Public Health Flashcards
How are mortality rates collected?
The doctor completes the certificate of cause of death, the ‘informant’ takes certificate to local registrar and registers death, copy is sent to ONS, and high compile and publish mortality statistics
What is the underlying cause of death?
The disease or injury that initiated the train of events directly leading to death or the violence that produced the fatal injury
What shows data quality?
C.A.R.T: completeness, accuracy, relevance and timeliness
What is morbidity?
The state of being diseased
What is the iceberg concept of disease?
The number of cases of disease ascertained is outweighed by those not discovered
What is the integrated household survey?
A composite survey combining questions asked in a number of office for national statistics social surveys to gather basic information for a very large number of households
What does the super output area level measure?
Multiple deprivation. Seven domains: income, employment, health, education, skills and training, barriers to housing and services, environment and crime
Why do we collect routine health data?
To monitor the health of the population; to generate hypotheses on causes of ill health; to inform planning of services to meet health needs; to evaluate performances and processes
What is critical appraisal?
Critical appraisal is the process of systematically examining research evidence to asses its validity, results and relevance, before using it to inform a decision
What are the three main questions used in appraisals?
Are the results valid? What are the results? Are the results useful?
What are the difficulties with randomised control trials?
Ethical issues – is it ethical to withhold a life saving treatment that we strongly suspect will be effective; Cost – often very expensive to run, large numbers of participants required, lots of data to collect, often resource heavy, payment to participants may be required; Attrition – trial participants dropping out over time
What is a systemic review?
A review of a clearly formulated question that uses systematic and explicit methods to identify, select and critically appraise relevant research, and to collect and analyse data from the studies that are included in the review.
What is meta-analysis?
The use of statistical techniques to integrate the results of several studies, which answer related research hypotheses
What is a forrest plot?
Graphical representation of the individual results of each study included in a meta-analysis, together with the combined meta-analysis result.
What is homogeneity?
occurs when studies have similar and consistent results
What is heterogeneity?
indicates variability between results above and beyond that expected by chance
What is the I2 index?
I2 index quantifies the degree of heterogeneity in a meta-analysis. 25% (I2=25) indicates low heterogeneity. 50%(I2=50) medium heterogeneity. 75%(I2=75) high heterogeneity
What is sensitivity analysis used for?
to determine how sensitive the results are to changes in how the review was done (used to assess how robust the results are)
What are the two types of stress?
Distress - negative stress which is damaging and harmful; Eustress - positive stress which is beneficial and motivating
What is stress?
A state of mental, emotional, or other strain
What are two types of causes of stress?
Internal stressors and external stressors
What are internal stresses?
Physical (inflammations, infections) and Psychological (personal expectations, attitudes and beliefs, worry about an event)
What are external stressors?
Environmental factors i.e. overcrowding; Work; Social & cultural pressures
What are the three stages of adaptation?
Alarm – When the threat or stressor is identified or realized, the body’s stress response is a state of alarm.; Adaptation/resistance - the body engages defensive countermeasures against the stressor; Exhaustion – the body begins to run out of defences, resources depleted
What are direct controls of meal size?
all factors relating to the direct contact of food to the gastrointestinal mucosal receptors
What are indirect controls of meal size?
Anything not involved in direct contact with food. metabolic, endocrine, cognitions, individual differences, social and environmental factors
What is satiation?
what brings an eating episode to an end
What is satiety?
inter-meal period
What is the satiating efficiency?
A nutrients capcity to make you feel full. Protein>CHO>fat>alcohol
What is oxidative heirachy?
The priority of utilisation of the body: alcohol > protein + CHO > fat
How does fat affect satiation and satiety?
relatively weak effect on satiation and satiety (relative to protein and CHO) so by the time you feel full you’ve already eaten too much fat
What is passive overconsumption?
Eating too much food before you feel full so you eat too much
What is energy density?
Kcal/g. A large energy density is associated with a large energy intake
How can we reduce energy density?
Incorporating water; Air (industry); Fruits and vegetables; Reducing fat (individual/ industry) • Method of cooking
What is energy compensation?
The adjustment of energy intake following the ingestion of a particular food
Is energy compensation higher with liquids or foods?
it is lower with liquids than solids other than the exception of soup!
How does alcohol affect over-eating?
Consumed in liquid form; Least satiating macronutrient; Efficiently oxidised at the expense of fat; Additive to total daily energy intake – passive overconsumption; Stimulatesintake–active overconsumption; Associated with poorer food choices – interaction with type of beverage consumed; Pattern of consumption is important
What is the variety effect?
