- Email: [email protected]
A survey of attitudes towards paediatric vaccinations amongst Canadian naturopathic students
Vaccine 22 (2004) 329–334
A survey of attitudes towards paediatric vaccinations amongst Canadian naturopathic students Kumanan Wilson a,b,∗,1 , Ed Mills c,2 , Heather Boon d,e,3 , George Tomlinson a,b,d , Paul Ritvo d b
a Department of Medicine, University of Toronto, Toronto, Ont., Canada M5G 2C4 Department of Health Policy, Management and Evaluation, Faculty of Medicine, University of Toronto, Toronto, Ont., Canada M5G 2C4 c Department of Research, Canadian College of Naturopathic Medicine, Toronto, Ont., Canada M5G 2C4 d Department of Public Health Sciences, Faculty of Medicine, University of Toronto, Toronto, Ont., Canada M5G 2C4 e Faculty of Pharmacy, University of Toronto, Toronto, Ont., Canada M5G 2C4
Received 9 May 2003; received in revised form 11 August 2003; accepted 12 August 2003
Abstract Previous studies have suggested that providers of alternative medicine may harbour anti-vaccination attitudes and that these attitudes may develop at an early stage in their careers. We further explored this question by conducting a survey to determine the attitudes of students of naturopathic medicine, a growing alternative medicine discipline, towards recommended paediatric vaccines. We sampled all 4 years of students at the Canadian College of Naturopathic Medicine (CCNM) and obtained a response rate of 59.4% (312 of 525). We found that only 12.8% (40 of 312) of the respondents would advise full vaccination; however, 74.4% (232 of 312) of the respondents would advise partial vaccination. Importantly, both willingness to advise full vaccination and trust in public health and conventional medicine decreased in students in the later years of the programme. Our findings suggest that public health and conventional medical supporters of vaccination need to identify mechanisms for engaging in discussion with this population of complementary/alternative medical professionals at an early stage in their careers. © 2003 Elsevier Ltd. All rights reserved. Keywords: Immunisation; Naturopathic medicine; Attitudes
1. Introduction Universal vaccination programmes have been central components of public health programmes around the world. Most developed nations have introduced universal childhood vaccination for a variety of conditions. In Canada, all provinces have instituted public childhood vaccination programmes for measles, mumps and rubella (MMR), Haemophilus influenzae type b (HIB), diphtheria, pertussis and tetanus (DPT) and polio [1]. In addition, several new vaccines are being considered for widespread implementation [2–4]. Despite the documented successes of vaccinations, a growing anti-vaccination movement appears to be emerging. Factors contributing to this movement are thought to ∗ Corresponding author. Present address: ENG-254, Toronto General Hospital, University Health Network, 200 Elizabeth Street, Toronto, Ont., Canada M5G 2C4. Tel.: +1-416-340-3662; fax: +1-416-595-5826. E-mail address: [email protected] (K. Wilson). 1 He is a Canadian Institutes of Health Research new investigator. 2 He is an Essiac scholar. 3 She is an Ontario Ministry of Health and Longterm Care career scientist.
0264-410X/$ – see front matter © 2003 Elsevier Ltd. All rights reserved. doi:10.1016/j.vaccine.2003.08.014
include the increased media attention given to the theoretical risks associated with vaccination, the spread of anti-vaccination information via the internet and the disappearance of vaccine-preventable diseases [5–7]. It has been suggested that another contributor to the anti-vaccination movement may be the beliefs of some complementary and alternative medicine (CAM) providers [8]. Naturopathic medicine is a specific CAM discipline that is growing in popularity [9]. Naturopathy promotes a holistic approach to the treatment of medical conditions. It supports the use of “natural methods” to treat illnesses which make use of the body’s inherent “self-healing process” [10,11]. Patients may use naturopaths in combination with their family physicians or as substitute family physicians [12,13]. As a consequence, naturopathic practitioners have the potential to influence behaviour on issues such as paediatric vaccination. It is, therefore, important to understand naturopaths’ attitudes towards vaccination, particularly at an early stage in their career. To do so, we conducted a survey of students at the Canadian College of Naturopathic Medicine (CCNM) to determine attitudes towards vaccination and to examine predictors of these attitudes.
330
K. Wilson et al. / Vaccine 22 (2004) 329–334
2. Methods The Canadian College of Naturopathic Medicine is located in Toronto, Ont. and is the largest and only accredited Naturopathic College in Canada. The Naturopathic programme consists of 4 years of in-school training at the end of which students receive a Doctor of Naturopathy degree. Students at this college are required to have a previous bachelor’s degree with requisite sciences. The college graduates approximately 120 students per year. In conjunction with CCNM, and with the approval of their institutional ethics review board, we developed a survey to determine the willingness of students currently enrolled at the college to advise parents to vaccinate their children. This survey is part of an ongoing collaborative exercise between CCNM and medical researchers to examine potential difference in CAM and conventional practitioners’ attitudes towards vaccinations. Our primary objective was to determine the willingness of students to recommend childhood vaccinations, specified in the introduction to the survey as MMR, DPT, HIB and polio. We also sought to identify factors associated with their willingness to recommend vaccinations, as well as to assess their perceptions of the risks of vaccination. In order to accomplish these objectives, we developed a 22-question survey, which we pre-piloted on five students to determine if they adequately understood the questions. The anonymous self-administered questionnaires were then distributed following regularly scheduled classes to all 4 years of students in the CCNM programme. Students answered the questionnaires while in class and returned them to the front of the class where they were then collected by one of the investigators (Mills). Students had the option to not participate if they wished. The survey was administered in March 2001 to students enrolled in the academic year 2000/2001. Of the 22 questions in the survey, five provided baseline demographic information. We asked questions related to perceived risks and benefits of vaccines, willingness to advise parents to vaccinate their children, reasons for not advising vaccination, sources of information on vaccination and trust in sources of information. 