General Issues in Prevention
Is Prevention Better than a Cure?
(Version of July 2013)
Printable PDF Version
Preventive medicine is widely assumed to be much better than a cure. However, critical assessment has
shown that this is often untrue (Gervas, Starfield, Heath, 2008; Russell 1996).
Preventive activities such as immunization are very attractive given the apparent simplicity of the
intervention and the resulting long-term prevention of disease. However, efficacy of many immunizations
is less than perfect and the time, effort and cost required for a very small benefit is not always worthwhile.
Behavior changes, such as smoking cessation, increased physical activity, and a healthy diet, can be very
effective in reducing risks associated with disease and death. Yet providing behavior change advice to
people who have the ‘wrong' behavior is only effective for a few individuals (Kingsbury, 1998). Hence,
considerable effort is expended in order to see benefits among the few who change. In addition, these
benefits may not be noticeable until many years later, when the individual does not die of the cancer or
heart disease, but instead survives a few more years to die from a different cause. By comparison, treating
an individual who has a disease provides immediate payoff and has a much higher chance of benefit.
There are fields where screening has been used very effectively, such as in child health and obstetrics. Most
antenatal care is effectively a screening program. In these fields, screening programs are delivered along
with patient education, immunization, and behavior change. Yet in both situations there have also been
failures wherein programs were introduced prematurely or inappropriately and were subsequently
withdrawn. Arguably, there has also been excessive servicing with preventive services beyond what is
necessary, and these have entailed substantial extra cost, effort and wasted time that could have been used
for other purposes. Thus, it remains necessary to carefully appraise all preventive care programs to ensure
that they are appropriate, particularly as society changes and as medical knowledge and technology
increases.
In recent years commercial and professional organizations that profit from increased treatment of particular
"diseases", have developed and promoted screening. There is always an underlying scientific rationale, for
a small proportion of the public. However, to increase the market, the margins of recommendations are
often stretched, especially including more people from the working age population, who can afford both the
diagnosis and the long-term treatment. Those trends are particularly notable in the United States, where the
pressures from commercial medical and pharmaceutical companies are highest, and preventive care
recommendations most susceptible to such commercial bias. Therefore, while US based recommendations
are often cited, we have been cautious and prefer those from countries where policies and recommendations
are more evidence-based and less subject to conflict of interest.
Levels of Preventive Activity, and Scope of this
Document
Preventive activities are conventionally divided into social or public health, and clinical. The public health
activities are arguably more important of the two, but there is some overlap between the approaches. These
guidelines focus on clinical preventive activities of the types that occur in medical consultations,
particularly with respect to those aimed at patients in the general population who have not yet developed
disease.
There are three classes of preventive approaches, differentiated according to disease status.
Primary Prevention: Stopping disease before it starts: this includes general behavior change in fields such
as smoking cessation, dietary change, and exercise. It also includes more disease-specific activities, such as
immunization.
Secondary Prevention: Detecting early disease at a time when treatment is more effective than waiting for
clinical presentation. This includes screening, and to some extent early diagnosis of symptomatic disease.
Tertiary Prevention: Activities targeted to individuals with established disease, with the aim of reducing
adverse events and complications associated with treatment. In addition, tertiary prevention efforts seek to
limit further events that are likely because of high risk. These are often highly effective, since making a
small change among high risk patients can provide a high pay off. For example, an intensive quit smoking
campaign can reduce mortality after hospitalization for ischemic heart disease with NNT of 11 (Mohiuddin
et al 2007). Recommendations for this tertiary prevention are specific to patients' clinical problems. We
have not gathered them here.
Barriers to Preventive Care
Though most physicians practice some preventive medicine, there is wide variability in its administration,
and effective preventive medicine is underutilized. The causes of these include:
1.
2.
3.
Physician Factors: Some methods of preventive medicine such as counseling are unfamiliar and
many doctors are not comfortable using them. Gratification from the process is often delayed and
indirect. In busy clinical practices it is difficult to spend time unless specifically allotted and
encouraged by the payment system. There may also be conflicting recommendations. Finally the
attitude and personal practices of the physician influence their delivery of preventive care.
Patient Factors: Lack of awareness of the benefit of preventive measures and not recognizing
them as personally relevant, lack of desire to change unhealthy behavior often due to social and
cultural norms, cost of the procedure and discomfort all discourage patients from seeking, or
following through on preventive medicine.
