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From mandatory to voluntary vaccination: intention to vaccinate in the case of policy changes
Public Health 180 (2020) 57e63
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Public Health journal homepage: www.elsevier.com/locate/puhe
Original Research
From mandatory to voluntary vaccination: intention to vaccinate in the case of policy changes M. Vrdelja a, *, V. U cakar a, A. Kraigher b a b
National Institute of Public Health, Trubarjeva 2, 1000, Ljubljana, Slovenia Faculty of Health Sciences, University of Ljubljana, Zdravstvena pot 5, 1000 Ljubljana, Slovenia
a r t i c l e i n f o
a b s t r a c t
Article history: Received 4 July 2019 Received in revised form 6 October 2019 Accepted 30 October 2019
Objectives: The aim of the study was to assess the association between sociodemographic characteristics and attitudes according to health belief model (HBM) attributes with the intention to vaccinate children in cases of non-mandatory vaccination to support informed decisions in planned revision of our vaccination policy. Study design: This is a cross-sectional study carried out on a random sample of 3,854 women with young children in Slovenia. Methods: The participants’ attitudes were grouped within six HBM attributes (perceived susceptibility, severity, benefits, barriers, clue to action and self-efficacy). Possible associations between the intention to vaccinate children in cases of non-mandatory vaccination and sociodemographic characteristics or attitudinal attributes according to HBM were explored in univariate analyses by calculating odds ratios (ORs) with 95% confidence interval (CI) estimates. Results: Just more than half (56.2%; 95% CI: 53.8e58.5%) of the women reported on their intention to vaccinate their children in the case of non-mandatory vaccination, and 23.4% (95% CI: 21.4e25.5%) were undecided. There were no significant sociodemographic predictor variables in relation to this intention. Those who perceived higher susceptibility to vaccine-preventable diseases or the benefits of vaccination were more likely to intend to vaccinate in the case of non-mandatory vaccination (OR ¼ 5.70; 95% CI: 4.64e7.00) and (OR ¼ 7.62; 95% CI: 5.96e9.76). Perceived barriers to vaccinate (fear of side-effects or lack of comprehensive information from physicians) and parents not getting enough useful information in general as a clue to action were significant predictors of an intention not to vaccinate. Conclusions: Our results show that a mandatory vaccination policy is an important factor in ensuring high levels of vaccination coverage in Slovenia. In future, more comprehensive communication activities focused on vaccine-preventable diseases and the benefits and safety of vaccination (for the education of parents and their healthcare providers) are needed to diminish the reliance on a mandatory vaccination policy. © 2019 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.
Keywords: Vaccination Health belief model Mandatory vaccination Voluntary vaccination Non-mandatory vaccination Communication
Introduction Vaccine and immunization programs have prevented major epidemics of life-threatening diseases since their widespread use, and they are considered one of greatest public health achievements.1 As their widespread use has increased, so have anxieties about safety of vaccines and their regulation.2
* Corresponding author. National Institute of Public Health, Trubarjeva 2, 1000 Ljubljana, Slovenia. Tel.: þ 386 1 2441 572, Fax: þ 386 1 2441 447. E-mail addresses: [email protected], [email protected] (M. Vrdelja).
Maintaining high levels of vaccination coverage is very important, but difficult to achieve, as the incidence of vaccinepreventable diseases has decreased or they have even been eliminated. Consequently, some part of the public wonders why there is still the need for vaccination.3 Undoubtedly, the success of vaccine programs depends on their high acceptance.4 A high level of vaccination coverage is important because of the protection of individuals and also communities with herd immunitydwhich provides that those who are not vaccinated are also largely protected.5 Countries in Europe have different vaccination policies to maintain high vaccination coverage among children and adolescents. Enforcing mandatory vaccinations is one of the strategies
https://doi.org/10.1016/j.puhe.2019.10.026 0033-3506/© 2019 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.
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that some countries adopted and others are considering to achieve this goal.6,7 Mandatory childhood vaccination means a legislative lever whereby governments require individuals to vaccinate their children and may impose consequences when parents do not comply.8 Slovenia established a national vaccination program funded by the National Health Insurance for all children and adolescents, including mandatory (against diphtheria, tetanus, pertussis, poliomyelitis, Haemophilus influenzae type b, measles, mumps, rubella and hepatitis B) and non-mandatory vaccinations (against human papillomavirus (HPV) and pneumococcal infections).9 According to the mandatory vaccination policy in Slovenia, every child must receive vaccines determined by law without the possibility for the parent to decline the vaccination except for medical reasons. The health inspectorate can impose a fine on parents who do not comply. Non-vaccinated children without medical exemption are allowed to attend kindergarten or school. Immunization data for Slovenia show that the vaccination coverage is 90e95% for mandatory vaccinations, whereas coverage for non-mandatory vaccinations is around 50% for HPV and pneumococcal infections.10 To sustain coverage as high as possible for most diseases in Slovenia, intensive communication strategies for different populations should be established, particularly for parents of young children to improve their trust in vaccination.11 Moreover, as in many countries, Slovenia is also faced with vaccine hesitancy,12 which can have immense consequences on vaccine coverage and the recurrence of vaccine-preventable diseases. In some health regions, this system is no longer effective in ensuring the vaccination coverage of 95% or more, thus the Ministry of Health is planning to revise the existing vaccination policy. There are several theoretical frameworks of behaviour change that can be used to understand and influence specific health behaviour. Some of them such as health belief model (hereafter referred to as ‛HBM’), theory of planned behaviour or risk perception attitude framework were already used in the field of vaccination.13 For assessing the intention to vaccinate when vaccination is not mandatory, we used the HBM because it is one of the most widely used models for examining attitudes for predicting health behaviour in public health, not very common in the field of vaccination but more common than other models. The HBM was originally developed to look at barriers to polio vaccination among parents14 and has proven to be useful for measurement of beliefs linked with vaccine hesitancy and for predicting the parental decision to delay or refuse vaccines for their child.15 The systematic review examining different behaviour change frameworks when studying healthcare worker influenza vaccination uptake showed that the HBM was most frequently used in this regard. The HBM constructs along with other behavioural variables were successful in predicting vaccine uptake. The findings of this review support the use of the HBM as an appropriate theory that may be used to inform future intervention studies.13 The HBM posits six constructs for predicting health behaviour: risk susceptibility, risk severity, benefits to action, barriers to action, self-efficacy and cues to action.14,16 The HBM hypothesizes that health-related actions depend on the simultaneous occurrence of three classes of factors: (1) the existence of sufficient motivation (or health concern) to make health issues salient or relevant; (2) the belief that one is vulnerable to a serious health problem or to the consequences of that illness or condition, which means a perceived threat; and (3) the belief that a particular health recommendation would be beneficial in reducing the perceived threat at a subjectively acceptable cost, which is related to perceived barriers that must be overcome to follow the health recommendation.17 This model specifies whether someone engages in a suggested health behaviour such as vaccination.18 The model specifies that if individuals perceive a negative health outcome to be severe, perceive themselves to be susceptible to it,
