Test 1 Flashcards
1
Q
Define Observation
A
the act or instance of noticing a natural occurrence
2
Q
Define hypothesis
A
tentative explanation of a natural occurrence
3
Q
Define theory
A
well-substantiated explanation of a natural occurrence based on strong scientific evidence that has been repeatedly confirmed through observation and experiment
4
Q
What makes an idea sticky (6 traits of stickiness)
A
Simplicity unexpectedness concreteness credibility emotions stories
5
Q
Explain simplicity as it pertains to stickiness
A
dumbs down the message so it is easier to understand
6
Q
Explain unexpectedness as it pertains to stickiness
A
catch’s ones attention, shocking
7
Q
Explain concreteness as it pertains to stickiness
A
The person telling you is very sure of themselves
8
Q
Explain credibility as it pertains to stickiness
A
The source seems credible (should know what they are talking about), Ex. Dr. Oz
9
Q
Explain emotions as it pertains to stickiness
A
makes the person feel strongly about the topic either happy or sad/scared
10
Q
Explain stories as it pertains to stickiness
A
Stories make it more personal and easier to believe/remember
11
Q
What is a fact
A
something that can be check and demonstrated to be true
12
Q
What is an assertion
A
something that is held to be true but which has not or cannot be demonstrated to be true
13
Q
What is an opinion
A
something that is believed to be true by the speaker but which may or may not be shared by others
14
Q
Scientific method
A
accepted principles and procedures for the systematic pursuit of knowledge
15
Q
Soul goal of the scientific method
A
create comparable results
16
Q
define law of nature, and what branch of science has most of them
A
a body of rules inherent in the structure of nature and universally recognizable
mostly in physics/chemistry
17
Q
main components of the scientific method (done in order)
A
observation hypothesis prediction experiment repeat
18
Q
These are the results of individual studies
A
hypothesis
19
Q
this results from a review of many studies
A
theory
20
Q
Difference between a hypothesis and a prediction
A
A hypothesis is a prediction with set clear and specific objectives in its phrasing which allows it to be conclusively rejected/accepted based on the findings of the study. The hypothesis is thus something that can be tested in many trials.
21
Q
parts of a scientific article
A
introduction
methods
results
22
Q
Why is it important to have specific background information of a study
A
background information tells you what has been covered prior to the study, and gives a basis for the reasoning behind the study
23
Q
Why is it important to know the exact hypothesis, population, exposure, outcome (and how both are measured), as well as the confounders of
a scientific study?
A
So you can determine the validity of the results
24
Q
How can population and confounder impact the result of a study?
A
The results can be skewed by different aspects of these two portions of the study
25
what is the study population
specific group the study was performed on
26
variables of study population
```
gender
age
ethnicity
location
conditions potentially influencing outcome
selection method
single/multi center study
```
27
Define exposure
contact with a factor or the amount the factor impinges on the group
28
define outcome
consequence of the exposure
29
Define confounders
uncontrolled risk factors affecting the outcome of the study
30
examples of standard confounders (6)
```
age
gender
race/ethnicity
income
education
smoking status
```
31
Statistically controlled standard confounders (4)
age
sex
ethnicity
education
32
Examples of special confounders (8+1) (discrimination due to)
```
race
ancestry
sex
age
physical disability
physical appearance
sexual orientation
BASELINE BMI
```
33
What is selection bias
population is chosen so randomization is not achieved or the study population is not representative
34
How is selection bias introduced
self-selection
| selection of population skewing the results towards support for a certain hypothesis
35
Define correlation
an association between two factors
36
define causation
the exposure causes the outcome
37
See first few slides of section 3 video 2 for understanding how to tell if the results of a study are causation or correlation
3
38
Primary data study
newly created data (unpublished)
39
secondary data study
renewed analysis of recorded data
40
Primary data studies include this types of studies
observational study
| experimental study
41
Secondary data studies include these types of studies
narrative review
systematic review
meta-analysis
42
Types of observational studies
```
cross-sectional studies
cohort studies (longitudinal study)
case-controled studies
```
43
types of experimental studies
clinical studies which include: randomized, controlled trial, and case-controlled studies
biochemical, physiological experiment
44
What does an observational study do
sees how exposure influences the outcome over a particular perior of time withoutt intervention of the scientist
45
What does an experimental study do
identifying and quantifying the causation between exposure and outcome by targeted intervention
46
What is a meta-analysis
systemic pooling of data from several selected studies
47
what is a systemic or narrative review
a document often written by a panel that provides a comprehensive review of all relevant studies and unpublished data
48
Advantages of a meta-analysis
greater statistical power
confirmatory analysis
greater ability to extrapolate to population
considered evidence based resource
49
disadvantages of meta-analysis
difficult to select appropriate studies
advanced statistical techniques
heterogeneity of study populations
50
What to look for in a meta-analysis
do the pooled studies have similar design
are studies included with diverging results
do studies have same exposure and outcome
51
advantages of systemic/narrative review
exhaustive review of currently available data
less costly
greater ability to extrapolate to general population
more reliable than individual studies
considered evidence based resource
52
disadvantages of systemic/narrative review
greater degree of expertise necessary
time consuming
