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Knowledge and attitudes on pandemic and seasonal influenza vaccination among Slovenian physicians and dentists

Maja Sočan, Vanja Erčulj, Jaro Lajovic
DOI: http://dx.doi.org/10.1093/eurpub/cks006 92-97 First published online: 24 February 2012

Abstract

Background: The aim of our study was to determine vaccination coverage among Slovenian physicians and dentists and assess their knowledge and attitudes regarding the pandemic and seasonal influenza vaccine. Methods: In February 2010, an anonymous, self-administered questionnaire was developed and sent to all practising physicians and dentists in Slovenia. Results: Out of 7092 physicians/dentists, 1718 (24%) completed the questionnaire and 41.7% of the respondents were vaccinated against pandemic and seasonal influenza, while 58.3% of the study participants decided not to adhere to the recommendation: 15.6% received the pandemic vaccine only, 10.1% the seasonal vaccine only and 32.4% were not vaccinated at all. Acceptance of the pandemic and seasonal influenza vaccine was determined by higher age, being an internal medical trainee or specialist, working in a hospital, performing any kind of vaccination and having a chronic disease. Unvaccinated participants were more often working in out-patient clinics, were without a specialty, were dentists and were not performing any vaccinations. Those who declined vaccination believed that they did not need to be vaccinated, had safety concerns and were afraid of side effects. Physicians/dentists vaccinated against pandemic and seasonal influenza had better knowledge and a more positive attitude towards the issue compared with their non-vaccinated colleagues. Conclusions: Education on the efficacy and safety of vaccines should be one of the priority public health measures taken to improve knowledge and eliminate misconceptions and attitudinal barriers regarding immunization in physicians and dentists.

Introduction

The 2009 pandemic caused by the influenza A(H1N1) virus started in Mexico and spread over the entire world in the next couple of months.1 The 2009 pandemic was unique in human history—it was the first pandemic with the vaccine available at its relatively early stage.2

Vaccination with the pandemic vaccine was included in the Slovenian pandemic preparedness plan.3 Health-care workers (HCWs) were designated as a priority group for vaccination, followed by individuals at the highest risk of severe and complicated forms of pandemic influenza. The vaccination campaign was launched in October 2009. HCWs were vaccinated with the pandemic (and the seasonal influenza) vaccine on a voluntary basis in the last week of October 2009. Pandemic influenza vaccination was provided free of charge at approximately 70 sites (out-patient health clinics and hospitals) in Slovenia. Bad publicity in the press about immunization and growing anxiety regarding its side effects resulted in low coverage rates for the pandemic vaccine with <6% of the general population vaccinated.4 The vaccination rate for the seasonal vaccine was 7.5%, a percentage comparable to that attained in previous years.

HCW’s knowledge, attitudes and behaviour regarding vaccination have significant impact on the decision-making process of their patients.5,6 Previous studies on pandemic vaccine coverage did not specifically address dentists. The objective of this study was to determine the vaccination coverage among Slovenian physicians and dentists and to assess their attitudes and knowledge regarding the pandemic and seasonal influenza vaccine.

Methods

Study population and design

A questionnaire-based, cross-sectional study was conducted. An anonymous, self-administered questionnaire was developed and sent to all members of the Slovenian Medical Chamber (SMC). Under current legislation, membership in the SMC is mandatory for all practising physicians and dentists, working at all levels of health care either as specialist trainees (resident physicians) or staff physicians and dentists. At the time of the study, 7092 physicians and dentists were listed in the SMC registry.

In February 2010, a questionnaire with an accompanying invitation letter was sent to them via electronic mail or by post, depending on the availability of e-mail addresses in the SMC registry. The e-mail invitation to take part in the study, including the website address of the web-based questionnaire, was received by 5012 (71%) of the SMC members; 2080 (29%) physicians were asked to fill in the paper questionnaire sent by post.

The questionnaires included the following four groups of questions:

  1. demographics, health status and professional category: age group (≤40, 41–50, ≥51 years), gender, self-assessed health status (healthy or having a chronic disease), workplace (out-patient clinic, hospital or institute), education level, field of work;

  2. history of vaccination with the pandemic and/or seasonal influenza vaccine in 2009–10 and reasons for declining vaccination with one vaccine or both influenza vaccines;

  3. information source regarding the pandemic influenza vaccine; and

  4. knowledge regarding the indication groups for the influenza vaccination and possible side effects and attitude towards recommending influenza vaccine to their patients and introducing mandatory seasonal influenza vaccination for HCWs.