perceive the benefits of behaviours that reduce the likelihood of that outcome to be high and perceive the barriers to adopting those behaviours to be low, then the behaviour is likely for those individuals.19 The objective of this study was to assess the association between sociodemographic characteristics and attitudes according to HBM attributes with the intention to vaccinate children in cases of non-mandatory vaccination in a sample of women with young children in Slovenia to support informed decisions in a planned revision of our vaccination policy. As far as we know, this is the first research that uses the HBM for assessing intention on this topic. Methods A cross-sectional survey was carried out in 2016 on a random sample of 3,854 Slovenian women, who gave birth in 2014 and 2015 (39,497 births) as already published previously.11,12 The survey was performed by the Slovenian National Institute of Public Health and the Faculty of Social Sciences, University of Ljubljana, as part of a broader interdisciplinary research project about vaccination scepticism in Slovenia. Women were invited to participate in the study by post; they had the possibility to anonymously return the questionnaire by a prepaid envelope or to respond online by a Web-created questionnaire. The participants' intention to vaccinate their children in the case of non-mandatory vaccination was measured by asking them about the extent to which they agreed with the statement ‘I would vaccinate my children, even if vaccination wasn’t mandatory’, using a five-point Likert scale (1: ‘completely disagree’, 2: ‘mostly disagree’, 3: ‘neither disagree nor agree’, 4: ‘mostly agree’ and 5: ‘completely agree’). Similarly, the participants marked their level of agreement with items of six attributes according to the HBM (perceived susceptibility for vaccine-preventable diseases, perceived severity of vaccine-preventable diseases, perceived benefits of vaccination, perceived barriers for vaccination, clues to action for vaccination and self-efficacy statements). In addition, the questionnaire collected the individual participant's age, marital status, level of education, social class, number of children, health status perception, attendance of religious services and region of residence. Statistical analyses were performed using STATA package version 10.0 (Stata Statistical Software: release 10.0; Stata Corporation, College Station. TX). For dependent variables on the intention to vaccinate children without mandatory vaccination, we grouped the participants into three groups: no (1: ‘completely disagree’ and 2: ‘mostly disagree’), undecided (3: ‘neither disagree nor agree’) and yes (4: ‘mostly agree’ and 5: ‘completely agree’). We estimated the proportion of women who were undecided or lacking the intention to vaccinate their children in the case of nonmandatory vaccination with 95% confidence intervals (CIs) overall and according to sociodemographic characteristics. The HBM items were grouped within the six previously mentioned attributes (dimensions), Cronbach's alpha coefficient was calculated for the attributes with three items, and Pearson's correlation coefficient was used for the attributes with two items to assess reliability. A scale mean was calculated for attributes with an alpha coefficient or Pearson correlation >0.5. For examining associations between the intention to vaccinate children without mandatory vaccination and the collected explanatory variables (sociodemographic characteristics or attitudinal attributes according to the HBM), the dependent variable was dichotomized so that participants who completely agree or mostly agree to vaccinate their children in the case of non-mandatory vaccination were coded as ‘1’, participants who mostly disagree or completely disagree were coded as ‘0’ and participants who were
M. Vrdelja et al. / Public Health 180 (2020) 57e63
undecided (neither disagree nor agree) were excluded. Possible associations between the intention to vaccinate children in the case of non-mandatory vaccination and the collected explanatory variables were explored in univariate analyses by calculating odds ratios (ORs) with 95% confidence interval (CI) estimates and using Pearson's chi-squared tests for significance. The level of statistical significance was set at P < 0.05. Results A total of 1,704 participants completed the questionnaire, and the participation rate was 44.4%. The median age of participants was 32 years (range: 23e44 years). The distribution of the study population according to sociodemographic characteristics is shown in Table 1. Most participants were between 30 and 34 years of age (43.3%). More than 60% of the participants reported college or university as their highest level of education. The majority of the participants placed themselves in the middle social class (77.4%) and perceived the status of their health in general as good or very good (83.0%). Of 1,693 women with young children who reported on their intention to vaccinate their children in case of non-mandatory vaccination, just more than half (56.2%; 95% CI: 53.8e58.5%) would vaccinate, 23.4% (95% CI: 21.4e25.5%) were undecided and
59
20.4% (95% CI: 18.4e22.3%) reported that they would not vaccinate their children. There were no significant sociodemographic predictor variables in relation to the participants' intention to vaccinate their children in the case of non-mandatory vaccination (Table 1). Table 2 shows the number and proportion of women with young children according to their agreement with the statements/ items grouped by individual attributes of the HBM. Regarding the perceived severity of vaccine-preventable diseases, more than 15% of the participants mostly or completely agreed with the statement that it is much better to have the disease naturally than to be vaccinated, and 35% were undecided. The majority of Slovenian women with young children (more than 79%) perceived vaccination as beneficiary, to be effective, to protect individuals and the community and to contribute to the protection of others who cannot be vaccinated. However, there was also a surprisingly high proportion of women (51%) who agreed with the statement that they fear vaccinating their children because they are afraid of the side-effects. Similarly, more than 50% agreed that parents are not getting enough information to decide on vaccinating their children. The scale means for perceived susceptibility to vaccinepreventable diseases and the perceived benefits of vaccination attributes were 3.9 (standard deviation [SD]: ± 0.9) and 4.1
Table 1 Intention to vaccinate children in case of non-mandatory vaccination according to sociodemographic characteristics in a sample of women with young children in Slovenia in 2016. Variable
Age (years) <30 30e34 35e39 40 Marital status Married Living with a partner Not living with a partner, single, divorced, widowed Level of education Less than high school High school College, university Specialization, masters, PhD Social class Lower Middle Upper Number of children 1 2 3 or more Health status assessment Very good, good Satisfying Poor, very poor Attending religious services No Yes Region of residence Celje Koper Novo mesto Ljubljana Nova Gorica Ravne na Koroskem Maribor Kranj Murska Sobota
All (N ¼ 1704)
Intention to vaccinate children in the case of non-mandatory vaccination Yes
No
Undecided
OR
95% CI
P
389 709 412 129
54.6% 55.7% 59.8% 56.6%
21.6% 20.4% 17.3% 22.5%
23.7% 23.9% 22.9% 20.9%
1 1.08 1.37 0.98
0.79e1.49 0.95e1.98 0.60e1.64
0.617 0.089 0.992
772 878 37
57.1% 55.2% 67.6%
19.8% 20.6% 24.3%
23.1% 24.2% 8.1%
1 0.93 0.96
0.73e1.20 0.44e2.12
0.589 0.931
90 392 1035 174
62.2% 55.5% 55.2% 61.3%
17.8% 19.4% 21.1% 19.6%
20.0% 25.1% 23.7% 19.1%
1 0.82 0.74 0.89
0.44e1.51 0.42e1.33 0.45e1.75
0.516 0.321 0.738
176 1292 196
59.7% 55.7% 56.1%
17.6% 20.2% 22.4%
22.7% 24.0% 21.4%
1 0.82 0.74
0.53e1.25 0.43e1.26
0.353 0.263
824 648 215
55.2% 58.7% 53.0%
20.1% 20.1% 21.9%
24.7% 21.2% 25.1%
1 1.06 0.88
0.81e1.38 0.60e1.29
0.671 0.519
1402 269 19
56.2% 57.8% 42.1%
20.4% 20.1% 21.0%
23.4% 22.0% 36.8%
1 1.04 0.72
0.74e1.46 0.22e2.43
0.817 0.601
475 1671
56.2% 56.5%
23.6% 18.8%
20.2% 24.7%
1 1.26
0.96e1.64
0.089
234 91 171 552 104 50 228 187 61
56.4% 60.0% 52.0% 56.2% 53.8% 62.0% 56.8% 58.3% 57.4%
16.7% 20.0% 22.8% 20.6% 23.1% 20.0% 19.4% 21.9% 13.1%
26.9% 20.0% 25.1% 23.3% 23.1% 18.0% 23.8% 19.8% 29.5%
1 0.88 0.67 0.81 0.68 0.92 0.87 0.78 1.29
0.46e1.69 0.40e1.14 0.53e1.23 0.38e1.25 0.41e2.04 0.53e1.42 0.47e1.30 0.55e3.02
0.713 0.136 0.316 0.221 0.829 0.569 0.350 0.552
OR: odds ratio; CI: confidence interval; P: P value. The number of individuals varies according to the number of missing values for individual variables.
