 2014) were analyzed. More than 99.98% of the subjects responded to the question on influenza vaccination in the three surveys analyzed. The profile of subjects who claimed to have been vaccinated against influenza (n = 11,663) had the following characteristics: predominantly female sex (60.2%) and a mean age of 75.78 years (SD ± 7.43). In terms of marital status, 49.4% were married, and 40.2% were widowed. A total of 38.5% had completed primary education, and 39.3% considered their health status normal in a subjective question on the topic. Additionally, 85.3% of subjects answered affirmatively that they had a chronic or long-term disease, and 56.3% had some degree of limitation (85.3% had a physical limitation) in the last 6 months. The social class of the person of reference who had been vaccinated against influenza was also assessed, and 37.5% belonged to social class V (qualified workers in the primary sector and other semi-skilled workers) [14–16].
Please cite this article in press as: Dios-Guerra C et al. Prevalence and factors associated with influenza vaccination of persons over 65 years old in Spain (2009–2014). Vaccine (2017), https://doi.org/10.1016/j.vaccine.2017.10.086
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In the ENSE 2011, the subjects were also asked ‘‘Who recommended the vaccination?”: 71.0% were recommended by a health professional because of their age, 18.0% were recommended by a health professional because of the diseases they had, and 1.9% were recommended by a health professional because of other causes. Only 8.3% of subjects requested the vaccine themselves. However, if we compare participation in influenza vaccination with participation in other control and prevention measures against chronic conditions, mainly cardiovascular and metabolic conditions (arterial BP, blood glucose, and blood cholesterol levels) the participation in vaccination is inferior to participation in other measures, as shown in Table 1. In 90.9% of subjects, less than one year had elapsed since their last BP measurement; 86.2% and 86.8% affirmed that less than one year had elapsed since the last measurement of blood cholesterol and blood glucose levels, respectively. These measures were obtained by health professionals in all cases. Table 2 shows the sociodemographic profile of the people involved in the vaccination and other cardiovascular and metabolic preventive measures. Table 3 analyzes the coverage rates of influenza vaccination by Autonomous Communities (Comunidades Autónomas – CCAA) and nationwide (Spain); the evolution in the three periods was also studied. There were significant differences in the analysis of vaccination between the different Autonomous Communities in the different years studied (p < .001), with Extremadura reaching the highest vaccination rate (69.2% in 2014) and Ceuta having the lowest vaccination rate (30.8% in the same year). At the national level, there were significant differences (p < .001) in the participation in vaccination campaigns between the different years of study, reaching 74.7% coverage in 2009, compared to 57.4% in 2014 (Fig. 1). Finally, in the logistic regression (Table 4), men were 1.13 times more likely to participate in the vaccination campaigns than women (95% CI 1.05–1.22; p = .002). People of low social classes (groups IV, V, and VI) [14–16] were 1.24 times more likely to participate in vaccination campaigns than those of high social classes (groups I, II, and III) [14–16] (95% CI 1.13–1.34; p < .001). People without studies were 1.15 times more likely to participate in vaccination campaigns than people with studies (primary, secondary or university education) (95% CI 1.04–1.27; p = .006).
4. Discussion The National Health Survey is an important tool that has been used in previous studies because of its statistical potential as a representative national survey with a considerable sample size. In addition, it has been previously used for the calculation of vaccination coverage, evolution, and related factors during the period of 1997–2001[17,18]. Therefore, the results of the present study provide an update of the vaccination coverage rate in people over 65 years old in Spain, which ranged from 74.7% in 2009 to 57.4% in 2014, with a significant decline in the latter period. The higher coverage observed in 2009, in comparison with other years of study, may be due to pandemic H1N1 of 2009. However, the vaccination coverage rate has decreased equal to others studies and it is likely due to a loss of confidence in the influenza vaccine after the 2009
