After reading this chapter you will be able to:
- Consider the broader goals of health care in terms of disability-free survival;
- Summarize the arguments for preventive interventions at the individual patient level versus on the whole population;
- Give examples of population-level interventions:
• Health promotion
• Modifying determinants
• Targeting diseases
• Service provision
• Harm reduction
- Give examples of preventive strategies in clinical practice
• The evidence base for clinical prevention
• Implementing preventive practice
• Office systems for improving prevention
• Changing patient behaviour: the Stages of Change model
Linking these topics to the Medical Council exam objectives, especially section 78-3.
No disease, no problem?
In principle, health care aims to reduce morbidity and mortality. Individuals’ health declines over time as they are exposed to various noxious factors. It continues to do so at varying rates until death. This can be illustrated using survival curves, as shown in Figure 8.1. The blue line in the diagram shows the declining health of a population – the area below the blue line indicates the proportion of the population in each age group who are in good health. The red line represents the survival curve – the proportion of people who remain alive at each age (see Chapter 6). Health care that prevents—or at least delays—the onset of potentially fatal diseases shifts the survival curve up and to the right, so its shape becomes more rectangular. However, shifting only the survival curve increases the area between the survival curve and the disability-free survival curve, increasing the amount of disability, so that the life-years gained are lived in a state of poor health. Reassuringly, however, preventive actions that extend life also seem to improve health, so that the combination of disease prevention and health promotion tends to raise the disability-free survival curve also: it compresses morbidity. This squaring of the curve describes the hoped for delay in the decline in health associated with age so that people enjoy a good quality of life for as long as possible and die as late as possible.
Prevention or treatment?
Chapter 4 introduced the stages of prevention, but made the point that these are arbitrary distinctions that only have heuristic value. Chapter 1 showed that the definition of “disease” is also arbitrary. Many experts likewise believe that the distinction between disease and risk factors is artificial: it depends on the point in the disease’s natural history that is being considered. Tobacco addiction, hypertension, and diabetes are generally considered diseases in themselves that need to be treated. However, treating them can also be thought of as a way of preventing chronic lung disease, stroke and renal disease, respectively. Even surgery following subarachnoid haemorrhage has no effect on the haemorrhage that has occurred or on its effects: it simply aims to prevent another one.
According to WHO “disease prevention covers measures not only to prevent the occurrence of disease, such as risk factor reduction, but also to arrest its progress and reduce its consequences once established.” This implies that all effective clinical interventions prevent something: the occurrence, progression or duration of disease, or its resulting disability or handicap.2
Perhaps the main difference between prevention and treatment is the fact that so-called preventive interventions are applied to patients who do not have symptoms of the targeted disease and who have often not solicited the intervention. Intervening in an ostensibly healthy patient, especially one who has not asked for it, adds to the importance of the clinician taking care to minimize harm, maximize benefit, and ensure informed consent. For both treatment and prevention, the risks and benefits of intervening versus not intervening should be assessed and discussed with the patient in every case.
There are two main approaches to squaring the survival curve: the first is to identify individuals at high risk and intervene to reduce their risk. The second is to reduce the average risk level for the whole population; sometimes this occurs without the consent or even knowledge of people in the population.
The justification for a population approach comes from the work of Geoffrey Rose3 who noted that many cases of disease arise in people who are not in a high-risk group. Moreover, the number of cases arising from the population at average risk is often greater than the number occurring in the population at high risk simply because there are so many more people at average risk in a population. As an example, Figure 8.2 uses Canadian data to show that 61% of cases of diabetes mellitus arise from people at low or moderate risk, whereas only 39% arise from those at high risk. Rose showed similar patterns for heart disease, hypertension, and trisomy 21, and there are many other examples.