2.1. Statistical analysis The primary dependent variable assessed was willingness to advise vaccination, which had response categories: (1) not willing to advise any recommended vaccinations, (2) only willing to advise vaccination with some recommended vaccines, and (3) willing to advise full vaccination. To make the presentation of analysis easier, we collapsed this ordinal outcome to the dichotomous outcome “willing to advise full vaccination” versus “not willing to advise full vaccination”. We assessed simple relationships between this response and six pre-specified dichotomised characteristics of students: (1) degree of belief that vaccines are beneficial (high and moderate versus uncertain, low and none); (2) degree of trust in public health information (high and moderate versus low
and none); (3) year in the CCNM programme (1/2 years versus 3/4 years); (4) knowledge of someone with an adverse vaccine reaction (yes versus no); (5) degree of belief that vaccines are risky (high and moderate versus uncertain, low and none); (6) reliance upon only CAM providers for information about vaccines (yes versus no). We computed the difference in proportions (DP) for advising full vaccination for each of these variables and also carried out chi-squared (χ2 ) tests for the associated two-by-two tables. Using a multivariable regression model, we assessed the effects on advising full vaccination of these six variables, each adjusted for the others. A proportional odds model was used to assess the relationship between the degree of trust in public health information (none, low, moderate/high) and year in the programme. Comparing demographics for the entire student body (provided by the college) to those of our study respondents, we were able to infer the age and sex distributions for non-respondents and test for systematic age or sex differences between respondents and non-respondents. Analyses were carried out using S-Plus 6.0 (© 1998–2001, Insightful Corporation). 3. Results 3.1. Characteristics of respondents A total of 357 out of 525 enrolled students (68% of student body) completed the survey. Of these, 45 did not provide an answer to our primary question on willingness to vaccinate and were excluded from further analysis. We conducted the main body of analysis on the remaining 312 students (59.4% of original sample and 87% of respondents). The students included in our final analysis were distributed throughout the 4 years of the programme, with the highest representation from second year and the lowest from the third and fourth years. The majority of the students were single females and they ranged in age from 20 to 55 (mean age: 27.4 years, S.D.: 4.5 years). A total of 11 (3.5%) students had children under the age of three (see Table 1). The individuals who did not respond to our primary question (n = 45) were similar to those who did respond (n = 312) with respect to age, marital status, sex and graduating year. However, 8 of 45 (18%) of those who did not respond to our primary question had a child under the age of 3 years compared to the 3.5% who did respond, a large and statistically significant difference (P < 0.0001). The sex ratio and mean age of the students included in our final analysis did not differ significantly from that of the student body as a whole. 3.2. Responses to vaccine attitude questions 3.2.1. Willingness to vaccinate In response to the question “Based on your current knowledge, would you advise your patients to have their children fully vaccinated?” 12.8% responded “No, I would advise
K. Wilson et al. / Vaccine 22 (2004) 329–334 Table 1 Baseline characteristics
331
Table 3 Perception of benefits and risks of vaccination
Variable
Number (%)
Perception
Received questionnaire (n = 525) Answered primary question (n = 357)
357 (68.0) 312 (87.4)
Programme year (n = 312) First Second Third Fourth
78 115 57 62
Vaccine benefits (n = 311) Highly beneficial Moderately beneficial Minimally beneficial No benefit Uncertain
(25.0) (36.9) (18.3) (19.9)
Sex (n = 308) Males Female
61 (19.8) 247 (80.2)
Marital status (n = 308) Single Married Divorced/separated
253 (81.4) 56 (18.0) 2 (0.6)
Have children <3 years old (n = 311) Age (n = 304) (years) 20–24 25–29 30–34 35–55
11 (3.5) 61 188 30 25
(20.1) (61.8) (9.9) (8.2)
that they not receive any vaccinations”, 74.4% responded “No, I would only advise they vaccinated them with some of the recommended vaccines” and 12.8% responded “Yes, I would advise that they vaccinate them with all recommended vaccines”. Of the 87.2% that would not recommend full vaccination, the most common reasons for this position were concerns about harm (74.3%) and about lack of benefit (33.5%) (see Table 2). 3.2.2. Risks and benefits of vaccines Vaccines were believed to be highly or moderately beneficial by 41.2% of the students and of minimal or no benefit by 35.0% of students. Vaccines were believed to be highly or moderately risky by 67.3% and minimally risky or of no risk by 16.3% of students (see Table 3). When asked the question “How well understood are the risks of vaccination?” 56.4% responded “minimally”, Table 2 Recommendation of paediatric vaccines Variable
Number (%)
Willingness to recommend vaccination (n = 312) No 40 (12.8) Partial 232 (74.4) Yes 40 (12.8) Reasons for not recommending vaccinationa (n = 272) Concern about harm 202 (74.3) Concern about lack of benefit 91 (33.5) Philosophical objections 12 (4.4) Religious objections 2 (0.7) a
Allowed to mention more than one.