pandemic [19]. In addition, the figures are similar in surrounding countries. For example, a coverage rate of 65.5% was reached for people over 65 years old in 2013 in the Netherlands [20], whereas the rate was 74.7% in the USA for the same age group in the period of 2014–15 [21]. In this regard, both the Advisory Committee on Immunization Practices in the USA in a report on recommendations for influenza vaccination [22] and the World Health Organization [23], via its Executive Board, urge Member States to perform interventions and strategies to facilitate increased influenza vaccination coverage for the at-risk population and the elderly, setting a target influenza vaccination coverage rate of 75% for this group. In the present study, influenza vaccination coverage in older people was associated with the male sex, without studies, and low social level, in contrast with previous studies [24,25]. The behavior regarding this preventive intervention, influenza vaccination, indicates that the objectives proposed by the regional, national, and international institutions have not been reached. This data are comparable to those of other published studies. Numerous factors can affect this poor vaccination rate as other studies have shown [11,12]. One systematic review [13] addressed barriers, intent, and behavior for influenza vaccination: the greatest obstacle identified among older people was the lack of confidence in the vaccine, which was understood as a low perception of vaccine effectiveness and increased preconception about the risk of side effects (an important factor that determines the intention of the population to be vaccinated); another obstacle was not considering influenza a major health risk and/or the failure to consider the complications it may cause in people with chronic pathology (thus, people do not think it necessary to be vaccinated). In this sense, although vaccines have been proven an excellent strategy to reduce morbidity and mortality in respiratory infections, with an adequate safety profile [26], and although efforts are being made by health institutions and professionals with recruitment campaigns to vaccinate a maximum number of persons at risk; health services have noted an increase in patients and colleagues concerned about the arguments against vaccines [27]. Importantly, high participation was observed in the registries analyzed in the present study for other preventive or follow-up measures for chronic cardiovascular and metabolic processes, such as BP, blood glucose, and blood cholesterol level measurements; these are tests by which the subjects may have more notion of risk. In fact, in another study using the same methodology [28] with a smaller population that analyzed women of younger ages (40.8 years on average), 68.4% had a BP measurement and 64.1% and 53.9% had analytical measurements for cholesterol and blood glucose, respectively, performed at least once a year. In another study conducted in Italy [29] with a population of 119,073 people, in which the objective was to investigate behaviors toward the prevention of cancer and cardiovascular diseases, the highest participation percentages were obtained for the determination of cholesterol levels, BP, and blood glucose (83.3%, 66.4%, and 58.1%, respectively). In the registers analyzed, the participation reached higher figures, exceeding 98% for all three parameters, an increase that may be justified because the participants were older in our study (above 65 years old), whereas they were between 50 and 69 years old in Italy. In addition, it seems to be that older people
Table 1 Participation of Spanish people over 65 years (2009–2014) in vaccination campaigns for influenza and others preventive measures. Survey year
Vaccination for influenza Yes
Measure of blood pressure Yes
Measure of cholesterol Yes
Measure of glucose Yes
2014 (n = 6520) 2011/12 (n = 5896) 2009 (n = 6026)
57.4% 58.2% 74.5%
99.1% 97.9% 99%
98.3% 94.2% 97.7%
96.9% No registered 97.3%
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Table 2 Sociodemographic variables in Spanish people over 65 years (2009–2014) who have participated in vaccination for influenza. blood pressure. blood cholesterol and blood glucose.
a
Vaccination for influenza (n = 11,663)
Blood pressure (n = 18,197)
Cholesterol (n = 17,853)
Glucose (n = 12,185)
n (%)
p-value
n (%)
p-value
n (%)
p-value
n (%)
p-value
Sex
Man Woman
39.8% 60.2%
<.001
38.7% 61.3%
<.001
38.8% 61.2%
.003
39.4% 60.6%
.018
Marital status
Single Married Widowed Separated Divorced No response
8.1% 49.4% 40.2% 1% 1.1% 0.1%
<.001
8.5% 49.2% 39.2% 1.4% 1.6% 0.1%
<.001
8.4% 49.2% 39.3% 1.4% 1.6% 0.1%
<.001
8.6% 49.0% 39.2% 1.5% 1.6% 0.1%
.008
Educational level
Without studies Primary Secondary or professional training University
42.4% 38.5% 12.6% 6.5%
<.001
40.2% 38.8% 14% 7%
.27
39.9% 38.9% 14.2% 7%
.009
40% 38.9% 14.1% 7%
.242
Perception of health status
Very good Good Regulate Bad Very bad
4.5% 33.5% 39.3% 17.2% 5.5%
<.001
5.7% 36.0% 37.2% 15.8% 5.2%
<.001
5.7% 35.9% 37.3% 15.9% 5.2%
<.001
5.6% 35.4% 37.2% 16.0% 5.8%
<.001
Illnessa
Yes No
85.3% 14.7%
<.001
99.3% 0.7%
<.001
98.2% 1.8%
<.001
98.3% 1.7%
<.001
Limitation
Severely limited Limited but not severe Not Limited
14.9% 41.4% 43.7%
<.001
13.9% 39.1% 47.1%
<.001
13.8% 39.2% 47.0%
<.001
14.0% 39.2% 46.9%
<.001
Chronic or long-term illness.
