Evidence-Based Medicine Flashcards
What are baseline characteristics?
factors which might influence outcome
Give examples of baseline characteristics?
illness severity at entry; current treatment; disease duration and relevant PMHx
What are inclusion criteria?
likely to benefit from treatment and unlikely to be harmed
What are the requirements of outcome measures?
clinically relevant; easily measured; accurately measured; specifified in trial ptorocols
What are the types of cohort study?
prospective and retrospective
What are the purposes of a cohort study?
estimate of risk in general population; ability to pick up infrequent occurrences; ability to find outcomes that were unexpected
How is relative risk calculated?
incidence in exposed/incidence in not exposed
What other name is relative risk known as?
risk ratio
What does a risk ratio<1 mean?
incidence in exposed is less than incidence in control
How is absolute risk calculated?
risk in exposed group-risk in non-exposed group
How does a case control study work?
group and interest and compraison group, take historries to compare and draw conclusions
What is odds ratio?
odds of event when exposed/odds of event when not exposed
What does an odds ratio <1 mean?
risk in exposed < risk in control
What is the main difference between a cohort study and a case control study?
cast control study is retrospective whereas cohort study isnt
What is a P value?
numerical value indicating the probability that this observation has occurred due to chance
What is a confidence interval?
way of indicating a range of values which probably contain the true value
What does the null hypothesis stae?
no difference between 2 groups
What is a type 1 error?
rejecting the null hypothesis when it is true
What is a type 2 error?
accepting the null hypothesis when it isn’t true
What are the protective processes in research?
data protection; caldicott gaurdian approval; non-clinical ethics committee and clinical research ethics comittee
What is the function of the data protection act?
rules for the collection, managemtn and maintence of personal info
What does caldicott guardian approval allow?
access to patient records without individual consent
what is needed to get caldicott guardian approval?
data will be stored annonymously and securely; no identifiable patient data, onyl essential data is collected
When do you need clinical research ethics?
doing things to patients
What do you need to get clinical research ethics approval?
study protocol; participant info sheet and consent form
What are the methods of qualititaive research?
asking people; observing people
What is the difference between the reasoning in quantitative and qualitative research?
qualititative is deductive reasoning and qualitative is inductive
What is inductive reasoning?
observation/experiemnt—generalisations–theory
Wahat is deductive reasoning?
theory–predictions–observation/experiment
In a Gaussian distrubtion of a population sample what is the relationship between the median and the mean?
median has the same value as the mean
What is external validity?
extent to which one can appropriately apply the results to other populations
What does a 95% confidence interval mean?
5% chacne of hte true value lying outside of these limits
What does statistical significance mean?
results of s astudy are unlikly to have arisen by chance alone
What does a null hypothesis mean?
hypothesis that there is no relationship between the study variables
What would help a confidence interval become more narrow?
significantyl increasing sample size
Qualitiative research seeks to analyze the ….. people attribute to their ….. and circumstances?
data, experiences
What is it called when there is no longer any need to sample more people to reach new conclusions or back up or challenge existing conclusions?
saturation
What is the positivist paradigm?
belief in an objective reality
What is a study that compreas 2 randomised groups with similar characteristics with a drug and control?
randomised control trial
What is a study that aims to establish the normal height of 4 year old children by measuring heights at school entry?
cross-sectional trial
What is a study that compares a group of children whose heights are below the 10th centile with a group of match controls of normal height, aiming to identify possible causative factors?
case-control study
What is a study that compares the height of a group of 4year olds living near a nuclear plant with the height of a grou[ of 4 year olds who live elsewhere?
case-control study
What do you need to do for a cohort study?
follow over time
What is a meta-analysis?
way of combining data from many different research stidueis- stasticial process that combines the findings fro mindividual studies
waht is a cross-sectional study?
observation of a defined population at a single point in time
What is a case-control study?
begin with the outcomes and don’t follow people over time; choosoe people with a prticular result and interview or look at records- compare odds of having an experience with the outcome to the odds of having an experience without the outcome
What is a cohort study?
prospective observational study - 2 groups are compared
What is a systemiatic review?
summary of the clinical literature- critical assessment and eval of research studies that address a particular clinical issue
What is hte best way to minimise reporting bias?
preemtive study
What is the difference between relative risk and relative risk reduction?
relative risk is a ratio whereas relative risk reduction is a percentage
What is absolute risk calculated?
event rate of control- event rate of treatment group
How is number needed to treat calculated?
1/absolute risk reduction