Health System Factors: Inadequate reimbursement, lack of insurance, population mobility,
multiple physicians for a patient and inadequate information systems are all barriers placed by the
health system to administration of preventive maneuvers.
However, among some groups of both doctors and patients, preventive medicine is overdone. The reason
for this includes a general mindset in favour of intervention, and belief in the value of prevention without
critical appraisal of cost and harm. This may occur among those who request the "Annual Physical" and
"Executive Medicals" (Sackett 2002, Rank 2008, McCartney 2013).
Our recommendations are designed to help overcome the problems of conflicting recommendations by
providing a consistent approach, reducing the burden of tasks believed to be worth performing, and
assistance with changing attitudes and personal practices. Doctors may be able to change at least what
happens in their own offices, through reminder systems and use of staff to perform many tasks, especially
to the extent that payment systems now provide assistance.
Gradients and Cut-Offs
Most biological measurements exist on a measured scale gradient. Examples of biological gradient include
measure of blood pressure, cholesterol levels, calcification in x-rays, or the degree of abnormality in cell
nuclei. For purpose of decision-making and classification, a cut-off point on the gradient is set to
differentiate between normal and abnormal measures. The cut-off point serves as the action threshold
whereby abnormal measures from a screening test are further investigated while normal measures on the
other side of the cut-off are ignored. There is little difference between patients whose scores are adjacent to
the cut-off point on either side, while those well beyond the cut-off point clearly have more severe risk for
disease. This becomes more important when there is overlap in measurement between people who will not
develop the disease and those who are destined to get the disease. The choice of cut-off point determines
the sensitivity and specificity of the test and, therefore, the accuracy of the screening program.
In order to be most effective, screening policies should be based on high quality cut-points that are
followed precisely. Policies that lack ideal cut-points will mean that actions will be taken on some people
where the balance of harm outweighs the possibility of benefit, resulting in substantial harm.
On the other hand, some doctors tend to reify the result, so that a person whose level of glucose,
cholesterol, or blood pressure is just above the cut-off is regarded as having the “Disease” and treated as
vigorously as those with levels well above. Controlling results for patients with such slightly elevated
levels is much easier than those with higher levels, where the real harm and potential benefit from
intervention is found. Such black and white thinking often fails to recognize the potential for fluctuation in
results and statistical error in measurement. Indeed treating people with slightly high levels often succeeds
because of “regression to the mean” whereby a high level at one measurement is lower at the next, purely
because of random variation.
Since most cut-points are arbitrary rather than ideal, there should be some degree of flexibility in their use,
recognizing that people are individual, and risk assessment is an inexact science. Recently the use of risk
scores, combining several risk factors for disease allows better decisions about who should start treatment.
Examples are the Findrisk for diabetes screening, FRAX for risk of osteoporotic fractures, and various
iterations of Framingham risk scores for coronary heart disease. The graphical displays of the New Zealand
Guidelines Group depict how risk increases according to various factors in the Framingham scores
(http://www.health.govt.nz/publication/new-zealand-cardiovascular-risk-charts).
If preventive activities are applied to people who have no or extremely low risk of the disease, they are
very wasteful of time and effort, with minimal chance of benefit. Since most screening programs also have
substantial probability of causing harm, both minor in terms of anxiety and inconvenience from further
investigation, and major in terms of complications or even death from investigations or overtreatment,
screening is only worthwhile when the probability of benefit is greater than the chance of harm. It is critical
to follow age-specific screening guidelines in order to achieve the right balance between the benefits and
harms of screening. However, assessments of risk against benefit are subjective and often individual, so
there must be some flexibility, to respond to individual perceptions and values. This is allowed for in the
GRADE method of describing interventions used by the Canadian Task Force.
Age and Disease
The incidence of many diseases increases substantially with age. For example most cancers only start to
develop after the age of 40 and the incidence only becomes substantial after the age of 60 (see figure 1which shows the four most important cancers for male and female). However, some cancers develop earlier
- for example, cervical and testicular cancer. Hence, screening policies are decided on the basis of when
particular diseases are likely to be sufficiently common to make the prevention program worthwhile.
