PERSON-CENTERED DIAGNOSIS: PRINCIPLES AND PRACTICE It is more
important to know what person has the disease than which disease
the person has. —William Osler The purpose of this paper is to present an organizational structure for assessment of patients as unique individuals, an approach I have called person-centered diagnosis.[1] The goal of Person-Centered Diagnosis is to enable healers to develop individualized treatment plans that are based upon an understanding of the physiological, environmental, and psychosocial contexts within which each person's illnesses or dysfunctions occur. You must start by eliciting all of the patient's concerns. In actively listening to the patient's story, you attempt to discover the antecedents, triggers and mediators that underlie symptoms, signs, illness behaviors, and demonstrable pathology. Integrated medicine is based upon treatment that is collaborative, flexible, and focused on the control or reversal of each person's individual antecedents, triggers and mediators, rather than the treatment of disease entities. Eliciting the
Patient's Story The first step in patient-centered care is eliciting the patient's story in a comprehensive manner. It is the integrative practitioner's job to know not just the ailments or their diagnoses, but the physical and social environment in which sickness occurs, the dietary habits of the person who is sick (present diet and pre-illness diet), his beliefs about the illness, the impact of illness on social and psychological function, factors that aggravate or ameliorate symptoms, and factors that predispose to illness or facilitate recovery. This information is necessary for establishing an integrated treatment plan. The importance of understanding the patient's experience of his/her illness cannot be overemphasized. Extensive research on doctor-patient interactions indicates that doctors who fail to pay attention to the patient's concerns miss important clinical information. The conventional diagnostic paradigm, differential diagnosis, leads doctors to ignore or denigrate information that patients consider important, or that influences individual prognosis.[2],[3],[4] Not only does this ignorance impair the effectiveness of treatment,[5] it generates considerable dissatisfaction among patients.[6],[7],[8] Extensive research done within the context of conventional medical care reveals what most patients know: doctors do not pay enough attention to what their patients have to say. A study done at the University of Rochester found that most patients have three reasons for visiting a physician, are interrupted within eighteen seconds of starting to tell their stories, and never get the chance to finish.[9] Although doctors excuse this behavior by citing lack of time, it would have taken an average of one minute and rarely more than three minutes for a complete list of problems to be elicited. Even when doctors know what their patients' concerns are, they typically ignore them.[10] Most patients have different ideas about their illnesses than their doctors and some form of clarification or negotiation is needed for an effective therapeutic alliance to be established.[11] A study that carefully analyzed taped transcripts of visits to a medical clinic found that patients attempted to clarify or challenge what their doctor had said in 85% of the visits. Their requests were usually ignored or interrupted.[12] Understanding the patient's perspective allows the doctor to work in a collaborative way with patients, giving information that helps the patient make healthful choices.[13] The more information the patient receives from the doctor and the more actively the patient is involved in making decisions about treatment, the higher the level of mutual satisfaction, and the better the clinical outcome.[14],[15],[16],[17],[18] A systematic review of randomized clinical trials and analytic studies of physician-patient communication confirmed a positive influence of quality communication on health outcomes.[19] Such a collaborative relationship depends upon the practitioner recognizing and acknowledging the patient's experience of the illness. Useful questions to ask include: · How are you hoping that I can help you today? · What do you believe is the source of your problems? · What kind of treatment are you looking for? · What do you most fear about your illness? · What impact have your symptoms had on your life? Organizing and
Analyzing the Patient's Story What modern science has taught us about the genesis of
disease can be represented by three words: triggers, mediators and antecedents.
Triggers are discrete entities or events that provoke
disease or its symptoms.
Microbes are an example. The greatest scientific discovery of the nineteenth
century was the microbial etiology of the major epidemic diseases. Triggers are
usually insufficient in and of themselves for disease formation, however. Host
response is an essential component. Identifying the biochemical mediators that
underlie host responses was the most productive field of biomedical research
during the second half of the twentieth century. Mediators, as the word implies, do not "cause" disease.