Table 3 Participation in vaccination campaigns for influenza of Spanish people over 65 years analyzed by autonomous community (2009–2014) (N = 18,442). Autonomous community
2009 (n = 6026) Yes
2011/12 (n = 5896) Yes
2014 (n = 6520) Yes
Andalucía Aragón Principado de Asturias Baleares Canarias Cantabria Catilla-León Castilla-La Mancha Cataluña Comunidad Valenciana Extremadura Galicia Comunidad de Madrid Murcia Navarra País Vasco La Rioja Ceuta Melilla
70.5% 64.8% 73.4% 70.2% 67.3% 75.9% 78.1% 76.8% 76.3% 72.1% 84.1% 76.3% 76.7% 80.6% 73.1% 83.9% 72.9% 55.6% 75.4%
57.5% 60.4% 61.2% 51.3% 35.9% 63.7% 68.6% 55.8% 57.4% 58.7% 57.9% 55.3% 62.1% 52.3% 61.2% 64.7% 60.8% 29.4% 23.4%
52.6% 57.1% 62.2% 48.3% 35.4% 57.3% 65.3% 49.5% 58.3% 54.7% 69.2% 55.1% 63.6% 62.7% 56.7% 62.6% 62.6% 30.8% 56.6%
Total (N = 18,442)
74.7%
58.2%
57.4%
with chronic or long-term illness participate in others preventive measures (BP, blood glucose, and blood cholesterol level measurements) more than in influenza vaccination, due that, for instance, people who suffer HTA goes to nursing consultation for control their BP. But about influenza vaccination the reason is because old people are risk population, and not always they agree with that. Notably, when asked who recommended the vaccination, only 8.3% stated that they had requested the vaccine because they wanted to be vaccinated. The majority (71%) had been recom-
mended by a healthcare professional, so a lack of information or recommendation from health professionals does not seem to be the reason for non-vaccination. This result is contrary to other studies [30,31] that conclude that it is necessary to improve the recommendation of systematic vaccination for all patients at risk. Therefore, perhaps in Spain, the causes of low participation are not due to the lack of information or recommendation by health professionals but rather to the lack of motivation and/or attitude of the elderly. In this sense, health professionals must stress the benefits of this preventive practice and the low adverse effects it produces. Regarding the comparison of prevention measures analyzed, one study [32] analyzed the involvement of family physicians in recommendations for cardiovascular prevention. Anti-smoking advice was the most frequently recommended preventive activity (52.3%), followed by those aimed at controlling cardiovascular risk factors (hypertension – HTN, diabetes mellitus, and dyslipidemias; 22.7%). Although recommendation by a professional seems an important reinforcement to improve the rate of immunization in the present study, in agreement with other studies showing that it also reduces the morbi-mortality associated with influenza [17], it is striking that influenza vaccination in the healthcare professional community is low, both in Spain and in other countries [33–35]. The alternatives proposed by these studies are to introduce vaccination as mandatory in labor contracts, financial incentives, or improvement of the quality of care. One limitation of this study is that the ENSE and EESE are crosssectional studies; thus, it is not possible to know the causal direction between vaccination and related variables. The microdata are secondary data offered by Spanish National Institute of Statistics, so it was not possible to obtain the response rates. Furthermore, because they were surveys, the analyzed data are self-reported information. The aforementioned surveys also failed to ask the unvaccinated persons why they had not been vaccinated,
Please cite this article in press as: Dios-Guerra C et al. Prevalence and factors associated with influenza vaccination of persons over 65 years old in Spain (2009–2014). Vaccine (2017), https://doi.org/10.1016/j.vaccine.2017.10.086
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Fig. 1. Participation in vaccination campaigns for influenza in people over 65 years in Spain (2009–2014).
Table 4 Logistic Regression Model. for the association among sociodemographic characteristics and participation in vaccination campaigns for influenza. in Spanish people over 65 years (2009–2014). OR (CI del 95%)
p-value
Sex Man Woman
1.13 (1.05–1.22) Reference
.002
Social class Clase I. II y III Clase IV. V y VI
Reference 1.24 (1.13–1.34)
Educational level Without studies With studiesa
1.15 (1.04–1.27) Reference
Declaration of interests The authors declare they have no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
<.001
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
.006
CI: confidence interval; p: signification of the model; OR: odds ratio. a Persons with primary, secondary or university education.
which would be interesting to include in future surveys. However, the study of the registries that is presented has the strength of using national representative surveys, with a large sample size. In conclusion, the number of people over 65 years old who participated in the campaign for influenza vaccination in 2014 was lower than that recommended by the WHO [23]; moreover, an alarming and worrying progressive decline has been observed since 2009. The variables that are associated with greater adherence to the vaccination campaigns are male sex, low level of education, and low social class. There are differences in the proportions of elderly people involved in vaccination campaigns among the Spanish Autonomous Communities, with the highest vaccination rate occurring in 2014 in Extremadura. Finally, although health professionals play an important role in preventing influenza and can help improve this public health problem, their attitude regarding the subject is contradictory.