Item
Alpha or Mean (SD)a Likelihood of intention to vaccinate children in case of non-mandatory vaccination corr. coef. Completely Mostly Neither disagree or Mostly Completely OR 95% CI P disagree ¼ 1 disagree ¼ 2 agree ¼ 3 agree ¼ 4 agree ¼ 5
Distribution
2.1%
6.0%
20.1%
38.3%
33.5%
3.9 (0.9) e
5.70 e
4.64e7.00 e
<0.001 e
4.1%
6.1%
18.7%
38.5%
32.6%
e
e
e
e
1.0%
3.0%
11.4%
33.3%
51.4%
4.3 (0.8)
3.99
3.32e4.80
<0.001
20.1%
29.2%
35.1%
10.9%
4.6%
2.5 (1.1)
0.37
0.32e0.42
<0.001
2.5%
3.8%
14.5%
57.2%
22.0%
4.1 (0.8) e
7.62 e
5.96e9.76 e
<0.001 e
1.8%
2.7%
10.5%
38.0%
47.0%
e
e
e
e
3.2%
5.7%
16.6%
35.4%
39.2%
e
e
e
e
9.5%
19.1%
20.4%
23.1%
27.9%
3.4 (1.3)
0.35
0.31e0.41
<0.001
11.1%
23.2%
32.2%
20.0%
13.4%
3.0 (1.2)
0.41
0.37e0.47
<0.001
6.7%
15.7%
24.2%
25.1%
28.2%
3.5 (1.2)
0.45
0.40e0.51
<0.001
20.2%
40.4%
30.4%
7.5%
1.4%
2.3 (0.9)
0.98
0.86e1.12
0.740
13.1%
25.5%
36.6%
18.8%
5.9%
2.8 (1.1)
0.74
0.66e0.83
<0.001
0.58
0.41
0.84
0.50
/
0.16
Alpha: Cronbach's alpha; corr. coef.: Pearson's correlation; OR: odds ratio; CI: confidence interval; P: P value. a A scale mean was calculated for attributes with alpha coefficient or Pearson correlation >0.5.
M. Vrdelja et al. / Public Health 180 (2020) 57e63
Perceived susceptibility It is possible that without vaccination my child would get a disease that could otherwise be prevented by vaccination. (N ¼ 1691) As long as there are infectious diseases, regular vaccination should not be avoided at all. (N ¼ 1691) Perceived severity Vaccine preventable diseases are very dangerous and can have serious health consequences. (N ¼ 1692) It is much better to have the disease in a natural way than to be vaccinated. (N ¼ 1687) Perceived benefits Vaccination effectively protects the child from the disease. (N ¼ 1692) Vaccination of an individual is also very important for the protection of the community. (N ¼ 1692) By vaccinating my child, I significantly contribute to the protection of others who can't be vaccinated. (N ¼ 1693) Perceived barriers I'm afraid to vaccinate my child because I'm afraid of the side effects of vaccines. (N ¼ 1680) Physicians will never be willing to comprehensive provide all relevant information on children's vaccination. (N ¼ 1688) Clue to action Parents get too little useful information to decide on our children's vaccination without hesitation. (N ¼ 1692) Self-efficacy So far, regulations have never prevented me from working on my own. (N ¼ 1689) Science is no more useful than common sense. (N ¼ 1682)
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Table 2 Health belief model attitudinal variables associated with intention to vaccinate children in case of non-mandatory vaccination in a sample of women with young children in Slovenia in 2016.
M. Vrdelja et al. / Public Health 180 (2020) 57e63
(SD: ± 0.8), respectively. A summary of this information is presented in Table 2. Slovenian women with young children who perceived higher susceptibility to vaccine-preventable diseases (OR ¼ 5.70; 95% CI: 4.64e7.00) or benefits of vaccination (OR ¼ 7.62; 95% CI: 5.96e9.76) were more likely to intend to vaccinate their children in the case of non-mandatory vaccination. In addition, the perceived barriers to vaccinate, fear of side-effects (OR ¼ 0.35; 95% CI: 0.31e0.41), lack of comprehensive information from physicians (OR ¼ 0.41; 95% CI: 0.37e0.47) and parents not getting enough useful information in general as a clue to action (OR ¼ 0.45; 95% CI: 0.40e0.51), were significant predictors of an intention not to vaccinate children in the case of non-mandatory vaccination. Discussion Countries all over the world have different vaccination programs and also different legislation regarding vaccination. According to recent research, there are at least 62 countries with mandatory vaccinations; 14 of them, including Slovenia, are EU countries.8 In Slovenia, the policy of mandatory vaccination for nine vaccine-preventable diseases has been established for several decades. However, in recent years, both among professionals and among the lay public, there have been numerous debates about the appropriateness of such a policy. Procedures to carry out mandatory vaccination are very complicated, represent an additional administrative burden for physicians and are associated with additional costs. These procedures are rarely successful, resulting in a decrease in vaccination coverage in some health regions. The Ministry of Health is therefore preparing a revision of the vaccination policy, and the public debate on the justification for mandatory vaccination is expected, where also ethical issues will be highlighted, which are often problematized at the mandatory vaccination.20,21 The association of Slovenian pediatricians expressed the concern about the situation, and taking account of recent outbreaks of measles and increasing vaccine hesitancy, they endorsed the Velenje statement of European confederation of primary care pediatricians. The statement supports regulations for more mandatory vaccinations in the countries if the vaccination coverage is insufficient or decreasing. One way to reach high coverage is also requirement of complete vaccination before enrolment in kindergarten or school.22 To support the revision of the Slovenian vaccination policy, we performed a study on a representative sample of women with young children in our country to examine their intention to vaccinate their children in case of non-mandatory vaccination. Just more than half (56.2%) of the women reported on their intention to vaccinate their children in the case of non-mandatory vaccination, and 23.4% were undecided. Our results show that a mandatory vaccination policy is an important factor in ensuring high levels of vaccination coverage in Slovenia. Some European countries have recently reintroduced mandatory vaccination because of decreasing vaccination coverage and a recurrence of outbreaks of vaccine-preventable diseases. More specifically, Italy in 2017 implemented mandatory vaccination for ten diseases,23,24 and France in 2018 made eight more vaccines mandatory in addition to the three that were already required.25,26 According to their experience, the expansion of mandatory vaccination was well accepted.27 As shown in a large-scale global study comparing the State of Vaccine Confidence of 67 countries, Slovenia belongs to the ‘top 10’ countries where vaccine safety sentiment is more negative than that in others,28 although the proportion is still small.11 Our study gave us some insight into the factors that can influence the intention to vaccinate children in the case of non-mandatory
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vaccination. It confirmed that the fear of side-effects of vaccines is a major barrier with regard to vaccination, which is in line with other studies29 and can have a great impact on whether mothers would vaccinate their children in the case of non-mandatory vaccination. Those Slovenian women with young children included in our study who perceived higher susceptibility to vaccine-preventable diseases or the benefits of vaccination were more likely to intend to vaccinate in the case of non-mandatory vaccination. Recognizing vaccination as beneficial and being sure that it can protect their children from the disease is the most important factor. A recent French study similarly showed that perception of vaccine safety and benefits was major predictors for (positive or negative) opinions about this new policy in France, where two-thirds of its population was in favour of the extension of mandatory vaccines for children.30 Our study confirmed that mothers lacking access to enough useful information in general is a significant predictor of intention to vaccinate children in the case of non-mandatory vaccination. Communication activities should be focused on emphasizing the right to health and the benefits of vaccination for individuals and society, as proposed in some studies,32 and also on emphasizing the responsibilities of parents. Different communication channels and tools should be wisely used33 because the public use different sources to access information about health and vaccination.34 Many people now turn to the Internet35,36 or social media37 for health information when making health-related decisions. To be more specific, communication should link online and offline platforms to establish a dialogue with individuals who delay vaccination.38 Public health campaigns can be useful and effective,27 especially storytelling39 and telling personal stories, because they can encourage parents to take action.40 In addition, specific targeting communication using electronic vaccination registries with reminder functions can be very effective.41 Despite this, communication should focus on interpersonal communication between parents and health professionals because parents believe that healthcare workers are the most reliable source to provide information about vaccination.34,42 Nevertheless, their role can be critical,31 as they often seem to lack communication competence.12 As such, there is a need to establish a trusting relationship that satisfies parents and health professionals, the topics and the amount of information to be transferred and the ways in which they should be communicated.43 The results of our study indicate that the HBM can be applied to the very important topic of public health, such as impact of vaccination policy on parents' vaccination behaviour. They can be of use to the other countries who are considering modification of their vaccination policy. It seems that in some settings, owing to different cultural or historical factors and differences in the health system, some more rigorous measures may be needed to maintain adequate vaccination coverage in the population. Our study has some limitations. The response rate to the questionnaire was 44.4%; thus, the selection bias cannot be ruled out if more mothers with specific positive or negative opinions on vaccination were more or less likely to respond to the survey. If such a bias exists, it may lead to an overestimation or underestimation of the intention to vaccinate their children in the case of nonmandatory vaccination. Only mothers of young children were included in our study, so we must be cautious when generalizing our results to all parents in Slovenia. However, it is important to note that research from certain developed countries shows that women make the majority of healthcare decisions for their families,44 especially regarding vaccination.45e47 We were unable to compare the characteristics between participants who completed the study and non-respondents because participants anonymously completed the questionnaires. In addition, a ‘social desirability bias’ (participants choosing more socially acceptable answers) may have