They are intermediaries that contribute to the manifestations of disease. Antecedents are factors that predispose to acute or chronic illness.
For a person who is ill, they form the illness diathesis. From the perspective
of prevention, they are risk factors. Knowledge of antecedents has provided a
rational structure for the organization of preventive medicine and public
health. Medical genomics seeks to better understand disease by identifying the
phenotypic expression of disease-related genes and their products. The
application of genomic science to clinical medicine requires the integration of
antecedents (genes and the factors controlling their expression) with mediators
(the downstream products of gene activation). Mediators, triggers, and
antecedents are not only key biomedical concepts, they are also important
psychosocial concepts. In person-centered diagnosis, the mediators, triggers
and antecedents for each person's illness form the focus of clinical investigation. Antecedents and the Origins of
Illness Understanding the antecedents of
illness helps the physician understand the unique characteristics of each
patient as they relate to his current health status. Antecedents may be thought
of as congenital or developmental. The most important congenital factor is
gender: women and men differ markedly in susceptibility to many disorders. The
most important developmental factor is age: what ails children is rarely the
same as what ails the elderly. Beyond these obvious factors lies a diversity as
complex as the genetic differences and separate life experiences that
distinguish one person from another. Congenital factors may be
inherited or acquired in utero. They can most readily be evaluated from
a comprehensive family history, including mother's health before and during
pregnancy. Genomic analysis, which is now commercially available, can
supplement the family health history as a tool for investigating unique
nutritional needs or individual variability in sensitivity to environmental
toxins.[20],[21]
The commonest single gene disorders in North America, celiac disease and
hemochromatosis, may be confirmed by the presence of genetic markers, but
should first be suspected from abnormalities in routine lab tests. Elevated
serum ferritin concentration or transferrin saturation should prompt genetic
testing for the alleles associated with hereditary hemochromatosis.[22]
Increased small intestinal permeability, as measured by the inexpensive,
non-invasive and under-utilized lactulose/mannitol challenge test, has a
sensitivity approaching 100% for untreated celiac disease.[23]
Abnormal intestinal permeability should prompt the measurement of
celiac-specific immune markers in patients with chronic fatigue, autoimmune
disorders, or chronic gastrointestinal complaints of any type. Normal intestinal permeability in
patients consuming gluten almost always excludes celiac disease as a
consideration; however, this may not necessarily be the case for other
gluten-sensitive disorders. Because celiac disease and gluten-sensitive
disorders are common, have protean manifestations, and can be well controlled
by nutritional interventions, intestinal permeability should be a routine
component of the laboratory testing for antecedents of illness. The treatment
of choice for frank hemochromatosis is phlebotomy, but mild iron overload
without frank hemochromatosis is more common than the full-blown disease. These
patients generally have only one of the alleles associated with the disease,
but have elevated transferrin saturation and/or ferritin. They are not treated
with phlebotomy, and should be treated with dietary interventions. They should
not take iron or vitamin C supplements, because vitamin C reduces iron to its
more toxic form. Some familial disorders may
reflect intra-uterine rather than genetic influences. Twin studies of
hypertension, for example, indicate a higher concordance for blood pressure
between identical twins with a common placenta than identical twins with
separate placentas.[24]
Presumably, the shared placenta mediates subtle nutritional influences that
affect a tendency toward chronic illness in adulthood. Post-natal developmental factors
that govern the predisposition to illness include nutrition, exposure to
toxins, trauma, learned patterns of behavior, and the microbial ecology of the
body. Sexual abuse in childhood, for example, is associated with an increased
risk of abdominal and pelvic pain syndromes among women.[25],[26]
Recurrent otitis media increases the risk of a child developing attention
deficit disorder,[27],[28]
an effect that is not associated with hearing loss but may result from the