Acknowledgements To National Institute of Statistic (NIS) and the Ministry of Health, Social Services and Equality of Spain for the information and support offered.
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Contents lists available at ScienceDirect
Vaccine journal homepage: www.elsevier.com/locate/vaccine
Prevalence and factors associated with influenza vaccination of persons over 65 years old in Spain (2009–2014) Caridad Dios-Guerra a,b,c, Juan Manuel Carmona-Torres a,d,⇑, Pablo Jesús López-Soto a,b,e, Ignacio Morales-Cané a,b,e, María Aurora Rodríguez-Borrego a,b,e a
Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Córdoba, Spain Departamento de Enfermería, Universidad de Córdoba, Córdoba, Spain UGC Occidente, Distrito Sanitario Córdoba y Guadalquivir, Córdoba, Spain d Universidad de Castilla-La Mancha (UCLM), E. U. Enfermería y Fisioterapia de Toledo, Toledo, Spain e Hospital Universitario Reina Sofía, Córdoba, Spain b c
a r t i c l e
i n f o
Article history: Received 24 September 2017 Received in revised form 27 October 2017 Accepted 30 October 2017 Available online xxxx Keywords: Influenza Vaccines Vaccination coverage Elderly Attitude Associated factors
a b s t r a c t Background: Influenza is a major public health problem. Achieving 65% coverage in people over 65 years old is a health policy priority in Spain. Objective: To determine the coverage of influenza vaccination in Spain in 2014 for people over 65 years and to analyze the factors associated with coverage and its progression between 2009 and 2014. Methods: A descriptive cross-sectional study was conducted that included 18,442 non-institutionalized individuals over 65 years who had participated in the National Health Survey in Spain in 2011 and in the European Health Survey in Spain in 2009 and 2014. Socio-demographic variables, health variables, and influenza vaccination data were used. A logistic regression analysis was performed to determine the variables associated with anti-influenza vaccination. Results: Influenza vaccination coverage has declined from 2009 (74.5%) to 2014 (57.4%). There are significant differences in the vaccination coverage among the different Spanish autonomous communities in the different years studied. Influenza vaccination was associated with males, low social class, and low level of education. There is greater participation in other preventive measures, such as assessing blood pressure, blood glucose, and cholesterol, than in influenza vaccination. Conclusions: Fewer people over 65 years old than recommended by the WHO participated in the influenza vaccination campaign in Spain in 2014. This coverage declined progressively from 2009 to 2014. Ó 2017 Elsevier Ltd. All rights reserved.
1. Introduction Influenza is a major public health problem that can lead to mortality (directly or indirectly), high economic and social costs, and numerous repercussions and complications. Globally, influenza epidemics cause 3–5 million cases of serious illness and 250,000 to 500,000 deaths annually [1]. In industrialized countries, most influenza-related deaths occur in those older than 65 years old [2]. Each year in the USA, influenza is associated with approximately 30,000 deaths, 1250,000 hospitalizations, and billions of dollars in healthcare costs [3].
⇑ Corresponding author at: Edificio Sabatini, Despacho 1.14, Escuela Universitaria de Enfermería y Fisioterapia de Toledo, Campus Tecnológico Fábrica de Armas, Avd. Carlos III s/n, C.P, 45071 Toledo, Spain. E-mail address: [email protected] (J.M. Carmona-Torres).
In a study estimating the worldwide mortality associated with the influenza pandemic in 2009, there were reported 201,000 deaths from respiratory causes and 83,330 cardiovascular deaths. 80% of these deaths, both respiratory and cardiovascular, occurred in people over 65 years old [4]. In Spain, according to the Influenza Surveillance Report [5] of the 2015/16 season, 3101 confirmed severe hospitalizations for influenza were reported, of which 1071 (35%) were admitted to the ICU and 352 (11.4%) died. The highest proportion of hospitalized cases were concentrated in people over 65 years old (40%), as were cases of death (59%). Notably, more than half (59%) of the patients recommended for vaccination had not received the influenza vaccine that season. The most effective way to prevent influenza and its serious consequences is through vaccination [6]. In fact, safe and effective vaccines have been used to combat influenza for more than 60 years. The main objective of this immunization is to reduce the mortality
https://doi.org/10.1016/j.vaccine.2017.10.086 0264-410X/Ó 2017 Elsevier Ltd. All rights reserved.