Number (%)
Vaccine risks (n = 311) Highly risky Moderately risky Minimally risky No risk Uncertain
34 94 95 14 74
(10.9) (30.2) (30.5) (4.5) (23.8)
33 177 49 2 50
(10.6) (56.9) (15.8) (0.6) (16.1)
32.7% responded “moderately”. Only 2.9% responded “well understood” and 8% responded that they did not know. Almost half (48.7%) of the students reported that they were aware of someone who had a negative or harmful reaction to a vaccination. The vaccines most commonly reported to have produced these reactions were MMR (22.6% of those witnessing adverse reactions), the flu vaccine (14.0%) and DPT (10.0%) (this was an open-ended question). When asked which vaccine they considered to be the least safe, the majority (65.4%) did not know. MMR was identified by 7.8%, DPT by 4.7%, Hib by 4.4% and polio by 4.7%. Only 2.0% believed all vaccines were safe and 10.8% believed all were unsafe. When asked which vaccine they considered to be the most beneficial, again the majority (55.2%) did not know. DPT was identified by 11.2%, 8.0% chose polio, 6.3% chose MMR and 2.1% chose Hib. Only 7.7% said all were beneficial and 9.4% said none were beneficial. 3.2.3. Sources of information and trust in sources When asked where they obtained information on vaccination issues, 52.9% stated CAM providers, 19.9% stated textbooks and journals, 19.2% stated allopathic providers and public health officials and 9.3% stated the internet or media. Students expressed more trust in vaccination information provided by CAM providers as opposed to information provided by allopathic providers or public health information when it came to vaccination issues (Table 4). Only a few (7.2%) students had either low or no trust in advice provided by CAM practitioners. In contrast, 60.5% had low/no trust in public health information and 66.2% had low/no trust in advice from allopathic providers (see Table 4). Table 4 Trust in sources of information on vaccination Source of information
CAM Public Health Allopaths
Level of trust number (% within row) None
Low
Moderate
High
1 (0.3) 27 (8.7) 38 (12.3)
21 (6.9) 160 (51.8) 166 (53.9)
223 (72.9) 116 (37.5) 97 (31.5)
61 (19.9) 6 (1.9) 7 (2.3)
332
K. Wilson et al. / Vaccine 22 (2004) 329–334
Table 5 Factors predicting willingness to advise full vaccination (bivariate analysis) Survey response
Percentage willing to advise full vaccination
Difference in proportions (95% confidence interval)
P-value
Vaccines are of high/moderate benefit Vaccines are of no, minimal or uncertain benefit
28.9 1.6
27.3 (19.2–35.3)
<0.0001
High/moderate trust in public health information Low/no trust in public health information
27.1 3.7
23.3 (15.0–31.6)
<0.0001
Vaccines are of no, minimal or uncertain risk Vaccines are of high/moderate risk
26.7 6.2
20.5 (11.3–30.0)
<0.0001
No knowledge of individual with adverse reaction to vaccination Knowledge of individual with adverse reaction to vaccination
21.5 3.3
18.2 (11.1–25.2)
<0.0001
First/second year students Third/fourth year students
19.7 1.7
18.0 (11.9–24.1)
<0.0001
CAM is not only source of vaccination information CAM is only source of vaccination information
18.4 5.8
12.6 (5.6–19.5)
0.002
Table 6 Raw and adjusted odds ratios of variables predicting willingness to advise vaccinations Variablea
High or moderate belief that vaccines are beneficial High or moderate trust in public health information
Unadjusted analysis
Adjusted analysis
OR
OR
95% confidence interval
24.4 9.5
16.4 3.72
5.15–73.6 1.42–10.7
0.13 0.26 0.30 0.59
0.02–0.52 0.08–0.76 0.11–0.74 0.21–1.63
Progression through programme (3/4 years vs. 1/2 years) Knowledge of someone with adverse vaccine reaction Belief that vaccines are highly or moderately risky Reliance upon only CAM providers for information
0.07 0.13 0.18 0.28
a Each odds ratio is for the comparison of subjects with the characteristic in this column to subjects without this characteristic, unless otherwise specified.
3.2.4. Predictors of decision to advise vaccination Our bivariate analyses identified that the following factors were associated with a statistically significant difference in the proportions recommending full vaccination: perception
of benefit or risk of vaccines, trust in public health, year in programme, knowledge of an individual with an adverse vaccine reaction and reliance upon CAM information on vaccines (see Table 5). We also observed that the proportion of students who had low or no trust in public health information declined by year in programme (P < 0.001) (Fig. 1). The result of the multivariable analyses based on these variables was that all variables, except reliance upon CAM for vaccine information, remained statistically significant independent predictors of the decision to advise vaccination. Table 6 lists both unadjusted (bivariate) and the adjusted odds ratios associated with these variables. An odds ratio larger than one for a variable indicates that a student with the characteristic described has an increased probability of recommending full vaccination, compared to a student without that characteristic.
4. Discussion
Fig. 1. Trust in public health vs. year in programme. The dots show observed percentages and the lines show 95% confidence intervals.
Several messages emerge from our study of the attitudes towards vaccination of students at a major Canadian naturopathic college. Of most concern to public health officials is that only a minority of students would advise parents to have their children receive all recommended paediatric
K. Wilson et al. / Vaccine 22 (2004) 329–334
vaccinations. The decision not to recommend vaccination was due to a combination of concerns about the lack of benefit of these vaccines and their potential risk. Our study also found that “anti-vaccination” attitudes were present amongst students in their first year at the Naturopathic College and increased in students who had been in the programme for a longer duration. This trend appeared to be partially mediated by a progressive decrease in trust in public health sources of information on vaccination. We also identified that knowledge of an individual who has had a vaccination reaction was independently associated with a negative attitude towards vaccination. On a closer examination of the data, however, it appears that students have a considerable level of uncertainty regarding the risks and benefits of vaccination. The majority of students stated they would recommend vaccination with some of the recommended vaccinations. Many students were uncertain as to the level of risk and benefit associated with vaccines. We also found that students’ negative attitudes towards vaccination did not appear to be specific to any particular vaccine, but rather to vaccines in general as demonstrated by the high percentage of students who did not know which vaccine was the most beneficial or the most risky. The results of our survey are consistent with those of other studies. A study of practising naturopathic doctors in Massachusetts, USA found that only 3 of 15 (20%) naturopaths would actively recommend vaccinations, although only 1 (7%) openly opposed vaccinations [14]. Another study identified a substantial level of heterogeneity in attitudes towards vaccination amongst naturopaths with many discouraging their use [15]. Studies of other CAM disciplines also are consistent with our findings. Most notably, a survey of 467 students from the Canadian Memorial Chiropractic College found that while 53.5% of students were in favour of vaccination, the remainder of students did not agree (14.1%) with vaccination or were unsure (32.3%). This study also identified an upward trend in anti-vaccine beliefs as students progressed through the chiropractic programme [16]. A possible limitation of our study is the potential for both non-responder bias and item non-response bias. While we found that those who responded to the survey were similar in age and sex to the average student this does not necessarily imply that they shared similar attitudes towards vaccination. In examining the issue of item non-response, we found it interesting that those who chose not to answer the question of whether they would recommend vaccinations were more likely to have children under the age of 3 years. If we assumed that all of these individuals had supported full vaccination, the percentage of those supporting full vaccination would increase to 24%, still only a minority. Another important limitation of our study is that it cannot determine the directionality of the associations we observed. Specifically, it cannot establish whether individuals who are anti-vaccination are drawn towards naturopathic medicine or whether training in naturopathic medicine contributes to the development of anti-vaccination attitudes.
