The Biopsychosocial Model 25 Years Later: Principles, Practice, and Scientific Inquiry

In response to Drs. Borrell-Carrio, Suchman, and Epstein's request for "quotations from other authors...to verify our hypothesis that the biopsychosocial model began as a perceived need in many places simultaneously" -- I hereby submit one of my personal favorites. It comes from outside the clinical realm, but the ironic tone does seem to resonate, nowadays:

"It is fortunate that the Good Lord created the universe exactly divided into the traditional academic disciplines." -- Buckminster Fuller, Synergistics, 1975.

One might add that, indeed, it is truly fortunate that patients package their presenting problems into the traditional Office Visit increments. Indeed.

Competing interests:   None declared

I very much appreciated this article. For many of us, biopsychosocial practice is still the very definition of who we are as family physician generalists and a necessary paradigm for truly patient- centered care (yes I think it is a new paradigm). This article certainly goes a long way in reminding us of our roots, eliciting many of the difficulties encountered along the way both philosophical and practical, and tying biopsychosocial practice to new understandings such as complexity science. These are all critical to keeping us aware of how we think about what we do while grounding us in what we must do in practice to make it real and beneficial for our patients. This practical side is nicely outlined in the sections on the biopsychosocial model and relationship-centered care.

In addition to efforts at expounding new models for our future, we have to continually take time to reflectively consider the very ideas that drive what we do and ask ourselves if we still believe this or should it be relegated to the history books. Does this way of thinking still stir us to act differently than the systems around us? Does this supply us with fresh insights into how we ought to be advocating for our patients, defining quality, reshaping our practices, and formulating our research?

Though many have argued with me on this point, I believe we are still caught in a battle of paradigms, where the definition of differing “paradigms” is the difference in the ways we both THINK about ourselves and ACT on that understanding. Acknowledging that we do think and act differently than others is therapeutic and necessary to defining and explaining ourselves to patients that are hungry for a relationship- centered care and a system that can’t go on ignoring that fact. Biopsychosocial thinking and complexity (in essence a constructivist approach to the world) is illogical to logical positivistic thinking that still dominates most medical scientific theory and methods. Should we choose to acknowledge that and capitalize on that difference we too can move on into high gear with other successful examples of those moving on to something that better meets the needs of many of our patients, especially those with chronic disease and associated psychological distress. It wont be easy, but if we do we will be in good company. Examples include the movement toward highly successful Cognitive Behavioral approaches in Psychology and Transformative Education that is reforming many areas of education and practice. Do we have that kind of motivation in us for the future?

Competing interests:   None declared

I believe that Dr. Borrell-Carrió et.al. have provided us with a beautiful summary and discussion of the issues which are part of the currrent paradigm shift in medicine that continues to gain momentum. The authors and this journal have done an immense service by developing and publishing this article.

We are all familiar with laments about the failures and high costs of modern medicine, and the evils of managed care. Rather than looking at the technical service as the core "product", and the humanistic, relationship-centered, emotional aspects as the "packaging" and "customer service" parts that improve patient satisfaction, we need to realize that the latter are also essential parts of the total service. These aspects, integrated with the technical services are fully in line with the core intentions of medicine to prevent illness, support and promote the healing process for those who are ill, and maximize human potential.

Competing interests:   None declared

While we share Dr Medalie's skepticism about complexity science, it has become the lingua franca of theorists of family medicine, and thus deserves some mention; it would be conspicuous by its absence. In our (ALS and RE) conversations with George Engel in his later years, his view of biopsychosocial models seemed to evolving in that direction. If there are any further benefits to adding another set of jargon to the already complicated discussion of circular causality, these benefits will only be appreciated if, in the future, conceptualizing complexity can lend a different enough perspective on key issues in medicine, or at least crystallize what had been previously expounded in a more palatable and usable form. It is still too early to tell.