study design and results often heterogeneous
53
What to look for in a systemic/narrative review
do included studies look at same exposure and outcome
| are discrepancies between studies addressed
54
between systemic review or meta-analysis which is better for basing a recommendation from
systemic review
55
What is a cross-sectional study
data are collected across a population at a given time
| snapshot at a point in time
56
Advantages of cross sectional study
tend to uncover correlations
cheaper than longitudinal studies
can point out areas for further study
57
disadvantages of cross sectional studies
cannot infer causal relationships
| cannot measure changes over time
58
T/F: cross sectional studies are good sources of information for the public
f, they do not show causation and are only meant to determine if a causation that needs investigation exists
59
What is a longitudinal/cohort study
multiple ovservations for each individual in the population over time, used tomeasure changes due to exposure
60
cohort studies do this
study a specific group of people
61
prospective studies
people enroll in the study and are then followed
62
retrospective studies
people enroll in the study and then recall their past experiences
63
advantages of longitudinal studies
can measure changes
| greater validity than cross sectional studies
64
disadvantages of longitudinal studies
more expensive and time comsuming than cross-sectional studies
cannot infer causal relationship
65
Case-controlled study (observational)
compares two groups with the case and a control group
66
cohort/panel study
follows a defined group of the population that shares common characteristics
prospective or retrospective
67
nested case control study
extracts case and control group data from a large observational study
68
What is the gold standard of clinical studies
large, randomized, double-blind studies in which multiple centers participate
69
experimental stuides are more reliable and implies this due to this
causation
| confounding factors can be controlled, and bias is reduced
70
observational studies can do this
point out correlation between exposure and outcome
71
reasons to use an observational study
```
limited resources and practicality
less intrusive to base further study on
real world situation
used when control studies are unethical
larger data volume possible
```
72
Experimental clinical studies do this
identify and quantify the causation between exposure and outcome by targeted interventions
73
case controlled study (experimental)
groups with and without a certain condition are compared
74
controlled studies (experimental)
random assignment to treatment and non-treatment group
75
What is the control group
group not receiving the treatment
76
dietary record
subject is taught to weigh or estimate all food consumed and record it over a predetermined time
77
advantages of dietary record
most accurate data
| habitual diet of individual can be assessed
78
disadvantages of dietary record
respondent needs to be highly cooperative
respondent burnden is high
underreporting
expensive
79
24-hour food recall
respondant recalls the food consumption of previous 24-48 hours using household measures
80
advantages of 24-hour food recall
approprate for describing the MEAN intake of a group
respondent burden is acceptable
response rates higher
81
disadvanatages of a 24-hour food recall
accuracy depends on ability to recall
one-day recall does not represent usual individual intake
quality of data depends on interviewer
under reporting
82
dietary history
assesses the daily total food intake and usual meal pattern of an indiviudual over varied periods of time. Includes often a 24hour recall and checklist to assess long term meal patterns
83
advantages of dietary history
assessments of meal patterns and details of food intake of groups
84
weakness of dietary history
respondets needs to have regular diet pattern and good memory for accuracy
accurate administration only be trained professionals
under reporting
85
food frequency method
self-administered use of a pre-printed list of foods to extimate the frequency and sometimes amount of food eaten over a specified amount of time
86
advantages of food frequency method
assessments of meal patterns and usual food groups of populations
inexpensive
standardized
87
disadvantages of food frequency method
mostly homogenous populations
quantitative component not accurate
food list needs to be accurate and well tested
often self-administered
88
which phase of the study is most important, why?
planning, at this point things like study population, time frame, confounders and other things can been accounted for
89
incidence
measure the change from non-condition to condition
90
prevalence
measures the occurrence of condition/disease in total population
91
incidence is this to prevalence
incidence is a proportion of prevalence
92
cumulative incidence rate =
(number of new cases/total at risk population) over a period of time times multiplier
93
person-time incidence rate =
(number of new cases/person-time at risk) over a time period
94
What information does the incidence(cumulative) rate give us
how does exposure affect health outcome
description of risks associated with a certain exposure
estimating the probability for a disease, health condition, or death in a population
95
incidence rate does this
measures risk of condition over time
96
person-time incidence rate measures this
how fast a disease or condition is spreading
97
how can the information of incidence rate be used
plot of IR over time can be a good way to see if an intervention is really taking hold
98
point prevalence rate =
(number of people ill / total population) at a point in time
99
period prevalence rate =
(number of people ill / total population) over a period of time
100
what is risk
a measure of the proportion of people that develop an outcome between two specific points in time
101
Epidemiology
the study of the patterns, causes, and effects of health and disease conditions in defined populations
102
Risk =
number of people diagnosed over number of people at risk
103
What information do you need about a specific risk so you are able to fully understand it?