Rose proposed that preventing disease by trying to achieve a small shift in the distribution of a risk factor in the entire population can be more efficient than trying to identify everyone at high risk and getting them to drastically reduce their risk. For instance, estimates suggest that in North America an equal reduction in the number of cerebrovascular accidents could be achieved either by decreasing the average blood pressure by just 2 mm Hg or by successfully identifying and treating everyone with a diastolic pressure of 95 mm Hg or greater.5 However, not all diseases are amenable to this type of population strategy. For instance, an analysis of the potential effects of cholesterol reduction to prevent coronary artery disease suggested that a high risk strategy is more likely to be effective than a population strategy.6
Trisomy 21: high risk and population strategies
Comparing total eradication of risk in a high-risk group versus a small reduction of risk in the entire population
The following table shows historical figures that Rose used to illustrate his arguments;3 they refer to the risk of giving birth to a child with trisomy 21 by maternal age group in 1979.7 Women aged 35 and over are considered to be at high risk for giving birth to a baby with trisomy 21. If screening aimed at this group were 100% effective and could prevent all trisomy 21 births, this would reduce the total number by only 6 (5+0.95+0.05 – see column “Number of trisomy 21 births”).
|Mother’s age||Total births||Trisomy 21 per 1,000 births||Number of trisomy 21 births|
|30 to 34||12,308||1.3||16|
|35 to 39||1,351||3.7||5|
|40 to 44||73||13.1||0.95|
|45 and over||1||34.6||0.05|
By contrast, the next table illustrates the hypothetical impact of a population-wide intervention that reduced the risk by just 0.1 per thousand in all age groups:
|Mother’s age||Total births||Trisomy 21 per 1,000 births||Number of trisomy 21 births|
|30 to 34||12,308||1.2||15|
|35 to 39||1,351||3.6||5|
|40 to 44||73||13.0||0.94|
|45 and over||1||34.5||0.05|
Lowering the risk of trisomy 21 by just 0.1 per thousand pregnancies in all age groups would reduce the total number of trisomy 21 births to 87, a decrease of 13 – a better result than achieved by the high-risk strategy.
|Individual-centred “high-risk” strategy||Population “average-risk” strategy|
|Advantages||Intervention is relevant to the individual.
People who learn that they are at high risk should be more motivated to change their behaviour to reduce their risk (as predicted by the Health Belief Model – see Chapter 2).
Physicians feel justified in reducing risk factors in high-risk patients.
Arguably cost-effective as resources are directed to individuals most in need.
Favourable benefit to risk ratio: high-risk individuals are likely to gain more benefit from the intervention for the same likelihood of harm as lower-risk individuals.
|Intervention aimed at roots of problem reduces illness in the whole population so is egalitarian; it lessens the possibility of creating prejudice against high-risk groups.
Tackles condition before the risk factor causes irreversible damage.
A small change in the level of a risk factor in a population can improve the health of a large number of people.
Can engage self-sustaining social change—as non-smoking becomes the norm, smokers smoke less and are more likely to attempt to stop smoking.
|Disadvantages||Difficulties and costs of identifying high risk groups and individuals.
Dividing line between average and high-risk is often arbitrary, and many “average-risk” people can still be at risk.
Reaches those most at risk but has little impact on the disease burden in society, because most cases of disease occur in people at low or moderate risk.
Palliative and temporary—the determinants are not addressed, so there will always be individuals who need the intervention.
May be socially inappropriate—a change of behaviour sufficient to reduce risk significantly may put the individual outside the norms of his or her social circle.
|Most individuals will derive minimal benefit and this benefit may be outweighed by the risk of the intervention, even if this is also small.
Inefficient: it imposes change on a large number of people who would not have developed the disease at all.
There is little intrinsic motivation for low-risk individuals to change behaviour; indeed, there may be opposition to change.
There is a danger of increasing inequity in health8 (see Chapter 2) as vulnerable people in most need of change are often the least likely to do so, while less vulnerable but more health-aware people may make the change.
Intervening in apparently healthy people is ethically more sensitive that intervening in people with problems. It can be seen as close to social engineering, which is unacceptable in a liberal society.
Although Rose’s arguments may eventually become obsolete (See Nerd’s corner – The case against Rose), for the moment, intervention strategies should combine individual and population approaches. For instance, preventing the complications of hypertension should include the promotion of healthy nutrition and physical activity in the general population as well as screening and treating people at risk.
