Studybot answer

Question asked by: noatan123 - 12 months ago

Question

Maak een oefenexamen van de volgende tekst: 1 . 1 W H A T I S P R EV E N T I O N SC I E N C E ?
What are we doing today? Introduction to what prevention science is, hints of epidemiology, and nomenclature
Obligatory material for the exam: slides & article Rose (1981)
1.1.1 DE FI N I N G P R E VE N T I O N S C I E N C E
What is prevention science?
It is an interdisciplinary specialty that requires integration from multiple disciplines including psychology, counseling, social
work, education, health sciences, economics, and public affairs
o This class: especially focus on psychology
o When you want to implement a prevention campaign: talk to stakeholders (GPs, patients, possible agencies to
fund, ), design a policy (how to bring over the message, ) multiple disciplines involved
Example: nutriscores, forbidding smoking in public places, are outcomes of such campaigns
Psychological prevention science tries to prevent psychological and physical illness and promote overall health and well-
being through evidence-based practice at individual and systemic levels
Uses evidence-based practice
Aims (broad definition)
o Advancing health at the individual and societal levels
o Inform policymakers (to make it possible for actions to be taken)
How? Lets explore throughout this course
More concrete aims of prevention
Reduce preventable deaths
Reduce the number of lost years
Increase healthy life years
Increase quality of life
Reduce the economic impact of diseases
1.1.2 RE L E VA N C E O F P R E VE N TI O N S C I E N C E : TH E E X A MP L E O F L I FE E X P E C TA N C Y
Why would prevention be relevant?
Example: the case of life expectancy
Life expectancy had increased over the years, but
o Still big differences between higher and lower income
countries
o Still too much health life years lost
Causes of death (WHO)
Important: defining the problem and area of intervention
o What is the problem, and where?
Typical distinction in types of causes
o Communicable, maternal, neonatal, nutritional
You can catch it from someone else
o Noncommunicable
You cant catch it from someone else
o Injury
Top 10 global causes of deaths in 2016 (see picture)
o In general
o High (more noncommunicable) versus low-income countries (more communicable)
Take home message? Know your background
Figure 1: causes of death in general
Figure 2: causes of death in high versus low income countries
Ferre Muermans - 4 -
Be aware that when you want to implement a prevention campaign, you need to know where you are implementing it (e.g. prevention
campaign for diarrhoeal diseases in high income countries will not target a real problem and the advantages will not outweigh the financial
costs, while the same intervention might be very successful and important in some low-income countries)
1 . 2 G E N E R A L D E F IN I T IO N S
Definitions
Preventable deaths number of deaths that could be potentially prevented either by prevention (e.g. by promoting
movement and healthy eating habits), or by medical intervention (treatable)
Premature deaths deaths occurring before the age of 75 (number of deaths calculated as a percentage of the
total deaths)
75 years as a reasonable age on this side of the planet with in general a life
expectancy of approximately 80 years old
Years of Life Lost (YLL) number of years that people lose due to death or illness
Illness measured as having impairments in taking part in everyday life (had to be
worse enough, not just an annoying little pain in your left toe)
o E.g. chronic lower back pain: not being able to work as a classical consequence of the
pain, not being able to look after grandchildren, take part in a yoga class, go out walking
with friends,
Years Lost to Disability (YLD) number of years that a person lives with a limitation
Does not per definition implicate a loss of QoL, can be a major problem or not at all
(e.g. even after heavy accident findings new ways to live a meaningful, purposeful life
and being happy)
Healthy life expectancy life expectancy in good health
Disability-Adjusted Life Years
(DALY)
years lost by being sick or premature death
Quality-Adjusted Life Years
(QALY)
improvement in quality of living after an intervention
Disability an umbrella term, covering impairments, activity limitations, and participation restrictions
An impairment is a problem in body function or structure (e.g. blindness)
An activity limitation is a difficulty encountered by an individual in executing a task
or action (e.g. washing, running)
A participation restriction is a problem experienced by an individual in involvement
in life situations (e..g participation in class impossible due to handicap)
Disability is thus not just a health problem; it is a complex phenomenon, reflecting the
interaction between features of a persons body and features of the society in which he
or she lives
Quality of life (QoL) the individuals perception of their position in life in the context of the culture and value
systems in which they live and in relation to their goals
No absolute concept, may be very individual (also the impact of several factors may
vary)
Ferre Muermans - 5 -
1 . 3 C A U S E S O F D E A T H , ( M OD I F I A B L E ) R IS K F A CT O RS , D E A T H & D IS A B I L I T Y
What are the most common risk factors underlying death & disability?
