Use of data (2) Flashcards
give 3 medical factors affecting the uptake of care
new symptoms, visible symptoms, increasing severity
give 6 non medical factors affecting the uptake of care
crisis, peer pressure, patient beliefs, social class, age, gender, media
what are the 3 main aims of epidemiology
description, explanation and disease control
define description, explanation and disease control
description - to describe the amount and distribution of disease in human populations. explanation - to elucidate the natural history and identify aetiological factors for disease usually by combining epidemiological data with data from other disciplines eg biochemistry. disease control - to provide the basis on which preventive measures, public health practices and therapeutic strategies can be developed, implemented, monitored and evaluated for the purposes of disease control
define description, explanation and disease control
description - to describe the amount and distribution of disease in human populations. explanation - to elucidate the natural history and identify aetiological factors for disease usually by combining epidemiological data with data from other disciplines eg biochemistry. disease control - to provide the basis on which preventive measures, public health practices and therapeutic strategies can be developed, implemented, monitored and evaluated for the purposes of disease control
what does epidemiology compare?
compares groups in order to detect differences pointing to aetiological clues, the scope for prevention, and the identification of high risk groups in society
define incidence
no. of new cases of a disease in a population in a specified period of time
define prevalence
no. of people in a population with a specific disease at a single point in time or in a defined period of time
what is the relative risk
measure of the strength of an association between a suspected risk factor and the disease under study. incidence of disease in exposed group divided by incidence of disease in unexposed group
what is the relative risk
measure of the strength of an association between a suspected risk factor and the disease under study. incidence of disease in exposed group divided by incidence of disease in unexposed group
give some examples of sources of epidemiological data
mortality data, hospital activity stats, cancer stats, accident stats, drug misuse databases
define health literacy
people having the knowledge, skills, understanding and confidence to use health information, to be active partners in their care, and to navigate health and social care systems
what is the CHADS2 score?
estimates the risk of stroke in patients with AF
what are NOACs?
newer drugs not requiring regular blood test monitoring - expensive and not easily reversed
what score is used to measure major bleeding risk?
HAS-BLED
what are descriptive studies?
they attempt to describe the amount and distribution of a disease in a given population
what framework do descriptive studies follow?
time, place, person
when are descriptive studies useful?
assessing the effectiveness of screening programmes, generating hypotheses about disease aetiology
what is a cross sectional study and give some examples
in cross sectional studies observations are made at a single point in time. disease frequency, survey, prevalence study
what is a case control study
two groups of people are compared - a group of individuals who have the disease of interest, and a group of individuals who do not
what is a cohort study
baseline data on exposure are collected from a group of people who do not have the disease - the group is then followed through time until a sufficient number have developed the disease
what is the definitive method of assessing any new treatment in medicine?
randomised controlled trial
what factors should be considered when interpreting results?
standardisation, standardised mortality ratio, quality of data, case definition, coding and classification
what is standardisation
a set of techniques used to remove the effects of differences in age or other confounding variables, when comparing two or more populations
what is the purpose of case definition?
to decide whether an individual has the condition of interest or not
what is bias?
any trend in the collection, analysis, interpretation, publication or review of data that can lead to conclusions that are systematically different from the truth
give 4 types of bias
selection bias, information bias, follow up bias, systematic error
what is selection bias
occurs when the study sample is not truly representative of the whole study population about which conclusions are to be drawn
what is information bias
arises from systematic errors in measuring exposure or disease
what is follow up bias
arises when one group of subjects is followed up more assiduously than another to measure disease incidence or other relevant outcome
what is systematic error
a form of measurement bias where there is a tendency for measurements to always fall on one side of the true value - may be because an instrument is calibrated wrongly
define a confounding factor
one which is associated independently with both the disease and with the exposure under investigation, and so distorts the relationship between the exposure and disease