In that regard, we agree with Sturmburg et al. that the Biopsychosocial Model is incomplete, as are the revisions offered by Family Systems, Complexity Theory, and others. We take joy in the lack of completeness, and the impossibility of creating a theory that embraces all that is important in medicine. Our view is that our senses limit our ability to see the world-as-it-is, so any model based on our own sensory experience (including our own thoughts), shares that limitation. Some may add "spiritual", "relationship-centered" and "responsive" to the lineup of adjectives that we use in order to apprehend this complexity; when understood in an inclusive and scientifically verifiable way, these may also be acceptable additions. In other words, there will always be more dimensions, more interconnections among them, and more ways of apprehending them than we can imagine. Thus, we look forward to the somato -psycho-socio-semiotic model and all future models that supersede it.

Engel taught communication in the interest of furthering understanding of the patient, but I am not sure he proposed egalitarian relationships that later theorists proposed. He was a consummate observer of humanity, and often seemed more interested in understanding illness and suffering than treating it; anecdotally, he remarked publically (and proudly) on several occasions that he intentionally delayed treatment of hemorrhoids (from which bled until he was quite anemic) in order to study whether the pattern of bleeding in fact did correspond to the anniversary of his twin brother's death.

Thus, Engel may or may not have embraced all of the values that Sturmburg and others propose, but that is not the point; he, too, had his limitations, foibles and peculiarities. Dr Green provides us with sound advice -- to use theory, attention and reflection to inspire mindful action, not inhibit it.

Competing interests:   None declared

Interesting article. It is an important reflection concerning the future of the family medicine. Here in Porto Alegre, in the Rio Grande Do Sul, Brazil, since of 1974, we are with a proposal of comprehensive attention to the patient. With register in handbook of Family, work in team, territorial area of responsibility of the team. For such, since 1976, o Murialdo Health Center it initiated one of the pioneering programs in the formation of family doctors. Which the way to be taken more doctors to act with this logic?

Competing interests:   None declared

I had the good fortune of being a family medicine resident in Rochester under Gene Farley's visionary leadership and also to just happened to be in the family medicine center during a few weeks when George Engel was there, directly observing in real time the doctors and patients in their consultations. He permitted me to watch him watch--and I have said on occasion that I learned more about caring for patients from his off- hand muttering during his observations than any other single source. This personal experience of some 25 years ago gives me a context and a texture to my reading of this wonderful article and the track commentary so far. I want to pull out and comment on one of the paper's points.

The point in the paper about moving from objective detachment to reflective participant could serve as a galvanizing sound-bite for what is required to move into high performance primary care. We all, patients and physicians alike, so desperately need a time and place where we can consult, "mind-fully," and we physicians need a workload and practice systems that will permit us to be prepared, available, attentive--indeed "attending physicians."

The new model of family medicine articulated as a product of the Future of Family Medicine project that Dr. Scherger sees coming could provide such an environment. To be accomplished, almost certainly, policy must permit (1)sustained partnerships between personally chosen personal physicians and paitents, and (2)patient panel sizes that are right-sized and financed such that family physicians can actually get to know and share experience with a "reasonable" number of patients, perhaps 1000 or so, for now. The good news in all of this is that we have near-term, "linear approximations" of steps to be taken now to practically redesign the work of family physicians and implement new model family medicine.

This sort of paper provides intellectual anchors for what is probably the next moment of fertile revisions of family medicine. With a large primary care workforce, information technology, a will to collaborate with others, and a renewed respect for persons who dare become our patients-- couldn't substantial progress be made right now, to train and enable the reflective participant personal physician? How quickly can we get to multiple examples, coast to coast, of the new model of family medicine?

I personally hope we will not be seduced into arguing about what was or wasn't meant by the biopsychosocial model and just procede to use what we can from it. For me, this article energized me toward, not theory, but practical, transformative change. A good thing the last day of 2004.

Competing interests:   None declared

"We are not students of some subject matter but students of problems. And problems may cut right across the borders of any subject matter or discipline." (K.Popper, 1972)1

It is refreshing to see that Engel’s biopsychosocial model of health care hasn’t lost its appeal, at least to some. However, shouldn’t a retrospective also elaborate on what else has developed since? We feel that Engel responded to the thinking underpinning the “new physics and new biology”2 clearly identifying that complexity also occurs in clinical practice.

In retrospect Engel’s model has one major limitation, it is still “object” orientated in a material sense – the biology of the disease, the social context of the patient and his mental well-being. At the same time the model employs system hierarchies implying some linearity.