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affected our study, which could decrease the reliability of some of the answers. In the future, additional qualitative studies would be needed to further examine the importance of compulsory vaccination on parents' decision to vaccinate their children, as well as studies of cultural and historical influences, such as the long tradition of compulsory vaccination (which may also have a significant impact). To conclude, the results of our study show that a mandatory vaccination policy is still an important factor in ensuring high levels of vaccination coverage in Slovenia. Our study also demonstrated the usefulness of the HBM in examining the intention of mothers to vaccinate their children in the case of policy change. In the future, more comprehensive communication activities focused on vaccinepreventable diseases and benefits and safety of vaccination for parents and their healthcare providers are needed to diminish the reliance on a mandatory vaccination policy. Author statements Acknowledgments The authors thank Mr. Robert McKenzie for providing English proofreading. Ethical approval The research was conducted in accordance with Slovenian legislation and with the permission of the Commission of the Republic of Slovenia for Medical Ethics (decision number: 127/03/14). Funding The study presented in this article was a part of the interdisciplinary project ‘Control of Communicable Diseases by Vaccination: Who are the Sceptics and Opponents of Vaccination and How to Communicate with Them?’ financed by the Slovenian Research Agency and cofinanced by the Slovenian Ministry of Health. Competing interests None declared. Author contributions All authors contributed to the draft of the article and participated in the research. M.V., V.U. and A.K. were involved in the conception and design of the study; V.U. analyzed and interpreted the data, M.V. and A.K. contributed to analysis and interpretation of the data. All authors were involved in the revision and approval of the final content before submission. References 1. Centers for Disease Control and Prevention. Ten great public health achievements. 2011. 2. Larson HJ, Cooper LZ, Eskola J, Katz SL, Ratzan S. New Decade of Vaccines 5 Addressing the vaccine confi dence gap. Lancet 2011;378(9790):526e35. 3. Fine P, Eames K, Heymann DL. “Herd immunity”: a rough guide. Clin Infect Dis 2011;52(7):911e6. 4. Omer SB, Salmon DA, Orenstein WA, DeHart MP, Halsey N. Vaccine refusal, mandatory immunization, and the risks of vaccine-preventable diseases. N Engl J Med 2009;360(19):1981e8 [Internet]. 5. May T. Public communication, risk perception, and the viability of preventivie vaccination against communicable diseases. Bioethics 2005;19(4):407e21. 6. Haverkate M, Giambi C, Johansen K, Lopalco PL, Cozza V, Appelgren E. Mandatory and recommended vaccination in the EU , Iceland and Norway : results of the venice 2010 survey on the ways of implementing national vaccination programmes. Euro Surveill 2012;17(22):1e6.
7. Bozzola E, Spina G, Russo R, Bozzola M, Corsello G, Villani A. Mandatory vaccinations in European countries, undocumented information, false news and the impact on vaccination uptake: the position of the Italian pediatric society. Ital J Pediatr 2018;44(1):67. 8. Attwell K, Drislane S, Leask J. Mandatory vaccination and no fault vaccine injury compensation schemes: an identification of country-level policies. Vaccine [Internet] 2019;37(21):2843e8. 9. U cakar V, Jeraj I, Vitek Grgi c M, Kraigher A. Analiza izvajanja cepljenja v Sloveniji v letu 2015. 2016. Ljubljana. 10. U cakar V, Krnc K, Zupan B. Preliminarno porocilo o izvajanju cepljenje v Sloveniji v letu 2017. 2018. Ljubljana. 11. U cakar V, Fafangel M, Kraigher A. Vaccine confidence among mothers of young children, Slovenia, 2016 [Internet] Vaccine 2018;36:5544e50. Available from:. 12. Vrdelja M, Kraigher A, Ver ci c D, Kropivnik S. The growing vaccine hesitancy: exploring the influence of the internet. Eur J Public Health [Internet] 2018;28(5): 934e9. 13. Corace KM, Srigley JA, Hargadon DP, Yu D, MacDonald TK, Fabrigar LR, et al. Using behavior change frameworks to improve healthcare worker influenza vaccination rates: a systematic review. Vaccine 2016;34(28):3235e42. 14. Rosenstock IM. Historical origins of the health belief model. Health Educ Monogr 1974;2:328e35. 15. Smith PJ, Humiston SG, Marcuse EK, Zhao Z, Dorell CG, Howes C, et al. Parental delay or refusal of vaccine doses, childhood vaccination coverage at 24 months of age, and the Health Belief Model. Public Health Rep 2011;126(SUPPL. 2): 135e46. 16. Jones CL, Jensen JD, Scherr CL, Brown NR, Christy K, Weaver J. The health belief model as an explanatory framework in communication research: exploring parallel, serial, and moderated mediation. Health Commun 2015;30:566e76. 17. Rosenstock IM, Strecher VJ, Becker MH. Social learning theory and the health belief model. Health Educ Q 1988;15(2):175e83. 18. Cheney MK, John R. Underutilization of influenza vaccine: a test of the health belief model. SAGE Open 2013:1e12. 19. Carpenter CJ. A meta-analysis of the effectiveness of health belief model variables in predicting behavior. Health Commun 2010;25:661e9. 20. Isaacs D, Kilham H, Leask J, Tobin B. Ethical issues in immunisation. Vaccine 2009;27(5):615e8. 21. Salmon DA, Teret SP, MacIntyre CR, Salisbury D, Burgess MA, Halsey NA. Compulsory vaccination and conscientious or philosophical exemptions: past, present, and future. Lancet 2006;367(9508):436e42. 22. European confederation of primary care pediatricians. The ECPCP Velenje statement e how to deal with vaccination hesitancy in the comunity [Internet]. Velenje. 2017 [cited 2019 Sep 3]. Available from: https://www.ecpcp.eu/ resources/the-ecpcp-velenje-statement/. 23. Signorelli C, Odone A, Cella P, Iannazzo S. Childhood vaccine coverage in Italy after the new law on mandatory immunization. Ann Ig Med Preventiva Comunita 2018;30(Supple 1):1e10. 24. Ricciardi W, Boccia S, Siliquini R. Moving towards compulsory vaccination: the Italian experience. Eur J Public Health 2018;28(1):2e3. 25. Ward JK, Colgrove J, Verger P. Why France is making eight new vaccines mandatory [Internet] Vaccine 2018;36(14):1801e3. https://doi.org/10.1016/ j.vaccine.2018.02.095. Available from:. vy-bruhl D, Fonteneau L, Vaux S, Barret A-S, Antona D, Bonmarin I, et al. 26. Le Assessment of the impact of the extension of vaccination mandates on vaccine coverage after 1 year, France, 2019. Euro Surveill 2019;24(25):1e3. 27. Cohen R, Gaudelus J, Leboucher B, Stahl JP, Denis F, Subtil D, et al. Impact of mandatory vaccination extension on infant vaccine coverages: promising preliminary results. Med Maladies Infect 2019;49(1):34e7 [Internet]. 28. Larson HJ, de Figueiredo A, Xiahong Z, Schulz WS, Verger P, Johnston IG, et al. The state of vaccine confidence 2016: global insights through a 67-country survey. EBioMedicine 2016;12:295e301. 29. Guidry JPD, Carlyle K, Messner M, Jin Y. On pins and needles: How vaccines are portrayed on Pinterest. Vaccine 2015;33(39):5051e6 [Internet]. 30. Mathieu P, Gautier A, Raude J, Goronflot T, Launay T, Debin M, et al. Population perception of mandatory childhood vaccination programme before its implementation, France, 2017. Euro Surveill 2019;24(25). 31. Maisa A, Milligan S, Quinn A, Boulter D, Johnston J, Treanor C, et al. Vaccination against pertussis and influenza in pregnancy: a qualitative study of barriers and facilitators. Public Health 2018;162:111e7 [Internet]. €hm R, Meier NW, Groß M, Korn L, Betsch C. The willingness to vaccinate 32. Bo increases when vaccination protects others who have low responsibility for not being vaccinated. J Behav Med 2019;42(3):381e91. 33. Vrdelja M. Komuniciranje cepljenja skozi prizmo situacijske teorije javnosti. Fakulteta za dru zbene vede Univerze v Ljubljani; 2017. 34. Harmsen IA, Doorman GG, Mollema L, Ruiter RAC, Kok G, de Melker HE. Parental information-seeking behaviour in childhood vaccinations. BMC Public Health [Internet] 2013;13(1):1219. 35. Madden K, Nan X, Briones R, Waks L. Sorting through search results: a content analysis of HPV vaccine information online. Vaccine [Internet] 2012;30(25): 3741e6. 36. Xu Z. Personal stories matter: topic evolution and popularity among pro- and anti-vaccine online articles. J Comput Soc Sci 2019:1e14. 37. Shoup JA, Wagner NM, Kraus CR, Narwaney KJ, Goddard KS, Glanz JM. Development of an interactive social media tool for parents with concerns about vaccines. Health Educ Behav 2015;42(3):302e12 [Internet].