The participating physicians were asked whether or not they agree/disagree with the following statements:

  • – vaccination prevents influenza;

  • – influenza vaccination reduces the possibility of influenza virus transfer from HCWs to patients;

  • – influenza vaccination reduces the risk of influenza virus transfer from HCWs to their family members;

  • – the influenza vaccine should be recommended to elderly and/or chronically ill HCWs only;

  • – the influenza vaccine should be recommended to elderly and/or chronically ill adults;

  • – the influenza vaccine should be recommended for chronically ill children;

  • – the influenza vaccine should be recommended for small children;

  • – the influenza vaccine is not recommended for pregnant women;

  • – the influenza vaccine is not recommended during lactation;

  • – the efficacy of the influenza vaccine is low;

  • – influenza vaccination causes fever;

  • – pain at vaccination site is common after receiving the influenza vaccine;

  • – the influenza vaccine harms the immune system;

  • – spread of influenza can be prevented by adhering to hygienic measures;

  • – HCWs should recommend vaccination against influenza to their patients;

  • – influenza vaccination should be obligatory for all HCWs; and

  • – HCWS should be offered the influenza vaccine free of charge.

Statistical methods

Data on gender, age, education, workplace and area of work for the entire population of Slovenian physicians and dentists were obtained from the National Institute of Public Health HCW database and from the SMC registry. As the structure of the survey participants did not completely match the population structure (although there was no significant disagreement between the two), the representativeness of the sample was improved (adjusted) by using data weights calculated using the ranking method. Weights were calculated by using iterative post-stratification to match marginal distributions of survey samples to known population margins. All the variables mentioned above were used to iteratively calculate weights for each individual in the sample. The end result was that the sample structure entirely matched the population structure in regard to gender, age, education, workplace and area of work.

Analysis was performed for the following subgroups of respondents: (i) not vaccinated; (ii) vaccinated with both the pandemic and the seasonal vaccine; (iii) vaccinated with the pandemic vaccine only; and (iv) vaccinated with the seasonal vaccine only. Data were summarized descriptively. Differences between subgroups were tested using the chi-square test; in case the frequency of cells was too small (<5), we used the G-test or the log-likelihood test. All tests were performed at α < 0.05. The fact that multiple comparisons were done within the same dataset should be taken into account when interpreting the results.

Data analyses were performed using the R statistical software package version 2.12.0.7

Results

Demographics, health status and professional categorization

The questionnaires were completed by 1718 out of 7092 physicians and dentists, the overall response rate being 24%. Web-based questionnaires were filled in by 997 (19.9%) of 5012 physicians/dentists, and 721 (34.6%) out of 2080 returned the questionnaire by post. The non-adjusted and adjusted demographic data and professional characteristics of the study group are presented in table 1. The sample structure significantly differed (P < 0.001) from the population structure by age, education, workplace and area of work. The response rate was higher in the participants aged ≥51 years and in those working in areas other than out-patient clinics or hospitals. Dentists and specialist trainees were underrepresented in the sample.

View this table:
Table 1

Non-adjusted and adjusted (non-weighted and weighted) demographic and professional data of Slovenian physicians and dentists in the cross-sectional influenza vaccination study for the 2009–10 season

Demographic and professional dataNon-adjusted data, n (%)Adjusted data n (%)
Gender
    Male640 (37.2)693 (40.4)
    Female1063 (61.8)1006 (58.6)
Age groups (years)
    ≤40519 (30.2)588 (34.2)
    41–50377 (21.9)444 (25.9)
    ≥51815 (47.4)677 (39.4)
Education
    Specialist1066 (62.0)996 (58.0)
    Specialist registrar237 (13.8)305 (17.8)
    Intern92 (5.4)51 (2.9)
    Physician/dentist without specialty298 (17.6)332 (19.3)
Workplace
    Hospital600 (35.0)729 (42.4)
    Out-patient clinic803 (46.7)835 (48.6)
    Other280 (16.3)103 (6.0)
Area of work
    Gynaecology and obstetrics72 (4.2)86 (5.0)
    Internal medicine248 (14.4)263 (15.3)
    Surgery, anaesthesiology, ophthalmology and ENT271 (15.8)215 (12.5)
    Neurology, psychiatry, dermatology130 (7.6)117 (6.8)
    Paediatrics183 (10.7)142 (8.3)
    General and family practice352 (20.5)289 (16.8)
    Dental medicine279 (16.4)347 (20.2)
    Other136 (7.9)192 (11.2)

During the 2009–10 influenza season, 717 (41.7%) physicians/dentists included in the sample of 1718 respondents were vaccinated with pandemic and seasonal influenza vaccines, 15.6% received the pandemic vaccine only and 10.1% the seasonal vaccine only. Taking into account those who received both vaccines and those who decided on one influenza vaccine, 51.8% of the participants were vaccinated against seasonal and 57.3% against pandemic influenza. A total of 556 (32.4%) responding physicians and dentists remained unvaccinated (table 2). A significantly greater number of dentists and of physicians/dentists aged ≤40 years were not immunized against pandemic and seasonal influenza. Vaccination with both vaccines was significantly more frequently reported by hospital-employed physicians and specialists (especially internists) than by non-specialists (mainly dentists) and trainees (table 3).