There are two problems here, the first of which had been addressed by Pauli, White, McWhinney et al. They unequivocally stated that “Contemporary science, by reducing all life phenomena to their physical or biochemical mechanisms, and their roles in communication to that of carriers of communication, profoundly limits the understanding of disease and even more so of health.” and they continued to argue that one has to “conceptualize health and disease as due in part not just to our material circumstances (e.g. genes and germs) but also to our life situations and the meanings we assign to these and other non-material circumstances.”3 thus introducing the concept of biosemiotics.

The other problem arises out of systems theory itself – systems are not hierarchical they are interconnected wholes with no one part being more important than any other. Hence the distinction between seeing the patient in a systems way, but acting pragmatically in a linear way may not be helpful. Any “intervention” to any one variable will have multiple effects, some of whom are circular in nature, others that will impact on but terminate its effect at a variable that does not feed back to the origin – some describe this as the unforeseen consequences of a decision. What the article was trying to articulate was that medical care is based on a common set of patterns, and in the current paradigm of medical care it is generally possible (and easier) to operate within a limited set of patterns e.g. disease management in a pragmatic linear way. However, truly embracing the biopsychosocial model requires recognition of the dynamics of complex patterns and adaptive systems, and requires a shift to a pragmatic complex systems approach rather than maintaining a linear way of thinking. The tragedy is that 25 years after Engel, such an approach is only starting to emerge with social complexity approaches. The practice of medicine has not caught up with the biopsychosocial theory..

System models of health and health care – as Engel made so wonderfully explicit – open the mind of its practitioners to think “outside the square”, to be complexity minded when dealing with patients, colleagues and administrators.

Engel’s intention clearly was to foster improved healing, and it is highly likely that he would have accepted the need to expand his model to include the need for biosemiotics. A clinician must embrace “understanding the patient” in his or her entirety in order to be able to enhance his or her “inherent self-healing capabilities” as Socrates put it.4 Understanding the entire patient is the secret of the healer’s power.

Engel was visionary in so far as he understood the limitations imposed by the – at his time accelerating – reductionist momentum of medical research; we need to be visionary to take his induction further for the sake of humanity and society at large.

We have proposed a redefinition of health translating Engel’s and Pauli’s work into a functional somato-psycho-socio-semiotic model,5 and extended from there to suggest that the health system, focusing on health rather than the current focus on disease management, can be conceptualized through a vortex model, the vortex being a metaphor of health as a complex adaptive systems.6 Both of these papers are currently under peer-review.

1. Popper K. Conjectures and refutations: the growth of scientific knowledge. London: Routledge and Kegan Paul, 1972. 2. Capra F. The Web of Life. London: HarperCollins Publishers, 1996. 3. Pauli H, White K, McWhinney I. Medical Education, Research, and Scientific Thinking in the 21st Century (Part two of three). Education for Health 2000;13(2):165-172. 4. Moes M. Plato's Conception of the Relationship between Moral Philosophy and Medicine. Perspectives in Biology and Medicine 2001;44(3):353-367. 5. Sturmberg J, Martin C. Defining Health - a Dynamic Balance Model. 2004 submitted. 6. Sturmberg J, Martin C. Rethinking General Practice - Part 1: The Health Care System and General Practice/Family Medicine, Part 2: Strategies for the Future. Patient-Centred, Socially and Economically Responsible Primary Care and the Leadership Challenges. 2004 submitted.

Competing interests:   None declared

Approximately 25 years ago, George Engel brilliantly conceptualized the comprehensive approach to medical diagnosis and treatment in what became known as the Psychosocial model.

The authors Borrell-Cario, Suchman and Epstein in a very interesting article, pay tribute to Engel and at the same time, proceed to fine-tune and detail certain aspects of the model. Are they splitting hairs, or adding to our understanding and further thinking of accepted concepts?

The majority of the points they raise are valid and important, but some should be further discussed and questioned. An example of the latter -- Does Complexity theory really help us understand and treat problems better than "circular causality with a series of feedback loops" -- I doubt if it is better at determining the hierarchy of options and the selection of the treatment priorities to effect change in behavior and health outcomes.

The other points are well taken and make interesting reading, and whether Engel would have agreed or not, the authors should be congratulated for their article which makes the reader think more deeply about accepted notions.

