INTRODUCTION
Vitalism is a philosophical school of thought of ancient origin1–3 and ongoing influence.4–10 In essence, it posits that living organisms and non-living things differ fundamentally in that the former possess some principle, force, or energy which the latter do not.11 The use of vitalistic terms such as “vital force” by D.D. Palmer, the founder of chiropractic, placed vitalism at the ontological core of the profession as a system for the preservation of health.12–14
Some chiropractors believe that vitalism contributes positively to a strong sense of coherence and guidance in understanding life, health, and practice and so is an essential core value of the profession and its unique identity.15–20 In contrast, others see vitalism negatively, as a controversial, unorthodox, and obsolete religious dogma or ideology21–26 believed by a minority of the profession24,27 and associated with unethical behaviour.24,28 They posit that this belief has for decades maintained the profession in a state of divisive crisis,29,30 excluded it from acceptance by science and society23,24,31 and threatened its future existence.24,31,32 Yet another group has described a “new” chiropractic vitalism (or neo-vitalism) as “a recognition and respect for the inherent self-organizing self-maintaining, self-healing abilities of every individual.”33 However, all these perspectives are based on opinions, which can be prone to bias.34,35
Only limited empirical research has explored vitalism in chiropractic. One small qualitative study found that most of the interviewed New Zealand College of Chiropractic (NZCC) lecturers perceived vitalism as an understanding of the body as a self-healing, self-organising and self-regulating organism.36 They believed that this understanding offered value in guiding the teaching, learning, and practice of chiropractic.
Other mixed methods research explored 2 research questions.37 The first asked what chiropractors mean when they speak about vitalism. The second asked what value do chiropractors believe that chiropractic thinking and practices based on vitalism might offer in addressing current global prevalence of non-communicable lifestyle-related conditions. To a majority of 18 purposively selected interviewed chiropractors from 8 countries, vitalism meant the chiropractic concept of innate intelligence, a guide to a good life, and an essential part of the identity of the profession.37 To separate minorities, vitalism meant either neo-vitalism or an obsolete unscientific doctrine. Most interviewees strongly maintained that vitalistic thinking and practices by chiropractors could offer value in addressing current global prevalence of non-communicable lifestyle-related conditions.37 As many individuals lack connection with the order of the universe and the innate intelligence of their bodies, vitalistic chiropractic could offer a conceptual gateway to self-empowering reconnection and realignment to that order, that intelligence, and to health.38 A vitalistic practice model was described as chiropractic care to keep individuals free of chiropractic subluxations (considered interferences to that connection and order), by adjustments (to facilitate removal of those interferences), plus the offering of healthy lifestyle advice.37
However, it is not known whether these findings might be generalizable to the wider profession. The aim of this present study was to survey a broader section of the profession to test such generalizability39,40 with respect to the above research questions about the meaning and value of vitalism. This article presents the methods and demographic results of that survey, statistical analysis of the responses to the survey’s closed-ended questions, and factor analysis of them.
METHODS
Survey Development
The Qualtrics online survey was used for data collection.41 The findings of a review of the relevant literature37 and of the above-mentioned interviews26 informed the development of the content of the survey questionnaire, which was pilot-tested. Apart from some items concerning demographics, all survey items were novel and developed by us. The survey was composed of up to 82 items, and the use of the Qualtrics display logic feature meant that the number of items presented to each participant depended on their answers to previous items. Up to 62 items were closed-ended and up to 22 were open-ended. Question types included 43 which involved Likert scale responses (with possible responses as follows: Strongly disagree/Somewhat disagree/Neither agree nor disagree/Agree/Strongly agree) and 10 which involved Boolean responses (Yes/No/Don’t know). The survey, the documents associated with it, and their use were approved by the Southern Cross University Human Research Ethics Committee (Approval Number ECN-16-161).