View this table:
Table 2

Vaccination history of Slovenian physicians/dentists for the 2009–10 season

Vaccination statusNon-adjusted data, n (%)Adjusted data, n (%)
Not vaccinated556 (32.4)567 (33.0)
Vaccinated with both influenza vaccines717 (41.7)703 (40.9)
Vaccinated with the pandemic vaccine only268 (15.6)271 (15.8)
Vaccinated with the seasonal vaccine only174 (10.1)177 (10.3)
No response3 (0.2)1 (0.04)
1718 (100.0)1718 (100.0)
View this table:
Table 3

Adjusted demographic and professional data of physicians/dentists by their influenza vaccination status in the 2009–10 season

Demographic and professional dataNot vaccinated, n (%)Vaccinated with the pandemic and the seasonal vaccine, n (%)Vaccinated with the pandemic vaccine only, n (%)Vaccinated with the seasonal vaccine only, n (%)
Gender
    Male216 (31.1)306 (44.2)98 (14.1)74 (10.7)
    Female342 (34)390 (38.8)172 (17.1)102 (10.1)
Age groups (years)
    ≤40213 (36.3)206 (35.1)*111 (18.9)57 (9.7)
    41–50157 (35.3)189 (42.6)51 (11.6)*47 (10.5)
    ≥51195 (28.8)301 (44.5)107 (15.8)73 (10.9)
Workplace
    Hospital197 (27.0)342 (47)*128 (17.6)61 (8.4)
    Out-patient clinic301 (36.0)303 (36.3)126 (15.1)105 (12.6)
    Other36 (34.4)43 (41.4)15 (14.6)10 (9.6)
Education level
    Young physicians in their first two postgraduate years22 (43.1)19 (38.6)7 (13.0)3 (5.3)
    Specialist trainees90 (29.5)127 (41.6)54 (17.6)34 (11.3)
    Specialists273 (27.5)*464 (46.6)163 (16.4)95 (9.5)
    Non-specialists (mainly dentists)165 (49.8)*84 (25.2)*44 (13.1)40 (11.9)
Field of work
    Gynaecology and obstetrics20 (23.8)44 (51.4)11 (12.3)11 (12.5)
    Internal medicine68 (25.9)131 (49.8)*44 (16.7)20 (7.6)
    Surgery, anaesthesiology, ophthalmology and ENT69 (31.9)90 (41.8)40 (18.6)17 (7.7)
    Neurology, psychiatry, dermatology43 (36.4)52 (44.5)19 (16.5)3 (2.6)
    Paediatrics37 (26.0)71 (50.1)22 (15.7)12 (8.2)
    General and family practice72 (25.0)130 (44.8)37 (12.8)50 (17.4)
    Dental medicine170 (49.0)*83 (23.8)*52 (14.9)43 (12.3)
  • *Statistically significant difference between groups (P < 0.001)

Healthy physicians/dentists were less likely to be vaccinated against seasonal and pandemic influenza compared with those with chronic diseases predisposing them to serious and complicated forms of influenza (P < 0.0001). Physicians/dentists with cardiovascular diseases were significantly more often vaccinated with both influenza vaccines (P < 0.001). The vaccination coverage was significantly higher among those participants who knew that the pandemic/seasonal vaccine was free of charge and among those who regularly performed any kind of vaccinations.

Reasons for declining vaccination with the pandemic or the seasonal influenza vaccine

A total of 49.5% of the participants declining both vaccines did not give a reason for the decision they made. Most physicians/dentists who declined either the pandemic or seasonal influenza vaccination believed that they did not need to be vaccinated (23.3%), had safety concerns (14.7%) and were afraid of side effects (10.4%). Some female participants regarded pregnancy as a contraindication for the pandemic vaccine. Less than 4% of them were convinced that the vaccine has devastating effects on the immune system. The idea of the pandemic vaccine not being safe was more common among those physicians/dentists who were vaccinated with the seasonal but not with the pandemic vaccine. The belief that they do not need vaccination against seasonal influenza was shared by 90.6% of the physicians who decided for the pandemic influenza vaccine only.