High Risk Populations
Most recommendations about screening and preventive activities are made for the general population based
on standard risk populations, largely because the research has been done on such groups. However, the
multicultural nature of Canada presents the need to recognize subpopulations within the general population
that have substantially higher or lower risks of disease. Differences in risk may be based on genetic,
lifestyle, exposure or socio-economic factors. These guidelines will include, whenever possible,
recommendations specific for subgroups within the Canadian populations, such as Aboriginal, Asian,
Indian and eastern European. They will also include the other factors where their application is clear.
Group data applied to individuals in our setting
Family physicians perform individual care. This requires understanding the personal risk of the patient in
front of them. The majority of information in medical literature is developed from group data, which
necessitates that physicians extrapolate from the group back to the individual. Unfortunately research is
often done originally in high-risk groups - for example, the West Of Scotland Coronary Prevention Study
(WOSCOPS) was deliberately performed in a population with one of the highest risks of heart disease in
the world, in order to make it easier to demonstrate the value of statins in primary prevention of coronary
heart disease. However, results from this population cannot easily be applied to populations that do not
have the high level of risk found in that location. A study recommending screening for STDs among United
States inner city adolescent populations will not apply to a rural Mennonite girl. Thus, evaluations must
always include an assessment of the external validity of the primary research to the population of which our
patient is a member.
Relative value of alternative interventions
Interventions of different types are difficult to compare. For example, to prevent coronary heart disease,
helping patients to quit smoking early in life is probably the most effective. However, it is difficult and
only a small proportion of patients change. Reducing blood pressure is a more effective intervention, and
the majority of patients take enough medication to reduce their blood pressure and consequently their heart
and stroke risk. Encouraging people to exercise and diet works less effectively, since once again, only a
proportion of people are able to sustain these changes, though those who do possibly gain more benefit than
the drug treatments. On the other hand, cholesterol-lowering drugs are expensive, reduce risk only
moderately and have substantial side effects but a higher proportion take their drugs than persist with
exercise. Making a choice between these interventions, each performed on slightly different segments of
the population with different effectiveness and acceptability is difficult. Currently, no simple system exists
to allow clear ranking of these efforts. However, doctors must make these choices, given the limited time
and energy available for preventive activities compared to all the other useful activities we could perform.
At present we must prioritize based only on rough assessments of individual disease risk, how much it can
be changed, how likely that change is to happen, and how much cost or effort is needed both by the
professional and by the patient.
What periodic interval?
In North America, “the annual physical” has become institutionalized. Assessment of its value shows that it
provides minimal benefits, is costly, and diverts energy form worthwhile medical activities. Rather than
“annual physical” the focus should be on periodic health assessments: at appropriate intervals for the
person, and focused on activities that may benefit health: which mainly comprise behaviour screening and
change, immunizations, some pharmacological interventions, and a very few screening activities, some of
which require physical examination. These are described in our spreadsheet.
This may seem counter-intuitive, but there is substantial literature on the subject, and most countries of the
world do not perform these rituals, often with better health outcomes than in North America
The interval for periodic assessment of an individual should be based on the shortest suggested interval for
activities relevant to them. For example, since Pap smears are performed every three years, it is convenient
to also undertake other preventive activities every three years for young women. However, for a woman
over 50 years, mammography is recommended every two years, so this becomes the primary interval.
Because effective activities are so few it is not appropriate to spend a great deal of time on a healthy
person. Many simple preventive activities can be included in a consultation for other purposes. For example
a young woman obtaining oral contraceptives can be reviewed, asked about smoking habits, and folate
recommended if she plans on becoming pregnant. Only every third year does she need to have a fuller
examination, to undertake a Pap smear.
For patients who have a major chronic health problem it is appropriate for the approach to differ. For
example, each consultation for a patient with well-controlled and stable diabetes can include a quick
assessment of the diabetes and cardiac risk factors. These consultations may occur every six months, and
more often if the disease is not well controlled. At intervals, consultations may also include more
comprehensive assessments of the diabetes, including peripheral neuropathy, visual and renal effects. At
these times, it is also appropriate to take a wider view and recognize the need for cancer screening and
other activities.
The periodic health approach should be utilized for issues unrelated to the major presenting problems, and
for patients with disease that tends to dominate consultations, who often have co-morbidity, it is
worthwhile doing a general assessment at intervals to deal with these other issues.
