Public Health Flashcards
Definition of economic evaluation?
Comparative study of the costs and benefits of healthcare intervention
What is 1 QALY
1 year of perfect health
What 4 things must be considered in health economics?
opportunity cost
economic efficiency
equity
economic evaluation
what is opportunity cost
the cost of what you cannot do now du to an action you have undertaken (i.e. spending £100,000 on PCI means there is £100,000 less to spend on GP)
What is economic efficiency
achieved when resources are allocated between activities in such a way as to maximise benefits
What are the three domains of public health
health protection
health improvement
improving services
what are the key concerns of public health
inequalities of health
wider determinants of health
prevention
what is the domain of health protection concerned with?
measures to control infectious disease risk and environmental hazards i.e. infectious disease, radiation, chemicals etc.
what is the domain of health improvement concerned with?
societal interventions such as inequalities, education, housing and empolyment
what is the domain of improving services concerned with?
organisation and delivery of safe high quality services for prevention and treatment of care
in which three ways can health interventions be applied?
individual level - vaccines
community level - outdoor excersise programme
population level - iodine in salt to prevent iodine deficiency
what is a health needs assessment
a systematic method for reviewing the health issues facing a population leading to agreed priorities and resource allocation that will improve health and reduce inequalities
what is the health needs assessment model?
needs assessment -> planning -> implementation -> evaluation -> needs assessment
what are the three approaches to health needs assessment?
- epidemiology
- comparative
- corporate
define need
ability to benefit from an intervention
give some examples of how a health need is measured
mortality, morbidity, socio-demographic measure
what are the 4 sociological perspectives of a health need?
- felt need- individual perceptions of variation from normal health
- expressed need- individual seeks to overcome the variation
- normative need- the professional defines intervention appropriate for the expressed need
- comparative need- comparison between severity, range of intervention and cost
what does an epidemiological approach to the a health needs assessment involve?
define the problem,look at the size of the problem (incidence, prevelance), services available, evidence base, models of care and existing serivces to make a recommendation
what are some potential sources of data for an epidemiological health needs assessment?
disease registry
hospital admissions
GP database
mortality data
what are the advantages of an epidemiological HNA?
uses existing data
provides data based on incidence/mortality
can evaluate service by trends over time
what are the disadvantages?
quality of data is variable
data collected may not be required
does not consider the felt needs or opinions of the people affected
what does a comparative health needs assessment involve
compares the services recieved by one population with another population e.g. comparing mental health services in two different areas
what factors does a comparative health needs assessment examine?
health status
service provision
service utilisation
health outcomes
what are the advantages of a comparative health needs assessment?
quick and cheap
indicates whether a health or service provision is better or worse in comparable areas
what are the disadvantages of a comparative health needs assessment?
may be difficult to find a comparable population
data may not be high quality
may not yield what the most appropriate level of intervention should be
what does a corporate approach to a health needs assessment involve?
ask the local population what their health needs are - uses focus groups, public meetings, interviews and a wide variety of stakehloders i.e. teachers, social workers, charity workers etc.
what are the advantages of a corporate HNA?
it is based on the felt and expressed needs of the population in question
recognises the experience of those working in the population
takes into account a wider range of views
disadvantages of a HNA?
difficult to distinguish a need from a demand
groups may have invested interested
may be influenced by a political agenda
what is a secondary prevention and give an example?
catching a disease in its early or pre-clinical phase
i.e. breast screening
what is a tertiary prevention and give an example?
preventing complications of an established disease
e.g. diabetic foot care review
what are 2 approaches to prevention?
population approach - preventative measures for everyone
high risk approach - identify individuals above a chosen cut off point and treat
what is the prevention paradox?
a preventative measure brings much benefit to the population but little to each participant
what is the wilson criteria for screening programme? (8)
- important problem
- known and detectable latent stage
- natural course/progression
- test is acceptable to population
- treatment available
- agreed at risk population to screen
- agreed policy on who to treat
- must be economically balanced
disadvantages of screening? (3)
exposure of well individuals to distressing or harmful diagnostic tests
detection and treatment of subclinical disease that would never cause problems
preventative interventions may cause harm
what is sensitivtiy of screening test and how do you calculate it
the proportion of people with the disease who are correctly identified by the screening test
true positive / (true positive + false negative)
what is the specificity of screening and how is it calculated?
proportion of people without the disease that are correctly excluded
true negative / true negative + false positive
what is positive predicted value and how is it calculated?
proportion of people with a positive test result who actually have the disease
true positive/ true positive + false positive
what is the negative predicted value and how is it calculated?
the proportion of people with a negative test result who do not have the disease
true negative/ (true negative + false negative)
incidence?
number of new cases of a disease in a population in a given time frame
define prevelance?
total number of people with the condition per 100,000 per year
what is lead time bias?
when a screening test identifies an outcome earlier than it would otherwise been identified resulting an apparent increase in survival time
what is a length time bias?
bias resulting from differences in the length of time taken for a condition to progress to severe effects that may affect the efficacy of the screening method
who does a case report study?
individuals
what is an ecological study?
study used routinely to show trends in data - used for generating hypothesis but cannot show causation
what are 2 descriptive study types?
case report study
ecological study
what are cross sectional studies?
divide populations into those without the disease and those with the disease and collects data on these groups t one point in time
advantages and disadvantages of cross sectional study?
large cohort
cheap
good for surveillance
prone to bias
cannot infer causation
risk of reverse causality
recall bias and non-response