M. Vrdelja et al. / Public Health 180 (2020) 57e63 38. Yaqub O, Castle-Clarke S, Sevdalis N, Chataway J. Attitudes to vaccination : a critical review. Soc Sci Med 2014;112:1e11 [Internet]. 39. Guidry JPD, Carlyle K, Messner M, Jin Y. On pins and needles: How vaccines are portrayed on Pinterest. Vaccine 2015;33(39):5051e6 [Internet]. 40. Shelby A, Ernst K, Shelby A, Ernst K. Story and science How providers and parents can utilize storytelling to combat anti-vaccine misinformation. Hum Vaccines Immunother 2013;9(8):1795e801. €€ €inen S, Nohynek H, Puumalainen T, Jokinen J. 41. Baum U, Sundman J, Ja askela Establishing and maintaining the national vaccination register in Finland. Euro Surveill 2017;22(17):1e9. 42. Peretti-Watel P, Ward JK, Vergelys C, Bocquier A, Raude J, Verger P. ‘I Think I Made the Right Decision … I Hope I'm Not Wrong’. Vaccine hesitancy, commitment and trust among parents of young children [Internet] Sociol Health Illn 2019:1e15. xx(xx).
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43. Fritz Z, Holton R. Too much medicine: not enough trust? J Med Ethics 2019;45(1):31e5. 44. Buck Luce C, Ann Hewlett S, Taylor Kennedy J, Sherbin L. The power of the purse: engaging women decision makers for healthy outcomes. 2015 [Internet]. New York. 45. Benin AL, Wisler-Scher DJ, Colson E, Shapiro ED, Holmboe ES. Qualitative analysis of mothers' decision-making about vaccines for infants: the importance of trust. Pediatrics 2006;117(5):1532e41 [Internet]. 46. Wu AC, Wisler-Sher DJ, Griswold K, Colson E, Shapiro ED, Holmboe ES, et al. Postpartum mothers' attitudes, knowledge, and trust regarding vaccination. Matern Child Health J 2008;12(6):766e73. 47. Hughes CC, Jones AL, Feemster KA, Fiks AG. HPV vaccine decision making in pediatric primary care: a semi-structured interview study. BMC Pediatr [Internet] 2011;11:74.
Contents lists available at ScienceDirect
Public Health journal homepage: www.elsevier.com/locate/puhe
Original Research
From mandatory to voluntary vaccination: intention to vaccinate in the case of policy changes M. Vrdelja a, *, V. U cakar a, A. Kraigher b a b
National Institute of Public Health, Trubarjeva 2, 1000, Ljubljana, Slovenia Faculty of Health Sciences, University of Ljubljana, Zdravstvena pot 5, 1000 Ljubljana, Slovenia
a r t i c l e i n f o
a b s t r a c t
Article history: Received 4 July 2019 Received in revised form 6 October 2019 Accepted 30 October 2019
Objectives: The aim of the study was to assess the association between sociodemographic characteristics and attitudes according to health belief model (HBM) attributes with the intention to vaccinate children in cases of non-mandatory vaccination to support informed decisions in planned revision of our vaccination policy. Study design: This is a cross-sectional study carried out on a random sample of 3,854 women with young children in Slovenia. Methods: The participants’ attitudes were grouped within six HBM attributes (perceived susceptibility, severity, benefits, barriers, clue to action and self-efficacy). Possible associations between the intention to vaccinate children in cases of non-mandatory vaccination and sociodemographic characteristics or attitudinal attributes according to HBM were explored in univariate analyses by calculating odds ratios (ORs) with 95% confidence interval (CI) estimates. Results: Just more than half (56.2%; 95% CI: 53.8e58.5%) of the women reported on their intention to vaccinate their children in the case of non-mandatory vaccination, and 23.4% (95% CI: 21.4e25.5%) were undecided. There were no significant sociodemographic predictor variables in relation to this intention. Those who perceived higher susceptibility to vaccine-preventable diseases or the benefits of vaccination were more likely to intend to vaccinate in the case of non-mandatory vaccination (OR ¼ 5.70; 95% CI: 4.64e7.00) and (OR ¼ 7.62; 95% CI: 5.96e9.76). Perceived barriers to vaccinate (fear of side-effects or lack of comprehensive information from physicians) and parents not getting enough useful information in general as a clue to action were significant predictors of an intention not to vaccinate. Conclusions: Our results show that a mandatory vaccination policy is an important factor in ensuring high levels of vaccination coverage in Slovenia. In future, more comprehensive communication activities focused on vaccine-preventable diseases and the benefits and safety of vaccination (for the education of parents and their healthcare providers) are needed to diminish the reliance on a mandatory vaccination policy. © 2019 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.
Keywords: Vaccination Health belief model Mandatory vaccination Voluntary vaccination Non-mandatory vaccination Communication
Introduction Vaccine and immunization programs have prevented major epidemics of life-threatening diseases since their widespread use, and they are considered one of greatest public health achievements.1 As their widespread use has increased, so have anxieties about safety of vaccines and their regulation.2
* Corresponding author. National Institute of Public Health, Trubarjeva 2, 1000 Ljubljana, Slovenia. Tel.: þ 386 1 2441 572, Fax: þ 386 1 2441 447. E-mail addresses: [email protected], [email protected] (M. Vrdelja).
Maintaining high levels of vaccination coverage is very important, but difficult to achieve, as the incidence of vaccinepreventable diseases has decreased or they have even been eliminated. Consequently, some part of the public wonders why there is still the need for vaccination.3 Undoubtedly, the success of vaccine programs depends on their high acceptance.4 A high level of vaccination coverage is important because of the protection of individuals and also communities with herd immunitydwhich provides that those who are not vaccinated are also largely protected.5 Countries in Europe have different vaccination policies to maintain high vaccination coverage among children and adolescents. Enforcing mandatory vaccinations is one of the strategies
https://doi.org/10.1016/j.puhe.2019.10.026 0033-3506/© 2019 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.