The case against Rose
Geoffrey Rose published his article “Sick individuals and sick populations” in 1985, followed by his book The Strategy of Preventive Medicine in 1992.9 His ideas initially stimulated major interest, but subsequently his approach has been criticized. Some critics argue against the ethics of the population approach to prevention, declaring that for many diseases evidence of causation is weak. Information on risk factors comes from observational studies and risk factors are not necessarily causal factors. Proactive preventive actions should be based on solid evidence, but controlled trials on entire populations would be difficult. If a scientifically secure basis is not required before intervening on the lives of all people, the possibilities of abuse are considerable.10
An additional argument holds that Rose took an unduly negative view of the high-risk intervention approach. As our understanding of risk factors improves, it should be possible to target interventions more precisely to those at risk, making the high-risk approach at least as effective as a population approach in preventing specific diseases. Rose’s demonstration focused on the use of a single marker to identify high-risk people, producing too many false positives and false negatives to allow accurate identification of a person’s risk. More recent risk algorithms, some of which include genetic markers, allow more accurate identification of individuals at high risk, including many who would not have been identified using only a single risk factor. Use of these algorithms may well prove more effective in lowering the burden of specific diseases than the use of population strategies.6
Health promotion (see Chapter 4) aims to help people improve their health by taking control of it. Even though it may affect specific diseases, its goals are more general: to increase the determinants of good health and to increase resistance to the determinants of poor health. This can be at the level of the individual, as when health professionals help patients come to a health decision by making sure they know the advantages and disadvantages of the available options, by respecting the patient’s priorities and by understanding the patients’ situation – that is practising patient-centred care.
Health promotion can also be aimed at a community or a population. To guide population health promotion activities, the Public Health Agency of Canada developed an “integrated model of health promotion” – see figure 8.3. This model integrates notions of health promotion with those of population health (see Chapter 2). In planning any kind of health intervention, the integrated model specifies certain questions to be asked: Who needs the intervention? What should the intervention target? How should the objectives be achieved? The answers to these questions should be based on evidence, the available strategies and services, and should consider the ethical issues relating to possible interventions, as well as patients’ and populations’ health determinants and priorities.
Community mobilization is the strategy of choice for sustainable health promotion. In this approach, community members are involved in defining the problems and in proposing solutions. Unlike classic top-down health education, where health professionals study and prioritize problems and then develop solutions, community mobilization involves community members in defining and resolving problems. It is a long-term process that empowers communities; as such, the process itself promotes community health.
A brief look at the list of health determinants confirms that no one authority can be responsible for the health of a population. Health promoters believe that it should be the responsibility of all members of a population or community, and a core responsibility for all government.12, 13 Although those working within the health services have a particular responsibility to advocate for health, expertise in public and population health can be found in a variety of different academic disciplines, professions, and organizations.
Examples of population-wide interventions that target health determinants include income redistribution policies aimed at alleviating poverty. If successful, such policies should reduce the burden of disease associated with poverty. Improving built environments can address many health determinants and risk factors at once. For instance, walkable neighbourhoods with traffic calming measures encourage people to become physically active, so reducing the burden of, for instance, arthritis. Adequately lit neighbourhoods reduce the risk of accidents and crime, while increasing the sense of security. However, such broad interventions can be difficult to bring about because they require collaboration across a number of sectors, each one of which has its own agenda.
At a population level, interventions to reduce particular diseases include legislation, awareness raising, community development and implementation of health programmes. Examples include legislation which allows the addition of iodine to salt to reduce goitre, the replacement of vitamin D removed by skimming milk, replacement of B vitamins removed with the bran in the processing of wheat flour. Raising awareness of the illnesses caused by tobacco and alcohol paved the way for legislation on advertising and sales. These types of population-wide intervention work by shifting the entire distribution of risk factor exposure in the population. Although some individuals retain a higher than average risk, the overall burden of disease is reduced.
Finally, interventions such as breast cancer screening or childhood immunisation target individuals, yet may be organised on a population basis. This approach makes the programmes available to the entire population but they can also be promoted specifically among those in most need, so they can be more equitable than piecemeal services offered by individual clinicians. Also, they can more easily draw on experts for planning and evaluation, thus services are likely to be of high quality and patient follow-up may be more systematic.