Please cite this article in press as: Dios-Guerra C et al. Prevalence and factors associated with influenza vaccination of persons over 65 years old in Spain (2009–2014). Vaccine (2017), https://doi.org/10.1016/j.vaccine.2017.10.086
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and morbidity associated with influenza and the impact of its consequences on the community [7]. To achieve this objective, the persons at greatest risk should be protected. One of the priorities in the use of influenza vaccines is increased coverage in the population 65 years old or older. In Spain, the objective is to reach 65% coverage in this group and to become closer to the goal established by the World Health Organization (WHO) and the European Commission of achieving coverage of at least 75% in this elderly population [8]. Many countries have currently implemented vaccination programs, and the influenza vaccine is included in the Catalog of Benefits of the National Health System for Primary Care in Spain that guarantees free and open access at the point of service. Vaccination against influenza in the elderly prevents between 30 and 40% of all hospital admissions and deaths from diseases related to this viral infection in developed countries [9]. In the USA, the seasonal influenza vaccine prevented more than 40,000 influenza-related deaths over a 9-year period from 2005–2006 through 2013–2014 [10]. Therefore, it is essential to continue working on the awareness of citizens and health professionals regarding the importance of influenza vaccination. Despite the different studies on the benefits of influenza vaccine, a considerable proportion of people over 65 years old remain unvaccinated every year, with the negative consequences that this entails, as detailed in the previous sections. Furthermore, previous studies [11–13] that have assessed the beliefs and attitudes of populations older than 65 years old regarding influenza vaccination emphasized that the subjects reject influenza vaccination for the following reasons: they do not consider themselves susceptible to infection (22%), they fear adverse vaccination events (18%), or they believe that alternative treatments are more effective than vaccination for preventing the disease. Therefore, the objectives of the present study were to identify the coverage of influenza vaccination in Spain in 2014 for people over 65 years old, to analyze the factors associated with influenza vaccination, and to analyze its progression from 2009 to 2014.
2. Methods 2.1. Design Cross-sectional descriptive study
a total of 18,442 records; 6026, 5896, and 6520 for the years 2009, 2011, and 2014, respectively. 2.3. Variables The independent variables included in the study were year of the survey, sociodemographic variables (autonomous community, age, gender, marital status, educational level, current domestic situation, and social class), and health-related variables (chronic or long-term illness, perception of health status, degree of limitation, blood pressure (BP) taken by a healthcare professional in the last year, blood cholesterol level measurement in the last year, measurement of blood glucose level in the last year, body mass index (BMI), and who recommended influenza vaccination). The dependent variable was the response (‘‘yes” or ‘‘no”) to the question have you been vaccinated for influenza in the last year. 2.4. Procedure Anonymized microdata files were downloaded from the INE website, which is publicly accessible and does not require special permission for downloading. After the download, the database was debugged, transferred, and processed using the IBM SPSS Statistics 22 program for analysis. For the purpose of this study we only used the records from people over 65 years using the subpopulation command in SPSS. Regarding the inter-annual comparability of the surveys, the question of have you been vaccinated against influenza in the last year was identical (and therefore comparable) in the surveys of 2009, 2011/12, and 2014. 2.5. Data analysis For the statistical analysis, the coverage of influenza vaccination in the three periods studied was estimated by calculating counts (n) and percentages (%) for the qualitative variables and by calculating the mean (m) and standard deviation (SD) for the quantitative variables. We also compared proportions of categorical variables using chi-square tests for contingency tables. In addition, a multiple logistic regression was performed to identify how the independent variables influenced participation in vaccination campaigns. Participation was assessed using the Wald statistic, in which the variables with p .15 were eliminated one by one from the model. Significant values were those whose confidence level was 95% (p < .05); all contrasts of hypotheses were bilateral.
2.2. Source of information, scope of study, and sample 3. Results Data were obtained from the records of the National Health Survey in Spain (Encuesta Nacional de Salud en España – ENSE) of 2011/12 [14] and the European Health Survey in Spain (Encuesta Europea de Salud en España – EESE) of 2009 [15] and 2014 [16] (the institutional latest records published). The ENSE and EESE were performed in a representative manner (each participant was assigned a weighting coefficient to ensure representativeness) by the National Institute of Statistics (Instituto Nacional de Estadística – INE) and the Ministry of Health, Social Services and Equality (Ministerio de Sanidad, Servicios Sociales e Igualdad – MSSI). These surveys were conducted in a non-institutionalized population residing in Spain, with representation from all the autonomous communities to constitute representative samples of the population. The sampling design was multistage stratified cluster sampling with the proportional probability of selection of primary sampling units (municipalities), and the secondary (sections) and third (individuals) units by random routes and sex and age quotas. For the current study, all the records corresponding to people older than 65 years old were selected. The final sample constituted
A total of 18,442 records of people aged 65 and older who participated in the ENSE 2011 and EESE 2009 and 2014 (6026 in 2009, 5896 in 2011, and 6520 in 2014) were analyzed. More than 99.98% of the subjects responded to the question on influenza vaccination in the three surveys analyzed. The profile of subjects who claimed to have been vaccinated against influenza (n = 11,663) had the following characteristics: predominantly female sex (60.2%) and a mean age of 75.78 years (SD ± 7.43). In terms of marital status, 49.4% were married, and 40.2% were widowed. A total of 38.5% had completed primary education, and 39.3% considered their health status normal in a subjective question on the topic. Additionally, 85.3% of subjects answered affirmatively that they had a chronic or long-term disease, and 56.3% had some degree of limitation (85.3% had a physical limitation) in the last 6 months. The social class of the person of reference who had been vaccinated against influenza was also assessed, and 37.5% belonged to social class V (qualified workers in the primary sector and other semi-skilled workers) [14–16].
