Knowledge, risk perception and attitudes toward vaccination among Austrian health care workers: A cross-sectional study

ABSTRACT

The aim of this study was to evaluate the vaccination coverage of Austrian health care workers (HCWs), their knowledge concerning the current guideline on vaccination for HCWs and their attitudes toward vaccination. A cross-sectional survey was performed by distributing 200 questionnaires among the nursing staff of several medical wards and intensive care units of the Vienna General Hospital. 116 questionnaires were returned for analysis with 77.4% female and 22.6% male participants. While certain vaccines like hepatitis B, tetanus and polio had high vaccination rates of up to 94% and good knowledge concerning the vaccination status, other vaccines like measles (59.8%), mumps (60.7%), rubella (70.5%), influenza (42.1%) or pertussis (58.2%) showed much lower coverage. The main sources of information were nursing school (59.1%), secondary school (46.1%), parents (45.2%) and media in general (45.2%). Only 21.9% of HCWs claimed to know the current guideline on vaccination. Those who knew the guideline were significantly more likely to consider certain vaccines like measles, mumps, rubella, diphtheria, polio and varicella as recommended (p ≤ 0.04). The most important reasons for receiving vaccination were self-protection (87.5%), prevention of epidemics (54.5%), protection of others (55.4%) and of patients (42.9%). Fear of side effects (67.2%), negative experiences with vaccines (22.4%), the additional doctor's appointment (20.7%) and considering vaccines as an invention by the pharmaceutical industry (19%) were hindering factors for vaccination of HCWs. Considering the essential role of HCWs in preventing diseases, this study noted a remarkable lack of information on vaccination in this profession.

KEYWORDS:

• attitudes
• guideline
• health care workers
• vaccination
• vaccination coverage

Introduction

Vaccination is one of the most effective ways to prevent the transmission of certain bacterial and viral diseases and it has reduced the associated morbidity and mortality significantly during the last decades.¹ On the one hand, health care workers (HCWs) have an increased risk for contracting certain vaccine-preventable diseases and on the other hand they can also transmit these diseases to highly vulnerable patients.^2-4 Therefore, the appropriate vaccination for HCWs is of particular importance to reduce the spread of infectious diseases.

In 2012 the Austrian Ministry of Health updated its guideline concerning the vaccination of HCWs.⁵ The guideline recommends vaccination against tetanus, diphtheria, pertussis, polio, hepatitis A, hepatitis B, influenza, varicella, measles, mumps, and rubella for all HCWs. The pneumococcal and meningococcal vaccines are recommended for certain risk areas like infectious disease and intensive care units.

The guideline also proposes that upon entry into their profession all HCWs should have their vaccination documents reviewed by a doctor and serological testing performed if natural immunity to certain diseases like measles is assumed. Vaccination should be provided at the work place, but only vaccines against diseases with increased risk for HCWs (e.g. hepatitis B) are offered for free. Mandatory vaccination is not permitted by Austrian law as it is considered to compromise the individual's right to refuse invasive physical procedures.

Several studies concerning the vaccination rate for influenza have been conducted among HCWs evaluating beliefs, attitudes and motivating factors for vaccination.^6-10 However, little is known about the general vaccination status of HCWs and about their knowledge regarding the current national recommendations. The aim of this study was to evaluate the vaccination coverage of Austrian HCWs, their knowledge concerning the current guideline by the Austrian Ministry of Health and their attitude toward vaccination in a single center in Vienna.

Results

Study population

Of 200 distributed questionnaires 116 (58%) were returned at least partly completed. The study population consisted of 89 female (n = 115; 77.4%) and 26 male (22.6%) HCWs with a median age of 40 (n = 113; range 20; 59). Considering the work place, 45 (n = 114; 39.5%) HCWs worked at a medical ward and 69 (60.5%) at an intensive care unit.