Problems of Screening
The view of many doctors and patients regarding screening is often limited to the actual test itself (Robson,
1998). However, the WHO guidelines for selecting screening tests correctly point out that effective
screening requires a comprehensive program and not just a test. Each test performed requires a substantial
foundation of laboratory or radiology quality control, a system for follow up investigation of positives to
differentiate true positives from false positives, and treatments must be available that are effective,
acceptable and safe to patients. Unfortunately, the evaluation of screening is hampered by multiple biases
which make it difficult to assess, even when randomized trials have been performed, and much more
difficult when they have not.
In order to develop a good screening policy, it is necessary to have good evidence demonstrating what
activity to perform, what patient population is appropriate, the age group to start and stop, and the interval.
There should be measurements of the benefit produced, and also the harms caused directly or incidentally.
Very few screening programs have good evidence across all these facets.
Causing more Harm than Benefit
Many screening tests produce harm to the patient (Irwig, McCaffery, Salkeld, 2006). Nearly all positive test
results, whether true or false, cause considerable anxiety to people who are told that they might have a
serious disease or a higher risk for developing a major complication. This is acceptable if the information is
indeed true, and by taking action, the disease is prevented. However, nearly all screening tests produce
false positive results that require further testing (for example, biopsies of potential cancers) while in others,
a risk is identified and treated, in the hope of averting the bad outcome. Preventive treatment may be costly
in time and money, and it may cause adverse side effects. Examples include treatment for diabetes and high
cholesterol, where some drugs have been taken off the market because they caused harm. In colon
screening, a few people sustain bowel perforations during colonoscopy. Importantly, these costs are
incurred by many as a result of screening, while only a few benefit.
The danger of expending resources on mass screening is demonstrated by the following analogy. If I stop at
the side of the road to help someone whose car has broken down, even my limited mechanical skills may
help to get the vehicle moving again and the driver on their way home. However, if I were to stand on the
roadside and stop cars racing past at full speed, telling their drivers that I can make their car work better
and last longer, the level of mechanical skill required is much higher. Furthermore, by investigating and
checking out their car, I am likely to actually make things worse rather than better. If there is absolutely
nothing wrong with the car and it is working to its maximum potential, I have no chance of improving it
and only a chance of causing harm. Thus, there is a moral obligation of a very different nature when
physicians promise their healthy patients that periodic health assessments can improve outcomes, as
compared to when a sick person seeks help from a physician to help fix their problem. (Sackett, 2002)
Biases in Screening Assessment
Unfortunately, many inappropriate screening programs have been introduced into clinical practice without
adequate assessment of the screening tests' validity. One of the reasons why these inappropriate screening
programs are introduced is the failure to understand how difficult it is to assess screening, because nonexperimental studies are so susceptible to bias. There are five biases in the assessment of a potential
screening program: the lead time bias, the length bias, the volunteer bias, over-diagnosis and inappropriate
gratitude.
The lead time bias occurs when comparisons are made between the outcomes of a screened group against
those who were treated under the previous pattern of care. Screened patients have their disease discovered
earlier in life. Even if the treatment of early-diagnosed disease has no effect, they will have an apparently
longer survival from the date of diagnosis than those who were diagnosed at later stages through ordinary
clinical presentation.
The length bias occurs because screening picks up prevalent early cases. Disease with insidious onset will
develop over a longer period before becoming clinically apparent. Therefore screening picks up a higher
proportion of slowly developing cases than rapidly developing disease, especially in the first screening
round. Thus, assessments of the first round of screening often contain a higher proportion of cases with a
favorable outcome than would normally be seen clinically, including some that would never develop into
clinically apparent disease in the patient's lifetime. Later rounds of screening detect only newly developed
cases, which often have a higher proportion of rapidly developing cases, similar to what would normally
occur in clinical practice. Hence, critical assessment of screening must include several rounds, and should
identify the types of cases developed in both initial and subsequent rounds to determine whether there is a
real difference in outcome.
The Volunteer bias often occurs when a screening test is initially evaluated using volunteer patients in
specialized centers. Patients recruited at these centers tend to be healthier, wealthier, have less
comorbidities, and obtain better treatment outcomes following screening as compared to the typical
individual in the community. Thus, screening the general population may have less value because of the
less healthy population. This bias is particularly problematic in non-randomized cohort studies, where
patients volunteering for tests are compared to the rest of the population.