The first research question asked what chiropractors mean when they speak about vitalism. There are many varying understandings and descriptions of vitalism.4,42 So, to focus these meanings into a clearer concept, the first relevant survey item about vitalism was:
Proponents of the concept of vitalism argue that living organisms are fundamentally different from non-living entities in that the phenomenon of life involves a force or energy in addition to the physical or chemical. How strongly do you agree or disagree with this viewpoint?
This wording was derived from sources we considered authoritative,11,43 to offer respondents a general descriptive meaning of vitalism on which their levels of agreement could be determined. This wording was broadly congruent with the meanings given to vitalism by most interview participants.28
Recruitment
At the time of the survey there were 5,420 chiropractors registered in Australia and 606 in New Zealand. The largest potential sample accessible was the 2,174 chiropractor members of the Chiropractors’ Association of Australia (CAA) and the 440 chiropractor members of the New Zealand Chiropractors’ Association (NZCC), as these associations agreed to publicize and distribute email invitations to the survey. The survey was publicized by the CAA and the NZCA in their newsletters and via emails to potential respondents before these organizations issued email invitations to participate. These emails explained the study, the survey, and related ethics considerations, and invited these persons to use a link embedded in the email to access the survey.44 The invitations were then issued weekly while the survey was open for a month.
Data Preparation
The minimum sample size needed to detect an effect in the population at a prescribed statistical power was calculated45 based on a confidence level of 95%, a margin of error of 5% and an estimated effect size46 of 20.1%.47 The calculated minimum sample size was 226.48
The IBM SPSS statistics program was used to analyse the data into descriptive statistics to summarize and present the main data features and results.49 Then, based on the research questions noted above and responses to them,28,37,38 the constructs belief in vitalism (labelled Construct 1), belief in neo-vitalism (Construct 2), and value of vitalism (Construct 3) were devised to be addressed by confirmatory factor analysis.50,51 This process enabled investigation of the underlying structures of 3 groups of survey items by confirming a lesser number of more significant latent variables termed factors. The construct of belief in neo-vitalism was not included as there were only 27 responses to items concerning it.
The pre-factoring criteria of independence, sample size, normality, and linearity were met.50 Missing responses after data cleaning were replaced with the mean for that question to enable the use of those incomplete response sets in the factor analysis. Determinant values were calculated to assess whether collinearity was a concern, as were Kaiser-Meyer-Olkin (KMO) measures of sampling adequacy to assess factorability of the data. As all determinants were greater than .00001 there was no concern with multicollinearity, and as all KMO measures were above .6, all data were suitable for factor analysis.50
Factor analysis was then performed on each construct using principal axis factoring. For each construct, only 1 factor with an eigenvalue > 1 was identified, with such factors explaining enough variance to be retained.50 For all constructs the calculated factor explained substantial amounts of variance in the questionnaire data. See Table 1.
These results supported the use of the selected constructs in dimensional reduction to simplify and facilitate further data analysis. Because each factor was unidimensional, the items within each construct could later be averaged to compute mean scale scores. These scores were then used in calculating relationships between other variables in the survey data.
Factor loadings were calculated for the questions associated with each factor to indicate the relative amount each question involved with a factor correlated with that factor.46 This process aimed to improve the quality of the constructs by identifying questions that contribute poorly to the calculated factors. Results are shown in Appendix A. No items were excluded because of low loadings. All questions loaded highly onto their relevant related factors termed belief in vitalism, belief in neo-vitalism, and value of vitalism and these factors were highly correlated. This is strong evidence that these constructs could be legitimately used in factor analysis and statistical analysis based on them.
Factor analysis scale reliability was measured using Cronbach’s alpha.46,52 This was done separately for the 3 subscales, each comprising the original questions of the factors. For belief in vitalism Cronbach’s alpha was calculated to be .96; for belief in neo-vitalism .89; and for value of vitalism .98. All subscales therefore had very high reliabilities and all questions were highly correlated with an overall correlation between every possible pair of questions.