333
We also have to be cautious about interpreting conclusions about anti-vaccination attitudes increasing as students’ progress through the programme because this inference is based on a comparison of different populations of students in different years rather than observing one population over several years. A hypothesis that needs to be further examined is that individuals who have belief systems more consistent with choosing naturopathy as a career are more likely to be sceptical of vaccinations. These individuals’ attitudes may then be reinforced by their continued exposure to CAM. However, CCNM states that it does not actively teach about the risks of vaccinations. Students are also told not to make recommendations against childhood vaccinations. Therefore, a possible explanation for our observations is that students’ anti-vaccination attitudes are intensified and validated by the presence of other students with similar beliefs. More in depth qualitative research is required to better establish why these anti-vaccination beliefs develop. Our survey, and the chiropractic student survey, also suggest that public health officials need to identify mechanisms to counteract the apparent progressive decrease in trust of conventional sources of vaccination information as students progress through these programmes. This would require determining how to effectively engage CAM providers, particularly early in their training. A possible strategy would be to cautiously acknowledge some of their concerns, for example that vaccines are not 100% safe and that they are not 100% effective [17]. At the same time, public health officials need to provide a clear message that the benefits of vaccination are large compared to the risks. These messages need to be presented in a manner that CAM providers will be most receptive to and that respects their concerns. The emphasis on individualising therapy in many CAM disciplines may suggest that case examples of individuals who have developed potentially vaccine-preventable conditions could be effective in persuading CAM providers of the benefits of vaccination. The potential effectiveness of such “anecdotal” information is supported by our survey finding of a negative association between knowledge of a patient with an adverse vaccine reaction and willingness to advise vaccination. The effectiveness of different forms of evidence in changing attitudes towards vaccination needs to be tested in future studies. The potential receptivity of the CAM practitioner community to be engaged in debate with the conventional medical community on the issue of vaccination is demonstrated by the willingness of CCNM and the Canadian Memorial Chiropractic College allowing their students’ attitudes towards vaccination to be examined. Additionally, the apparent uncertainty towards vaccination identified by our study suggests that the right strategy may help to alleviate concerns about vaccination. This uncertainty is also reflected in the cautiously supportive official statement from the Canadian Naturopathic Association regarding vaccinations. The association states that “immunisations may be effective for controlling the incidence of specific contagious
334
K. Wilson et al. / Vaccine 22 (2004) 329–334
diseases” and that “immunisations can cause serious adverse reactions, possibly even fatal, in a small minority of children”. The Association also states that parents should be well informed of the benefits and risks of vaccination and that there are no natural “substitutes” for immunisation [18].
5. Conclusion Public health officials need to ensure that current high levels of vaccination coverage are maintained. Concerns about the safety and benefit of vaccination amongst naturopathic providers have the potential to erode parents’ confidence in vaccines. Finding effective mechanisms to communicate the benefits of vaccination to naturopathic providers during their training is an important first step to prevent this from occurring. Naturopathic providers who support vaccination should also be aware of these results and consider introducing changes in curriculum to inform students about the favourable risk/benefit profile of many paediatric vaccines. We strongly recommend that members of the public health community, conventional medicine and naturopathic medicine begin a dialogue on these issues.
Acknowledgements This study was funded by a Canadian Institutes of Health grant. References [1] Current Immunisation Programs in Canada. Canadian national report on immunisation, 1996. Canada communicable disease report, Supplement vol. 23S4. Laboratory Centre for Disease Control, Health Canada; May 1997 [Chapter 10].
[2] Pinker S. Quebec’s $100-million campaign targets meningococcal disease (news). CMAJ 2001;165(11):1520. [3] Province-wide meningococcal immunisation program gets underway. Government of Alberta news release (http://www.gov.ab.ca/acn/ 200104/10533.html, accessed 15 January 2002). [4] Scheifele D, Halperin S, Pelletier L, Talbot J. Invasive pneumococcal infections in Canadian children, 1991–1998: implications for new vaccination strategies. Canadian Paediatric Society/Laboratory Centre for Disease Control Immunisation Monitoring Program, Active (IMPACT). Clin Infect Dis 2000;31:58–64. [5] Cookson C. Benefit and risk of vaccination as seen by the general public and the media. Vaccine 2002;20:S85–8. [6] Wolfe RM, Sharp LK, Lipsky MS. Content and design attributes of anti-vaccination websites. JAMA 2002;287:3245–8. [7] Gangarosa EJ, Galazka AM, Wolfe CR, et al. Impact of antivaccine movements on pertussis control: the untold story. Lancet 1998;351:356–61. [8] Ernst E. Rise in popularity of complementary and alternative medicine: reasons and consequences for vaccination. Vaccine 2002;20:S90–3. [9] Cooper RA, Laud P, Dietrich CL. Current and projected workforce of nonphysician clinicians. JAMA 1998;280:788–94. [10] What is naturopathic medicine? Canadian Naturopathic Medicine (http://www.naturopathicassoc.ca/qa1.html, accessed 23 July 2002). [11] Definition of naturopathic medicine. The American Association of Naturopathic Physicians (http://www.naturopathic.org/about/ definitions.htm, accessed 23 July 2002). [12] Featherstone C, Godden D, Gault C, Emslie M, Took-Zozaya M. Prevalence study of concurrent use of complementary and alternative medicine in patients attending primary care services in Scotland. Am J Public Health 2003;93:1080–2. [13] Spigelblatt L, Laine-Ammarra G, Pless IB, Guyver A. The use of alternative medicine by children. Pediatrics 1994;94:811–4. [14] Lee ACC, Kemper KJ. Homeopathy and naturopathy. Arch Pediatr Adolesc Med 2000;154:75–80. [15] Halper J, Berger LR. Naturopaths and childhood immunisations: heterodoxy among the orthodox. Pediatrics 1981;68:407–10. [16] Busse JW, Kulkarni AV, Campbell JB, Injeyan HS. Attitudes toward vaccination: a survey of Canadian chiropractic students. CMAJ 2002;166:1531–4. [17] Plotkin SA. Lessons learned concerning vaccine safety. Vaccine 2002;20:S16–9. [18] Childhood vaccinations. Position Paper ratified by CNA/ACN Board of Directors, 29 March 2000.
