Secondary Resources and Primary Literature Flashcards
Secondary Resources
databases which index/abstract primary resources
types of features
search engine
indexing database
abstract database
AI models
many databases include a combination of
indexing and abstract database elements
google scholar
not limited to health science topics specifically links to scholarly articles
ChatGPT is most analogous to _____________ because it
tertiary resources
summarizes and synthesizes information based on a wide range of sources
chatGPT is not a _________ reference
static
MEDLINE
NLM journal citation database since 1960s
primary database of citations and abstracts that PubMed searches
Medical Subject Headings (MeSH) index meddling results
PubMed
free to use index database
ahead of print and in process MEDLINE bound citations
NCBI bookshelf
some research articles not yet indexed in MEDLINE
MedlinePlus
health topics, genetics, drugs, tests, dietary supplements and recipes
easy to understand for patients
PubMed central
free archive for full text biomedical and life sciences journals
Excerpts Medica database (EMBASE)
subscription 3 part indexing database
international database
conference abstracts
CINAHL
cumulative index to nursing
subscription database
Cochrane Library
not for profit collection of 3 individual databases
Cochrane Database of Systemic Reviews (CDSR)
systemic reviews
extensive overview of current literature
Cochrane Central Register of Controlled Trials (CENTRAL)
abstracts of controlled trials
Cochrane Clinical Answers (CCAs)
short summaries written in user friendly question answer format
which part of the Cochrane database is used for point of care clinical decision making?
Cochrane Clinical Answers
IPA (international pharmaceutical abstracts)
drug related information
meeting presentations
pharmacy information, administration
compounding and stability information
SCOPUS
subscription
additional coverage of literature from the life sciences, physical sciences, social sciences and humanities
Researcher Discovery and Affiliation finder
PICOS
population
intervention
comparator
outcomes
study design
population, patient, problem (PICOS)
description of study population/patient/problem
age
gender
ethnicity
condition
disease
intervention (PICOS)
medication
surgery
lifestyle
psychological
educational
public health
comparator (PICOS)
active comparator (standard of care)
supportive care
placebo
difference between active comparator and supportive care
active - treats disease
supportive - treats symptoms
Outcomes of interest (PICOS)
death and birth
morbidity
quality of life
safety
adherence
study design (PICOS)
types of studies
hierarchy of evidence
what evidence is most useful in PICOS?
meta analyses of random controlled trials
boolean operators and what they imply
AND (need both)
OR (either/or)
NOT (excludes)
AND is inserted ___________ PICOS
OR is inserted ____________ PICOS
between
within
tiab
title, abstract
tw
title, abstract, keywords
when searching secondary resources, we do not limit by __________ because it causes bias in results
free text
primary literature
written accounts of original thought or discovery
includes new knowledge in the scientific body
sources of primary literature
top biomedical journals
journals covering specific topics
conference posters
dissertation/thesis of published original research
most reports of primary literature follow a
structured format
peer review
ensuring the articles published in the journal meet a minimum quality standard
impact factor
average number of times each article appearing in a journal during a given period of time was sited during a subsequent period
consult primary literature when
conflicting info in tertiary
unusual/non standard clinical situations
rapid developments make tertiary outdated
developing protocols/guidelines
routine questions are often answered by
tertiary literature
descriptive reports examples
case report/studies
cross sectional studies
evaluative studies examples
experimental/interventional
quasi-experimental
observational/non-interventional
descriptive reports
provide baseline data for planning further research
groundwork for evaluative studies
case report/series focus mainly on __________ while cross sectional studies focus on _______________
single patients/rare conditions
snapshot of a population at a point in time
experimental studies
randomization
experimental and control
RCT
Quasi-experimental studies
appear experimental but lack randomization
non-experimental studies
cannot establish causative relationships
provide associations/correlations
causal interference
process of drawing a conclusion that a specific treatment was the cause of effect
selecting a study sample
groups are similar and representative of the population
decrease selection bias
subject selection involves
inclusion and exclusion criteria
inclusion criteria
explicit definition of the genera; study population
exclusion criteria
study results are not calculated to patients whom they should not be
in order to participate in a clinical study, patients must sign
informed consent
power analysis
determines a suitable sample size
must be calculated a priori (before study takes place)
validity
accuracy and trustworthiness of research findings
internal validity
results of a study can be attributed to manipulations
met endpoints and follow rules
external validity
finding of a study can be generalized to other settings, populations
results apply to general population
when internal validity increases
external validity decreases
randomization
major differentiating factor from observational trials
randomly assigned
eliminates confounding
confounders
variable that is related to the independent variable (intervention) AND the dependent variable (outcome)
if randomization is not possible, consider
matching
matching
different patient groups to be similar as possible
every 1 person in one group should have a similar person in the other
disadvantages of matching
time/labor intensive
difficult to identify similar subjects
can only match factors you know
blinding
prevents knowledge of treatment from influencing the results of a study
reduces bias
single blind
subject OR investigator unaware of treatment
double blind
both subject and investigator unaware of treatment assignment
triple blind
subject, investigator and other personnel involved in study
open label
subjects and investigators are aware of treatment
masking