Vaccination status of HCWs

Health care workers were asked about their own vaccination status concerning 13 vaccines recommended for HCWs at least in certain work places. The best vaccination rate existed for tetanus (93.9%), hepatitis B (93.8%) and polio vaccine (93%). The coverage was moderate for rubella (70.5%), mumps (60.7%) and measles (59.8%). In addition, about 12–15% claimed not to know their vaccination status for these diseases. Pertussis showed a low vaccination coverage of 58.2% and 29.1% of HCWs did not know if they were vaccinated against it. Varicella was another vaccine with a very low vaccination rate (16%) and limited knowledge concerning the vaccination status. Influenza vaccination had a low coverage of only 42.1%, but most HCWs (98.1%) were informed about their vaccination status. The lowest vaccination rate was found for meningococcal (6.7%) and pneumococcal (6.6%) vaccine. For complete data concerning the vaccination status refer to Table 1.

Table 1. Vaccination status of health care workers for recommended vaccines (vaccines sorted from highest to lowest vaccination coverage).

	valid	vaccinated		not vaccinated		not known
Vaccine	n	n	%	n	%	n	%
Tetanus	114	107	93.9	5	4.4	2	1.8
Hepatitis B	113	106	93.8	6	5.3	1	0.9
Polio	114	106	93.0	1	0.9	7	6.1
Diphtheria	110	90	81.8	4	3.6	16	14.5
Hepatitis A	113	85	75.2	23	20.4	5	4.4
Rubella	112	79	70.5	19	17.0	14	12.5
Mumps	112	68	60.7	27	24.1	17	15.2
Measles	112	67	59.8	29	25.9	16	14.3
Pertussis	110	64	58.2	14	12.7	32	29.1
Influenza	107	45	42.1	60	56.1	2	1.9
Varicella	100	16	16.0	60	60.0	24	24
Meningococcal	105	7	6.7	87	82.9	11	10.5
Pneumococcal	106	7	6.6	86	81.1	13	12.3

Predictors for measles and influenza vaccination

Both influenza and measles are highly contractible diseases and their vaccination coverage among HCWs was moderate to low (59.8% for measles, 42.1% for influenza). To assess factors which influence whether HCWs are vaccinated against these diseases or not, univariate and multivariate regression models were employed. The coverage of measles vaccination decreased with age (adjusted odds ratio (AOR) 0.85, 95% confidence interval (CI) 0.78–0.92), while the coverage for influenza vaccination increased with age (AOR 1.1, 95% CI 1.01–1.13). There was no significant difference between male and female HCWS or between different work places concerning the vaccination status. Assessing the influence of different information sources on vaccination, persons who used internet were more likely to be vaccinated against measles (AOR 7.1, 95% CI 1.18–42.2). On the other side, television as information source had a negative influence on measles vaccination (AOR 0.2, 95% CI 0.06–0.98). Nursing school as information source was also a negative predictor for the measles vaccine (AOR 0.2, 95% CI 0.06–0.8). Information gained from colleagues had a positive impact on influenza vaccination (AOR 3.3, 95% CI 1.19–8.95), while radio had a negative influence on it (AOR 0.1, 95% CI 0.01–0.84). Information from nursing school (AOR 0.3, 95% CI 0.1–0.72) and older age (AOR 0.9, 95% CI 0.84–0.94) were also found to be negative predictors for mumps vaccination which is usually offered in combination with measles. However, for other vaccines no significant association between sources of information and vaccination status were found.

Knowledge about current recommendations for vaccination of HCWs

Only 21.9% (n = 25) of HCWs claimed to know the current guideline on vaccinations for HCWs. First, the knowledge of HCWs about recommended vaccines was assessed and if there were significant differences between HCWs claiming to know the guideline and those who were not informed about it. The majority of HCWs perceived hepatitis B (98.2%), hepatitis A (68.1%) and influenza (66.4%) as recommended vaccines. 48.7% of HCWs thought that tetanus and 33.6% that pneumococcal and meningococcal vaccine were part of the recommendation. Only a small proportion considered measles (16.8%), mumps (16.8%) or rubella (19.5%) as recommended. Of those HCWs who knew the guideline, significantly more considered these vaccines as part of it (OR 4.3, p = 0.01 for measles and mumps; OR 3.2, p = 0.03 for rubella). Vaccines against diphtheria, polio and varicella were also not considered as part of the guideline by most HCWs with significant differences considering the knowledge of the recommendations (p ≤ 0.04). For further details concerning the knowledge of HCWs about the vaccination guideline refer to Table 2.