effects of antibiotics on the microbial ecology of the gut. Precipitating events are critical
antecedents that closely precede the development of chronic illness. They
represent a boundary in time: before this event, the person was considered
healthy; since the event, the person has become a patient. Understanding the
nature of the precipitating event may aid in unraveling the triggers and
mediators that maintain the state of illness. The commonest precipitating
events among my patients are a period of severe psychosocial distress, an acute
infection (sometimes treated with antibiotics), exposure to environmental
toxins at work or home, or severe nutrient depletion related to illness or
crash dieting. Useful questions for uncovering precipitating events include: · When is the last time you felt really well for more than a
few days at a time? · During the six months preceding that date, did you
experience any illness or major stress, change your use of medication or
dietary supplements, or make any significant life changes? Other publications of this author
present cases in which cryptogenic illness was found to be precipitated by
foreign travel, antibiotic use, dietary changes,[29]
smoldering infection, or the illness of a spouse.[30] Triggers and the Provocation of
Illness A trigger is anything that
initiates an acute illness or the emergence of symptoms. The distinction
between a trigger and a precipitating event is relative, not absolute; the
distinction helps organize the patient's story. As a general rule, triggers
only provoke illness as long as the person is exposed to them (or for a short
while afterward), whereas a precipitating event initiates a change in health
status that persists long after the exposure ends. Common triggers include
physical or psychic trauma, microbes, drugs, allergens, foods (or even the act
of eating or drinking), environmental toxins, temperature change, stressful life
events, adverse social interactions, and powerful memories. For some
conditions, the trigger is such an essential part of our concept of the disease
that the two cannot be separated; the disease is either named after the trigger
(e.g., "Strep throat") or the absence of the trigger negates the
diagnosis (e.g., concussion cannot occur without head trauma). For chronic
ailments like asthma, arthritis, or migraine headaches, multiple interacting
triggers may be present. All triggers, however, exert their effects through the
activation of host-derived mediators. In closed head trauma, for example,
activation of NMDA receptors, induction of nitric oxide synthase (iNOS), and
liberation of free intra-neuronal calcium determine the late effects.
Intravenous magnesium at the time of trauma attenuates severity by altering the
mediator response.[31],[32]
Sensitivity to different triggers often varies among persons with similar
ailments. A prime task of the integrative practitioner is to help patients
identify important triggers for their ailments and develop strategies for
eliminating them or diminishing their virulence. Although the identification and
elimination of triggers is not a foreign concept in conventional medicine, many
physicians neglect the search. A study was conducted by telephone in which
practicing physicians were asked how they would treat a new patient with
abdominal pain, who had a recent diagnosis of gastritis made by a specialist in
another town. Almost half were ready to put the patient on acid-lowering
therapy without asking about the patient's use of aspirin, alcohol or tobacco,
all of which are potential triggers for gastritis. The authors of the study
concluded, "In actual practice, ignoring these aspects of the patient may
well have reduced or even negated the efficacy of other therapeutic plans
implemented."[33]
Mediators and the Formation of
Illness
A mediator is anything that
produces symptoms, damage to tissues of the body, or the types of behaviors
associated with being sick. Mediators vary in form and substance. They may be
biochemical (like prostanoids and cytokines), ionic (like hydrogen ions),
social (like reinforcement for staying ill), psychological (like fear), or
cultural (like beliefs about the nature of illness). A list of common mediators
is presented in Table 1. Illness in any single person usually involves multiple
interacting mediators. Biochemical, psychosocial, and cultural mediators
interact continuously in the formation of illness. Table 1 Common Illness Mediators
Cognitive/emotional mediators
determine how patients appraise symptoms and what actions they take in response
to that appraisal.[34]
They may even modulate the symptoms themselves. People in pain, for example, experience