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In the ENSE 2011, the subjects were also asked ‘‘Who recommended the vaccination?”: 71.0% were recommended by a health professional because of their age, 18.0% were recommended by a health professional because of the diseases they had, and 1.9% were recommended by a health professional because of other causes. Only 8.3% of subjects requested the vaccine themselves. However, if we compare participation in influenza vaccination with participation in other control and prevention measures against chronic conditions, mainly cardiovascular and metabolic conditions (arterial BP, blood glucose, and blood cholesterol levels) the participation in vaccination is inferior to participation in other measures, as shown in Table 1. In 90.9% of subjects, less than one year had elapsed since their last BP measurement; 86.2% and 86.8% affirmed that less than one year had elapsed since the last measurement of blood cholesterol and blood glucose levels, respectively. These measures were obtained by health professionals in all cases. Table 2 shows the sociodemographic profile of the people involved in the vaccination and other cardiovascular and metabolic preventive measures. Table 3 analyzes the coverage rates of influenza vaccination by Autonomous Communities (Comunidades Autónomas – CCAA) and nationwide (Spain); the evolution in the three periods was also studied. There were significant differences in the analysis of vaccination between the different Autonomous Communities in the different years studied (p < .001), with Extremadura reaching the highest vaccination rate (69.2% in 2014) and Ceuta having the lowest vaccination rate (30.8% in the same year). At the national level, there were significant differences (p < .001) in the participation in vaccination campaigns between the different years of study, reaching 74.7% coverage in 2009, compared to 57.4% in 2014 (Fig. 1). Finally, in the logistic regression (Table 4), men were 1.13 times more likely to participate in the vaccination campaigns than women (95% CI 1.05–1.22; p = .002). People of low social classes (groups IV, V, and VI) [14–16] were 1.24 times more likely to participate in vaccination campaigns than those of high social classes (groups I, II, and III) [14–16] (95% CI 1.13–1.34; p < .001). People without studies were 1.15 times more likely to participate in vaccination campaigns than people with studies (primary, secondary or university education) (95% CI 1.04–1.27; p = .006).
4. Discussion The National Health Survey is an important tool that has been used in previous studies because of its statistical potential as a representative national survey with a considerable sample size. In addition, it has been previously used for the calculation of vaccination coverage, evolution, and related factors during the period of 1997–2001[17,18]. Therefore, the results of the present study provide an update of the vaccination coverage rate in people over 65 years old in Spain, which ranged from 74.7% in 2009 to 57.4% in 2014, with a significant decline in the latter period. The higher coverage observed in 2009, in comparison with other years of study, may be due to pandemic H1N1 of 2009. However, the vaccination coverage rate has decreased equal to others studies and it is likely due to a loss of confidence in the influenza vaccine after the 2009
pandemic [19]. In addition, the figures are similar in surrounding countries. For example, a coverage rate of 65.5% was reached for people over 65 years old in 2013 in the Netherlands [20], whereas the rate was 74.7% in the USA for the same age group in the period of 2014–15 [21]. In this regard, both the Advisory Committee on Immunization Practices in the USA in a report on recommendations for influenza vaccination [22] and the World Health Organization [23], via its Executive Board, urge Member States to perform interventions and strategies to facilitate increased influenza vaccination coverage for the at-risk population and the elderly, setting a target influenza vaccination coverage rate of 75% for this group. In the present study, influenza vaccination coverage in older people was associated with the male sex, without studies, and low social level, in contrast with previous studies [24,25]. The behavior regarding this preventive intervention, influenza vaccination, indicates