time frame is #1
does the risk apply to me? (population factors)
how does it compare to other risks
104
Always look for this when assessing risk
the 'strike', what is the risk? being diagnosed or dying
105
starting risk
chance of experiencing an outcome without intervention
106
modified risk
risk of experiencing an outcome with intervention
107
relative risk =
modified risk over starting risk
108
interpreting relative risk
>1 increased risk
| 1 no change
109
absolute risk reduction =
starting risk - modified risk
110
absolute risk looks at this
difference between the starting risk and modified risk
111
absolute risk is also called this
risk difference
112
relative risk reduction
relates how much lower the modified risk is in relationship to the starting risk
113
relative risk reduction =
(starting risk - modified risk) / starting risk
114
which risk number is most common in publication
Relative risk reduction because it generates a large number
115
Why do you need the starting risk or absolute risk reduction if you want to fully understand a risk reduction?
gives you a basis for comparison
116
Compare relative risk and absolute risk reduction
RRR tends to remain unchanged across spectrum of disease severity or the magnitude of the outcome while ARR will reflect this
117
What additional information do you
need about a specific risk reduction to
be able to understand the risk reduction?
time frame, does it apply to you
118
what effects does multiple testing have
several null hypothesis are tested simultaneusly so the probability increases that one is true by chance
119
What does significant mean in science
the result is probably true
120
what does statistically signifcant not mean
can never prove that the result was not due to chance or
| that there is a meaningful or important differance
121
How is statistical significance measured
P
122
explain p value
P
123
Odds are slightly higher than
risk
124
Odds =
number of people experiencing outcome during a period over the number of people who do not experience outcome of the observation period
125
What is an odds ratio
measure to determine the relationship between an exposure and outcome
126
odds ratio =
((n)exposed cases / (n) unexposed cases) / ((n)exposed non-cases/ (n) unexposed non-cases)
127
What are odds ratios used for
compare relative odds of the occurrence of an outcome with an without exposure
determine if a particular exposure is a risk factor for an outcome
compare the magnitude of various risk factors
128
hazard ratio
reflects the analysis of time survived to an event
129
hazard ratio is calculated as
ratio of time it takes for an event to happen in the treatment group vs. time it takes in the control group
130
what is hazard ratio used for
initially to analyze survival in medical research
| increasingly to describe how many people can reach the end of the observation period without experiencing the hazard
131
how to interpret hazard or odds ratios
value 1: better survival in the control group
132
If the starting risk is high the odds ratio tends to do this
overestimate the effect of the exposure
133
95% confidence interval
indicates the reliability of the ratio
134
what the 95% confidence interval says
we are 95% confident that the true value of the ratio is in our confidence interval
135
when looking at a 95% confidence interval this is better
narrower
| do no include 1
136
z-score
a number that tells you how unusual a single piece of data is, and where a result is in relationship to the mean
137
reading a z-score
negative is less than average
0 is right at average
positive is more than average
138
patient outcome
measure how a person feels, functions, or survives
139
surrogate outcome
laboratory measurement or physical sign used as substitutes for a clinically meaningful endpoint for the patient outcome
140
changes of the surrogate outcome are expected to reflect this
changes in the patient outcome
141
advantages of using a surrogate outcome
less expensive
quantifiable
faster results
outcome might be undesirable (death)
142
placebo effect
when symptoms are better in the patient after receiving the placebo (inert substance)
143
nocebo effect
when symptoms are worse in the patient after receiving the placebo (inert substance)
144
two different routes for publishing a scientific paper
scientific meeting
| scientific journal
145
purpose of scientific meeting
open forum for the advancement of ideas between scientists where many things are discussed
146
purpose of scientific journals
much more valid way of letting other scientists know about the studies you've performed.
147
What is peer review
evaluation of the works suitability for publishing by one or more independent and often anonymous expers with similar competence than the author
148
how does this peer review process generally work (4)
accept manuscript as is
return manuscript for revision
reject manuscript but encourage resubmission after addressing shortcomings
reject manuscript as unsuitable
149
Impact factor
measure calculated by journal citation reports (JCR) how often the average article in a journal is cited during a time period
150
what is impact factor used as
a proxy for the importance of a journal
151
press release
narrative style release from a journal on a topic
152
T/F: quality of a press release issued by medical journals seem to influence the quality of the associated new report
t
153
Press releases must include the following fundamental information
explain basic facts
list absolute risk
explain harm from intervention
acknowledge study limitations
154
agenda setting
strong correlation between the emphasis the media sets on a topic and the importance perceived by the general public
155
priming
extension of agenda setting, activation of one though may trigger related thoughts
156
framing
the presentation of a topic in the news media will influence how it is understood by the general public
157
what are the main sources of bias in publication of scientific articles
investigator bias
publication bias
reporting bias