Jack H. Medalie

Competing interests:   None declared

Response to Drs Spencer and Scherger

Drs Spencer and Scherger remind us that the “proof is in the pudding.” This article was about theory, which hopefully will be of some use in highlighting the strengths of prior innovations and in informing new practices. The problem-oriented record is one such innovation. Dr Scherger advises us of the limitations of brief face-to-face meetings with patients that currently comprises the daily work of physicians. Technology can now provide several means for virtual presence, both synchronous and asynchronous, which we support wholeheartedly; we are involved in design of systems to support relationship-centered-care, including using the most sophisticated media available. But, such systems tend to break down in the total absence of direct human contact. As a business, medicine should learn from other sectors of industry, which still go to great effort and expense to afford personal meetings to the most important players (just walk through any major airport at 6am on a weekday), even in the era of video-conferencing. As humans, our basic neural structure still requires multisensory interaction that cannot yet be afforded what is shamelessly called “virtual reality.”

Competing interests:   None declared

Response to Dr Reis:

Dr Reis points out the disappointing efforts to incorporate promised new paradigms of health care, including evidence-based medicine, a biopsychosocial approach and, more recently, complexity theory (and, to add, narrative-based medicine, family-oriented primary care, community- oriented primary care and others). This is true even in domains where several such paradigms converge to provide the same message, as with the example of back pain that Dr Reis mentions, as well as unexplained somatic symptoms, and, for that matter, any chronic illness. However, all models of health are, by definition, incomplete. Practice guidelines do not teach prudence, a biopsychosocial model may not teach efficiency, and complexity theory may not allow for simple solutions to cut through the Gordian knot. Even if we can overcome these barriers, there is one that always will remain. Clinical Practice is a complex web of habits and responses to patient’s needs, and our capacity to change these responses and habits has a certain threshold, a certain limitation that we are unable to cross. If we are not aware of our own limitations, we can delude ourselves into thinking that we have incorporated a philosophical approach completely into our clinical practice. All of us are capable of applying new approaches during a period of time, but, when tired or unobserved, we find sometimes ourselves reverting to less effort-demanding habits. In that regard, the highest level of clinical practice cannot be achieved in a vacuum – we all need organizational and systemic factors that make it difficult not to get ongoing feedback about utilization and clinical outcomes and, most importantly, from patients.

Competing interests:   None declared

Response to Professor Gracia

Professor Diego Gracia highlighted several importants points, not always recognized in the biopsychosocial literature. We thank him for the opportunity to expand upon some ideas. The first point Professor Gracia introduces is the lack of philosophical interest of biopsychosocial model. Historically, Engel was a clinician first, and based his model on empirical observation; philosophical justification came later (1). This model is loosely based on General Systems Theory (GST). This theory probably is more a model than a true theory, and even though this argument is beyond the focus of our article, it should be said that GST has not been seriously revisited or updated, as far as we know. After more than 25 years of existence, it is interesting to consider at what point GST has helped to promote new knowledge for scientists. As we have said in Appendix, EO Wilson’s “consilience” concept emphasizes a similar and now- familiar theme – that all scientific fields are moving towards each other, launching bridges that help us to see our world and the cosmos in a presumed original unity. However, the way knowledge advances is much more chaotic. Sometimes we have the gift of discovering some of these bridges; other times we simply find ourselves exploring an island without apparent connections with the rest of scientific knowledge. Is it a mere question of time to discover these bridges that will bring to us the whole picture of the universe, and more concretely, of the human being? It seems that to answer “yes” or “no” has little intrinsic value – would one act differently if it were or were not true?

In the Appendix we have argued that it is not certain that our formal languages, such as mathematics, would be the perfect tools to explain such as complete reality. Maybe we will invent other languages to approach more complex problems. In any case, GST was formulated in a moment that multi- disciplinary approaches appeared as a new frontier to many fields; it is a question for historians of science to what extent GST facilitated this new climate, spawning new fields such as sociobiology and psycholinguistics, and to what extent it provided insights to these new fields. Perhaps some similar process took place in Medicine, and the biopsychosocial vision facilitated some multidisciplinary approaches. Is it a modest result, considering expectations biopsychosocial model generated? An accurate answer should take into account to what extent the biopsychosocial model facilitated an interrelationship between different fields, and if that relationship would have taken place without the biopsychosocial model.