more pain when they fear that pain control will be inadequate than when they
believe that ample pain management is available.[35] Perceived self-efficacy (the
belief in one's ability to cope successfully with specific problems) is a
cognitive mediator that determines coping with illness. People with a high
degree of health self-efficacy usually adapt better to chronic disease,
maintaining higher levels of activity, requiring lower doses of pain
medication, adopting healthier lifestyles, and cooperating with prescribed
therapies, compared to people with low self-efficacy.[36]
Self-management education is designed to enhance self-efficacy,[37]
and has been shown to improve the clinical outcome for patients with several
types of chronic disease, including asthma,[38]
arthritis,[39],[40],[41]
and diabetes.[42]
The biochemical mediators of disease listed in Table1 are best known for their ability to promote cellular damage. Most are organized into circuits and cascades that sub-serve homeostasis and allostasis. In these networks, each mediator is multi-functional and most functions involve multiple mediators, so that redundancy is the rule, not the exception. The most striking characteristic of biochemical mediators is their lack of disease specificity. Each mediator can be implicated in many different, apparently unrelated diseases, and every disease involves multiple chemical mediators in its formation. Mediator networks that regulate
inflammatory and neuroendocrine stress responses have been the subject of
intensive research with important clinical implications. Comprehensive reviews
have appeared elsewhere.[43],[44],[45],[46]
Within the framework of integrated medicine, a key feature of biochemical
mediators is the natural rhythm of mediator activity, which is strongly
influenced by the common components of life: diet, sleep, exercise, hygiene,
social interactions, solar and lunar cycles, age, and sex. Aging, illness, and
chronic psychological distress up regulate activity of the inflammatory and
neuroendocrine-stress response networks. Regular physical activity down
regulates both. Integrating the Patient's Story After listening to the concerns
that led each patient to seek a consultation in integrated medicine, the
clinician makes a series of distinctions: 1)
For patients whose
main concern is optimal health and prevention, ask about present and past
health problems and the family health history. If these supply no indication of
illness susceptibility, then turn your attention to risk factors for future
illness: weight, fitness, type and level of physical activity, dietary pattern,
sleep habits, use of alcohol, drugs, tobacco, firearms, environmental exposures
at home and work, travel, sources of stress and pleasure, degree of involvement
with others, spiritual beliefs and practices, sexual relationships, hopes and
fears for the future. 2)
For patients with an
active health problem, always ask, "What was your health like before this
problem began?" An intake questionnaire that asks about previous health
problems is also helpful, because it gathers information in a different fashion
concerning what the patient was like prior to the present illness. Such a tool
is condition-specific, not open-ended. The two approaches complement one
another. a)
Some patients will say
that they were really healthy prior to their present illness. In that case,
look for a precipitating event. If you or the patient can identify one, then
ask about ongoing triggers that bear some relationship to the precipitating
event. For example: if the precipitating event was marital or job stress, focus
on stress-related psychological triggers. If the precipitating event was an
environmental exposure, focus on on-going exposures to volatile chemicals or
mold. b)
The most challenging
patients will usually indicate that their health was poor even before their
present illness. In that case, take a detailed, chronological history from
birth to the present that includes information about early life experience
(including illness, injury and abuse), school and work performance, diet, drug
and medication use, leisure activities, travel, family life, sexual
experiences, habits, life stressors and places of residence. Because gathering
this data can be very time consuming, a self-administered questionnaire
completed by the patient before the interview may help to prompt responses and
improve memory of remote events. For many patients with complex, chronic health
problems, it may be useful to take a detailed life history before
seeking detailed information about present symptoms. Problems that emerge from
such a review have to be addressed for a successful outcome of treatment.