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M. Vrdelja et al. / Public Health 180 (2020) 57e63
that some countries adopted and others are considering to achieve this goal.6,7 Mandatory childhood vaccination means a legislative lever whereby governments require individuals to vaccinate their children and may impose consequences when parents do not comply.8 Slovenia established a national vaccination program funded by the National Health Insurance for all children and adolescents, including mandatory (against diphtheria, tetanus, pertussis, poliomyelitis, Haemophilus influenzae type b, measles, mumps, rubella and hepatitis B) and non-mandatory vaccinations (against human papillomavirus (HPV) and pneumococcal infections).9 According to the mandatory vaccination policy in Slovenia, every child must receive vaccines determined by law without the possibility for the parent to decline the vaccination except for medical reasons. The health inspectorate can impose a fine on parents who do not comply. Non-vaccinated children without medical exemption are allowed to attend kindergarten or school. Immunization data for Slovenia show that the vaccination coverage is 90e95% for mandatory vaccinations, whereas coverage for non-mandatory vaccinations is around 50% for HPV and pneumococcal infections.10 To sustain coverage as high as possible for most diseases in Slovenia, intensive communication strategies for different populations should be established, particularly for parents of young children to improve their trust in vaccination.11 Moreover, as in many countries, Slovenia is also faced with vaccine hesitancy,12 which can have immense consequences on vaccine coverage and the recurrence of vaccine-preventable diseases. In some health regions, this system is no longer effective in ensuring the vaccination coverage of 95% or more, thus the Ministry of Health is planning to revise the existing vaccination policy. There are several theoretical frameworks of behaviour change that can be used to understand and influence specific health behaviour. Some of them such as health belief model (hereafter referred to as ‛HBM’), theory of planned behaviour or risk perception attitude framework were already used in the field of vaccination.13 For assessing the intention to vaccinate when vaccination is not mandatory, we used the HBM because it is one of the most widely used models for examining attitudes for predicting health behaviour in public health, not very common in the field of vaccination but more common than other models. The HBM was originally developed to look at barriers to polio vaccination among parents14 and has proven to be useful for measurement of beliefs linked with vaccine hesitancy and for predicting the parental decision to delay or refuse vaccines for their child.15 The systematic review examining different behaviour change frameworks when studying healthcare worker influenza vaccination uptake showed that the HBM was most frequently used in this regard. The HBM constructs along with other behavioural variables were successful in predicting vaccine uptake. The findings of this review support the use of the HBM as an appropriate theory that may be used to inform future intervention studies.13 The HBM posits six constructs for predicting health behaviour: risk susceptibility, risk severity, benefits to action, barriers to action, self-efficacy and cues to action.14,16 The HBM hypothesizes that health-related actions depend on the simultaneous occurrence of three classes of factors: (1) the existence of sufficient motivation (or health concern) to make health issues salient or relevant; (2) the belief that one is vulnerable to a serious health problem or to the consequences of that illness or condition, which means a perceived threat; and (3) the belief that a particular health recommendation would be beneficial in reducing the perceived threat at a subjectively acceptable cost, which is related to perceived barriers that must be overcome to follow the health recommendation.17 This model specifies whether someone engages in a suggested health behaviour such as vaccination.18 The model specifies that if individuals perceive a negative health outcome to be severe, perceive themselves to be susceptible to it,
perceive the benefits of behaviours that reduce the likelihood of that outcome to be high and perceive the barriers to adopting those behaviours to be low, then the behaviour is likely for those individuals.19 The objective of this study was to assess the association between sociodemographic characteristics and attitudes according to HBM attributes with the intention to vaccinate children in cases of non-mandatory vaccination in a sample of women with young children in Slovenia to support informed decisions in a planned revision of our vaccination policy. As far as we know, this is the first research that uses the HBM for assessing intention on this topic. Methods A cross-sectional survey was carried out in 2016 on a random sample of 3,854 Slovenian women, who gave birth in 2014 and 2015 (39,497 births) as already published previously.11,12 The survey was performed by the Slovenian National Institute of Public Health and the Faculty of Social Sciences, University of Ljubljana, as part of a broader interdisciplinary research project about vaccination scepticism in Slovenia. Women were invited to participate in the study by post; they had the possibility to anonymously return the questionnaire by a prepaid envelope or to respond online by a Web-created questionnaire. The participants' intention to vaccinate their children in the case of non-mandatory vaccination was measured by asking them about the extent to which they agreed with the statement ‘I would vaccinate my children, even if vaccination wasn’t mandatory’, using a five-point Likert scale (1: ‘completely disagree’, 2: ‘mostly disagree’, 3: ‘neither disagree nor agree’, 4: ‘mostly agree’ and 5: ‘completely agree’). Similarly, the participants marked their level of agreement with items of six attributes according to the HBM (perceived susceptibility for vaccine-preventable diseases, perceived severity of vaccine-preventable diseases, perceived benefits of vaccination, perceived barriers for vaccination, clues to action for vaccination and self-efficacy statements). In addition, the questionnaire collected the individual participant's age, marital status, level of education, social class, number of children, health status perception, attendance of religious services and region of residence. Statistical analyses were performed using STATA package version 10.0 (Stata Statistical Software: release 10.0; Stata Corporation, College Station. TX). For dependent variables on the intention to vaccinate children without mandatory vaccination, we grouped the participants into three groups: no (1: ‘completely disagree’ and 2: ‘mostly disagree’), undecided (3: ‘neither disagree nor agree’) and yes (4: ‘mostly agree’ and 5: ‘completely agree’). We estimated the proportion of women who were undecided or lacking the intention to vaccinate their children in the case of nonmandatory vaccination with 95% confidence intervals (CIs) overall and according to sociodemographic characteristics. The HBM items were grouped within the six previously mentioned attributes (dimensions), Cronbach's alpha coefficient was calculated for the attributes with three items, and Pearson's correlation coefficient was used for the attributes with two items to assess reliability. A scale mean was calculated for attributes with an alpha coefficient or Pearson correlation >0.5. For examining associations between the intention to vaccinate children without mandatory vaccination and the collected explanatory variables (sociodemographic characteristics or attitudinal attributes according to the HBM), the dependent variable was dichotomized so that participants who completely agree or mostly agree to vaccinate their children in the case of non-mandatory vaccination were coded as ‘1’, participants who mostly disagree or completely disagree were coded as ‘0’ and participants who were