Over-diagnosis bias occurs because screening discovers ‘abnormalities' that do not progress to disease, or
progress slowly. Whenever screening programs have been developed, we have discovered new pathologies
whose progression is unclear. These include cervical dysplasia, carcinoma in situ of the breast, slightly
raised blood sugars or serum cholesterol. Details are given in the monographs on each disease. One
exemplar is Neuroblastoma, where it was discovered that many of the "cancers" detected by screening tests
in newborn infants actually regressed completely back to normal without treatment. This phenomenon is
made worse by the understandable tendency of radiologists and pathologists to "overcall" doubtful cases,
because of their anxiety to ensure that they do not miss any possible disease. For some individuals, it is
probably a good thing not to make the error of under-diagnosis, but the penalty is a substantial rate of overdiagnosis for others who receive treatment of disease that would not progress.
Inappropriate gratitude bias for a screening program follows from over-diagnosis, whereby patients who
have had a disease diagnosed and treated are understandably grateful to the medical staff and institutions
that have "saved their lives". This may particularly be the case for those who had the appearance of disease
that would never have developed clinically. Following treatment, they are healthy and well, except for the
side effects and complications of the treatment that continually remind them of their "close escape" from
death. Many "survivors" of breast and prostate screening programs are actually such people who never had
severe disease to start with.
The Periodic Health Assessment VS the end of the
Annual Physical
Few Canadians are aware that the ritual of the annual physical (the annual fiasco) is largely a peculiar
North American phenomenon. This activity was invented by American insurance companies in the 1920's
and was shortly thereafter adopted by the American Medical Association (AMA) as a helpful method for
generating income. It was largely useless medically but was expensive and generated substantial income for
doctors. The annual physical examination at that time consisted of a head-to-toe standard clinical
examination and whatever lab tests were available at the time. The AMA based its recommendations on the
basis of simplistic studies, which showed that participants who had annual physical examinations lived
longer and better than those who did not. The annual physical was successful among the healthiest - the
worried well. It was also supported by reputable organizations such as the American Cancer Society, which
regrettably at times has functioned as a lobby for the "Cancer Industry", and recommended many activities
before evidence was available to determine effectiveness (Mukherjee, S. 2010)
The Canadian Task Force
Canadians have good reason to be proud of the Canadian Task Force on Preventive Healthcare, an
internationally respected innovation. It was established in 1976 to examine the effectiveness of the annual
physical examination. Shortly after the beginning of Medicare in the 1960s, provincial ministries of health
across the country recognized the huge cost of performing annual physical examinations for a large portion
of the population. The Task Force was established under the chairmanship of Dr. Walter Spitzer and in
their first report published in 1979, the main recommendation was that the undefined "annual checkup"
should be abandoned and replaced with a series of age specific "health protection packages". That first
report changed the title to the Task Force on the Periodic Health Examination and subsequently to the Task
Force on Preventive Healthcare.
These title changes emphasized that the process should not be necessarily be annual and focused on
examination, but rather it should focus on the identifying the greatest risks and most effective changes that
impact health, at intervals that are right for each person. The rating system developed by the task force
emphasized the need to stop providing ineffective and potentially dangerous activities. The Canadian Task
Force was widely admired internationally, and it was copied by the US Preventive Services Task Force.
Many of us physicians who were overseas at the time looked on with admiration and adopted many of the
Canadian Task Force's recommendations. Sadly, within Canada many practitioners were slow to change
and persisted in providing unproven, ineffective and potentially harmful activities. The term "your annual
physical" rolls off the tongue so readily that magazine articles aimed at women use it almost exclusively,
thereby continually reinforcing this inappropriate activity. Since syndicated magazine articles are often
written in New York, then published in local editions around the world, this concept is now international,
even in countries where official recommendations oppose it.
Unfortunately, the periodic health assessment is most readily accepted by patients who least need it, such as
the already healthy vegetarian, non-smoking teetotal marathon runners, and not by those who most need
assessment. One example is demonstrated by the leveling off of cervical cancer incidence in Canada over
the past 15 years. This happens largely because volunteers have the test, and do not get the cancer any
more. Cervical cancer still occurs in women who have never had a Pap smear or have allowed a long
interval to elapse. Women who live in rural settings, are immigrants, Aboriginals, and those who work long
hours are less likely to attend for cervical screening, and consequently are still at highest risk for
developing invasive cancer, because they do not obtain the benefit of this procedure.
These high-risk people do attend doctors, but for illness consultations. Therefore, doctors should try to
incorporate at least some preventive activities into consultations for illness, especially for such high-risk
patients. Focusing on a limited number of highly effective preventive activities will make it easier for
doctors to choose the most valuable ones for their high-risk patients.