collection of steps that makes the test and the control regimen difficult to distinguish by the involved parties
random sampling
participants resemble the population
random allocation
assigns participants to treatment groups evenly
simple random allocation
equal chance
systemic random allocation
ex: every 5th subject
block random allocation
total number of subjects divided into a series of blocks
clustering random allocation
population first divided into clusters based on any type of division
stratification random allocation
samples of each relevant subgroup are distributed to each arm
allocation concealment
protects the sequence of each assignment
hawthorne effect
alteration of human behavior when individuals are aware they are being observed
necessitates the use of a placebo comparator
controls reduce
the threat of bias
different types of controls
placebo
active
historical
active placebo
placebo is unethical
represent standard of care using commonly accepted dosing
historical placebo
use data from previously treated patients observed at a different time as control
less costly
non controlled interventional studies
no control group
clinical trials of rare diseases or serious diseases
hypothesis
tentative claim or statement
created a priori
testable and falsifiable
logical
clinical studies aim to determine if an
independent variable (intervention) impacts a dependent variable (outcome)
null hypothesis
what you are trying to disprove
alternative hypothesis
opposite of null hypothesis
goal of a study is to
attempt to falsify the hypothesis
studies should result in
rejection or revision of theories
more hypothesis testing equals
a stronger theory
non inferiority margin
one treatment is not substantially worse than the other
equivalence margin
one treatment is no worse or no better than the other treatment
superiority studies
most common
determine whether one intervention is superior to another
superiority studies can be
two sided - favor either intervention
one sided - only one possible superior
confidence interval
point estimate +/- margin of error
confidence intervals represent the __________________ of the actual difference
best estimate
point estimate
reported difference between intervention is an estimate based on the studied sample
a wider confidence interval means __________
a narrower interval means _____________
more uncertainty
more precision
equivalence studies
determine whether two treatments are essentially the same
for equivalence studies, start with the
baseline null hypothesis – the drugs are not equivalent
non-inferiority study
must have an active control
placebo is unethical
one treatment is worse than another
NI margin
determined by maximum acceptable clinical difference
identify a priori in the original trial protocol
for confidence interval in a non-inferiority study, the smallest treatment effects is the
NI margin for the test drug
when the available evidence is not strong enough to warrant rejection of the null hypothesis you say
you fail to reject the null hypothesis
study outcome/endpoint
result of each hypothesis examined
should be determined before the study begins
determined posteriori
primary outcome
the focus of the study
determined a priori
ties back to study objective
shapes the study design
the primary outcome is most often related to
efficacy of the intervention
composite endpoint
combine a group of endpoint measures into one primary endpoint
efficacy
ability of intervention to get desired effect in controlled, ideal conditions
effectiveness
how well an intervention works in the real world
a drug may perform well in __________ conditions but this may not translate into _____________
controlled
real world benefit
secondary endpoints
important but not primary
determined a priori
ability to affect study design
without a primary endpoint there is no
secondary endpoint
tertiary outcomes
less critical exploratory outcomes
study design is minimally impacted
low additional burden to subjects
hypothesis generating
safety outcomes
assess adverse effects associated with the intervention
examine study withdraws due to adverse effects
when are safety outcomes made - before or after the study design?
actually both!
a priori if monitoring for anticipated averse events
a posteriori if new
subgroup analyses
assess smaller subject groups based on factors that have relatively significant chance of altering results
post hoc analyses
analyses after the study is complete
informs new research questions
risk of post hoc analyses
risk of data dredging or fishing
surrogate endpoint
clinical outcomes are difficult or time consuming to measure
used as a substitute for clinical outcomes
exploratory endpoints
outcomes are expected to be rare/show up infrequently
parallel study design
simplest
participants in same group until the end
short duration
large sample size
cross over study design
participants are their own comparator
receive all treatments separated by a washout period
avoid baseline differences
issues with cross over studies
drugs with slow elimination half lives
dropout rates can be an issue
factorial arm study
multiple interventions evaluated in a single experiment
a group may have more than one intervention
exclusive groups
double dummy design
uses more than one placebo to help treatments look the same in all groups
treatments can be different ROAs
pragmatic trials
attempt to collect information about effectiveness under real world conditions
protocols are flexible
advantages of pragmatic trials
higher external validity
highly applicable to public health
disadvantages of pragmatic trials
lower internal validity
harder to establish causal relationship
effected by confounders
intent to treat
once randomized, always analyzed regardless if they complete entire duration
modified intent to treat (mITT)
subset of ITT population
allows the exclusion of some randomized subjects in a justified way
as treated
only patients who receive the therapy are included in analysis
per protocol
only the patients that completed the study are included in the analysis
which study assessment is less reflective of the real world?
per protocol
disadvantages of RCT
blind isn’t always blind
applicability is limited
no intervention without risks
definition of risk not uniform
threats to external validity of RCT
subjects not representative of target population
conditions too restrictive
threats to internal validity of RCT
different trials may give different results