Following the consumption of a food, there is a reported decrease in the pleasantness of the appearance, smell, taste, & texture of that food, whilst other foods remain pleasant
How does distraction affects the amount of food eaten?
There is a high energy intake when you are distracted (eg. socially or watching tv)
What is dietary restraint?
Disinhibited eating behaviour is not only associated with weight gain and obesity, less healthful food choices
How does sleep affect the amount of food eaten?
Short sleep duration sleep is associated with reduced diet quality and overeating. This is also observed in children
What is reward sensitivity?
Correlation between sensitivity to reward traits and neural responses to palatable food images. Obese individual are more responsive to visual images of food
What is the epidemiological pattern?
Effects rich first & then association is reversed (ie. obesity associated with low social economic class).
How does the social gradient of obesity differ between men and women?
For women, disparity in obesity by social class is longstanding. Among men, become more pronounced in recent years.
What is sexual and reproductive health?
Complete physical, mental, and social well-being and not merely the absence of disease, dysfunction or infirmity, in all matters relating to the reproductive system and to its functions and processes.
What is the aim of sexual and reproductive health promotion?
The objective of SRH promotion is to enable individuals, communities and population groups to enhance control over the determinants of health and thus increase people’s capacity to achieve optimal sexual and reproductive health over their life course
What are behavioural HIV interventions?
Sex education; stigma and discrimination reduction programmes; counselling
What are biomedical HIV interventions?
Voluntary male circumcision; needle exchange programmes
What are structural HIV interventions?
Decriminalisation of sex work, homosexuality; micro-finance schemes
What are the key challenges to sexual and reproductive health interventions?
Deep seated hierarchies and inequalities difficult to address - gender and poverty; Close linked to religious and moral understandings; Stigma, discrimination, confidentiality concerns, compounded by legality issues; Wide range of providers-disjointed
What is globalisation?
An openness to trade, to ideas, to investment, to people, and to culture; Transnationalisation of the world economy; The widening, deepening and speeding up of interconnectedness between countries; A process of transformation at the international systems level; A process that blurs and dissolves national boundaries
What affects refugee health needs?
where they have come from
the migration process
where they end up
What are the key challenges of an aging population?
strains on pension and social security systems;
increasing demand for health care;
bigger need for trained-health workforce;
increasing demand for long-term care;
pervasive ageism that denies older people the rights and opportunities available for other adults.
What are the causes of population aging?
Improvements in sanitation, housing, nutrition, medical interventions.
Life expectancy is rising around the world.
Substantial falls in fertility.
Decline in premature mortality.
More people reaching older age while fewer children are born.
What is intrinsic aging?
Intrinsic: natural, universal, inevitable, chronological
What is extrinsic aging?
Extrinsic: dependent on external factors, eg exposure to UV rays, smoking, air pollution etc
What are the physical changes in aging?
◦loss of skin elasticity;
◦loss of hair and hair colouring;
◦decrease in size and weight;
◦loss of joint flexibility;
◦increased susceptibility to illness;
◦decline in learning ability;
◦less efficient memory
Which gender live longer?
Women live longer than men (5 to 8 years typically)
In very old age, the ratio of women/men is 2:1
Why do women live longer than men?
20% biological:
◦Until menopause hormones protect women from heart disease
80% environmental:
◦Men take more lifestyle risks than women
What are the consequences of the aging population?
- Pensions will have larger pay outs than those currently planned
- Health and social care services will have to serve an older population with chronic and comorbid conditions.
- Rising inequalities as more affluent social groups use health and social services for longer.
What socio-economic class is likely to have the most chronic illness?
People with lower socio-economic status have higher incidence of chronic illness
What are the alternatives for recurrent admission of elderly patients?
Supporting discharge from inpatient hospital care}
Providing alternatives in acute care (in the community)
Supporting chronic disease management in the community
What are the principals of good primary health care of older people?
◦To help prevent unnecessary loss of function
◦To prevent and treat health problems which adversely affect quality of life in old age
◦To supplement the existing system of informal care and prevent its breakdown
◦To give older people a good death as well as a good life
What is the caregiver ‘burden’?
◦Problems – disability & disturbance behaviours
Incontinence; nocturnal disturbance; demands; apathy/disengagement
◦Physical disabilities less problematic than mental
distortion & loss of relationship
◦Mental & physical health problems as outcome
Carer requires care
What is health?
Health is a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity.
How does social class effect life expectancy?
Life expectancy decreases as social class decreases.
How is the gap between the upper and lower changing?
The gaps between the upper and lower classes are increasing.
What happens to a country when it reaches a certain income threshold?