2009 vs 2019: evolution
o Tobacco use still the highest
o High increase in high fasting plasma glucose, decrease in LDL and air pollution
Discrimination between
o Metabolic risks (high BMI, high plasma glucose, high LDL, kidney disfunction)
o Environmental/occupational risks (air pollution, )
o Behavioral risks (dietary, alcohol, tobacco, )
Often go together (e.g. high alcohol and blood pressure)
Four important groups of risk behaviors in Europe, each of them associated with the risk of illness and premature death
What can we prevent (medically): some can, some cant (or not yet)
Illnesses related to risk behavior
Infectious diseases
Cancer: some more, some less
o WHO: an estimated 40% of all cancers in Europe could be prevented if the current understanding of established
risk factors and protective factors was translated into effective primary prevention , also an important role of
cancer screening and other approaches to early detection
o What is more/less preventable?
Classified as non-preventable stronger genetic factors, still an unknown trigger,
Hopefully in the future more preventable
Implementations come with a cost, but come also with advantages that possibly outweigh the costs
Implementing preventions has a cost (e.g. a screening program for breast cancer - when no genetic predisposition, women
between - 50-70 y/o are invited for a screening once in X years)
Has a cost, but a lower cost than healthcare system would have to carry if it had no screening but had to cure all people at
a later stage of breast cancer
Relationship between spending on health & life expectancy (increase)?
o Positive relationship btw. [amount spent on health per capita, life expectancy]
o Positive relationship btw. [annual average growth rate in health spending per capita, change in life expectancy]
Ferre Muermans - 6 -
Modification of risk behaviors (most prominent risk factors in Europe)
Tobacco use
o Example: really effective in altering tobacco use, is increasing the price of cigarettes,
In countries where this happened, the moment of an increase in price dip in number of packages sold
The inverse is true for when the price decreased
Price as an important influential factor of health behavior
o Distribution of amount of daily smokers and current smokers in Europe: big variations along between countries
Alcohol
o More campaigns for this in Belgium (e.g. dry January, tourne minrale) to prevent the hazardous use of alcohol
o Threshold of what is dangerous or not varies (some say 14 per week, some say 10, some say even a few)
More use of men than women
Daily use increases with age up to 75+
Overuse peaks in the age category of 55-64 y/o
Notice: when implementing a campaign, always consider what group you want to address (whole population, age category, ) beca use
the behavior of every (e.g.) age group might be driven by (partially) different determinants/factors
Eating/drinking behavior
o Healthy eating
5 portions of fruit/vegetables per day is recommended
Quite some differences across countries in the amount of portions eaten per day
Daily intake of sugary drinks in Belgium peaks in adolescence and young adulthood (15-34 years old)
o Healthy drinking
A lot of discussions about sugar-sweetened drinks versus artificially sweetened drinks and their risks
(some say A is better, some say B)
Daily intake of snacks in Belgium peaks in the earliest age groups (highest in children, slightly lower in
adolescents, a bit lower in adulthood)
Sedentary behavior
o Well-established risk factor
o Sedentary habits in Belgium: highest in groups of 15-24 and 75+ y/o
o Minimum 150min/week movement in Belgium: higher for men, lowest in highest age groups
1 . 4 T Y P E S OF PR E V E N T IO N , T A R G E T G R O U PS A ND PS Y C H O LO G IC A L T H E O R IE S
When you want to change unhealthy behaviors, you have to decide what type of prevention, which target group, which determinants
you want to address (and thus the psychological theory you rely on)