To simplify the data set for further analysis, mean scale scores were calculated for each respondent for each of the factors. This reduced the group of responses to each question within each construct into a single score. The score was computed as the mean of the responses for the questions within each construct. If not all questions within a construct had a response, the mean was computed using the subset that was available.
The direction and strength of the linear association between the mean factor scale scores of belief in vitalism, of belief in neo-vitalism and of value of vitalism were assessed by calculating a bivariate Pearson’s product-moment correlation coefficient (r).46 The results are shown in Table 2. These data showed highly significant correlation between these mean factor scale scores at the 0.01 level.
Calculations were also performed to determine whether the mean scores for each of the three constructs were significantly affected by demographic variables. The Kruskal-Wallis test was chosen to determine whether there were statistically significant differences between the mean scale scores of the factors for all but one of the demographic question.46,50 This test was done as the variables were not normally distributed.
When a significant outcome was determined by the Kruskal-Wallis test, it was followed up by a pairwise comparison to determine which groups differ from the others.46 In one case, the Jonckheere-Terpstra test was used to discern a trend across ordered groups. The independent-samples Mann-Whitney test was also used for responses to the question concerning roles in the profession, as there were only 2 independent samples (i.e. the respondents reported either participating or not participating in that role) involved for each response.46,50 See Appendix B.
In calculations concerning levels of agreement or disagreement placed on Likert scales, responses were numbered from one for Strongly disagreed through to five for Strongly agreed. In calculations concerning Yes/No/Don’t know responses, those responses were numbered from one to three respectively.
RESULTS
The survey yield of 411 responses represented 15.72% of the members of the CAA and the NZCA and was within the 10% - 20% response rate common for online surveys of this type.53 The raw data were cleaned54 to remove data from respondents who had failed to answer more than 3 survey questions. This resulted in 307 responses, which exceeded the minimum sample size of 226. Details of responses by country can be seen for Australia and New Zealand in Table 3.
Detailed sample group demographics can be seen in Appendix C. Of the survey sample, 72.6% were male and 27.0% female. The largest of the 4 amalgamated age categories was 30-44 years old (40.2%). Over half of respondents were under 44 years old. The largest single category for principal place of practice was the Australian state of New South Wales (24.4%). However, the response rate from New Zealand (24.1%) was proportionally the highest category as New Zealand practitioners represented 16.8% of potential respondents to the survey. The vast majority of respondents (89.3%) were in practice, with 69.4% in full-time practice and 24.4% in part-time practice. Some respondents reported multiple roles, such as practice and university clinical supervision.
While the largest single category of patients/clients/practice members per week was 50-100 (37.9%) patients visits per week, a majority (64.6%) of respondents saw between 50 and 150 patients per week. The largest categories of responses for institution of graduation were Phillip Institute of Technology/Royal Melbourne Institute of Technology University (28.8%) and Sydney’s Macquarie University (23.9%), reflecting that these are the largest and longest-established programs in Australia and New Zealand. Responses for the United Kingdom (n = 5), Europe (n = 3) and South Africa (n = 2) were small and were amalgamated into the ‘Other’ category.
The Meaning of Vitalism
As noted above, the survey section which addressed the meaning of vitalism offered a viewpoint on vitalism devised by the authors. With percentages rounded to 1 decimal point, a substantial majority (74.2%) agreed with this viewpoint, including 55.2% who strongly agreed. In contrast, 19.6% disagreed to some extent, including 15.0% who strongly disagreed. There was 1 missing response to this question (and 0-3 missing responses to most other questions). As can be seen in Figure 1, survey responses to this item formed the first of many similar asymmetrical bimodal distribution patterns throughout the results of this survey.
Universal and Innate Intelligence
Survey respondents were also asked for their level of agreement with terms interview participants had suggested for use in discussions of vitalism.28 These terms were universal intelligence, innate intelligence, organised energy, consciousness, interconnectedness, and vibration. Agreement (at 61.6%) was strongest for the use of the traditional chiropractic terms universal intelligence (UI) and innate intelligence (II). The term interconnectedness also received majority support (52.4%). The other terms, organized energy, consciousness, and vibration received less than 50% support, with the largest individual category of response in each being neither agree nor disagree.