When a country reaches a certain income threshold, the epidemic diseases of poverty are replaced with degenerative diseases, then further increase in per capita income make little or no difference to the health of a nation.
How does average household income within a country affect health
Within a country, income has a relationship to health with people on lower incomes having worse health than those on higher incomes.
What has the biggest effect economically on a countries health: the mean household income or the difference between the rich and poor?
Between countries there is no relationship between mean income and health (above a threshold).
It is the extent of income division within a society that determines population health. Therefore more unequal societies have worse health.
What is social class?
Social class is a measure of occupation, stratification, social position and access to power and resources.
How can social class be quantified?
It can quantified using the Registrar General’s model (occupation focused) or the NS-SEC model.
What is the inverse care law?
The availability of good medical care tends to vary inversely with the need for it within a population.
How can incidence be increased or decreased?
Incidence can be increased by screening identifying new cases and increasing risk factors. It can be reduced by decreasing risk factors e.g. primary preventions.
What increases and decreases prevelance?
Screening programmes identifying new cases, increasing risk factors and increased life-expectancy due to better treatments can increase prevalence. Cures for the conditions and decreasing risk factors can reduce prevalence.
What is sociology?
Sociology is the study of social relations (the bonds between people and groups of people) and social processes (where direct human actions are a result of collective human actions). It is the measure of social interdependencies.
Name some social structure examples:
Social structures can include religion, family or the medical profession.
What roles does the sick role involve?
Is exempt from normal social roles
Is not responsible for their condition
Should try to get well
Should seek help from and co-operate with the medical profession.
What is the medicalisation hypotheses?
Professional’s tend to see problems in terms of their own profession. Doctors therefore see everything medically. Therefore some conditions that seem medical can be in fact products of social forces. For example: ADHD/depression?
What is latrogenesis?
Latrogenesis is the unintended adverse effects of a therapeutic intervention. It can be clinical, social or cultural.
What is the health belief model?
Health belief model: perceived susceptibility, perceived barriers, benefits and self efficacy are all influences on changing behaviours
What is the nudge theory?
Changing the environment to make the healthy option the easiest option
What is public health involved in?
Public health is concerned with health protection, promotion and improving and organising health sciences.
It can be on a local, regional, national or international level.
How is the total number of children per woman changing?
The total number of children per woman is decreasing in less developed countries and remains stable in developed countries. World fertility is generally decreasing.
How are the ages of the population changing?
The population is aging, especially in the middle class. There is also a high population of under 15s.
How much of the world burden of disease is in developing countries?
Developing countries account for 84% of world population and 93% of the world burden of disease.
How much of global income and spending are in developing countries?
They account for only 18% of global income and 11% of global health spending.
How does the prevelance affect negative and positive predictive values?
If the prevalence of a disease is high, the incidence of false positives will fall. The positive predictive value therefore increases and the negative predictive value falls.
What is the high risk approach to screening?
Target highest risk individuals
Aim to reduce risk to below set limit
Accepted by society - treat those outside “normal levels”
What is the population approach to screening?
Target all individuals
Aim to reduce the risk for each individual
Recognises that the low risk majority may contribute most cases
Concerns over treating the well and the “nanny state”
Who does the high risk approach of screening benefit?
The high risk approach favours those who are more affluent and better educated. They are:
More likely to engage with health services
More likely to comply with treatments
More likely to have the necessary means to change their lifestyle
How does population approach screening affect inequalities?
The population approach generally reduces social inequalities
How many mortalities in the UK are due to CVD? What is happening to this statistic?
Cardiovascular disease accounts for 40% of deaths in the UK (1 in 5 men and 1 in 8 women). Rates are decreasing due to lifestyle changes and effective treatments.
What does primary prevention of CHD involve?
Primary prevention in CHD involves lifestyle changes and prevention and management of the related conditions of hypertension, hypercholesterolaemia and diabetes.
How are the risk factors for CHD changing?
Obesity and diabetes have risen and physical activity is decreasing. These increase the risk of CHD.
Smoking, cholesterol, blood pressure levels, deprivation and other factors have fallen. This decreases the risk of CHD.
Treatments for CHD are improving.
Name some unmodifiable risk factors for CHD:
Sex
Age
Ethnicity
Family history
Early life circumstances
Name some potentially modifiable risk factors for CHD:
High blood cholesterol
Hypertension
Type 2 diabetes
Smoking – single avoidable risk factor which causes more death and disability than any other. Decreasing in rate.
Physical inactivity
Overweight. BMI = weight in kg/(height in metres)2 normal BMI is 18-25
Poor nutrition
Alcohol intake
What are type A behaviours?