Table 2. Knowledge of health care workers (HCWs) about recommended vaccines for HCWs according to current vaccination guideline. Differences between HCWs who claimed to know the current guideline and those who claimed not to know the guideline were calculated using univariate regression analysis.

	all HCWs(n = 113)		knowledge of guideline (n = 25)		no knowledge of guideline (n = 86)		univariate regression analysis(n = 111)
Vaccine	n	%	n	%	n	%	OR	95% CI	p
Measles	19	16.8	9	36	10	11.6	4.3	1.5–12.2	0.01
Mumps	19	16.8	9	36	10	11.6	4.3	1.5–12.2	0.01
Rubella	22	19.5	9	36	13	15.1	3.2	1.2–8.6	0.03
Tetanus	55	48.7	13	52	40	46.5	1.2	0.5–3.0	0.6
Diphtheria	20	17.7	9	36	11	12.8	3.8	1.4–10.8	0.01
Pertussis	14	12.4	6	24	8	9.3	3.1	0.9–9.9	0.06
Polio	24	21.2	10	40	14	16.3	3.4	1.3–9.2	0.01
Hepatitis A	79	68.1	15	60	62	72.1	0.6	0.2–1.5	0.3
Hepatitis B	111	98.2	25	100	84	94.4	—	—	—
Varicella	13	11.5	6	24	7	8.1	3.6	1.1–11.8	0.04
Influenza	75	66.4	20	80	54	62.8	2.4	0.8–6.9	0.1
Meningococcal	38	33.6	9	36	29	33.7	1.1	0.4–2.8	0.8
Pneumococcal	38	33.6	10	40	28	32.6	1.4	0.6–3.5	0.5

Next, the impact of knowledge about recommended vaccines on the individual vaccination behavior was assessed. On the one hand, HCWs who claimed knowledge about the guideline were not more likely to be vaccinated than others (p > 0.05, data not shown). On the other hand, HCWs who considered the influenza vaccine as recommended were significantly more likely to be vaccinated against influenza (OR 6.8, 95% CI 2.4–19.7, p < 0.001). For further details concerning the impact of knowledge about recommended vaccines on the vaccination behavior refer to Table 3.

Table 3. Impact of knowledge about recommended vaccines on vaccination behavior.

	HCWs consider vaccine as recommended: (n = 113)
	yes	vaccinated		no	vaccinated		univariate regression
Vaccine	n	n	%	n	n	%	OR	95% CI	p
Measles	19	15	78.9	94	49	52.1	3.1	0.97–10	0.06
Mumps	19	13	68.4	94	52	55.3	1.6	0.6–4.5	0.4
Rubella	22	17	77.3	91	59	64.8	1.6	0.5–4.8	0.4
Tetanus	55	53	96.4	58	51	87.9	6.2	0.7–53	0.1
Diphtheria	20	17	85.0	93	71	76.3	2.0	0.4–9.7	0.4
Pertussis	14	8	57.1	99	54	54.5	0.9	0.3–3.0	0.9
Polio	24	20	83.3	89	84	94.4	0.3	0.1–1.5	0.2
Hepatitis A	79	66	83.5	34	17	50.0	4.2	1.7–10.5	<0.01
Hepatitis B	111	102	91.9	2	2	100	—	—	—
Varicella	13	3	23.1	100	13	13.0	1.6	0.4–6.8	0.5
Influenza	75	39	52.0	38	5	13.2	6.8	2.4–19.7	<0.001
Meningococcal	38	3	7.9	75	4	5.3	1.5	0.3–7.3	0.6
Pneumococcal	38	3	7.9	75	3	4.0	1.9	0.4–10	0.4

Young age was a significant risk factor for lack of knowledge about the guideline (AOR 1.1, 95% CI 1.02–1.15). In the youngest age group (20–29 y of age, n = 20) no one knew about the recommendations. Gender and work place were not found to be associated with knowledge about the guideline.

Sources of information on vaccination used by HCWs

The main sources of information were nursing school (59.1%), secondary school (46.1%), parents (45.2%) and media in general (45.2%). Other important sources were colleagues (32.2%) and friends (16.5%). 40.9% named their general practitioner and 28.7% the company physician as advisors for vaccinations. 65.2% claimed that they had received some information about vaccination by the company physician of the hospital. All HCWs were divided into 4 age groups to assess age-related differences in use of information sources. In the youngest group (20 to 29 y) 90% named their parents as the main source of information. The correlation between age and parents as information source was significant (Spearman-Rho 0.3, p < 0.001). Internet and television were more important for the youngest age group than for their older colleagues of 50 to 59 y of age (40% vs. 11% for internet and 35% vs. 22% for television, p > 0.05). Although the use of media differed between age groups, there was no significant correlation detected. There was also no significant difference in use of information sources between female and male HCWs (p > 0.05).