Types of Guidelines: Evidence Based, Consensus
Conferences
Clinical decision making is a complex process. Clinical practice guidelines should serve to make this
process easier but a large number of bodies come out with conflicting recommendations. Thus it falls to the
front line clinician to decide which to follow.
As noted at the beginning we have tried to select information from the best evidence available. In doing so,
we have been cognizant of the potential for bias from the influence of biomedical and pharmaceutical
companies. In recent years, there is increasing evidence and outrage regarding the ability of commercial
interests to distort recommendations for preventive health (Moynihan R, 2008). This can occur through
both blatant and subtle means. In many medical fields it is difficult to find an expert who has not incurred a
conflict of interest through funding from a drug or device manufacturer. Even Cochrane reviews are
sometimes written by authors with conflict of interest(Lenzer 2013). Consensus conferences of experts are
often funded directly or indirectly by drug companies. Most of the conference participants have conflicts of
interest themselves. Therefore, consensus conferences are likely to recommend policies that result in
increased use of modern and expensive drugs and technologies. Based on this potential bias, we have been
particularly cautious about recommendations made in consensus conferences.
We are also cautious about "grassroots organizations" of patient representatives because of the welldocumented evidence that many of these organizations are either developed or substantially supported by
commercial interests to push their agendas. (Lenzer J 2003) Such organizations have been dubbed
"Astroturf" organizations because their policies are artificially biased.
Guideline makers should have an explicit system to rate quality of evidence and assess strength of
recommendations. GRADE (Grading of Recommendations Assessment Development and Evaluation) is
one such system developed by a group of health professionals, researchers, and guideline developers
worldwide. This has been adopted by many organizations like the Cochrane foundation and more recently
the new Canadian Task Force.
The GRADE system (Guyatt GH, Oxman AD, Vist GE, Kunz R, Alonso-Coello P, Schunemann HJ, 2008)
groups them as a strong or weak recommendation based on:
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Quality of evidence: There are 4 levels of quality of evidence determined by study design,
consistency of the results, precision of the results, directness of the evidence (use of patient
important outcomes such as mortality instead of surrogate markers) and possibility of publication
bias.
o High: Good quality RCTs.
o Moderate
o Low: Observational studies.
o Very Low
The balance between desirable and undesirable consequences: If the magnitude of benefit far
outweighs the undesirable effects the recommendation is likely to be strong even if the quality of
evidence is not high. Similarly uncertain balance between benefit and harm even if from high
quality evidence is likely to result in a weak recommendation.
The values and preferences: Even in the presence of high quality evidence, values and preference
of the population may change the strength of recommendation. E.g. Use of Warfarin in low risk
patients with atrial fibrillation to prevent 8 strokes (4 major and 4 minor) at the risk of 22 episodes
of serious GI bleed is a weak recommendation as patients and physicians are unwilling to accept
the risk of GI bleed
Use of resources: This is often the most difficult to incorporate owing to conflict of interests,
difficulty in assessing cost owing to changing prices and perspective adopted (whether at the level
of the hospital or health care system or society at large) and difficulty in finding adequate evidence
to support the analysis.
A recommendation whether it is strong or weak has different implications for the patient, the physician and
the policy makers.
Implications for the
Patient
Physician
Policy maker
Strong recommendation
most people in your situation
Weak recommendation
most people in your situation
would want the recommended
course of action &only a small
proportion would not; request
would want the recommended
course of action, but many would
not
discussion if the intervention is not
offered
most patients should receive the
different choices will be appropriate
for different patients; assist patient
to make
recommended course of action
can be adopted as policy in most
situations
decision consistent with her/ his
values & preferences
will require substantial debate &
involvement of many
stakeholders
This method of developing and grading recommendations with minor variations depending upon the
discretion of guideline group helps the process become more transparent. This allows the user to
understand the guideline, its context and most importantly its applicability to the patient at hand.
Shared Decision Making
Effective clinical decisions are defined as the best course of action given the current scientific evidence,
healthcare resources, clinical circumstances, and patient preferences. There are many "gray zones" where
there is poor evidence for a single best course of action or where the choices may vary according to patient
preference. More and more patients want to be actively involved in health care decision. A decision-making
process jointly shared by patients and health care provider includes:
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Establishing the context in which the patient's preferences on available options are valued and
considered necessary;
Providing evidence-based information;
Making explicit the inherent uncertainty in the clinical decision making process;
Making sure the patient understands the information;
Eliciting patient's values, ideas, concerns and expectations;
Understanding the patient's preferred role in decision making; and
Formulating a plan of action and arranging follow-up.