that the objectives proposed by the regional, national, and international institutions have not been reached. This data are comparable to those of other published studies. Numerous factors can affect this poor vaccination rate as other studies have shown [11,12]. One systematic review [13] addressed barriers, intent, and behavior for influenza vaccination: the greatest obstacle identified among older people was the lack of confidence in the vaccine, which was understood as a low perception of vaccine effectiveness and increased preconception about the risk of side effects (an important factor that determines the intention of the population to be vaccinated); another obstacle was not considering influenza a major health risk and/or the failure to consider the complications it may cause in people with chronic pathology (thus, people do not think it necessary to be vaccinated). In this sense, although vaccines have been proven an excellent strategy to reduce morbidity and mortality in respiratory infections, with an adequate safety profile [26], and although efforts are being made by health institutions and professionals with recruitment campaigns to vaccinate a maximum number of persons at risk; health services have noted an increase in patients and colleagues concerned about the arguments against vaccines [27]. Importantly, high participation was observed in the registries analyzed in the present study for other preventive or follow-up measures for chronic cardiovascular and metabolic processes, such as BP, blood glucose, and blood cholesterol level measurements; these are tests by which the subjects may have more notion of risk. In fact, in another study using the same methodology [28] with a smaller population that analyzed women of younger ages (40.8 years on average), 68.4% had a BP measurement and 64.1% and 53.9% had analytical measurements for cholesterol and blood glucose, respectively, performed at least once a year. In another study conducted in Italy [29] with a population of 119,073 people, in which the objective was to investigate behaviors toward the prevention of cancer and cardiovascular diseases, the highest participation percentages were obtained for the determination of cholesterol levels, BP, and blood glucose (83.3%, 66.4%, and 58.1%, respectively). In the registers analyzed, the participation reached higher figures, exceeding 98% for all three parameters, an increase that may be justified because the participants were older in our study (above 65 years old), whereas they were between 50 and 69 years old in Italy. In addition, it seems to be that older people
Table 1 Participation of Spanish people over 65 years (2009–2014) in vaccination campaigns for influenza and others preventive measures. Survey year
Vaccination for influenza Yes
Measure of blood pressure Yes
Measure of cholesterol Yes
Measure of glucose Yes
2014 (n = 6520) 2011/12 (n = 5896) 2009 (n = 6026)
57.4% 58.2% 74.5%
99.1% 97.9% 99%
98.3% 94.2% 97.7%
96.9% No registered 97.3%
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Table 2 Sociodemographic variables in Spanish people over 65 years (2009–2014) who have participated in vaccination for influenza. blood pressure. blood cholesterol and blood glucose.
a
Vaccination for influenza (n = 11,663)
Blood pressure (n = 18,197)
Cholesterol (n = 17,853)
Glucose (n = 12,185)
n (%)
p-value
n (%)
p-value
n (%)
p-value
n (%)
p-value
Sex
Man Woman
39.8% 60.2%
<.001
38.7% 61.3%
<.001
38.8% 61.2%
.003
39.4% 60.6%
.018
Marital status
Single Married Widowed Separated Divorced No response
8.1% 49.4% 40.2% 1% 1.1% 0.1%
<.001
8.5% 49.2% 39.2% 1.4% 1.6% 0.1%
<.001
8.4% 49.2% 39.3% 1.4% 1.6% 0.1%
<.001
8.6% 49.0% 39.2% 1.5% 1.6% 0.1%
.008
Educational level
Without studies Primary Secondary or professional training University
42.4% 38.5% 12.6% 6.5%
<.001
40.2% 38.8% 14% 7%
.27
39.9% 38.9% 14.2% 7%
.009
40% 38.9% 14.1% 7%
.242
Perception of health status
Very good Good Regulate Bad Very bad
4.5% 33.5% 39.3% 17.2% 5.5%
<.001
5.7% 36.0% 37.2% 15.8% 5.2%
<.001
5.7% 35.9% 37.3% 15.9% 5.2%
<.001
5.6% 35.4% 37.2% 16.0% 5.8%
<.001
Illnessa
Yes No
85.3% 14.7%
<.001
99.3% 0.7%
<.001
98.2% 1.8%
<.001
98.3% 1.7%
<.001
Limitation
Severely limited Limited but not severe Not Limited
14.9% 41.4% 43.7%
<.001
13.9% 39.1% 47.1%
<.001
13.8% 39.2% 47.0%
<.001
14.0% 39.2% 46.9%
<.001
Chronic or long-term illness.