A Guide to a Good Life
To investigate how respondents might use vitalism in guiding patients toward a good life, respondents were asked to select from a list of types of advice they offered in their practices. No advice was offered by more than 50% of respondents. The 8 most commonly selected types of advice were offered by between 40% and 50% of respondents. See Figure 3.
Vitalism as an Essence of the Identity of Chiropractic
A survey item asked whether vitalism is of essential importance to the identity of chiropractic as a distinct profession. In another distinct asymmetrical bi-modal pattern, 57.8% of survey respondents agreed, while 32.5% disagreed.
Vitalism as an Obsolete Historical Doctrine
As many interview participants had strongly supported the current existence of vitalism in chiropractic, survey respondents were asked whether they thought there was an ongoing stream of vitalistic thinking in chiropractic. This proposition was endorsed by 78.2% of survey respondents, while 12.7% disagreed. It was then agreed by 67.8% that this stream was a positive for the profession, while 25.8% disagreed. Why there were 67 missing responses to this question is not clear. In addition, 62.0% of survey respondents agreed that vitalism was a legitimate school of thought in chiropractic, while 34.6% of respondents disagreed to some extent. A majority (72.6%) disagreed that vitalism had no place in contemporary chiropractic practice, while 23.7% agreed. See Figure 4.
Similarly, a majority (65.4%) disagreed that vitalism had no place in evidence-based chiropractic practice, while 28.8% agreed. Indeed, when survey respondents were asked whether vitalistic thinking should be emphasised in all aspects of chiropractic, 60.0% agreed and 31.2% disagreed.
Vitalism and Neo-Vitalism
A total of 61.9% of respondents agreed with a description of neo-vitalism as a recognition and respect for the inherent self-organizing, self-maintaining, self-healing abilities of every individual. The 24.1% of respondents who neither agreed nor disagreed formed a larger group than those recorded in this response category for most questions on vitalism. However, the marked asymmetrical bimodal patterns of responses which were present in many questions about vitalism were not seen in other responses concerning neo-vitalism. When respondents were asked how strongly they agreed or disagreed that vitalism and neo-vitalism were essentially the same thing, 54.3% agreed and 36.7% neither agreed nor disagreed. Only 9.0% of respondents disagreed that vitalism and neo-vitalism were the same thing (i.e. believed that they were different), See Figure 5.
When respondents were asked whether they agreed that neo-vitalism was a more relevant concept than vitalism, by far the largest single response category, at 63.8%, was neither agree nor disagree. The disagreed categories totalled 18.8% and agreed 17.5%. See Figure 6. A similar result occurred when 57.3% of respondents neither agreed nor disagreed that neo-vitalism was a more acceptable concept than vitalism, while 13.5% disagreed and 19.2% agreed.
The Value of Vitalism
Responses concerning the value of vitalism also formed asymmetrical bimodal distribution patterns, with 72.5% of respondents somewhat or strongly agreeing that vitalism could offer value to the services chiropractors offer. This figure included 50.5% of respondents who strongly agreed. In contrast, 21.4% of respondents disagreed to some extent. When survey respondents were asked whether they agreed that activities based on vitalistic thinking and used in chiropractic practice could help address current global prevalence of chronic non-communicable conditions, 62.0% agreed and 25.9% disagreed.
Factor Analysis and Effects on Demographic Variables
These calculations indicated that none of the 4 amalgamated age groups differed significantly from the others with respect to endorsement of the 3 constructs. There was similarly no difference between how much respondents in the roles of full-time practice, or part-time practice, or university clinical supervising endorsed the constructs, and how much the other respondents did.
In contrast, female respondents had a statistically significant higher level of endorsement of belief in vitalism and of value of vitalism than males. Respondents practicing in New Zealand had a higher level of endorsement of belief in vitalism than did other respondents and New Zealand College of Chiropractic graduates had a higher level of endorsement of belief in vitalism and of value of vitalism.