Sometimes community or individual priorities are contrary to healthy choices: a community may not want a polluting factory to be shut down because it employs many community members; an opiate addict wants to avoid the pain of withdrawal and cannot imagine life without opiates. In these cases, harm reduction can be used: educate the community to stay indoors on days when pollution is particularly bad, find ways to reduce the addict’s risk of contracting blood-borne illness. Harm reduction is based on the idea that risk is an unavoidable part of our world. It can be difficult – even impossible – to eliminate the risk, but its harmful effects can be reduced. The approach is generally talked about in relation to substance abuse: providing clean equipment to prevent sepsis, providing methadone maintenance to move the addict away from illicit drugs and their risks; Operation Red Nose reduces traffic accidents by providing people with a safer way to get home after consuming alcohol to excess.
Harm reduction refers to reducing the negative consequences of risky behaviour, rather than trying to eliminate the behavior itself, for instance smoking outdoors only so children are not exposed to second-hand smoke in the house. It can be defined as a set of practical strategies that help reduce the risks associated with a danger (adapted from the U.S. Harm Reduction Coalition, 2000; definition supported by Canadian AIDS Society, 2000).
Harm reduction has evoked significant debate and is often opposed by people who disapprove of the risky behaviour. For example, placing condom vending machines in high school washrooms raises the argument that it condones, even encourages, sexual activity. Similarly providing safe injection sites and clean injection equipment is construed as condoning illegal drug use. In particular, providing clean equipment is prisons is said to be unacceptable because drugs are banned from prison anyway.
From a health perspective, however, if efforts to eradicate a behaviour repeatedly fail, it is logical to implement evidence-based approaches that reduce the harm associated with it. This does not mean that attempts to reduce the risky behaviour should be abandoned. Harm reduction is just one component in reducing the burden of unhealthy behaviour. Others are healthy public policies, prevention, treatment, and enforcement.14
Harm reduction advice for people who use recreational drugs15
- Stay healthy – eat well, get enough sleep and exercise regularly.
- Use drugs only in a safe place, indoors, with people you trust.
- Know what you are taking, remember that the effects on you may be different from the effects in others.
- Start with small doses when trying a new drug or when you have not used for a while.
- Don’t use alone and get someone to stay straight so they can help or get help if needed.
- Don’t mix substances.
- Know where you can go for help.
Additional advice for users who snort or inject:
- If possible, avoid snorting and injecting.
- Make sure you are up to date with hepatitis A and B vaccinations.
- Avoid overdose: inject slowly, pay attention to the quality and purity of the drug.
- Use safe infection practices and don’t share equipment.
- Bring used needles to a drop box.
- Stay in control of your drug use.
- Take drugs less often and in lesser quantities.
- Stay clean most of the time.
Politics and harm reduction
In 2003, North America’s first supervised injection facility, Insite, was established in Vancouver’s Downtown Eastside, one of Canada’s poorest neighbourhoods. There were an estimated 12,000 injection drug users in Vancouver, one third of whom lived in the Downtown Eastside. Insite was designed to increase access to health care and addiction services, to reduce overdose-related death and reduce the transmission of blood-borne infections.16
Insite users bring their own drugs to an infection booth where they are provided with clean injection equipment, including needles. Nurses, trained to respond to overdoses, supervise the injections. Insite also provides onsite addictions counselling and referral to detoxification facilities and other forms of community support, as well as providing a point of access to the health care system for drug users who are not otherwise well connected.16
The facility has been successful in encouraging its patrons to use detoxification services. It has reduced the number of deaths from overdoses and it is associated with a decrease in high-risk behaviour, including needle sharing, though there has been no documented decrease in transmission of HIV or HCV. Insite has also led to improved public order, with decreased rates of public injecting and less injection-related litter. Its critics argue that safer injection facilities will lead to an increase in drug-related crime and promote drug use in the community, but these claims are not supported by the current evidence.17, 18
Insite initially operated under a federal exemption of the national drug policy. Despite the growing body of evidence supporting safer injecting facilities, in 2006, when the pilot phase was due for renewal, the federal government threatened to withdraw this exemption and close down the facility. However, local community-based organizations, with the support of the scientific and medical community, took the federal government to court, stating that federal drug policy was inconsistent with the Charter of Rights and Freedoms. On May 27th 2008, a provincial judge found in their favour and Insite remained open. Since this time, the BC Court of appeal has upheld this ruling.19 In September 2011, the Supreme Court of Canada was unanimous in its decision to allow Insite to continue operating.