A survey of attitudes towards paediatric vaccinations amongst Canadian naturopathic students Kumanan Wilson a,b,∗,1 , Ed Mills c,2 , Heather Boon d,e,3 , George Tomlinson a,b,d , Paul Ritvo d b
a Department of Medicine, University of Toronto, Toronto, Ont., Canada M5G 2C4 Department of Health Policy, Management and Evaluation, Faculty of Medicine, University of Toronto, Toronto, Ont., Canada M5G 2C4 c Department of Research, Canadian College of Naturopathic Medicine, Toronto, Ont., Canada M5G 2C4 d Department of Public Health Sciences, Faculty of Medicine, University of Toronto, Toronto, Ont., Canada M5G 2C4 e Faculty of Pharmacy, University of Toronto, Toronto, Ont., Canada M5G 2C4
Received 9 May 2003; received in revised form 11 August 2003; accepted 12 August 2003
Abstract Previous studies have suggested that providers of alternative medicine may harbour anti-vaccination attitudes and that these attitudes may develop at an early stage in their careers. We further explored this question by conducting a survey to determine the attitudes of students of naturopathic medicine, a growing alternative medicine discipline, towards recommended paediatric vaccines. We sampled all 4 years of students at the Canadian College of Naturopathic Medicine (CCNM) and obtained a response rate of 59.4% (312 of 525). We found that only 12.8% (40 of 312) of the respondents would advise full vaccination; however, 74.4% (232 of 312) of the respondents would advise partial vaccination. Importantly, both willingness to advise full vaccination and trust in public health and conventional medicine decreased in students in the later years of the programme. Our findings suggest that public health and conventional medical supporters of vaccination need to identify mechanisms for engaging in discussion with this population of complementary/alternative medical professionals at an early stage in their careers. © 2003 Elsevier Ltd. All rights reserved. Keywords: Immunisation; Naturopathic medicine; Attitudes
1. Introduction Universal vaccination programmes have been central components of public health programmes around the world. Most developed nations have introduced universal childhood vaccination for a variety of conditions. In Canada, all provinces have instituted public childhood vaccination programmes for measles, mumps and rubella (MMR), Haemophilus influenzae type b (HIB), diphtheria, pertussis and tetanus (DPT) and polio [1]. In addition, several new vaccines are being considered for widespread implementation [2–4]. Despite the documented successes of vaccinations, a growing anti-vaccination movement appears to be emerging. Factors contributing to this movement are thought to ∗ Corresponding author. Present address: ENG-254, Toronto General Hospital, University Health Network, 200 Elizabeth Street, Toronto, Ont., Canada M5G 2C4. Tel.: +1-416-340-3662; fax: +1-416-595-5826. E-mail address: [email protected] (K. Wilson). 1 He is a Canadian Institutes of Health Research new investigator. 2 He is an Essiac scholar. 3 She is an Ontario Ministry of Health and Longterm Care career scientist.
0264-410X/$ – see front matter © 2003 Elsevier Ltd. All rights reserved. doi:10.1016/j.vaccine.2003.08.014
include the increased media attention given to the theoretical risks associated with vaccination, the spread of anti-vaccination information via the internet and the disappearance of vaccine-preventable diseases [5–7]. It has been suggested that another contributor to the anti-vaccination movement may be the beliefs of some complementary and alternative medicine (CAM) providers [8]. Naturopathic medicine is a specific CAM discipline that is growing in popularity [9]. Naturopathy promotes a holistic approach to the treatment of medical conditions. It supports the use of “natural methods” to treat illnesses which make use of the body’s inherent “self-healing process” [10,11]. Patients may use naturopaths in combination with their family physicians or as substitute family physicians [12,13]. As a consequence, naturopathic practitioners have the potential to influence behaviour on issues such as paediatric vaccination. It is, therefore, important to understand naturopaths’ attitudes towards vaccination, particularly at an early stage in their career. To do so, we conducted a survey of students at the Canadian College of Naturopathic Medicine (CCNM) to determine attitudes towards vaccination and to examine predictors of these attitudes.
330
K. Wilson et al. / Vaccine 22 (2004) 329–334
2. Methods The Canadian College of Naturopathic Medicine is located in Toronto, Ont. and is the largest and only accredited Naturopathic College in Canada. The Naturopathic programme consists of 4 years of in-school training at the end of which students receive a Doctor of Naturopathy degree. Students at this college are required to have a previous bachelor’s degree with requisite sciences. The college graduates approximately 120 students per year. In conjunction with CCNM, and with the approval of their institutional ethics review board, we developed a survey to determine the willingness of students currently enrolled at the college to advise parents to vaccinate their children. This survey is part of an ongoing collaborative exercise between CCNM and medical researchers to examine potential difference in CAM and conventional practitioners’ attitudes towards vaccinations. Our primary objective was to determine the willingness of students to recommend childhood vaccinations, specified in the introduction to the survey as MMR, DPT, HIB and polio. We also sought to identify factors associated with their willingness to recommend vaccinations, as well as to assess their perceptions of the risks of vaccination. In order to accomplish these objectives, we developed a 22-question survey, which we pre-piloted on five students to determine if they adequately understood the questions. The anonymous self-administered questionnaires were then distributed following regularly scheduled classes to all 4 years of students in the CCNM programme. Students answered the questionnaires while in class and returned them to the front of the class where they were then collected by one of the investigators (Mills). Students had the option to not participate if they wished. The survey was administered in March 2001 to students enrolled in the academic year 2000/2001. Of the 22 questions in the survey, five provided baseline demographic information. We asked questions related to perceived risks and benefits of vaccines, willingness to advise parents to vaccinate their children, reasons for not advising vaccination, sources of information on vaccination and trust in sources of information. 