Source of information about pandemic vaccine

The survey participants were asked where they obtained information about pandemic influenza and the vaccine. The same percentage (46%) of those not vaccinated and those vaccinated with both vaccines had reportedly attended at least one lecture on pandemic influenza and preventive measures six months before completing the questionnaire. The National Institute of Public Health website on pandemic influenza was statistically significantly less often visited by non-vaccinated physicians/dentists than by their colleagues who received both vaccines (41% and 51%, respectively, P = 0.003). Eighty-three per cent of the physicians/dentist vaccinated with both vaccines, 80% of those vaccinated with pandemic vaccine only, 82% vaccinated with seasonal vaccine only and 83% of non-vaccinated responding physicians/dentists got the information about pandemic influenza from the press.

Knowledge, attitudes and beliefs regarding the influenza vaccine

The biggest difference in the opinions of non-vaccinated physicians and those vaccinated with both vaccines was on behalf of the vaccine’s efficacy. Statistically significantly, more vaccinated physicians (P < 0.001) agree with statements referring to vaccine efficacy, while, statistically significantly more non-vaccinated physicians give high importance to hygienic measures in influenza prevention and were more reluctant to vaccinate pregnant women and women during lactation (figure 1).

Figure 1

Difference in percentage of ‘I agree’ statements between non-vaccinated physicians and physicians vaccinated with both vaccines

Discussion

This is the first cross-sectional study among physicians and dentists in Slovenia addressing their behaviour, knowledge and attitudes regarding pandemic and seasonal influenza vaccination. The study showed that 41.7% of the respondents had received both the pandemic and the seasonal vaccine. Vaccination with both influenza vaccines was recommended by health authorities, and official recommendations were published on the official websites of the Ministry of Health and National Institute of Public Health, yet 58.3% of the study participants chose not to adhere to the recommendations: 15.6% received the pandemic vaccine only and 10.1% the seasonal influenza vaccine only; 32.4% of the respondents were not vaccinated at all. A considerable variation in pandemic vaccine coverage of physicians has been reported across countries. The pandemic vaccine was given to 38.3% and to 47.5% of physicians in two Spanish tertiary care hospitals in Madrid, to 85% of Dutch general practitioners (GPs) and GP trainees, to 34.9% of physicians in a secondary care hospital in Istanbul, 60.9% of physicians in a tertiary care hospital in France and to 80.7% of physicians practising in the Frankfurt University Hospital.813 The lowest vaccination rate (12.3% of the respondents) among physicians was reported in a Qatar study,14 the only one that documented no considerable difference in the pandemic and/or the seasonal influenza vaccination coverage between medical and nursing staff; all other studies reported a significantly higher percentage of vaccinated physicians.15

Higher age was associated with higher rates of acceptance of the pandemic influenza vaccine in practically all studies conducted during and soon after the pandemic period, with a few exceptions.813,1618 Physicians >50 years of age with longer periods of service were probably more knowledgeable of the risk of a severe and complicated disease triggered by the pandemic virus. In our study, ∼54% of the physicians aged ≤40 years and 41–50 years were vaccinated with the pandemic influenza vaccine only or in combination with the seasonal vaccine. The percentage was slightly higher for the participants >50 years (60.3%). The acceptance of the seasonal influenza vaccine also increased with age: the acceptance rate was 44.8, 53.1 and 55.4% for age groups of ≤40, 41–50 and ≥51 years, respectively. Younger age groups were recognized as more vulnerable for pandemic influenza (but not for seasonal influenza), which caused younger physicians/dentists to accept the pandemic vaccine more often than seasonal vaccine, as observed in a study from Turkey.19 No need for the seasonal influenza vaccine was stated as the main reason for non-vaccination, and was reported by 90% of the non-vaccinated physicians/dentists. Younger doctors do not perceive seasonal influenza as a serious disease and choose not to protect themselves with vaccination.20

According to the published studies, self-protection is by far the most important self-declared reason for receiving the seasonal influenza vaccine.20 The official vaccination campaign in Slovenia, targeted towards HCWs, emphasized three key rationales for vaccination against seasonal and pandemic influenza: self-protection, reducing the risk of transmission from infected HCWs to their patients or to family members. Protecting patients by vaccinating themselves with the seasonal vaccine was not a strong enough driving force for ∼50% of the participants aged ≤50 years, and for 40% of those >51 years old. It was also not strong enough of a driving force for 61% of the dentists as well as for 42% of the GPs. The latter at least have more contact with patients than, for example, surgeons, but it is interesting that the share of non-vaccinated surgeons was quite similar to the share of non-vaccinated GPs. It seems that even an intensive official campaign launched in autumn 2009 had a limited impact on the perception that seasonal influenza is a serious disease, and that even though it is not detrimental to HCWs themselves, it is likely to endanger fragile patients in healthcare-associated environments.