To read about Vancouver’s safe injection Insite, visit the Vancouver Coastal Health website.
Using a market model to reduce substance abuse
Three strategies derived from market economics may also help to reduce substance abuse:
Supply reduction (e.g., destroying crops from which illicit drugs are derived or interrupting drug shipments). This has been tried for years, but it is expensive, tends to cause an escalation of violence and may not be cost-effective. Further, underlying determinants such as poverty, corruption and need for foreign currency in the supplying countries continue to drive the supply side of the equation.
Price increases are effective in reducing the use of legal substances such as cigarettes. It is somewhat analogous to supply reduction in that both reduce access to the substance. Selling a substance only in large quantities also reduces access by increasing the unit price – for instance, in Canada cigarettes are sold only in packets of 20 or more. Pricing is particularly effective in limiting consumption among youth, who generally have less disposable income. Note that tobacco manufacturers have bypassed legislation on the quantity of cigarettes that can be sold by promoting the use of cigarillos to young people. As these are not technically cigarettes, they can be sold singly. The price of illegal substances is outside legal control, although supply reduction drives prices up. Patterns of consumption of illegal substances are generally dictated by their street prices.
Demand reduction focuses on the other side of the equation: discouraging people from seeking drugs. Education and information, community programmes, or legal penalties are used for this. Research suggests that these work best for those who are least dependent on drugs, but are less effective in the high risk population.
Prevention in Clinical Practice
Clinicians contribute to the health of the population when they intervene appropriately to:
- promote health,
- prevent disease,
- reduce the duration or severity of illness,
- reduce disability and handicap.
The main types of preventive intervention in clinical practice are shown in Table 8.2.
|Type of intervention||Examples from the recommendations of the U.S. Preventive Services Task Force*|
|Counselling||Tobacco cessation for smokers
Dietary counselling for people with hyperlipidemia and other diet-related risk factors for chronic disease
Counselling on breast feeding for pregnant women
|Screening||Hypertension in adults
Chlamydial infection in sexually active women under 25
Colorectal cancer in adults aged 50 to 70
|Immunisation||Routine immunisation in childhood
Specific immunisations for people at risk due to work or travel
|Pharmacoprophylaxis||Ocular topical medication for newborns to prevent gonococcal ophthalmia neonatorum
Discuss the use of tamoxifen or raloxifene with women at high risk for breast cancer
Folate supplements for before and during early pregnancy to prevent neural tube defects
*Note: task force recommendations are being updated continually. By the time you read this the recommendation may have changed.
Every day the popular and scientific media are filled with new health recommendations; the problem is to decide which are effective. For this, the methods of evidence-based medicine (See Chapter 5) are useful. However, because the amount of evidence is overwhelming and because individual studies often provide conflicting results, various professional and academic organizations have been set up to review the research and produce evidence-based guidelines for disease management and prevention. A number of credible agencies use systematic review methods to produce clinical preventive guidelines that are available online, for instance:
- the Canadian Task Force on Preventive Health Care
- the US Preventive Services Task Force
- the National Institute for Care Excellence in the UK
- the Royal Australian College of General Practitioners offers several books of guidelines.
Because different working groups use different notations to summarize their findings, an international working group has proposed the GRADE system of classification which is gaining ground as a common system of classification.20, 21 According to this system, recommendations are classified as weak or strong depending of the quality of evidence, and for or against the intervention depending on the balance of risk and benefit.
The Canadian Task Force on Preventive Health Care
North Americans used to assume that an annual physical examination was essential for maintaining health. The annual check-up was promoted by insurance companies in the 1920s and later by the American Medical Association in the 1930s and so became part of the collective medical creed. It consisted of a head-to-toe physical examination and the use of whatever tests were available: blood count, urine glucose and protein, chest X-ray ECG and, more recently, CT scans, and MRIs.