A second question Professor Diego Gracia introduce is the causality problem. It is true that our naïve perception of the world captures some patterns, and we are prone to say that these patterns are “causal” merely because they appear in proximity. In these cases, “modus tollens” (indirect proof) might suggest a more comfortable and secure perception of the world. For example, tuberculosis is most of the time cured using medication that eradicates the tubercle bacillus, so probably it is true, at least, that this bacillus has a role. We think about causality and "true" causality as far as we are able to modify our world.

Pragmatism has in this "final" result the cornerstone of its philosophy: be aware in what way we can see the world to find solutions that give us truly different results. That means: "if I think about the world in this new way, do I have a different result from the previous way?" In our case: "is it worthwhile to think about our reality ignoring a causality model?" "Is there an alternative and more productive model?" In this respect we can say that our assumptions about causality many times are weak, for example, modus tollens is a tricky way to assess a treatment, (it may not always work as expected, and there may be other factors influencing the result, etc.), and we need some model to explain how this treatment works. In fact we don´t achieve a level of knowdledge until we explain how it works, for ex.- how an antibiotic works. Only then we can distinguish between a probably true casuality from a functional and evasive relationship. Unfourtunatly our explanations of the World always are limited, as Hume pointed out. Is there a mere contiguity or succession mechanism, at submolecular level, as he though? If we answer "yes" to this question, as Hume did, we are not forced (as he presumed) to renounce a causal model. It may be argued, for example, that this mechanism is not acting universally, but selectively, and to know the precise way "bodies", (that is, persons, atoms, subparticles...), interact with each other, we need some causal model. In this respect, the purpose of a structural causality model is not only because it contains a sense of truth, but also because it helps us to think about reality. Following the philosophy of pragmatism, if this structural or circular model helps in this way, we can go along with it, until we develop another more useful model.

It can be argued that we should not confuse our theories of causality with “true” reality. Kant was one of the first philosophers to point out that the perception of the reality is not true reality, but we are limited, as humans -- the only way to progress towards reality is through our perceptions. We agree in this respect with Professor Gracia that our knowledge, now, is more fragile than ever, and constantly put at risk by other theories. But this fragile character should not eclipse the utility of a limited structural causality model, when it provides a means for scientists to explore problems.

Considering structural causal model and circular causal model, in the sense to query in what way actually both are helping us to think about the world, we suggest that a circular model helps the clinician to open his/her mind to think about the world with less prejudices. But circular model is not enough when we have to choose a strategy to influence illnesses and clinical outcome. When we decide that one clinical strategy is better than another, or that we introduce a small intervention in a family to produce great changes, we always are keeping in mind a certain structural causality model, (recognized or not recognized).

Finally Professor Gracia pointed out – and we agree -- that the construction of a holistic model of the human being model is still an open question. In our Appendix we suggest that the historical discussion between monistic and dualistic positions was a false way to face this question. Our knowledge advances, always describing new fields and new systems, and, afterwards, connecting them, exploring their properties and frontiers. It is not helpful to emphasize either the boundaries or the “consiliences”, because science is advancing due both. We think that we are still quite far from understanding this holistic model because our knowledge about human being is still fragmentary; consider, for example, how little we know about the influence of genetics on brain function, and the influence of that interrelationship on self-concept – who we think we are. Human philosophers and scientists – now and in the past- are prone to think that we are almost to capture the full complexity of what we are studying, as if we were at the highest level of possible human knowledge. But we are not. And sometimes it is worthwhile for us -as Professor Diego Gracia did- to recognize it.

REFERENCES.-

1. Brown T. George Engel and Rochester's Biopsychosocial Tradition: Historical and Developmental Perspectives. In: Frankel R.M., Quill TE, Mc Daniel S.H., editors. The Biopsychosocial Approach: Past, Present, Future. Rochester New York: University of Rochester Press, 2003: 199-218.

