PH

• Why is prevention often overlooked?

  -due to the focus on curative medicine
• What is primary prevention?

  Prevention of the onset of disease before any signs of the disease have developed
• When can it be hard to distinguish between primary and secondary intervention?

  -if the onset of disease is uncertain
• Give examples of primary prevention (5)

  -immunisation -> used to prevent deadly infectious diseases of childhood and tropical diseases

  -outbreaks can be well controlled by public health measures (isolation of cases, identification and isolation or elimination of the source of infection, and if no vaccine is available then quarantine and disinfection methods are used)

  -some screening procedures prevent clinical onset of disease e.g. by changing diet

  -chronic disease usually have multiple causes of more complex -> can limit alcohol consumption, increase price of cigarettes, encourage healthier diets

  -legislation can be passed to prevent things e.g. asbestos being slowly phased out in industrial products
• What is secondary prevention?

  -interruption of the full development of the disease and restoration of normal health
• Give examples of secondary prevention (2)

  -screening for breast tumours and catching them early

  -used in preventing recurrence of the disease e.g. checking and modifying cardiovascular risk factors on discharge of patients who had a myocardial infarction
• What is tertiary prevention?


  Focuses on people who are already affected by a disease; goal is to improve the quality of life by reducing disability, limiting or delaying complications, and restoring function
• Give examples of tertiary prevention (2)

  -rehabilitation of patients W/ long-term disability from stroke

  -development of effective treatments and efficient management for diseases
• How is information routinely collected?

  -10 year census - survey that happens every 10 years + gives a picture of all the people and households in England and Wales

  -mortality stats

  -cancer registration data -> cancer data nhs collects data on all people living in England who are diagnosed with cancer

  -hospital episode stats: database containing details of all admissions, a&e attendances and outpatient appointments at NHS hospitals in England

  -general practice consultation stats

  -notification data: infectious diseases, congenital malformations, maternal deaths

  -lab reporting stats

  -morbidity surveys

  -lifestyle surveys

  -qualitative and quantitative research studies

  -national confidential enquiries -> national confidential inquiry into suicide and safety in mental health: in-depth information on all suicides in the UK since 1996
• How is the data that's been collected analysed? (2)

  -undertaken at a local level and published as a joint strategic needs assessment to inform commissioning of NHS and local authority services

  -also leads to annual independent report of the director of public health
• What are some other sources of data? (4)

  -death certificates

  -cancer registrations

  -birth registrations

  -royal college of General Practitioners weekly return
• How does data vary?

  -availability and quality of data

  -data may be collected on a systemic and ongoing basis or only intermittently

  -may be entire populations or samples

  -may be available nationally, regionally or locally

  -may be cohort or cross-sectional

  -may be person or episode based

  -data collection might not be standardised between different countries (diff for england, Wales, Scotland, and NI)

  -classification of certain cancers may vary significantly between countries
• What is a health needs assessment?

  -the systematic approach to ensuring that the health service uses its resources to improve the health of the population in the most efficient way

  -involves epidemiological, qualitative, and comparative methods to describe health problems of a population, identify inequalities in health,and determine priorities for the most effective use of resources
• What are health needs?

  -those that can benefit from health care or from wider social and environmental changes

  -if needs are to be identified then an effective intervention should be available to meet these demands and improve health -> no benefit from an intervention that is not effective or if there are no resources available
• What is demand?


  -what patients ask for; the needs that most doctors encounter

  -GPS have a key role as gatekeepers controlling this demand
• What is supply? What does it depend on?

  -the health care provided

  -depends on the interests of health professionals, priorities of politicians, and the amount of money available
• What is a health impact assessment (hia)?

  - a combination of procedures, methods and tools by which a policy, programme or project may be judged as to its potential effects on the health of a population , and the distribution of those effects within the population
• What questions are asked when assessing health needs?

  -what is the problem

  -what is the size and nature of the problem

  -what are the current services

  -what do patients want

  -what are the most appropriate and effective (clinical and cost) solutions

  -what are the resource implications

  -what are the outcomes to evaluate change and the criteria to audit success
• What is a case definition?

  -a set of standard criteria for deciding whether an indivdual should be classified as having the health condition of interest
• Why is case definition important? (2)

  -ensures uniformity of case classification because every case must meet the same criteria

  -for an epidemiological study, it reduces bias from misclassification of the outcome by ensuring that classiffied as cases truly have the disease of interest
• How are case definitions determined? (3)

  -determined by clinical criteria

  -restrictions on time, place, and person

  -confirmatory laboratory tests- use of positive laboratory culture resuluts for a case defintion in the absence of symptoms should be weighed carefully
• Why should the case definition generally not include the exposure of interest?


  -the purpose of the epidemiological study is to determine whether the exposure is associated with the disease, if exposure is included in the case definition, all cases will have been exposed, so that exposure will be associated with disease even if, in actuality, it's not
• What are the issues with only using laboratory tests? (2)

  -organisms can sometimes be present without causing disease

  -BUT infection can be asymptomatic and people with asymptomatic infections should be considered cases, not controls
• How can case definitions vary?

  -in a local area -> relatively sensitive or inclusive to capture as many potential cases as possible

  -if enrolling people into an epidemiological study to identify risk factors it should be relatively specific or narrow to minimise misclassification and bias
• What are controls? Why is it hard to define controls?

  -people who do not have the disease in question

  -difficulty arises with people who have mild or asympomatic cases of the disease -> if these people are enrolled as controls, the control group includes people who are really cases