When Medicare began in Canada and everyone could have a government-funded annual physical examination, provincial ministers of health realized that the annual physical would be very expensive, that its components varied considerably, and that some were of questionable value. In 1976, the conference of Deputy Ministers of Health established a Task Force on the Periodic Health Examination, chaired by Dr. Walter O. Spitzer, to determine what services should be provided in the annual physical examination. Spitzer brought together epidemiologists, family physicians, general paediatricians, internists, and a psychiatrist. Experts in the topics under study assisted in assembling evidence for the effectiveness of preventive procedures; the evidence was then assessed by those without particular expertise in the topic. The Task Force established a set of rules for searching the available evidence, assessing its quality, and expressing judgements in simple terms. A Task Force declaration that not enough evidence was available became a stimulus to research. In this way the Task Force laid the foundations of what has now become known as evidence-based medicine.
The central recommendation of the Task Force’s first report in 1976 was to abandon the annual check-up altogether. Because of this, it changed its name to the Canadian Task Force on Preventive Health Care. The report also recommended when and how to use a series of preventive interventions, including counselling on various topics, screening, chemoprevention (e.g., vitamin and micronutrient supplementation), and immunisation.
The Canadian Task Force Report became respected around the world. A few years later the United States set up its own Task Force on Preventive Care. The Canadian and U.S. groups worked together, producing a series of revisions and new topic reports. Even though the two groups studied the same evidence, their recommendations sometimes differed, reflecting differences in culture and context (see Chapter 14). New evidence accumulated and the first report was updated continually until a second full report appeared in 1994. It was presented in a large red book, fondly known as “the red brick”. The second report continued to be updated until 2006. Lack of funding caused the Task Force members to resign in 2005, but it was reformed in 2010.
A major obstacle facing the Canadian Task Force is its lack of influence over the health care system, so that, while its guidelines are appreciated, their implementation is hampered by lack of incentives and the difficulty of changing established practice patterns and professional roles. In recent years a number of changes in the system have improved the conditions for implementation. In particular, developments in physician remuneration mean that physicians are more likely to be rewarded for practising prevention. Also, the development of the multidisciplinary approach to care is likely to favour preventive practice.
When considering prevention in a clinical setting, we tend to think only of the interaction between a clinician and a patient, but this interaction does not occur in isolation. It lies at the centre of a set of influences and constraints on the patient and clinician, illustrated in Figure 8.4. Some factors are intrinsic to patients or physicians, others are extrinsic, related to the determinants of health or to the organisation of services. The numerous influences on prevention mean that there is no single solution to improving preventive practice.22 Positive attitudes of clinicians and their staff—and knowledge of the evidence for the effectiveness of prevention—are essential, but there are practical steps a clinician can take to modify features of the practice setting:
- the implementation of office systems that promote the practice of prevention, as described in the next section
- implementation of continuous quality improvement, as described in Chapter 13
- ensuring that the practice setting promotes health (e.g., provide bicycle stands; make sure the location is easily accessible on foot or by public transport and is accessible to people with physical handicaps; provide appropriate waiting-room reading material; provide no soft drinks or junk food outlets or vending machines)
- advocating for the health of their practice population. This includes the promotion of equity and high quality preventive care oriented towards the needs of the population. Similarly, clinicians involved in teaching should ensure that their teaching takes account of population needs.
Within a health care setting, a range of tools can help remove obstacles to preventive practice.24 They include providing cues for clinician action as well as ways to motivate and educate patients. The following are some types of tools that can improve the practice of prevention.
- Chart reminders for clinicians: can include coloured stickers indicating that patient has a specific risk behaviour or is at risk for a specific illness and chart flow sheets which can track interventions and results. The placement of stickers must respect patient confidentiality.
- Computerized or paper tracking systems: similar to flow sheets and chart reminders which can track the interventions and their results. Computer systems can be used to generate prevention prescriptions and patient-specific information.
- Reminders for patients: mail, email or telephone patients when an intervention is due.
- Visual prompts in office: for example, posters showing recommended interventions by age group.
- Health risk appraisal: questionnaire and physical measures of health risks that inform the patient of their risk of selected diseases.25 Should be used in context; may be given to patients as they await their appointment.
- Patient information and patient-held preventive records: similar to care flow sheets, they give the patient the ownership of care.