Competing interests:   None declared

Response to Dr Farley

We appreciate very much Dr. Farley’s contribution to the discussion of the biopsychosocial model. It is interesting to note that in Spain, at the same time as Dr Engel was elaborating his model, others (such as Drs Gol i Gurina, Tizón, Casares, and Ramis) were thinking in a similar way. Here are two quotes from Dr Gol i Gurina:

“The ill person achieves a state of health not with the simple restitution to normal of an organ or an altered function, but also includes attending to personal values, and mental and social well-being; in this sense, partial understandings never quite right.(1)”

For the second quote, note that in Spanish there are two verbs, “to be”. Estar connotes a state of affairs, whereas ser connotes a more enduring trait.

“It is necessary to find a word for “[a state of] well-being” that correctly expresses the notion of a satisfactory existence. The proposed word is “[a trait of] well-being” that accentuates the more fundamental and personal traits that define a satisfactory life, and not just good fortune or superficial accomplishments. This trait is compatible with all types of undesirable states of health while the core personality does not seem to be affected; even in the face of physical pain and social unrest, for example, one can still experience a deep sense of contentment, or at least enjoy a state of satisfactory engagement with the world. It is a harmony with oneself and others, establishing a a positive relationship with reality, as much with external reality as that reality that resides within each of us. By, “positive relationship”, I do not wish to imply that it is a passive, resigned, or even friendly relationship. I wish to say that this is a relationship that is not based on resentment or frustration; [rather], it is a relationship that motivates one to change reality, or at least one’s attitude towards reality. And that all of this is experience with a sense of satisfaction.(2)”

These quotations mean that probably in those days (1970-1980) there were in Western societies a more global movement against biomedicine ideology than previously recognized. We invite other readers of the Annals of Family Medicine to afford quotations from other authors and countries to verify our hypothesis that the biopsychosocial model began as a perceived need in many places simultaneously, in response to a medicine that was forgetting human values, with convergent thinking -- and, in some cases, similar solutions.

However, as a construct that grew out of a social need defined by time and space, we remain cautious about which aspects are empirically sound and which have become superseded, and also the degree to which a model that was based on empirical observations risks becoming a rigid belief system that resists questioning and change.

REFERENCES-

1. Roselló,Oriol. Entrevista amb el Dr. Jordi Gol i Gurina. En: Jordi Gol i Gurina (1924-1985). Els grans temes d´un pensament i d´una vida. Ed. La Llar del Llibre. Punt de vista. Barcelona 1986.

2.Gol i Gurina J. El benestar, la joia i la salut: acotacions al plaer des de fora del tema. En: “Els homes davant el plaer” Qüestions de Vida Cristiana. Nº 96, 1979.

Competing interests:   None declared

Borrell-Carrio, Suchman and Epstein’s “The Biopsychological Model 25 Years Later:…” was a much needed and timely contribution and should be read by all medical students and young physicians. What I missed in the article and in the comments so far (apart from a hint by Scherger)was any mention of “tools” to facilitate the practice of BPS medicine – past, present and future.

I still think that to date the best – maybe the only – tool is the updated problem-oriented problem list, which Larry Weed taught us to use in every medical record, at about the same time that George Engel taught us the BPS model. In a famous speech, which Weed gave at breakfast during an early WONCA meeting in Australia, he said:

“You can’t get patients well unless you know their psychiatric and medical and social problems. Don’t send them out on a low salt diet for problem #1: heart failure, and problem #5: lives all alone, no heat in the house, cooks his own meals, is 85 and half blind. You don’t need to be a cardiologist to know that this wont work.”

Maybe someone should write a companion-article enitled: The Problem- Oriented System: 25 Years Later…”

Competing interests:   None declared

Brief office visits are not conducive to practicing the biopsychosocial model or relationship-centered care. The productivity targets of visits per shift and RVUs simply have family physicians racing through patient visits, and make the philosophy expressed in this excellent article a pipe dream. I believe that a new model of family medicine can be much more biopsychosocial and relationship centered when we provide continuous care not dependent on visits. With an online platform of communication, patients and physicians have an open and frequent portal to sharing and caring. I hope that the authors, leaders in keeping the biopsychosocial model alive, and promoting relationship- centered care, will study the new communication tools and how helpful they can be.