However, university lecturers and researchers endorsed belief in vitalism and value of vitalism much less than other respondents did. Higher levels of belief in all constructs were associated with reported higher numbers of patients seen each week and lower levels of belief were associated with lower numbers. Overall, respondents with high belief in vitalism were proportionately much more likely to say that they give advice on healthy lifestyle specifically, or to give any of the forms of advice offered, than those with low belief.
DISCUSSION
This present research sought to test the generalizability to a broader sample of the profession of opinions expressed in the literature and the findings of previous research concerning the meaning and value of vitalism in chiropractic.28,38 Survey respondent demographics closely matched those of registered chiropractors in Australia55 and New Zealand,56 except for some variation in gender. While the age data were similar to that of chiropractors registered in Australia,55 corresponding data for New Zealand were not available. The data for principle place of practice in Australia were similar to those of chiropractors registered in Australia.55 The percentages of respondents who reported participating in the roles of practice, university lecturing, university clinical supervision and/or research were similar to those reported in a 2015 Australian survey.57 The data for number of patient visits per week were in accordance with the finding of a workforce survey57 that Australian chiropractors each see an average of 87 patients visits per week.
The similarities between the survey demographic results and the demographic characteristics from these other sources suggest that the survey’s results can be cautiously generalized more broadly to the profession in these countries. This is a key finding of this present research.
Overall, there was substantial majority support for the pro-vitalism literature and interview content.15,17–20,28,38 Specifically, majorities supported that an ongoing stream of traditional vitalism in the profession expressed in traditional terms was a positive and legitimate core value which was essential for the identity of chiropractic as a separate profession and which should be emphasised in all aspects of it.
In contrast, there was minority support for anti-vitalism opinions in the literature and interviews. Specifically, minorities supported opinions that vitalism was a negative, an obsolete dogma held by a minority of the profession and which should be eliminated because it excluded chiropractic from acceptance by science and society.21–28,31 However, only minorities supported opinions that vitalism had no place in contemporary and evidence-based chiropractic.21,24,27 Another important finding is that, for respondents to this survey, vitalism is the majority perspective and anti-vitalism is the minority perspective. This finding does not support literature that places vitalism in the minority position.21,27
While a majority of respondents agreed with the offered description of neo-vitalism, very few felt that it differed from vitalism and a substantial majority neither agreed nor disagreed that neo-vitalism was a more relevant concept than vitalism. Developments to replace traditional chiropractic meanings of vitalism with a new meaning33 therefore appear to have had little effect in Australia and New Zealand except perhaps among NZCC faculty.36
As noted above, the 3 constructs of belief in vitalism, belief in neo-vitalism, and value of vitalism were confirmed by factor analysis. Further calculations mostly showed no statistically significant differences between most demographic groups with respect to endorsement of these concepts. This consistent level of endorsement, regardless of age, is an important finding in light of previous results which found majority support for the meaning and value of vitalism and also suggests that the results of other research28,38 may be generalizable across a broader section of the profession.
However, there were some statistically significant differences between some demographic groups and the other respondents. Why female respondents endorsed vitalism more strongly than did respondents as a whole is not clear. However, as the percentage of the profession composed of female students and practitioners has been increasing for some time,58,59 vitalism may become even more deeply supported within the profession. The higher endorsement of vitalism by New Zealand graduates and practitioners probably reflects the vitalistic teachings of the NZCC.36,60,61
While just over 50% of respondents reported giving no healthy lifestyle advice to patients (including exercise), higher endorsement of vitalism was related to higher levels of giving such advice and to reporting seeing higher numbers of patient visits per week. This latter finding may support previous similar research.62 In contrast, lower levels of endorsement of vitalism were related to very low levels of giving such advice and to reporting lower visit numbers. While some have opined that vitalism could be associated with unethical practices, such as overservicing,21,28 there may be multiple reasons for these findings. For example, it may be that the personalities, explanatory frameworks, and services offered by many vitalistic chiropractors are attractive to many people who seek chiropractic care.