In a routine clinic it is difficult to provide time to fully discuss these issues with the patient. Here decision
aids are useful. They can take various formats: booklets, audio/video tapes, interactive internet programs
etc. Many such aids are available, although some are poor quality and many are untested. The
characteristics of the ideal decision aid according to the International Patient Decision Aid Standards
checklist are:
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Content: The decision aid should provide detailed information in an easy to understand format.
Include methods to incorporate patient values and provide guidance for systematic decision
making.
Development process: The information presented should be evidence based and referenced. It
should have a systematic development process with disclosure of developers, their credentials and
conflicts of interest if any
Evaluation: It should be tested to ensure that it allows the patient to comprehend entirely the
nature of the decision to be made and that the decision is compatible with the features that matter
most to the patient.
In comparison with standard care, patients using decision aids generally perform better in terms of: a)
greater knowledge, b) more realistic expectations, c) lower decisional conflict related to feeling informed,
d) increased proportion of people active in decision making, and e) reduced proportion of people who
remained undecided post intervention. However decision aids do not change satisfaction with decision
making, anxiety and health outcomes. Using decision aids helped patients adopt a more conservative
approach to major elective surgery, had no effect on minor surgery, reduced the use of PSA screening and
increased use of other screening.
Shared decision making is essential to the ultimate goal of patient-centered care. The Ottawa Health
Research Institution is a source for reviewing and choosing decision aids.
What Family Physicians Should Do
The recommendations that we have found to be evidence-based and worthwhile are summarized in the
spreadsheet on this website. We try to keep it up to date. It is based on what is worth doing for someone
who is basically healthy. Those who have one or more medical conditions should have a risk assessment
based on their conditions, and appropriate activities should be performed according to their special risks, as
well as those on the normal set, for conditions where they are at normal risk. For example, a person with
juvenile-onset diabetes taking insulin has a series of problems related to the diabetes, including higher risk
of infection, has a higher risk of cardiovascular disease, and also the same risk of acquiring cancer as the
rest of the population.
We developed the spreadsheet in a format that should allow its use in the consulting room: on the desk or
posted on the wall. The recommended activities for a particular person can be obtained by running down
the column under their age. The list of non-recommended activities can be printed on the back. The website
can be consulted quickly to obtain details of the recommendations, and the reasons for them, if a patient
asks about particular activity, or challenges the reason.
Whether seeing a patient in an illness consultation or for periodic health assessment, physicians should
assess the overall risk for disease and focus on the highest value activities. All preventive activities should
be performed on the right patient at the right time, in the proper way. We must learn the best approaches for
high standards in behavior change, in immunization protocols, and in screening.
We must make appropriate measurements, such as with physical examination, to ensure that we obtain
accurate results. For example when measuring blood pressure, we must use proper technique as
recommended by the Canadian Heart and Stroke Foundation to ensure that measurements are reproducible
and appropriate for decision-making*. This may require rethinking how we organize our examination
rooms so that patients can sit in a chair with arms supported rather than on the edge of the examination
bench, and the sphygmomanometer must be located in the proper location for accurate readings. They must
use the proper size cuffs.
Where appropriate, we should use non-medical staff to undertake such activities. For example, LPNs or
Medical Office Assistants can take blood pressure. Nurses can learn to perform Pap smears, and newer
ways of Medicare payment allow us to delegate the task.
* http://canadiantaskforce.ca/wp-content/uploads/2013/01/HTN-Poster-ENG_13-01-15.pdf?9d7bd4
Conclusion
Evaluating and choosing preventive activity is not easy. It can create more harm than benefit. As doctors
we need to focus vary carefully on doing really well the activities that are most beneficial and stop doing
those which are harmful. As writers we have been very conservative, focusing on what has good evidence
to support the case, rather than only hope.
Our list is designed to assist clinical practice, by emphasizing the relatively small number of truly effective
activities, and organizing them in an easy to use format. We hope that the essays justifying our choice will
be helpful for those who seek the reasons, especially when prior learning has been different.
Any challenges and suggestions are welcomed: please contact us by e-mail.
References
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