A slightly higher percentage of male than female physicians received the pandemic vaccine (alone or in combination with the seasonal influenza vaccine) (58.3% vs. 55.9%); the same holds for the seasonal vaccine (54.9% vs. 48.9%), the difference not being statistically significant. Male gender was a factor related to better acceptance of the seasonal vaccine.20 No significant gender difference in the willingness to obtain a pandemic influenza vaccination was found among French GPs, and neither was gender the determinant for being vaccinated against seasonal and pandemic influenza in the study of Dutch GPs.10,21

In our study, the presence of chronic disease (especially self-reported chronic heart disease) facilitated the participants’ decision to accept the pandemic and the seasonal influenza vaccine. Chronic disease, however, was not a determinant for vaccination against seasonal or pandemic influenza in the Dutch study of GPs and in the study from the teaching hospital in France, as a much higher percentage of the physicians were vaccinated in those two countries compared with participants in this study.10,11

There was no significant difference in the vaccination rate between physicians working in hospitals and those practising in out-patient clinics. Medical staff in internal medicine and paediatric departments had the highest rates of vaccination against pandemic influenza (66.5% and 65.8%, respectively), followed by gynaecologists and obstetricians (63.7%), neurologists and psychiatrists (61.0%), surgeons and anaesthesiologists (60.4%) and GPs (57.6%). Dentists were less willing to get vaccinated: only 38.7% of them received the pandemic vaccine. To our knowledge, there has been no published study to date specifically addressing the rate of pandemic influenza vaccination among dentists. Even studies of seasonal vaccine coverage among HCWs involved in dental care are sparse. In an Italian study, approximately one-third of the dentists claimed to have been vaccinated with the seasonal influenza vaccine.22 Low vaccination coverage calls for focused educational intervention to improve this unfavourable situation.2325

The major barriers to accepting the pandemic vaccine were safety concerns and the perception of not being at risk of infection, i.e. the main reasons reported in previous studies.813,16 Soon after the vaccination campaign launch, the media began to cast doubt on the vaccine's safety—the same situation found in other countries.19 There was lively public discussion regarding the safety of the adjuvant in the pandemic vaccine and non-availability of the cell-derived, non-adjuvanted pandemic vaccine in Slovenia, which was ‘better’ and ‘safer’ in the eyes of the media and, consequently, perceived as such by the general public. In a number of media articles, vaccination was regarded as unnecessary and pandemic influenza was apparently perceived as a trivial infection by most people. Undoubtedly, this negative publicity had some impact on the decision-making process of Slovenian HCWs, including physicians and dentists, despite many reassuring messages generated by experts and public health authorities. The questions remain: what is the best practice to eliminate the misconceptions about vaccine safety, and even more important, how to get HCWs to understand the importance of influenza prevention through annual vaccination? This is not an easy task: mandatory influenza vaccination for all HCWs would probably not be an acceptable standard considering that ∼60% of the physicians and dentists participating in our study disagreed with this approach. Mandatory vaccination against influenza for HCWs is supported by scientific data as well as by ethical principles.2325 Mandating influenza vaccination of HCWs may fuel a discussion with contrasting public opinions—evidence-based views supporting the vaccination on the one hand versus scientifically unsound arguments against vaccination on the other—which could have an adverse effect on vaccination rates in the general population. In Slovenia, the number of opponents to mandatory vaccinations (most vaccinations in the national immunization programme for children are compulsory) is growing and any attempt to add an additional obligatory vaccination would probably intensify anti-vaccination activities.

The main drawback of the study was the low response rate, which may limit the generalisability of the results and could suggest that those who did respond tended to support vaccinations and were more likely to be vaccinated. The anonymity of the responders prevented addressing a reminder letter to the non-responders.

Conclusions

Undergraduate programmes for physicians and dentists should put greater focus on vaccines and vaccination education in order to gain a more objective and solid knowledge of this topic. Continuing postgraduate education tailored to meet various levels of knowledge should be one of the priority public health interventions aimed at eliminating misconceptions regarding communicable diseases and their prevention.

Funding

The research study was funded by the Slovenian Research Agency (Programme Research in Public Health, No. P3-0339).

Conflicts of interest: None declared.

Key points

  • Misinformed physicians and dentists constitute an important barrier to achieving adequate pandemic and seasonal influenza vaccination coverage.

  • It is necessary to build trust in official recommendations by providing evidence-based information on the vaccine efficacy and adverse effects.

  • It is important to reduce the impact of the media on the decision-making process of HCWs through continuing education.

References

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