2.1. Statistical analysis The primary dependent variable assessed was willingness to advise vaccination, which had response categories: (1) not willing to advise any recommended vaccinations, (2) only willing to advise vaccination with some recommended vaccines, and (3) willing to advise full vaccination. To make the presentation of analysis easier, we collapsed this ordinal outcome to the dichotomous outcome “willing to advise full vaccination” versus “not willing to advise full vaccination”. We assessed simple relationships between this response and six pre-specified dichotomised characteristics of students: (1) degree of belief that vaccines are beneficial (high and moderate versus uncertain, low and none); (2) degree of trust in public health information (high and moderate versus low
and none); (3) year in the CCNM programme (1/2 years versus 3/4 years); (4) knowledge of someone with an adverse vaccine reaction (yes versus no); (5) degree of belief that vaccines are risky (high and moderate versus uncertain, low and none); (6) reliance upon only CAM providers for information about vaccines (yes versus no). We computed the difference in proportions (DP) for advising full vaccination for each of these variables and also carried out chi-squared (χ2 ) tests for the associated two-by-two tables. Using a multivariable regression model, we assessed the effects on advising full vaccination of these six variables, each adjusted for the others. A proportional odds model was used to assess the relationship between the degree of trust in public health information (none, low, moderate/high) and year in the programme. Comparing demographics for the entire student body (provided by the college) to those of our study respondents, we were able to infer the age and sex distributions for non-respondents and test for systematic age or sex differences between respondents and non-respondents. Analyses were carried out using S-Plus 6.0 (© 1998–2001, Insightful Corporation). 3. Results 3.1. Characteristics of respondents A total of 357 out of 525 enrolled students (68% of student body) completed the survey. Of these, 45 did not provide an answer to our primary question on willingness to vaccinate and were excluded from further analysis. We conducted the main body of analysis on the remaining 312 students (59.4% of original sample and 87% of respondents). The students included in our final analysis were distributed throughout the 4 years of the programme, with the highest representation from second year and the lowest from the third and fourth years. The majority of the students were single females and they ranged in age from 20 to 55 (mean age: 27.4 years, S.D.: 4.5 years). A total of 11 (3.5%) students had children under the age of three (see Table 1). The individuals who did not respond to our primary question (n = 45) were similar to those who did respond (n = 312) with respect to age, marital status, sex and graduating year. However, 8 of 45 (18%) of those who did not respond to our primary question had a child under the age of 3 years compared to the 3.5% who did respond, a large and statistically significant difference (P < 0.0001). The sex ratio and mean age of the students included in our final analysis did not differ significantly from that of the student body as a whole. 3.2. Responses to vaccine attitude questions 3.2.1. Willingness to vaccinate In response to the question “Based on your current knowledge, would you advise your patients to have their children fully vaccinated?” 12.8% responded “No, I would advise
K. Wilson et al. / Vaccine 22 (2004) 329–334 Table 1 Baseline characteristics
331
Table 3 Perception of benefits and risks of vaccination
Variable
Number (%)
Perception
Received questionnaire (n = 525) Answered primary question (n = 357)
357 (68.0) 312 (87.4)
Programme year (n = 312) First Second Third Fourth
78 115 57 62
Vaccine benefits (n = 311) Highly beneficial Moderately beneficial Minimally beneficial No benefit Uncertain
(25.0) (36.9) (18.3) (19.9)
Sex (n = 308) Males Female
61 (19.8) 247 (80.2)
Marital status (n = 308) Single Married Divorced/separated
253 (81.4) 56 (18.0) 2 (0.6)
Have children <3 years old (n = 311) Age (n = 304) (years) 20–24 25–29 30–34 35–55
11 (3.5) 61 188 30 25
(20.1) (61.8) (9.9) (8.2)
that they not receive any vaccinations”, 74.4% responded “No, I would only advise they vaccinated them with some of the recommended vaccines” and 12.8% responded “Yes, I would advise that they vaccinate them with all recommended vaccines”. Of the 87.2% that would not recommend full vaccination, the most common reasons for this position were concerns about harm (74.3%) and about lack of benefit (33.5%) (see Table 2). 3.2.2. Risks and benefits of vaccines Vaccines were believed to be highly or moderately beneficial by 41.2% of the students and of minimal or no benefit by 35.0% of students. Vaccines were believed to be highly or moderately risky by 67.3% and minimally risky or of no risk by 16.3% of students (see Table 3). When asked the question “How well understood are the risks of vaccination?” 56.4% responded “minimally”, Table 2 Recommendation of paediatric vaccines Variable
Number (%)
Willingness to recommend vaccination (n = 312) No 40 (12.8) Partial 232 (74.4) Yes 40 (12.8) Reasons for not recommending vaccinationa (n = 272) Concern about harm 202 (74.3) Concern about lack of benefit 91 (33.5) Philosophical objections 12 (4.4) Religious objections 2 (0.7) a
Allowed to mention more than one.