Dealing with the present concerns by themselves almost never succeeds for
patients in this group. Whatever rapport you establish
with patients initially, maintaining the therapeutic relationship usually
depends upon significant improvement in symptoms or in a sense of well being
within a few days to a few weeks of the initial evaluation. Addressing the
triggers that provoke symptoms and helping the patient decrease exposure to
them most efficiently achieve this. When triggers cannot be identified or
avoided, then symptomatic improvement must rest on control of mediator
activation. A combination of the two will usually produce the most satisfactory
long-term benefits. Assessment of Triggers A comprehensive search for
triggers requires that you know the following about your patient: each
drug—prescription, over-the-counter or recreational—that the patient has used
and when; nutritional habits and each dietary supplement used and when; what
effects the patient noted from the use of each substance; sources of
stress—life events, environmental exposures, thoughts or memories, and social
interactions—and when they occurred in relation to symptoms. Elicit the
patient's own ideas about possible triggers by asking, "What do you think
causes or aggravates your symptoms?" The patient's observations may be
insightful and accurate in ascribing causality. Of course the patient’s—and the
clinician’s—observations can also mislead, or focus on non-essential factors.
Teach patients to challenge their own observations by looking for consistency
and replicability, wherever possible. Suggest alternative theories for the
patient to consider and explain that the search for triggers works best as a
collaborative effort between patient and doctor. The patient's ability to
recognize triggers is an important step in self-care. Food and environment supply
important triggers for the practice of integrated medicine. Food intolerance is
a very common phenomenon,
reported by thirty-three per cent of the population in one large study.[47]
Relatively few of these reactions (4-14%) are due to true food allergies. Most
food intolerance has no clear immunologic basis. Mechanisms include sensitivity to the pharmacological effect of
alkaloids, amines or salicylates in food.[48],[49],[50],[51]Histamine
poisoning from scombroid fish and tyramine-induced headache are dramatic
examples.[52]
Although most food intolerance is short-lived, severe chronic
illness can occur, and the food trigger may elude identification unless the
physician starts the investigation with a high index of suspicion. Gluten
intolerance, with its protean manifestations, is probably the best example.
Affecting about two per cent of people of European ancestry,[53]
gluten intolerance is common and often unrecognized. In addition to being the
essential trigger for celiac disease, gluten sensitivity may be manifest in
patients with neurological disorders of unknown cause,[54]
cerebellar degeneration,[55]
dermatitis herpetiformis,[56]
failure to thrive,[57]
pervasive developmental delay,[58]
inflammatory arthritis,[59],[60],[61],[62],[63]
psoriasis,[64],[65]
Sjögren’s syndrome,[66],[67]
and schizophrenia.[68],[69]
The different presentations of gluten sensitivity may derive from genetic
differences among affected patients.[70]
Published studies on food
intolerance and your patients' symptoms may be found through the National
Library of Medicine. If the patient has a disease diagnosis, an Internet search
may reveal previously observed associations between specific foods and the
patient's condition. Access PubMed over the Internet (www.pubmed.gov) and run a
search that cross-references the name of the patient's condition with
"Hypersensitivity, Food" and also with "Food, adverse
reactions.” Both of these are Medline Subject Headings (MESH). There is no MESH
listing for "Food Allergy" or "Food Intolerance.” Your search
will be more efficient if you list the patient's condition as it appears in
MESH. A negative search does not eliminate food intolerance as a trigger for
the condition being searched, but the number of positive findings may surprise
you.[1] Health effects of ambient air
quality are as important as those of foods. Numerous studies conducted in U.S.
cities demonstrate a close correlation between fine particle air pollution and
daily mortality rates, even at levels of pollution considered safe by the World
Health Organization.[71]
In the industrialized world, most people spend most of their time indoors, and
indoor air pollution has become a serious cause of morbidity. Studies using
experimental chambers have shown that volatile organic compounds (VOCs)
released from building materials, furnishings, office machines, and cleaning
products can cause irritation of the respiratory system in humans and animals
at levels which are one hundred times weaker than permissible exposure levels
or the World Health Organization Indoor Air Guidelines.[72],[73],[74]
Controlled experiments with people who describe themselves as sensitive to VOCs
confirm that VOC exposure causes headache, fatigue, and difficulty
concentrating. People who deny such sensitivity also experience symptoms but do
not experience mental impairment when exposed. Air samples of buildings with
and without “sick building” complaints have established an association between
VOC exposure and human sickness.[75],[76],[77],[78] A questionnaire can elicit important
information about environmental exposures at home and at work. The open-ended
question, "Has your work or home environment been a concern to you?"
should be accompanied by a checklist of potential exposures. Microbial triggers for chronic
illness present a particular challenge, as exemplified by the many facets of Helicobacter pylori infection.
