Research Exam Flashcards
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True positive
Those with the disease who get a positive test result
False positive
Those without the disease who get a positive test result
True negative
Those without the disease who get a negative result
False negative
Those with the disease who get a negative result
Sensitivity
Ability of a test to correctly classify a positive result
Specificity
Ability of a test to correclty classify a negative result
Precision
Measure of ability to get the same value repeatedly, reliablility
Accuracy
Measure of ability to get the correct value, validity
Rate
Quantity measure over time, time is most often measured in person years
Incidence rate
Probability of developing a disease over a period of time
Person years
A measure of theoretical person per year, either 1 person per year or 2 people for 6 months each, etc.
Prevalence=
Incidence x average duration
Incidence
New diagnoses made in a year
Prevalence
The number of people who currently have the condition
Prevalence and incidence are….
…inversely related
Mortality and incidence relationship
Mortality=incidence x fatality rate
What are ways we look for reliability of a journal article? Specifically, what things do we look for in the author/journal/references/relevancy
Author - background, employment, history
Journal - well known, who funds and reviews?
References - who are they citing and why, any conflict of interest?
Relevance - must be addressing something related to what you are exploring
Abstract
A brief summary of intro, purpsoe, methods, results, and findings - quick place to assess relevancy
Critical appraisal of article
specifically looking at the study design and if the conclusions are supported by the results, best done using the FRISBE acronym
FRISBE
Follow up - were patients outcomes accounted for at end of study
Randomization - Equal chance being assigned to experimental or control group
Intention to treat analysis - are the results analyzed based on intended original treatment
Similar baseline characteristics - did patients have characteristics that could cause even outocome distribution
Blinding - study blinded
Equal treatment - controlling for any other confounding variables not being tested
Case control study characteristics
Analysis of a patient with the disease (case) and without (control) to analyze effect of known risk factors with specific outcome, study rare conditions
Cohort study characteristics
Dividing up of patient with one characteristic versus another who all already have a disease to follow them to see differences in outcome to determine cause and effect of characteristic
Randomized clinical trial characteristics
Often used to study intervention or cure of disease state, highest level of causality because can be blind
Reference test
Also known as gold standard test, the most accurate way of confirming a diagnosis but typically not preferred to use in treatment because it may be very invasive or cause significant problems for the patient in question
MAARIE framework acronym
Method Assignment Assessment Results Interpretation extrapolation
Method (maarie framework)
What is the question, who are the subjects/population being studied?
Assignment (maarie framework)
What is the method to assign participants to control and study groups, is this a good method or flawed?
Assessmnet (maarie framework)
Does the measurement of outcomes address the study’s question?
Results (maarie framework)
What is the magnitude of strength of relationship, is it statistically significant?
Interpretation (maarie framework)
What can we say about those involved in the study
Extrapolation (maarie framework)
What can we generalize about others not involved in the study
Systematic review
Belongs to synthesis 5S model. Seeks to answer a specific clinical question by analyzing all the findings from an entire body of primary research regarding the topic. Involves several experts collaborrating over a long time
A systematic review includes
Eligibility criteria Search strategy Assessment of findings Discussion of results Reference list
Background research
Forms the foundation of the 5S model, includes information in textbooks, databases, encyclopedias, etc often useful for getting a general idea or picture
Randomized controlled trial
Highest ranked study type using 5S model, examines outcomes of 2 randomly assigned groups with one group receiving a standard intervention and another receiving a new or different one
Filtered, pre-appraised, secondary research
systematic reviews or cricially appraised topics, drawing conclusions on the synthesis of primary research
Unfiltered, non- pre-appraised, primary research
randomized controlled trials, cohort studies, case-controlled studies, and expert opinion, limited scope in how well understood the overall trends are
Key questions of method
Study hypothesis: what is the study question being investigated?
Study population: what population is being investigated and what are the inclusion and exclusion criteria for the subjects of the investigation?
Sample size and statistical power: how many individuals are included in the study and in the control groups? What is the statistical power?
Statistical power
The likelihood that a study will detect an effect when there is an effect there to be detected, when high decreases likelihood of type II error
Type II error
A false negative
Key issues of assignment
What process was used to identify and assign? What confounding variables are there? Is there masking or blinding?
Relative risk
Ratio of probability of developing outcome if risk factor is present divided by probabiliyt of developing outcome if risk factor is not present
Reverse causality
Reversal of cause and effect presumption or a causal loop
Biological plausibility
The establishment of a biological factor and disease cause and effect relationship
Dose response relationships
effect on an organism produced by a given amount of an agent
Numbers needed to treat (NNT)
100/(control group rate - treatment group rate)
Study of prognosis
Analyze factors that impact prognosis over time
Studies of differential diagnosis
Involve multiple patients exhibiting similar symptoms, diagnostic tests map the patient’s symptoms to known signs associated with specific conditions
Phase 1, 2 and 3 drug trials
1 - assess the safety on very small select group
2 - assess the efficacy on a small scale
3 - randomized blind testing in hundreds to thousands of patients part of drug approval process
Retrospective cohort study
Study medical records of a group of similar individuals in order to determine which factors are related to a certain outcome
Meta analysis
statistical procedure for combining data from multiple studies