Risk perception and attitudes of HCWs toward vaccination

Most HCWs considered vaccinations to be partly (71.6%) or even absolutely necessary (20.7%). Only a small percentage claimed that vaccines are mostly not necessary (6%) or dangerous (1.7%). The most important reasons for receiving vaccination were self-protection (87.5%), prevention of epidemics (54.5%), protection of others (55.4%) and of patients (42.9%). The recommendation by a doctor (14.3%) and the opportunity to get vaccination for free (8%) were considered less important. Provided that HCWs had ever refused to get vaccinated, they were asked about their reasons for doing so. Fifty percent (n = 58) of HCWs answered this question and the main reason for refusing vaccination was the fear of side effects (67.2%). Other important issues were negative experiences with vaccines (22.4%) and the need for an additional doctor's appointment (20.7%). Nineteen percent claimed that they mistrusted vaccines because they were a product of the pharmaceutical industry which they did not consider as trustworthy. Negative reporting about vaccines in the newspaper (12.1%), in the internet (8.6%) or in television (5.2%) was also a reason for refusing vaccination. The negative opinion of colleagues influenced 12.1% and the fact that their colleagues were not vaccinated 8.6% of HCWs. Less important reasons were that the vaccine was painful (5.2%) or that vaccine-preventable diseases were not considered as severe (8.6%). 15.5% of HCWs claimed to be against vaccination in general. However, 39% of HCWs would approve mandatory vaccination for HCWs. There was no significant association with age, gender, work place or information source concerning the attitude toward mandatory vaccination.

Discussion

In this cross-sectional study a broad variation of vaccination rates was found for different vaccines which are recommended for HCWs. While certain vaccines like hepatitis B had a high coverage and were widely accepted as recommended vaccine for HCWs, other vaccines like measles or influenza showed much lower vaccination rates. Similar results have been found by other studies that reported low vaccination rates against these diseases.^7,11

A negative predictor for measles vaccination was age, and it is quite likely that many HCWs of the older age group were not vaccinated because they acquired natural immunity when experiencing the disease during childhood. However, 14.3% of HCWs were not sure about their vaccination status and only determining a positive serological titer can confirm acquired immunity for this disease. Considering that measles is a highly contagious disease, the rate of unvaccinated HCWs is certainly a worrying fact. Since the nineties measles, mumps and rubella are offered as a combination vaccine in Austria, but before that rubella had been vaccinated separately. Vaccination against rubella had been offered to girls during puberty and vaccination had also been recommended for women without a positive rubella titer who had planned a pregnancy. This might explain the higher vaccination rate of 70% for rubella compared to 60% for measles and mumps.

Pertussis was the vaccine with the highest rate of HCWs not knowing their vaccination status (29.1%). One problem might be that pertussis is usually part of a combination vaccine with tetanus, diphtheria and polio. However, there are several different vaccines available and this might lead to uncertainty whether pertussis was part of the combination vaccine. A limitation of the study is that HCWs were not asked to consult their vaccination record cards before answering the questionnaire. Therefore a certain recall bias might have influenced the declared vaccination status. A rise in pertussis cases in Austria has been reported over the last years and therefore vaccination becomes even more essential.¹² The use of the less efficient acellular pertussis vaccine and the waning immunity in older people has increased the necessity for regular booster vaccines.^13,14

Most HCWs were informed about their vaccination status concerning influenza, but only 42.1% decided to receive the vaccine. Especially young HCWs often declined the influenza vaccine with only 26.3% of the 20 to 29 y olds being vaccinated. Interestingly, influenza vaccine was considered to be recommended for HCWs by 66.4%. The pneumococcal and meningococcal vaccines were also considered as part of the recommendations by 33.6%, but less than 7% were vaccinated against these diseases. This raises the question if knowledge about recommended vaccines did actually influence the individual vaccination behavior. Those HCWs who thought that the influenza vaccine was recommended for HCWs were also more likely to be vaccinated against influenza (p < 0.001). However, even in this group only 52% received influenza vaccination. For other vaccines, with the exception of hepatitis A, there was no significant association between considering a vaccine as recommended for HCWs and a positive vaccination status.