M. Vrdelja et al. / Public Health 180 (2020) 57e63
undecided (neither disagree nor agree) were excluded. Possible associations between the intention to vaccinate children in the case of non-mandatory vaccination and the collected explanatory variables were explored in univariate analyses by calculating odds ratios (ORs) with 95% confidence interval (CI) estimates and using Pearson's chi-squared tests for significance. The level of statistical significance was set at P < 0.05. Results A total of 1,704 participants completed the questionnaire, and the participation rate was 44.4%. The median age of participants was 32 years (range: 23e44 years). The distribution of the study population according to sociodemographic characteristics is shown in Table 1. Most participants were between 30 and 34 years of age (43.3%). More than 60% of the participants reported college or university as their highest level of education. The majority of the participants placed themselves in the middle social class (77.4%) and perceived the status of their health in general as good or very good (83.0%). Of 1,693 women with young children who reported on their intention to vaccinate their children in case of non-mandatory vaccination, just more than half (56.2%; 95% CI: 53.8e58.5%) would vaccinate, 23.4% (95% CI: 21.4e25.5%) were undecided and
59
20.4% (95% CI: 18.4e22.3%) reported that they would not vaccinate their children. There were no significant sociodemographic predictor variables in relation to the participants' intention to vaccinate their children in the case of non-mandatory vaccination (Table 1). Table 2 shows the number and proportion of women with young children according to their agreement with the statements/ items grouped by individual attributes of the HBM. Regarding the perceived severity of vaccine-preventable diseases, more than 15% of the participants mostly or completely agreed with the statement that it is much better to have the disease naturally than to be vaccinated, and 35% were undecided. The majority of Slovenian women with young children (more than 79%) perceived vaccination as beneficiary, to be effective, to protect individuals and the community and to contribute to the protection of others who cannot be vaccinated. However, there was also a surprisingly high proportion of women (51%) who agreed with the statement that they fear vaccinating their children because they are afraid of the side-effects. Similarly, more than 50% agreed that parents are not getting enough information to decide on vaccinating their children. The scale means for perceived susceptibility to vaccinepreventable diseases and the perceived benefits of vaccination attributes were 3.9 (standard deviation [SD]: ± 0.9) and 4.1
Table 1 Intention to vaccinate children in case of non-mandatory vaccination according to sociodemographic characteristics in a sample of women with young children in Slovenia in 2016. Variable
Age (years) <30 30e34 35e39 40 Marital status Married Living with a partner Not living with a partner, single, divorced, widowed Level of education Less than high school High school College, university Specialization, masters, PhD Social class Lower Middle Upper Number of children 1 2 3 or more Health status assessment Very good, good Satisfying Poor, very poor Attending religious services No Yes Region of residence Celje Koper Novo mesto Ljubljana Nova Gorica Ravne na Koroskem Maribor Kranj Murska Sobota
All (N ¼ 1704)
Intention to vaccinate children in the case of non-mandatory vaccination Yes
No
Undecided
OR
95% CI
P
389 709 412 129
54.6% 55.7% 59.8% 56.6%
21.6% 20.4% 17.3% 22.5%
23.7% 23.9% 22.9% 20.9%
1 1.08 1.37 0.98
0.79e1.49 0.95e1.98 0.60e1.64
0.617 0.089 0.992
772 878 37
57.1% 55.2% 67.6%
19.8% 20.6% 24.3%
23.1% 24.2% 8.1%
1 0.93 0.96
0.73e1.20 0.44e2.12
0.589 0.931
90 392 1035 174
62.2% 55.5% 55.2% 61.3%
17.8% 19.4% 21.1% 19.6%
20.0% 25.1% 23.7% 19.1%
1 0.82 0.74 0.89
0.44e1.51 0.42e1.33 0.45e1.75
0.516 0.321 0.738
176 1292 196
59.7% 55.7% 56.1%
17.6% 20.2% 22.4%
22.7% 24.0% 21.4%
1 0.82 0.74
0.53e1.25 0.43e1.26
0.353 0.263
824 648 215
55.2% 58.7% 53.0%
20.1% 20.1% 21.9%
24.7% 21.2% 25.1%
1 1.06 0.88
0.81e1.38 0.60e1.29
0.671 0.519
1402 269 19
56.2% 57.8% 42.1%
20.4% 20.1% 21.0%
23.4% 22.0% 36.8%
1 1.04 0.72
0.74e1.46 0.22e2.43
0.817 0.601
475 1671
56.2% 56.5%
23.6% 18.8%
20.2% 24.7%
1 1.26
0.96e1.64
0.089
234 91 171 552 104 50 228 187 61
56.4% 60.0% 52.0% 56.2% 53.8% 62.0% 56.8% 58.3% 57.4%
16.7% 20.0% 22.8% 20.6% 23.1% 20.0% 19.4% 21.9% 13.1%
26.9% 20.0% 25.1% 23.3% 23.1% 18.0% 23.8% 19.8% 29.5%
1 0.88 0.67 0.81 0.68 0.92 0.87 0.78 1.29
0.46e1.69 0.40e1.14 0.53e1.23 0.38e1.25 0.41e2.04 0.53e1.42 0.47e1.30 0.55e3.02
0.713 0.136 0.316 0.221 0.829 0.569 0.350 0.552
OR: odds ratio; CI: confidence interval; P: P value. The number of individuals varies according to the number of missing values for individual variables.
Item
Alpha or Mean (SD)a Likelihood of intention to vaccinate children in case of non-mandatory vaccination corr. coef. Completely Mostly Neither disagree or Mostly Completely OR 95% CI P disagree ¼ 1 disagree ¼ 2 agree ¼ 3 agree ¼ 4 agree ¼ 5
Distribution
2.1%
6.0%
20.1%
38.3%
33.5%
3.9 (0.9) e
5.70 e
4.64e7.00 e
<0.001 e
4.1%
6.1%
18.7%
38.5%
32.6%
e
e
e
e
1.0%
3.0%
11.4%
33.3%
51.4%
4.3 (0.8)
3.99
3.32e4.80
<0.001
20.1%
29.2%
35.1%
10.9%
4.6%
2.5 (1.1)
0.37
0.32e0.42
<0.001
2.5%
3.8%
14.5%
57.2%
22.0%
4.1 (0.8) e
7.62 e
5.96e9.76 e
<0.001 e
1.8%
2.7%
10.5%
38.0%
47.0%
e
e
e
e
3.2%
5.7%
16.6%
35.4%
39.2%
e
e
e
e
9.5%
19.1%
20.4%
23.1%
27.9%
3.4 (1.3)
0.35
0.31e0.41
<0.001
11.1%
23.2%
32.2%
20.0%
13.4%
3.0 (1.2)
0.41
0.37e0.47
<0.001
6.7%
15.7%
24.2%
25.1%
28.2%
3.5 (1.2)
0.45
0.40e0.51
<0.001
20.2%
40.4%
30.4%
7.5%
1.4%
2.3 (0.9)
0.98
0.86e1.12
0.740
13.1%
25.5%
36.6%
18.8%
5.9%
2.8 (1.1)
0.74
0.66e0.83
<0.001
0.58
0.41
0.84
0.50
/
0.16
Alpha: Cronbach's alpha; corr. coef.: Pearson's correlation; OR: odds ratio; CI: confidence interval; P: P value. a A scale mean was calculated for attributes with alpha coefficient or Pearson correlation >0.5.
M. Vrdelja et al. / Public Health 180 (2020) 57e63
Perceived susceptibility It is possible that without vaccination my child would get a disease that could otherwise be prevented by vaccination. (N ¼ 1691) As long as there are infectious diseases, regular vaccination should not be avoided at all. (N ¼ 1691) Perceived severity Vaccine preventable diseases are very dangerous and can have serious health consequences. (N ¼ 1692) It is much better to have the disease in a natural way than to be vaccinated. (N ¼ 1687) Perceived benefits Vaccination effectively protects the child from the disease. (N ¼ 1692) Vaccination of an individual is also very important for the protection of the community. (N ¼ 1692) By vaccinating my child, I significantly contribute to the protection of others who can't be vaccinated. (N ¼ 1693) Perceived barriers I'm afraid to vaccinate my child because I'm afraid of the side effects of vaccines. (N ¼ 1680) Physicians will never be willing to comprehensive provide all relevant information on children's vaccination. (N ¼ 1688) Clue to action Parents get too little useful information to decide on our children's vaccination without hesitation. (N ¼ 1692) Self-efficacy So far, regulations have never prevented me from working on my own. (N ¼ 1689) Science is no more useful than common sense. (N ¼ 1682)
60
Table 2 Health belief model attitudinal variables associated with intention to vaccinate children in case of non-mandatory vaccination in a sample of women with young children in Slovenia in 2016.