Competing interests:   None declared

Borrel-Carrio, Suchman and Epstein are making the bold leap of trying to take stock of Engel's work over 25 years after it has been written up and gained a widespread recognition. Their paper lends a panoramic view, almost breathtaking, while integrating new and deep approaches that have emerged since Engel. I enjoyed reading it and found it valuable both as a state-of the art summary and as a springboard for further elaborations. It is placing the interest in complexity science at the center of the contemporary iteration of Engel's model, where it belongs. It also underscores a practical view of clinical practice which I share with tenets such as mindfulness, clinician calibration, attending to emotions and a flexible Patient-Doctor relationship.

Engel inspired a generation of clinicians and educators who were happily embracing the "paradigm shift" that his vision predicted. I agree with the authors that this shift has not occurred. The breakthrough that will transform health care, health professions education or medical research is still a dream.

It should be stated also that in the same way as the biopsychoscial (BPS) model have not come up with a widespread clinically useful and widely accepted transformed patient care protocols, so do the complexity model applications to health care. For example, Low Back Pain in Primary Care- a clinical care, education and research domain I am familiar with that may be looked at as a metaphor of Health Care in general. It has enjoyed a remarkable 2 decades of high quality research, a proliferation of evidence-based guidelines,a strong biopsychosocial approach and multi- level interventions on the patient, physician, health and social systems as well as the public at large. This was called a "LBP revolution"( 1 ) and yet, LBP care is still technology dominated, primary care clinicians feel disempowered when faced with LBP care and there is an ever-growing burden of suffering due to LBP( 2 ). The way from this dire assessment to a genuine shift through the application of an updated BPS model reinforced by relationship-centered care and backed by complexity science is neither clear nor simple.

The story told in the paper and in the present comment is neither a triumph, nor a chaos one. It is a clinician's quest narrative.(3) Our community of reflective practitioners will continue its quest informed by this welcome contribution.

1. Waddle G. The Back Pain Revolution. Edinburgh: Churchil Livingstone.1998. 2. Deyo RA, Weinstein JN. Primary Care: Low Back Pain .NEJM 2001;344:363-370. 3. Frank AW. Just Listening: Narrative and Deep Illness. Fam Syst & Health 16:197-212, 1998

Competing interests: None declared

Competing interests:   None declared

Borrell-Carrió, Suchman, and Epstein begin their article with the statement that Engel’s biopsychosocial model “is both a philosophy of clinical care and a practical clinical guide.” My personal impression has always been that Engel’s contribution has been much more important in the clinical level than in the philosophical one. And reading the paper of the authors I concluded that they are also of the same opinion. Nowadays, 25 years after his seminal work, there is no doubt that the biopsychosocial model has had very important and positive consequences in the clinical setting, changing behaviours, and promoting a more comprehensive understanding of patients. My only caveat is about its philosophical relevance. In general, philosophers aren’t very prone to construct systems through the sole addition of different perspectives. Addition is not considered enough. And appealing to Bertalanfy’s General System Theory does not, I think, resolve the problem. That is the reason why the influence of Engel’s model in the philosophical setting has been so little. The question is how a “holistic” model should be built. Can the “whole” of the human being be defined as bio-psycho-social, or it is necessary a completely different approach in order to understand this “whole”? This is the first problem. The rejection of the monistic molecular reductionism, and the holistic-energetic view, is not enough.

Another question is about “causality”, and the use of it not only by Engel but also by the authors of this paper. After the critical analysis of the idea of causality written by David Hume in the mid 18th Century, causality is a very strong word. “When I cast my eye on the known qualities of objects -wrote Hume-, I immediately discover that the relation of cause and effect depends not in the least on them. When I consider their relations, I can find none but those of contiguity and succession; which I have already regarded as imperfect and unsatisfactory.” Causality is only a “belief”, impossible of being tested in the empirical world. The only thing we can assert is the existence of “relations”, and, therefore, of “correlations.” The traditional idea of causality in medicine should be substituted by the more humble term “functional relationships” or “functional correlations.”

I completely agree with the authors of the article when they say that the work of Engel can’t be considered a “paradigm shift” from the philosophical point of view, even though its importance from the clinical point of view is indisputable. I agree also when they stress the importance of the biopsychosocial model in clinical practice, as the background of what they call “a relationship-centered care.” The problem is the construction of a holistic model about the human being, healthy and sick. To my mind, this is still an open question.

Competing interests:   None declared