Notice that there can be some overlap between the different classifications, might be sometimes a bit confusing
Prevention psychology: 3 types of prevention (Caplan)
o Primary prevention: interventions designed to prevent problems for ever occurring across the population of
within a subgroup or system (e.g. vaccinations)
o Secondary prevention: targets groups that are at risk for developing a problem (e.g. early mammograms for
women with a family history of cancer, or older than 50)
o Tertiary prevention: limiting the impact on a problem that has occurred (e.g. alcoholics anonymous programs)
Prevention psychology: target groups (Gordon)
o Universal prevention: interventions that offer value to an entire group or population (e.g. use of seat belts)
o Selective prevention: interventions targeted to individuals or subgroups above average risk (e.g. Head Start
program)
o Indicated prevention: interventions targeted to individuals or subgroups at high risk or showing some symptoms
of a problem (e.g. support groups for widowers experiencing depression and anxiety)
Ferre Muermans - 7 -
1 . 5 S T R A T E G Y O F P R E V E N T IO N : L E SS ON S F RO M C AR D I OV A SC U L A R D I S E A SE ( R O S E , 1 9 81 )
1.5.1 PR O B L E M
While over the years the death rates of coronary heart disease have fallen in USA & Australia, the rate in the UK has experienced
no changes. In Japan, the rates kept very low over the years, and we know that the rates rise when they move to the US. This data
pattern shows that coronary heart disease is largely preventable (so the therapeutic advances are not the whole explanation, but
the biggest part of declines are result of the declining incidence of the disease).
Problem in the UK in 1980
Separation of the therapeutic and the preventive roles in many branches of medicine in the UK
Doctors only see the care for the sick as their responsibility
Britain fails to prevent a preventable disease
1.5.2 HI G H-R I SK STR A TE G Y
Situation: as doctors trained to feel responsible for patients
(to care for the sick people with major risk factors are almost seen as patients - e.g. when a symptomless man goes to a GP and it seems that
his blood pressure is high doctor says he suffers from high blood pressure and receives medication - actually he is no patient, this is an act in
preventive medicine the people with no problematic blood pressure are not seen as sick and thus no preventive actions are undertaken for
them)
ABSOLUTE AND RELATIVE RISK
Case of blood pressure:
o relative risk to die (ratio this group vs total (age) group) in function of age and blood pressure: in lower age
categories higher difference between blood pressure groups, less steeper gradient when older (because high
blood pressure not surprising at older ages)
o absolute risk to die (amount per 100 000): much higher in older people
Identifying risk in relative units rather than absolute units may be misleading
Example contraceptives
o Relative risk in younger vs older the same
o Absolute risk (attributable risk) way higher in older women
Advise must relate to absolute not relative risk
ABSOLUTE AND RELATIVE BENEFIT
The same argument goes for benefits of preventive action
Example: a trial in antihypertensive treatment
o Effectiveness in relative terms for everyone (regardless of age and pathology) 50-60%
o Absolute benefit (lives saved per 100 000 people): way higher in older people with pathology than in younger
people without pathology
To express results of trials only in terms of percentage effectiveness is to conceal what the user really needs to know
Overall conclusion: decisions should be made by measuring risks and benefits in absolute ( relative) terms
POPULATION RISK
The measures above tell us however nothing about the effects of a high-risk strategy (identifying and addressing only the
people at a higher risk on the whole community
Effects of a high-risk strategy may be more limited than imagined why?