Number (%)
Vaccine risks (n = 311) Highly risky Moderately risky Minimally risky No risk Uncertain
34 94 95 14 74
(10.9) (30.2) (30.5) (4.5) (23.8)
33 177 49 2 50
(10.6) (56.9) (15.8) (0.6) (16.1)
32.7% responded “moderately”. Only 2.9% responded “well understood” and 8% responded that they did not know. Almost half (48.7%) of the students reported that they were aware of someone who had a negative or harmful reaction to a vaccination. The vaccines most commonly reported to have produced these reactions were MMR (22.6% of those witnessing adverse reactions), the flu vaccine (14.0%) and DPT (10.0%) (this was an open-ended question). When asked which vaccine they considered to be the least safe, the majority (65.4%) did not know. MMR was identified by 7.8%, DPT by 4.7%, Hib by 4.4% and polio by 4.7%. Only 2.0% believed all vaccines were safe and 10.8% believed all were unsafe. When asked which vaccine they considered to be the most beneficial, again the majority (55.2%) did not know. DPT was identified by 11.2%, 8.0% chose polio, 6.3% chose MMR and 2.1% chose Hib. Only 7.7% said all were beneficial and 9.4% said none were beneficial. 3.2.3. Sources of information and trust in sources When asked where they obtained information on vaccination issues, 52.9% stated CAM providers, 19.9% stated textbooks and journals, 19.2% stated allopathic providers and public health officials and 9.3% stated the internet or media. Students expressed more trust in vaccination information provided by CAM providers as opposed to information provided by allopathic providers or public health information when it came to vaccination issues (Table 4). Only a few (7.2%) students had either low or no trust in advice provided by CAM practitioners. In contrast, 60.5% had low/no trust in public health information and 66.2% had low/no trust in advice from allopathic providers (see Table 4). Table 4 Trust in sources of information on vaccination Source of information
CAM Public Health Allopaths
Level of trust number (% within row) None
Low
Moderate
High
1 (0.3) 27 (8.7) 38 (12.3)
21 (6.9) 160 (51.8) 166 (53.9)
223 (72.9) 116 (37.5) 97 (31.5)
61 (19.9) 6 (1.9) 7 (2.3)
332
K. Wilson et al. / Vaccine 22 (2004) 329–334
Table 5 Factors predicting willingness to advise full vaccination (bivariate analysis) Survey response
Percentage willing to advise full vaccination
Difference in proportions (95% confidence interval)
P-value
Vaccines are of high/moderate benefit Vaccines are of no, minimal or uncertain benefit
28.9 1.6
27.3 (19.2–35.3)
<0.0001
High/moderate trust in public health information Low/no trust in public health information
27.1 3.7
23.3 (15.0–31.6)
<0.0001
Vaccines are of no, minimal or uncertain risk Vaccines are of high/moderate risk
26.7 6.2
20.5 (11.3–30.0)
<0.0001
No knowledge of individual with adverse reaction to vaccination Knowledge of individual with adverse reaction to vaccination
21.5 3.3
18.2 (11.1–25.2)
<0.0001
First/second year students Third/fourth year students
19.7 1.7
18.0 (11.9–24.1)
<0.0001
CAM is not only source of vaccination information CAM is only source of vaccination information
18.4 5.8
12.6 (5.6–19.5)
0.002
Table 6 Raw and adjusted odds ratios of variables predicting willingness to advise vaccinations Variablea
High or moderate belief that vaccines are beneficial High or moderate trust in public health information
Unadjusted analysis
Adjusted analysis
OR
OR
95% confidence interval
24.4 9.5
16.4 3.72
5.15–73.6 1.42–10.7
0.13 0.26 0.30 0.59
0.02–0.52 0.08–0.76 0.11–0.74 0.21–1.63
Progression through programme (3/4 years vs. 1/2 years) Knowledge of someone with adverse vaccine reaction Belief that vaccines are highly or moderately risky Reliance upon only CAM providers for information
0.07 0.13 0.18 0.28
a Each odds ratio is for the comparison of subjects with the characteristic in this column to subjects without this characteristic, unless otherwise specified.
3.2.4. Predictors of decision to advise vaccination Our bivariate analyses identified that the following factors were associated with a statistically significant difference in the proportions recommending full vaccination: perception
of benefit or risk of vaccines, trust in public health, year in programme, knowledge of an individual with an adverse vaccine reaction and reliance upon CAM information on vaccines (see Table 5). We also observed that the proportion of students who had low or no trust in public health information declined by year in programme (P < 0.001) (Fig. 1). The result of the multivariable analyses based on these variables was that all variables, except reliance upon CAM for vaccine information, remained statistically significant independent predictors of the decision to advise vaccination. Table 6 lists both unadjusted (bivariate) and the adjusted odds ratios associated with these variables. An odds ratio larger than one for a variable indicates that a student with the characteristic described has an increased probability of recommending full vaccination, compared to a student without that characteristic.
4. Discussion
Fig. 1. Trust in public health vs. year in programme. The dots show observed percentages and the lines show 95% confidence intervals.
Several messages emerge from our study of the attitudes towards vaccination of students at a major Canadian naturopathic college. Of most concern to public health officials is that only a minority of students would advise parents to have their children receive all recommended paediatric
K. Wilson et al. / Vaccine 22 (2004) 329–334
vaccinations. The decision not to recommend vaccination was due to a combination of concerns about the lack of benefit of these vaccines and their potential risk. Our study also found that “anti-vaccination” attitudes were present amongst students in their first year at the Naturopathic College and increased in students who had been in the programme for a longer duration. This trend appeared to be partially mediated by a progressive decrease in trust in public health sources of information on vaccination. We also identified that knowledge of an individual who has had a vaccination reaction was independently associated with a negative attitude towards vaccination. On a closer examination of the data, however, it appears that students have a considerable level of uncertainty regarding the risks and benefits of vaccination. The majority of students stated they would recommend vaccination with some of the recommended vaccinations. Many students were uncertain as to the level of risk and benefit associated with vaccines. We also found that students’ negative attitudes towards vaccination did not appear to be specific to any particular vaccine, but rather to vaccines in general as demonstrated by the high percentage of students who did not know which vaccine was the most beneficial or the most risky. The results of our survey are consistent with those of other studies. A study of practising naturopathic doctors in Massachusetts, USA found that only 3 of 15 (20%) naturopaths would actively recommend vaccinations, although only 1 (7%) openly opposed vaccinations [14]. Another study identified a substantial level of heterogeneity in attitudes towards vaccination amongst naturopaths with many discouraging their use [15]. Studies of other CAM disciplines also are consistent with our findings. Most notably, a survey of 467 students from the Canadian Memorial Chiropractic College found that while 53.5% of students were in favour of vaccination, the remainder of students did not agree (14.1%) with vaccination or were unsure (32.3%). This study also identified an upward trend in anti-vaccine beliefs as students progressed through the chiropractic programme [16]. A possible limitation of our study is the potential for both non-responder bias and item non-response bias. While we found that those who responded to the survey were similar in age and sex to the average student this does not necessarily imply that they shared similar attitudes towards vaccination. In examining the issue of item non-response, we found it interesting that those who chose not to answer the question of whether they would recommend vaccinations were more likely to have children under the age of 3 years. If we assumed that all of these individuals had supported full vaccination, the percentage of those supporting full vaccination would increase to 24%, still only a minority. Another important limitation of our study is that it cannot determine the directionality of the associations we observed. Specifically, it cannot establish whether individuals who are anti-vaccination are drawn towards naturopathic medicine or whether training in naturopathic medicine contributes to the development of anti-vaccination attitudes.