Table 3 Participation in vaccination campaigns for influenza of Spanish people over 65 years analyzed by autonomous community (2009–2014) (N = 18,442). Autonomous community
2009 (n = 6026) Yes
2011/12 (n = 5896) Yes
2014 (n = 6520) Yes
Andalucía Aragón Principado de Asturias Baleares Canarias Cantabria Catilla-León Castilla-La Mancha Cataluña Comunidad Valenciana Extremadura Galicia Comunidad de Madrid Murcia Navarra País Vasco La Rioja Ceuta Melilla
70.5% 64.8% 73.4% 70.2% 67.3% 75.9% 78.1% 76.8% 76.3% 72.1% 84.1% 76.3% 76.7% 80.6% 73.1% 83.9% 72.9% 55.6% 75.4%
57.5% 60.4% 61.2% 51.3% 35.9% 63.7% 68.6% 55.8% 57.4% 58.7% 57.9% 55.3% 62.1% 52.3% 61.2% 64.7% 60.8% 29.4% 23.4%
52.6% 57.1% 62.2% 48.3% 35.4% 57.3% 65.3% 49.5% 58.3% 54.7% 69.2% 55.1% 63.6% 62.7% 56.7% 62.6% 62.6% 30.8% 56.6%
Total (N = 18,442)
74.7%
58.2%
57.4%
with chronic or long-term illness participate in others preventive measures (BP, blood glucose, and blood cholesterol level measurements) more than in influenza vaccination, due that, for instance, people who suffer HTA goes to nursing consultation for control their BP. But about influenza vaccination the reason is because old people are risk population, and not always they agree with that. Notably, when asked who recommended the vaccination, only 8.3% stated that they had requested the vaccine because they wanted to be vaccinated. The majority (71%) had been recom-
mended by a healthcare professional, so a lack of information or recommendation from health professionals does not seem to be the reason for non-vaccination. This result is contrary to other studies [30,31] that conclude that it is necessary to improve the recommendation of systematic vaccination for all patients at risk. Therefore, perhaps in Spain, the causes of low participation are not due to the lack of information or recommendation by health professionals but rather to the lack of motivation and/or attitude of the elderly. In this sense, health professionals must stress the benefits of this preventive practice and the low adverse effects it produces. Regarding the comparison of prevention measures analyzed, one study [32] analyzed the involvement of family physicians in recommendations for cardiovascular prevention. Anti-smoking advice was the most frequently recommended preventive activity (52.3%), followed by those aimed at controlling cardiovascular risk factors (hypertension – HTN, diabetes mellitus, and dyslipidemias; 22.7%). Although recommendation by a professional seems an important reinforcement to improve the rate of immunization in the present study, in agreement with other studies showing that it also reduces the morbi-mortality associated with influenza [17], it is striking that influenza vaccination in the healthcare professional community is low, both in Spain and in other countries [33–35]. The alternatives proposed by these studies are to introduce vaccination as mandatory in labor contracts, financial incentives, or improvement of the quality of care. One limitation of this study is that the ENSE and EESE are crosssectional studies; thus, it is not possible to know the causal direction between vaccination and related variables. The microdata are secondary data offered by Spanish National Institute of Statistics, so it was not possible to obtain the response rates. Furthermore, because they were surveys, the analyzed data are self-reported information. The aforementioned surveys also failed to ask the unvaccinated persons why they had not been vaccinated,
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Fig. 1. Participation in vaccination campaigns for influenza in people over 65 years in Spain (2009–2014).
Table 4 Logistic Regression Model. for the association among sociodemographic characteristics and participation in vaccination campaigns for influenza. in Spanish people over 65 years (2009–2014). OR (CI del 95%)
p-value
Sex Man Woman
1.13 (1.05–1.22) Reference
.002
Social class Clase I. II y III Clase IV. V y VI
Reference 1.24 (1.13–1.34)
Educational level Without studies With studiesa
1.15 (1.04–1.27) Reference
Declaration of interests The authors declare they have no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
<.001
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
.006
CI: confidence interval; p: signification of the model; OR: odds ratio. a Persons with primary, secondary or university education.
which would be interesting to include in future surveys. However, the study of the registries that is presented has the strength of using national representative surveys, with a large sample size. In conclusion, the number of people over 65 years old who participated in the campaign for influenza vaccination in 2014 was lower than that recommended by the WHO [23]; moreover, an alarming and worrying progressive decline has been observed since 2009. The variables that are associated with greater adherence to the vaccination campaigns are male sex, low level of education, and low social class. There are differences in the proportions of elderly people involved in vaccination campaigns among the Spanish Autonomous Communities, with the highest vaccination rate occurring in 2014 in Extremadura. Finally, although health professionals play an important role in preventing influenza and can help improve this public health problem, their attitude regarding the subject is contradictory.
Acknowledgements To National Institute of Statistic (NIS) and the Ministry of Health, Social Services and Equality of Spain for the information and support offered.
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Please cite this article in press as: Dios-Guerra C et al. Prevalence and factors associated with influenza vaccination of persons over 65 years old in Spain (2009–2014). Vaccine (2017), https://doi.org/10.1016/j.vaccine.2017.10.086
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[23] World Health Organization. WHO Guidelines on the use of vaccines and antivirals during influenza pandemic. Geneva: World Health Organization; 2004. Available at:
Please cite this article in press as: Dios-Guerra C et al. Prevalence and factors associated with influenza vaccination of persons over 65 years old in Spain (2009–2014). Vaccine (2017), https://doi.org/10.1016/j.vaccine.2017.10.086