Similarly, there was no difference between how much respondents in practice or university clinical supervision endorsed vitalism, and how much respondents overall did. In contrast, university lecturers and researchers endorsed vitalism much less. It appears that fundamental differences may exist between the implicit ontological and epistemological positions of many practitioners and the positions of many educators and researchers. If so, this may suggest a gap between the philosophical approaches common in the larger practice wing of the profession and the approaches of many in the much smaller educational and research wings. This may not be an optimal situation for the development of the profession, as some lecturers may not share with undergraduate students ways of thinking common in the broader profession. In addition, the philosophical foundations of some research may not be congruent with the philosophical foundations of much of practice.19,21,25,26
Limitations
A larger sample size may have increased the generalizability of the survey. However, the sample used in analysis after data cleaning easily exceeded the calculated minimum sample size needed. The replacement of missing responses after data cleaning with the mean for that question enabled the use of those incomplete response sets in the factor analysis. However, this replacement may also have boosted correlations and upwardly biased factor loadings. Nonetheless, the severity of the data cleaning criteria (i.e. the removal of data from participants who had failed to answer more than three survey questions) should lessen this concern. In addition, the restriction of survey participation to members of the peak professional associations in Australia and New Zealand may have introduced an element of sampling bias63 and limit the generalizability of the results to other chiropractors in these and other countries.
The repeated patterns of similar asymmetrical bimodal distribution patterns seen in survey responses (e.g. Figure 1), suggest that few chiropractors hold opinions on vitalism between the extremes. However, this appearance may be due to volunteer bias, which can occur when only people with strong opinions participate in a survey.64 Opinions may actually range across a continuum.62 Finally, the ability of this present article to document respondents’ beliefs may have been limited by its reporting of only the responses to closed-ended survey questions. Responses to open-ended questions will be presented in a future article.
CONCLUSION
This research tested the generalizability to a broader sample of the profession of the contents of the relevant literature and of previous research findings concerning the meaning and value of vitalism in chiropractic. It did so via an online survey of a sample of chiropractors in Australia and New Zealand. That the demographic profile of respondents broadly matched that of registered chiropractors in those countries suggests that these previous findings might be cautiously generalized more broadly. However, such generalizability is limited by the sample selection and size.
Substantial majorities of respondents supported the pro-vitalism literature while much smaller minorities supported anti-vitalism positions. These findings build on the limited existing literature by greatly expanding knowledge of these issues from small samples of academics and interview participants to a much larger sample of practitioners and academics. The findings make a valuable contribution by enabling a shift in discussions on vitalism from opinion-based to evidence-based.
Future research should test the generalizability of the survey to larger samples of chiropractors world-wide; explore why there is a gap between many practitioners and lecturers and researchers concerning vitalism; consider whether this is an optimum situation for the profession and the public; examine why vitalistic practitioners report more patient visits than do non-vitalists; identify relevant vitalistic and non-vitalistic practice models; and, perhaps most importantly, explore why vitalism seems to be a popular and orthodox ontological position for many chiropractors.
ACKNOWLEDGEMENTS
Elizabeth Emmanuel, B.Nurs., M.Nurs. Ph.D., for assistance in design and analysis.
Jackson Richards, B.Eng., B.Sc., for assistance in statistical analysis.
CONTRIBUTION LIST
DR: Contributed to conception, design, data acquisition, analysis, drafting, and review. SG: Contributed to design, analysis, review, and editing.
ETHICAL STATEMENT
The Southern Cross University Human Research Ethics Committee provided ethics approval (Number ECN-16-161) for the study. Voluntary participation in the study survey signified informed consent.
FUNDING STATEMENT
This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
DECLARATION OF CONFLICTING INTERESTS
The Authors declare that there are no conflicts of interest.