Originally isolated from the gastric mucosa of patients with gastritis and
peptic ulcer disease, H. pylori has
been implicated in the pathogenesis of NSAID gastropathy,[79]
gastric carcinoma,[80]
lymphoma,[81]
and a variety of extra-digestive disorders, including ischemic heart disease,[82]
ischemic cerebrovascular disorders,[83]
rosacea,[84]
Sjögren’s syndrome,[85]
Raynaud's syndrome,[86]
food allergy,[87]
vitamin B12 deficiency,[88]
and open angle glaucoma.[89]
For elderly patients with open angle glaucoma and incidental H. pylori infection of the stomach,
eradication of H. pylori by antibiotics was associated with improved control of
glaucoma parameters at two years.[90]
The mechanism by which H. pylori
aggravates open-angle glaucoma is unknown, but may result from the ability of H. pylori colonization of the gastric
tract to trigger the local and systemic release of platelet-activating factor,
inflammatory cytokines, and vasoactive substances. In the case of untreated H. pylori infection, non-invasive
screening tests, including serum antibodies, stool antigens, and C-14 breath
testing, are available. For other types of infection, inquiring about the
previous response of a given symptom or symptom complex to antibiotics may be
useful. In 1988, physicians at the University of Minnesota conducted a study in
which they administered intravenous cephalosporins to patients with various
types of arthritis who also manifested antibodies to Borrelia burgdorferi. Most of these patients were not thought to
have Lyme disease. Some met diagnostic criteria for rheumatoid arthritis, some
for osteoarthritis, and some for spondyloarthropathies. The response to
antibiotics was quite variable and ranged from no response to dramatic and
sustained improvement. The authors noted that improvement in arthritis
following antibiotics was not related to the patient's clinical diagnosis or
the level of anti-Borrelia antibody.
The best predictor of a positive response to the experimental treatment was a
previous history of improvement of arthritis associated with the use of
antibiotics.[91] The most comprehensive way to ask
the antibiotic question is: "During the time you have had symptom X, have
you taken antibiotics for any reason? Which antibiotic? Did symptom X change
while you were taking the drug?" Among patients with chronic diarrhea of
unknown cause, for example, some will report that their gastrointestinal
symptoms improved when taking a specific antibiotic; others will report that
they worsened. The first case suggests that bacteria or protozoa sensitive to
the antibiotic may be causally related to the patient's gastrointestinal
problems. Repeating the antibiotic prescription can establish if this response
is replicable. If so, therapy can focus on treating the microbe and
understanding why a single course of antibiotics was ineffective. The second
case suggests that depletion of bacteria by antibiotics and concomitant
increase in antibiotic-resistant organisms, including yeasts, may be
contributing to diarrhea, and treatment can focus on restoration of normal
intestinal flora. Assessment of Psychosocial Mediators Useful questions for eliciting a
person's beliefs about his/her illness are: "What
do you think has caused your problem?" "What
do you most fear about your problem?" "How
much control do you think you have over your symptoms?" Useful questions for eliciting
information about the nature and sources of social support include: "Are
there people in whom you can confide?" "How
satisfied are you with your marriage/family/friends/social life?” "How
much support do you receive in dealing with your health problems?" "How
often do you feel loved or cared for?" Assessment of Biochemical
Mediators Understanding the biochemical alterations associated with a conventional disease diagnosis can be helpful in understanding the biochemical mediators of each person's illness. Inflammation is believed to play a critical role not only in response to infection and in the classic inflammatory diseases, but also in the pathogenesis of coronary artery disease, diabetes, cancer, depression, and the negative health effects associated with obesity and with aging.[92],[93],[94],[95]< |