333
We also have to be cautious about interpreting conclusions about anti-vaccination attitudes increasing as students’ progress through the programme because this inference is based on a comparison of different populations of students in different years rather than observing one population over several years. A hypothesis that needs to be further examined is that individuals who have belief systems more consistent with choosing naturopathy as a career are more likely to be sceptical of vaccinations. These individuals’ attitudes may then be reinforced by their continued exposure to CAM. However, CCNM states that it does not actively teach about the risks of vaccinations. Students are also told not to make recommendations against childhood vaccinations. Therefore, a possible explanation for our observations is that students’ anti-vaccination attitudes are intensified and validated by the presence of other students with similar beliefs. More in depth qualitative research is required to better establish why these anti-vaccination beliefs develop. Our survey, and the chiropractic student survey, also suggest that public health officials need to identify mechanisms to counteract the apparent progressive decrease in trust of conventional sources of vaccination information as students progress through these programmes. This would require determining how to effectively engage CAM providers, particularly early in their training. A possible strategy would be to cautiously acknowledge some of their concerns, for example that vaccines are not 100% safe and that they are not 100% effective [17]. At the same time, public health officials need to provide a clear message that the benefits of vaccination are large compared to the risks. These messages need to be presented in a manner that CAM providers will be most receptive to and that respects their concerns. The emphasis on individualising therapy in many CAM disciplines may suggest that case examples of individuals who have developed potentially vaccine-preventable conditions could be effective in persuading CAM providers of the benefits of vaccination. The potential effectiveness of such “anecdotal” information is supported by our survey finding of a negative association between knowledge of a patient with an adverse vaccine reaction and willingness to advise vaccination. The effectiveness of different forms of evidence in changing attitudes towards vaccination needs to be tested in future studies. The potential receptivity of the CAM practitioner community to be engaged in debate with the conventional medical community on the issue of vaccination is demonstrated by the willingness of CCNM and the Canadian Memorial Chiropractic College allowing their students’ attitudes towards vaccination to be examined. Additionally, the apparent uncertainty towards vaccination identified by our study suggests that the right strategy may help to alleviate concerns about vaccination. This uncertainty is also reflected in the cautiously supportive official statement from the Canadian Naturopathic Association regarding vaccinations. The association states that “immunisations may be effective for controlling the incidence of specific contagious
334
K. Wilson et al. / Vaccine 22 (2004) 329–334
diseases” and that “immunisations can cause serious adverse reactions, possibly even fatal, in a small minority of children”. The Association also states that parents should be well informed of the benefits and risks of vaccination and that there are no natural “substitutes” for immunisation [18].
5. Conclusion Public health officials need to ensure that current high levels of vaccination coverage are maintained. Concerns about the safety and benefit of vaccination amongst naturopathic providers have the potential to erode parents’ confidence in vaccines. Finding effective mechanisms to communicate the benefits of vaccination to naturopathic providers during their training is an important first step to prevent this from occurring. Naturopathic providers who support vaccination should also be aware of these results and consider introducing changes in curriculum to inform students about the favourable risk/benefit profile of many paediatric vaccines. We strongly recommend that members of the public health community, conventional medicine and naturopathic medicine begin a dialogue on these issues.
Acknowledgements This study was funded by a Canadian Institutes of Health grant. References [1] Current Immunisation Programs in Canada. Canadian national report on immunisation, 1996. Canada communicable disease report, Supplement vol. 23S4. Laboratory Centre for Disease Control, Health Canada; May 1997 [Chapter 10].
[2] Pinker S. Quebec’s $100-million campaign targets meningococcal disease (news). CMAJ 2001;165(11):1520. [3] Province-wide meningococcal immunisation program gets underway. Government of Alberta news release (http://www.gov.ab.ca/acn/ 200104/10533.html, accessed 15 January 2002). [4] Scheifele D, Halperin S, Pelletier L, Talbot J. Invasive pneumococcal infections in Canadian children, 1991–1998: implications for new vaccination strategies. Canadian Paediatric Society/Laboratory Centre for Disease Control Immunisation Monitoring Program, Active (IMPACT). Clin Infect Dis 2000;31:58–64. [5] Cookson C. Benefit and risk of vaccination as seen by the general public and the media. Vaccine 2002;20:S85–8. [6] Wolfe RM, Sharp LK, Lipsky MS. Content and design attributes of anti-vaccination websites. JAMA 2002;287:3245–8. [7] Gangarosa EJ, Galazka AM, Wolfe CR, et al. Impact of antivaccine movements on pertussis control: the untold story. Lancet 1998;351:356–61. [8] Ernst E. Rise in popularity of complementary and alternative medicine: reasons and consequences for vaccination. Vaccine 2002;20:S90–3. [9] Cooper RA, Laud P, Dietrich CL. Current and projected workforce of nonphysician clinicians. JAMA 1998;280:788–94. [10] What is naturopathic medicine? Canadian Naturopathic Medicine (http://www.naturopathicassoc.ca/qa1.html, accessed 23 July 2002). [11] Definition of naturopathic medicine. The American Association of Naturopathic Physicians (http://www.naturopathic.org/about/ definitions.htm, accessed 23 July 2002). [12] Featherstone C, Godden D, Gault C, Emslie M, Took-Zozaya M. Prevalence study of concurrent use of complementary and alternative medicine in patients attending primary care services in Scotland. Am J Public Health 2003;93:1080–2. [13] Spigelblatt L, Laine-Ammarra G, Pless IB, Guyver A. The use of alternative medicine by children. Pediatrics 1994;94:811–4. [14] Lee ACC, Kemper KJ. Homeopathy and naturopathy. Arch Pediatr Adolesc Med 2000;154:75–80. [15] Halper J, Berger LR. Naturopaths and childhood immunisations: heterodoxy among the orthodox. Pediatrics 1981;68:407–10. [16] Busse JW, Kulkarni AV, Campbell JB, Injeyan HS. Attitudes toward vaccination: a survey of Canadian chiropractic students. CMAJ 2002;166:1531–4. [17] Plotkin SA. Lessons learned concerning vaccine safety. Vaccine 2002;20:S16–9. [18] Childhood vaccinations. Position Paper ratified by CNA/ACN Board of Directors, 29 March 2000.