Type A behaviours are competitiveness, hostility and impatience. These are coronary prone behaviours. They can be assessed using questionnaires, self report and clinical interviews.
How does depression affect CHD risks?
Those people with higher depression ratings have higher CHD rates and associated mortality. Social deprivation could increase depression and anxiety. Major depression is associated with higher mortality in CHD.
How does occupation affect myocardial infarction risk?
A job with high demand and low control (leading to stress) has an association with MI.
Which area of the general public smoke the most?
Men smoke more than women
Smoking prevalence is decreasing
The gap between men and women is closing.
People from lower socioeconomic groups smoke more than those from higher ones.
What are the phases of a pandemic?
Phases 1-3 (mostly animal infections with few human infections)
Phase 4 (sustained human to human transmission)
Phases 5-6 ( Widespread human infection)
Post peak (possibility of recurrent events)
Post pandemic (disease returns to seasonal levels)
What changes have altered the risk of pandemics?
International travel
Large population
Crowding has increased
Population health has improved
Animal husbandry has changed
Interdependence between countries
What are the types of transmission?
Direct: Direct route e.g. STIs
Faecal oral route e.g. Viral gastroenteritis
Indirect: Vector-borne e.g. malaria/dengue
Vehicle-borne e.g. viral gastroenteritis/hep B
Airborne: Respiratory route e.g. TB/Legionella
How is healthy life expetancy changing in relation to life expectancy?
Healthy life expectancy is not increasing as much as life expectancy, this leads to more people living with disability.
What is specialist palliative care?
This involves health professionals who specialise in palliative care within and MDT. It is delivered in hospital, care homes, hospices or at home and is provided mainly to those with cancer.
What is generalist palliative care?
Available to anyone with advanced progressive disease likely to end in death by practitioners not exclusively concerned with specialist palliative care. Provided by GPs and hospital doctors, district nurses, nursing home staff, social workers etc.
How does age affect poverty?
Poverty and poor living conditions increase with age.
What is the differece betewen gerontology and geriatrics?
Gerontology is concerned with studying the changes in the body and mind that accompany aging, while geriatrics is concerned with the diagnosis and treatment of disorders that occur in old age.
How does COPD treatment differ from lung cancer?
COPD patients report a worse quality of life and have more cases of depression. COPD patients receive fewer visits from district nurses and are less likely to be aware of their prognosis. Lung cancer patients receive support from specialist palliative care.
What is the doctrine of dual effect?
If you administer a drug to relieve pain in doses that you know may be fatal, then provided your intention is not to shorten life but to relieve pain, the administration is not unlawful.
Normally, if you carry out an action knowing that X is a likely consequence of that act then the law regards you as intending to cause X.
How do you ask focused questions?
PICO
Population
Intervention
Comparator
Outcome
What are descriptive observational studies?
Case reports or case series study individuals.
Ecological studies use routinely collected data to show trends in data and thus is useful for generating hypotheses. Shows prevalence and association, cannot show causation.
What is a descriptive and analytical observational study?
Cross sectional study/survey. Divides population into those without the disease and those with the disease and collect data on them once at a defined time to find associations at that point in time. They are used to generate hypotheses but are prone to bias and have no time reference.
What does qualitative data tell us?
Qualitative research tells us about the kinds of things that exist in the social world rather than the amount of them and what it is like to be in a particular situation.
What are the problems of qualitative research?
- *Interactive kinds**: over-analysis of oneself using existing theories
- *Meaning imposition**: not truly understanding what someone else is thinking
- *Crisis of representation**: research cannot capture lived experiences
- *Reflexivity**: personal interpretations of data
Generalisation
What graphs show continuous data?
Stem and leaf diagram
Histogram
Box and whisker
What graphs show discrete data?
Bar charts
Pie charts
What is a reference range?
A reference range gives limits within which we would expect the majority of data to fall. For normally distributed data we would use 2 standard deviations above or below the mean (95% of the data).
How does sample size effect standard error?
Larger samples reduce the standard error of the mean. Standard errors quantify how good an estimate a sample result is likely to be.
What does standard error measure?
Standard error is an estimate of precision. It provides a measure of how far from the true value the sample estimate is likely to be.
What are confidence intervals?
The 95% confidence interval is found between two standard errors (1.96 standard errors) above and below the mean.
How does sample size affect confidence level?
It is smaller with larger sample sizes. If the size of the sample is squared, the confidence intervals are half the size.
What is the test statistic?
The test statistic reduces the data to a single value.
The test statistic = (observed value – hypothesised value)/Standard error of the hypothesised value
How is a p value found?