- Preventive prescriptions: these set out the objective to be achieved (negotiated with the patient), date for follow-up, and information about the changes to be made. A prescription reminds the patient what he has agreed to do.
Counselling David Richards
Having asked about David’s risk behavior, Dr. Rao puts a sticker on David’s chart as a reminder that he should be counselled on his risk factors. He asks David to see Nurse Jennings, who asks more about his use of tobacco and marijuana. David is reluctant to change his smoking habit: he doesn’t feel that it is doing him any harm. Nurse Jennings advises that his cough may be related to smoking and gives David a leaflet specially written for young people about smoking. Similarly, David feels his marijuana intake is not a problem: he thinks he can drive after a joint, which he can’t after alcohol. Most of his friends smoke marijuana without apparent problems. Nurse Jennings, having completed the first 3 A’s of counselling (Ask, Assess, Advise) begins to plan how she can Assist and what she can Arrange to reduce David’s risks.
From quitting smoking to taking one pill a day, many preventive and therapeutic interventions require patients to change their behaviour, so that understanding the process of behaviour change is essential for the clinician who wants to maintain or improve patients’ health. Patients’ behaviour has often been shaped by years of living a certain way within a certain social circle and changing it can have untoward consequences. For instance, quitting smoking may mean that the patient gives up the social contact with other smokers; reducing alcohol intake can reduce the pleasure of the Hockey Night in Canada session with friends; changing diet may mean no more convenient stops at fast food outlets.
Chapter 2 reviewed some theories of how health behaviour is shaped. Prochaska and DiClemente combined a number of these theories to develop their transtheoretical model of the stages through which behaviour changes, and this is particularly useful in clinical encounters.26, 27 The model describes the stages through which a patient typically passes in adopting a new behaviour, and identifies factors that may motivate or impede such progression. Using the transtheoretical model, a clinician can diagnose which stage of change a patient has reached and, drawing on knowledge of the various forces at play during each stage, he can tailor his intervention to provide “stage-appropriate” support for behaviour change.
The Stages of Change model states that at any time, for any behaviour, a person is in one of the following stages of behaviour change:
- Precontemplation: The person is not intending to change behaviour (e.g., the person has no interest in quitting smoking). For practical purposes, the time horizon is defined as not planning to change within the next six months.
- Contemplation: Although the individual has not begun to change his behaviour, he is thinking about it and intends to do so within the next six months (e.g., the person has at least talked to his doctor about stopping smoking).
- Preparation: The individual has not begun to change his behaviour, but has taken practical steps to do so (e.g., has set a quit date).
- Action: The individual has changed his behaviour within the past 6 months (e.g., has quit).
- Maintenance: The individual has kept up the new behaviour for at least 6 months.
- Relapse: Patients often find it hard to maintain the new behaviour and relapse. This may lead them either to abandon the idea of changing, so revert to precontemplation, or else stimulate them to try again, and so re-enter the contemplation or even the preparation stage, illustrated in Figure 8.5.
The clinician’s role varies according to the patient’s stage, as illustrated in Table 8.3.
|Stage||Explanation||Therapeutic goal||Tips for the clinician|
|1.||Pre-contemplation||The patient doesn’t see a need to change:
“My uncle was obese and hated exercise. He lived until he was 90.”
|The patient starts thinking about changing.||
|2.||Contemplation||Thinking about change; weighing the costs and benefits: “I know I should, but it would take too much time.”||The patient evaluates the benefits and barriers in a balanced fashion.||
|3.||Preparation||Making small changes:
“I’ve bought a pair of jogging shoes, but…”
|The patient develops a plan for change.||
|4.||Action||Taking definitive action: “I went jogging this morning.”||The patient puts the plan into action.||
|5.||Maintenance||Maintaining new behaviour: “I’ve been exercising regularly for about 6 months now.”||The new behaviour becomes “normal.”||
|6.||Relapse||“The weather got bad and I just couldn’t continue.”||The patient re-engages in the process.||
Understanding the process of behaviour change and the influences on it avoids “blaming the patient” for not adhering to health recommendations. Clinicians who feel frustrated that a patient is not changing should ask themselves if their diagnosis of the patient’s stage of change was correct, and if their intervention was stage-appropriate. Note that counselling can be an opportunity to learn from patients. The clinician can ask patients about the tricks they used to make and maintain the change and then pass these ideas on to other patients in similar situations.