M. Vrdelja et al. / Public Health 180 (2020) 57e63
(SD: ± 0.8), respectively. A summary of this information is presented in Table 2. Slovenian women with young children who perceived higher susceptibility to vaccine-preventable diseases (OR ¼ 5.70; 95% CI: 4.64e7.00) or benefits of vaccination (OR ¼ 7.62; 95% CI: 5.96e9.76) were more likely to intend to vaccinate their children in the case of non-mandatory vaccination. In addition, the perceived barriers to vaccinate, fear of side-effects (OR ¼ 0.35; 95% CI: 0.31e0.41), lack of comprehensive information from physicians (OR ¼ 0.41; 95% CI: 0.37e0.47) and parents not getting enough useful information in general as a clue to action (OR ¼ 0.45; 95% CI: 0.40e0.51), were significant predictors of an intention not to vaccinate children in the case of non-mandatory vaccination. Discussion Countries all over the world have different vaccination programs and also different legislation regarding vaccination. According to recent research, there are at least 62 countries with mandatory vaccinations; 14 of them, including Slovenia, are EU countries.8 In Slovenia, the policy of mandatory vaccination for nine vaccine-preventable diseases has been established for several decades. However, in recent years, both among professionals and among the lay public, there have been numerous debates about the appropriateness of such a policy. Procedures to carry out mandatory vaccination are very complicated, represent an additional administrative burden for physicians and are associated with additional costs. These procedures are rarely successful, resulting in a decrease in vaccination coverage in some health regions. The Ministry of Health is therefore preparing a revision of the vaccination policy, and the public debate on the justification for mandatory vaccination is expected, where also ethical issues will be highlighted, which are often problematized at the mandatory vaccination.20,21 The association of Slovenian pediatricians expressed the concern about the situation, and taking account of recent outbreaks of measles and increasing vaccine hesitancy, they endorsed the Velenje statement of European confederation of primary care pediatricians. The statement supports regulations for more mandatory vaccinations in the countries if the vaccination coverage is insufficient or decreasing. One way to reach high coverage is also requirement of complete vaccination before enrolment in kindergarten or school.22 To support the revision of the Slovenian vaccination policy, we performed a study on a representative sample of women with young children in our country to examine their intention to vaccinate their children in case of non-mandatory vaccination. Just more than half (56.2%) of the women reported on their intention to vaccinate their children in the case of non-mandatory vaccination, and 23.4% were undecided. Our results show that a mandatory vaccination policy is an important factor in ensuring high levels of vaccination coverage in Slovenia. Some European countries have recently reintroduced mandatory vaccination because of decreasing vaccination coverage and a recurrence of outbreaks of vaccine-preventable diseases. More specifically, Italy in 2017 implemented mandatory vaccination for ten diseases,23,24 and France in 2018 made eight more vaccines mandatory in addition to the three that were already required.25,26 According to their experience, the expansion of mandatory vaccination was well accepted.27 As shown in a large-scale global study comparing the State of Vaccine Confidence of 67 countries, Slovenia belongs to the ‘top 10’ countries where vaccine safety sentiment is more negative than that in others,28 although the proportion is still small.11 Our study gave us some insight into the factors that can influence the intention to vaccinate children in the case of non-mandatory
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vaccination. It confirmed that the fear of side-effects of vaccines is a major barrier with regard to vaccination, which is in line with other studies29 and can have a great impact on whether mothers would vaccinate their children in the case of non-mandatory vaccination. Those Slovenian women with young children included in our study who perceived higher susceptibility to vaccine-preventable diseases or the benefits of vaccination were more likely to intend to vaccinate in the case of non-mandatory vaccination. Recognizing vaccination as beneficial and being sure that it can protect their children from the disease is the most important factor. A recent French study similarly showed that perception of vaccine safety and benefits was major predictors for (positive or negative) opinions about this new policy in France, where two-thirds of its population was in favour of the extension of mandatory vaccines for children.30 Our study confirmed that mothers lacking access to enough useful information in general is a significant predictor of intention to vaccinate children in the case of non-mandatory vaccination. Communication activities should be focused on emphasizing the right to health and the benefits of vaccination for individuals and society, as proposed in some studies,32 and also on emphasizing the responsibilities of parents. Different communication channels and tools should be wisely used33 because the public use different sources to access information about health and vaccination.34 Many people now turn to the Internet35,36 or social media37 for health information when making health-related decisions. To be more specific, communication should link online and offline platforms to establish a dialogue with individuals who delay vaccination.38 Public health campaigns can be useful and effective,27 especially storytelling39 and telling personal stories, because they can encourage parents to take action.40 In addition, specific targeting communication using electronic vaccination registries with reminder functions can be very effective.41 Despite this, communication should focus on interpersonal communication between parents and health professionals because parents believe that healthcare workers are the most reliable source to provide information about vaccination.34,42 Nevertheless, their role can be critical,31 as they often seem to lack communication competence.12 As such, there is a need to establish a trusting relationship that satisfies parents and health professionals, the topics and the amount of information to be transferred and the ways in which they should be communicated.43 The results of our study indicate that the HBM can be applied to the very important topic of public health, such as impact of vaccination policy on parents' vaccination behaviour. They can be of use to the other countries who are considering modification of their vaccination policy. It seems that in some settings, owing to different cultural or historical factors and differences in the health system, some more rigorous measures may be needed to maintain adequate vaccination coverage in the population. Our study has some limitations. The response rate to the questionnaire was 44.4%; thus, the selection bias cannot be ruled out if more mothers with specific positive or negative opinions on vaccination were more or less likely to respond to the survey. If such a bias exists, it may lead to an overestimation or underestimation of the intention to vaccinate their children in the case of nonmandatory vaccination. Only mothers of young children were included in our study, so we must be cautious when generalizing our results to all parents in Slovenia. However, it is important to note that research from certain developed countries shows that women make the majority of healthcare decisions for their families,44 especially regarding vaccination.45e47 We were unable to compare the characteristics between participants who completed the study and non-respondents because participants anonymously completed the questionnaires. In addition, a ‘social desirability bias’ (participants choosing more socially acceptable answers) may have
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affected our study, which could decrease the reliability of some of the answers. In the future, additional qualitative studies would be needed to further examine the importance of compulsory vaccination on parents' decision to vaccinate their children, as well as studies of cultural and historical influences, such as the long tradition of compulsory vaccination (which may also have a significant impact). To conclude, the results of our study show that a mandatory vaccination policy is still an important factor in ensuring high levels of vaccination coverage in Slovenia. Our study also demonstrated the usefulness of the HBM in examining the intention of mothers to vaccinate their children in the case of policy change. In the future, more comprehensive communication activities focused on vaccinepreventable diseases and benefits and safety of vaccination for parents and their healthcare providers are needed to diminish the reliance on a mandatory vaccination policy. Author statements Acknowledgments The authors thank Mr. Robert McKenzie for providing English proofreading. Ethical approval The research was conducted in accordance with Slovenian legislation and with the permission of the Commission of the Republic of Slovenia for Medical Ethics (decision number: 127/03/14). Funding The study presented in this article was a part of the interdisciplinary project ‘Control of Communicable Diseases by Vaccination: Who are the Sceptics and Opponents of Vaccination and How to Communicate with Them?’ financed by the Slovenian Research Agency and cofinanced by the Slovenian Ministry of Health. Competing interests None declared. Author contributions All authors contributed to the draft of the article and participated in the research. M.V., V.U. and A.K. were involved in the conception and design of the study; V.U. analyzed and interpreted the data, M.V. and A.K. contributed to analysis and interpretation of the data. All authors were involved in the revision and approval of the final content before submission. References 1. Centers for Disease Control and Prevention. Ten great public health achievements. 2011. 2. Larson HJ, Cooper LZ, Eskola J, Katz SL, Ratzan S. New Decade of Vaccines 5 Addressing the vaccine confi dence gap. Lancet 2011;378(9790):526e35. 3. Fine P, Eames K, Heymann DL. “Herd immunity”: a rough guide. Clin Infect Dis 2011;52(7):911e6. 4. Omer SB, Salmon DA, Orenstein WA, DeHart MP, Halsey N. Vaccine refusal, mandatory immunization, and the risks of vaccine-preventable diseases. N Engl J Med 2009;360(19):1981e8 [Internet]. 5. May T. Public communication, risk perception, and the viability of preventivie vaccination against communicable diseases. Bioethics 2005;19(4):407e21. 6. Haverkate M, Giambi C, Johansen K, Lopalco PL, Cozza V, Appelgren E. Mandatory and recommended vaccination in the EU , Iceland and Norway : results of the venice 2010 survey on the ways of implementing national vaccination programmes. Euro Surveill 2012;17(22):1e6.
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