The test statistic is compared to a hypothesised critical value (using a distribution we expect if the null hypothesis is true) to obtain a P value.
What is the power of a study?
The probability of rejecting the null hypothesis when it is actually false is called the power of the study. It is the probability of concluding there is a difference when a difference truly exists.
What is clinical significance?
A clinically significant difference is one that is big enough to be worthwhile. It is important that the size of the sample is adequate to detect the clinically significant result, at the 5% significance level with at least 80% power.
What is the risk and absolute risk?
The risk is the incidence divided by the population. This is also known as absolute risk as is the probability that an event will occur. I.e. person A had a 10% risk of getting cancer
What is the relative risk?
Relative risk is the risk of an event in an exposed group divided by the risk in the not exposed group. E.g. people on the pill have a 50% increased risk in cancer. If original absolute risk was 10% their absolute risk is now 15%.
What is the null value for relative risk?
The null value for the relative risk is that there is no difference in risk between groups. If the confidence interval includes one or the relative risk is one, there is no difference between groups.
What is the absolute risk difference?
Absolute risk difference is the absolute additional risk of an event following an exposure.
ARD = risk in an exposed group – risk in unexposed group
I.e. there is a 5% increase in risk in developing cancer if you take the pill.
What is the null value for absolute risk difference?
The null value for ARD is that there is no difference. This occurs if the value or confidence interval includes 0.
What is the number needed to treat?
This is the additional number of people you would need to treat in order to cure one extra person compared to the old treatment.
What is the number needed to harm?
For a harmful exposure the number needed to harm is the additional number of individuals who need exposure to the risk in order to have one extra person develop the disease compared to an unexposed group.
How do you work out the number needed to treat?
The number needed to treat = 1/ absolute risk reduction
How do you work out the number needed to harm?
The number needed to harm =1/absolute risk difference
What is the odds of an event?
The odds of an event is the ratio of the probability of an occurrence compared to the probability of a non-occurrence.
Odds = probability/(1-probability)
What is the odds ratio?
The odds ratio is the ratio of odds for exposed group to the odds for the not exposed groups.
OR = {Pexposed/ (1 – Pexposed)}/
{Punexposed/ (1 – Punexposed)}
When is odds ratio used?
For case control studies it is not possible to calculate the relative risk and so the odds ratio is used.
For cross-sectional and cohort studies both can be derived but odds ratio is used if it is not clear which is the IV and which is the DV because it is symmetrical.
What is public health?
The science and art of: - preventing disease, prolonging life, promoting health through the organised efforts of society
What are the domains of public health?
Health improvement, health protection, improve services
What are the WHO screening criteria?
Important public health issue
Understanding of the illness
Sensitive, specific test
Common problem
Risks outweigh benefits
Early detection possible
Expenses are low
Non-invasive test
What is frailty?
Frailty is a broad, common-speech term for ‘weak physiological and psychological states’
Has connotations of low vigour, low resilience and physical and psychological vulnerability
How does the cardiovascular system become more frail with age?
Central and peripheral arteries thicken with age; when severe, atherosclerosis
- Stiffening of arterial walls
- Increase in pulse wave velocity
- Increase in systolic blood pressure
-Increase in left ventricular wall thickness of 30% between the ages of 25 and 80 years may be an adaptive response
How does the respiratory system become more frial with age?
With ageing, there is a decrease in the elasticity of the lung. Alveolar (air sac) diameters widen and the alveolar surface area per unit of lung volume decreases.
What are the most prevelant types of frailty that occur with age?
Many cancers
Arthritis
Diabetes
Respiratory capacity
Muscle strength
Eyesight
Hearing
What is opportunity cost?
The opportunity cost of an activity is the sacrifice in terms of the benefits forgone from not allocating resources to next best activity
What is economic efficiency?
Economic efficiency is achieved when resources are allocated between activities in such a way as to maximise benefit. The method used to assess whether benefit is maximised is called ‘economic evaluation’
What is economic evaluation?
Economic evaluation is the assessment of efficiency. Economic evaluation is a comparative study of the costs and effectiveness/benefits of health care interventions
What are the types of economic evaluation?
Cost-effectiveness analysis - Outcomes measured in natural units (e.g. incremental cost per life year gained).
Cost-utility analysis - Outcomes measured in quality adjusted life years (e.g. incremental cost per QALY gained).
Cost-benefit analysis - Outcomes measured in monetary units (e.g. net monetary benefit)
What is economic equity?
Equity is concerned with the fairness or justice of the distribution of costs and benefits. Economists are clear in principle about the definition of efficiency. There are, however, opposing views about what is ‘fair’