More stages of change
The arrows indicate that patients can progress through the stages in either direction. The physician’s role is to help the patient progress to “Maintenance”.
Nurse Jennings continues to counsel David
1. Name the stages of change and suggest how to recognize each one according to what patients say.
A patient might say
Pre-contemplation: The patient doesn’t believe that he is at risk and sees no need to change.
“My uncle never (always) did and lived until he was 90.”
Contemplation: The patient is aware of the risk and how to avoid it, but still lacks motivation to change. Typically weighing the costs and benefits.
“I know I should, but … ”
Preparation: The patient is beginning to make small changes, the plans are more concrete.
“I’ve bought a pair of jogging shoes (supply of chewing gum, a bus pass, recipe book…), but… ”
Action: Concrete plan with definite date in the near future.
“I’m starting tomorrow.”
Maintenance: The patient has made the change and is maintaining it, although it might not be fully integrated as “usual” behaviour.
“I’ve been sticking to it for a month now.”
Relapse. After behaving differently for a time, the patient falls into his previous behaviour patterns.
“I was doing well, but… ”
2. What are the major influences that determine if an intervention will be applied?
Patient factors: personal factors, such as the patient’s education, health knowledge, and income.Physician factors: the physician’s training and technical expertise.Health care delivery system factors: the costs, risks, effectiveness and acceptability of the intervention itself.Situational factors: cues to action during the consultation influence intervention.(See Figure 8.4 adapted from Walsh and McPhee 1992)
3. What are the advantages and disadvantages of reducing population risk as opposed to targeting high-risk individuals?
Advantages of a population strategy
Population strategies aim at the roots of the problem. As such, they reduce illness in the whole population, including those at low- or average risk. In a number of conditions, the population at low- or average-risk produce more cases of illness than the population at high risk (for example, see Figure 8.2), so that a population strategy may prevent more cases than strategies aimed at high risk individuals.
A small change in the level of a risk factor in a population can result in a large change in outcomes.
By emphasising the upstream, situational causes of the problem rather than individual factors, population strategies reduce the likelihood that individuals will feel blamed for their behaviour, and they provide a more sustainable outcome. Population strategies aid in making the desired behaviour “normal”. This encourages its adoption. They also eliminate the need to screen and identify a “high risk” group. This means that people at low or average risk are not falsely reassured and people at high risk are not needlessly made anxious.
Disadvantages of a population strategy
The small benefit to most individuals can be outweighed by the risk of the intervention, even if this is also small. As an example of the risk of intervention, recommendations about reducing fat in the diet have led some mothers to feed their baby low-fat milk in the mistaken belief that this is good for the child, who actually needs full-fat milk.
The lack of obvious personal benefit can reduce acceptability to the individuals who make up the population, particularly among those who consider themselves at low risk.
There is a danger of increasing health inequities: resources may not be directed to people most in need. Unless specifically designed strategies are used, vulnerable people in most need of change are least likely to do so. When a general population strategy is used, it is often the more educated and informed who follow the recommendations, that is those usually at least risk.
Interventions that affect apparently healthy people are open to ethical questions and they may be hard to justify politically. Interventions that affect people who have not consented to the intervention can be seen as social engineering, which is unacceptable in a liberal society.
4. What are the basic values of a health-promoting approach?
According to the Ottawa Charter (see figure 8.3) the values of a health promotion approach are the following:
· evidence forms the basis of agreements between programme and policy decision-makers;
· health promoters analyze all possibilities and act within their jurisdiction;
· there is a need for overall coordination of activity;
· society as whole must take care of all its members;
· interactions between people and their physical and social surroundings affect health and health behaviours;
· social justice, equity, mutual respect and caring are necessary for health;
· health care, health protection and disease prevention complement health promotion.
5. Give an example of a primary preventive intervention recommended in clinical practice.
6. Give an example of a primary preventive intervention that can be applied to a population.
2. In your experience of clinical situations, what increases the practice of prevention?
3. What information resources are available to clinicians to support the choice of intervention to reduce risk?
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