o The community benefit depends on (1) benefit that each individual receives, AND (2) the prevalence of the risk
factor
o Example: if a large benefit only holds for a few people, the population is not much better off
Population attributable risk = excess risk associated with a certain factor in the population as a whole
o Depends on
Individual attributable risk (excess risk in individuals with that factor)
Prevalence of that factor in the population
Implication
o Fundamental principle in strategy of prevention: large number of people exposed to a low risk (e.g. slightly
elevated blood pressure) likely to produce more cases than small number of people exposed to a high risk
o Analogue in business: profits larger when small amounts taken from masses than when large amounts taken from
the few rich people
Ferre Muermans - 8 -
In high-risk strategy, we identify those at the top end of the distribution and give them some preventive care
May indeed be successful and advantageous for these (few) people
Cannot influence the large proportion of deaths occurring among the many people with a slightly elevated risk
Conclusion (especially in the case of heart disease): offers only a limited answer to a community problem
1.5.3. MA SS STR A TE G Y
Therefore, we often can better focus on mass approaches to lower the whole distribution of a risk variable
E.g. diet: by reducing salt intake to some extent in everyone, we might be able to lower the blood pressure distribution in
the whole population
Benefits from a mass approach where everyone receives a small benefit may be large on the community level
Mass approach is inherently the only ultimate answer to the problem of a mass disease
THE INDIVIDUAL GAINS LITTLE
However it may deliver high benefits to the community as a whole, it offers little to each participating individual
E.g. mass diphteria immunization in the 40s: 600 children would have needed to be immunized in order to safe only 1 life;
everyone who has to wear seat belts for their whole life will end up with only one life being saved
This is a ratio that one has to accept in mass preventive medicine
A measure applied to many, will actually only benefit few
THE PREVENTION PARADOX
= a measure that brings large benefits to the community, offers little to each participating individual
Do not expect too much from things like individual health education: people will not be motivated to a great extent, since
there is little in it for each individual (especially in the short term)
To change behavior, there has to be a larger and/or more immediate reward
SOCIAL MOTIVATION, ECONOMICS AND CONVENIENCE
How to motivate people then?
Examples
o Decline in smoking over the years: most cases not because of the positive health effects, but because of social
pressure (more often people react to smokers with pity and despise
o Doctors have a hard time to motivate overweight patients to control their weight, while many young women
successfully shape perfect bodies difference? Thinness as ideal, social pressure to be thin, rewarding when
you conform to these norms
Social pressure brings immediate rewards for those who conform
Maybe also in medicine, we should create social pressure that makes healthy behavior easier and more acceptable
immediate social rewards
There are also the force of economics and convenience as important determinants of behavior
E.g. butter vs soft margarine: large market shift to soft margarine, why?
o Probably the medical argument did not do nothing
o Most important determinants
Economic: price
Convencience: butter in fridge becomes hard, margarine stays soft
Most important determinants: convenience, social, economic
SAFETY IS PARAMOUNT (I.E. MORE IMPORTANT)
Example: controlled trial with clofibrate although relatively safe in medical terms, a lot of side effects and even deaths
In patients with high hyperlipoproteinaemia, we would be able to take such a risk (balance costs and advantages) if it can
be shown that it lowers their risk of death substantially
Interventions for prevention where the risk is low is totally different
o If preventive measure exposes many people to a small risk, the harm can quickly outweigh the benefits
Problem: often not possible to conduct such large and long trials, and thus we often cannot identify the presence of possible harmful
side effects
Conclusion: we cannot accept long-term mass preventive medication
Ferre Muermans - 9 -
1.5.4 CO N C L U SI O N
Prevention is essential AND (at least partially) possible
Preventive strategy concentrating on high-risk individuals may be appropriate for them (and a wise/efficient use of limited
resources), BUT its ability to reduce burden of disease in the whole community tends to be disappointingly small
Potentially far more effective and ultimately the only acceptable answer is the mass strategy
Aim: shift the whole populations distribution of the risk variable
But: first concern here should be that this advice is safe
We may distinguish two types of preventive measures
Removal of an unnatural factor & restoration of biological normality (i.e. the conditions to which we are genetically
adapted)
o Example for coronary heart disease: reduce saturated fats, salt, give up cigarettes, reducing weight, some increase
in polyunsaturated fat,
o Such measures are assumed to be safe
Adding some other unnatural factor, in the hope of conferring protection
o Increase in biological abnormality, even further removed from condition to which genetically adapted
o Example for coronary heart disease: high intake of polyunsaturates, all forms of long-term medication
o Long-term safety cannot be assured, and possibly harm may outweigh the benefits
o The evidence for these measures (as well for the advantages as for the possible harms) should be very stringent
(accurate, punctual, detailed). De oefenexamen moet geschreven zijn in de Nederlandse taal. Onderin staan de antwoorden. Het aantal vragen dat het oefenexamen moet bevatten is onbeperkt.