Those HCWs who claimed to know the guideline were more likely to consider certain vaccines (measles, mumps, rubella, diphtheria, polio and varicella) as recommended than others (p ≤ 0.04). Especially in the youngest age group there was a significant lack of knowledge concerning the current guideline. Therefore, it appears necessary to provide better information on recommended vaccination for HCWs.

In one study knowledge about vaccines did increase the willingness to receive influenza vaccination.¹⁵ A prospective study to prove the effectiveness of educating HCWs on vaccine recommendations would be necessary. On the one hand nursing school was the most important source of information and better training concerning vaccination in general might be one effective way to increase vaccination rates especially among young HCWs. On the other hand information gained through nursing school was actually a negative predictor for measles vaccination. Therefore correct and proper training is essential to positively influence the attitude toward vaccination through education. Media was also a source which is often used by HCWs to gain information. Internet as information source was actually a positive predictor for measles vaccination while use of television was a negative predictor in the multivariate regression model. There is no clear explanation why certain media sources should exert a positive and others a negative effect on vaccination. Internet was more often used by the younger age group, but there was no significant correlation between age and use of internet. The small sample size of this study is certainly a limitation and larger studies are necessary to further evaluate the effect of different information sources on vaccination behavior.

Similar to studies on the influenza vaccine,^8,9 important motivating factors for vaccination were self-protection as well as preventing epidemics and protecting others. Hindering factors were fear of side effects, negative experiences, additional doctor's appointments and scepticism toward the pharmaceutical industry. Many of these factors could be influenced by proper education about vaccination to improve the risk perception. Offering vaccination during work time can also improve the acceptance. Only 65% of HCWs claimed that they had received information about vaccination by the company physician. Considering the important role of HCWs in preventing diseases, it should be mandatory that all HCWs receive proper advice concerning vaccination and the opportunity to receive vaccines at their work place. At least for certain vaccines like influenza and hepatitis B this is already possible. Considering the high vaccination rate and the good knowledge concerning hepatitis B vaccination, this might serve as a model for other vaccines. Therefore, a strategy that combines regular educational efforts about vaccination directed at HCWs with personal advice by the company physician and the opportunity to receive all necessary vaccines at the work place could be most adequate and efficient.

Only 39% of HCWs would approve of mandatory vaccination. Although mandatory vaccination against highly contractible diseases like influenza could provide an effective solution, it also constitutes a complicated legal issue as it will compromise individual rights.¹⁶

In conclusion, this study noted a remarkable lack of information on vaccination among HCWs. Therefore, proper training and professional advice are important to increase knowledge and acceptance of vaccination among HCWs.

Methods

The Ethics Committee of the Medical University of Vienna approved the study protocol (No. 1563/2013). Participation was voluntary and all information gathered was anonymous.

A cross-sectional survey was performed by randomly distributing 200 questionnaires among the nursing staff of several medical wards and intensive care units of the Vienna General Hospital in March 2014. The questionnaires were self-administered and returned anonymously into a letterbox. Only HCWs with a diploma for nursing were asked to participate in this study, but no other selection criteria were applied.

The questionnaire contained questions about demographic data (age, gender, work place) and about the vaccination status of all currently recommended vaccines for HCWs. The participating HCWs were not required to consult their vaccination record cards before answering the questions concerning their vaccination status. In addition, knowledge of the current recommendations for vaccination of HCWs was queried. Furthermore, the attitudes toward vaccination, reasons for and against vaccination, as well as the sources of information on vaccination were evaluated.

Statistical analysis of data was performed using SPSS version 23 (IBM, Armonk US). Continuous data was presented with median and range and categorical data with absolute counts and percentages. To determine significant associations we used logistic regression to calculate odds ratios with 95% confidence intervals. In a further step, we performed multivariate regression analysis to obtain adjusted odds ratios for risk predictors.

Disclosure of potential conflicts of interest

No potential conflicts of interest were disclosed.