Midterm Review Flashcards
(164 cards)
1
Q
of new cases of disease during a specified time interval {divided by} Population at risk at the start of the time interval
A
Incidence proption
2
Q
What are synonyms for incidence proportion?
A
Attack rate, risk, probability of developing disease, cumulative incidence
3
Q
of new cases among contacts {divided by} (total number of contacts)
A
secondary attack rate
4
Q
of new cases of disease during a specified time interval {divided by} time each person was observed summed together
A
Incidence rate, aka person-time rate
5
Q
of current cases at a certain point in time/total population at the time
A
point prevalence
6
Q
of current cases at a certain point in time/ avg population
A
period prevalence
7
Q
total # of deaths during a given time interval/mid-interval population
A
crude death rate, aka crude mortality rate
8
Q
of deaths assigned to a specific cause during a given time interval/ avg population
A
cause-specific mortality rate
9
Q
of deaths assigned to a specific cause during a certain time interval {divided by} the total # of deaths from all causes in the same time frame
A
proportionate mortality
10
Q
of deaths assigned to a specific cause during a given time interval {divided by} # of new cases of same disease during that time
A
Death-to-case ratio
11
Q
of deaths among children <28 days old in a certain time interval {divided by} # of live births in that time
A
neonatal mortality rate
12
Q
of deaths among children 28-364 days old during a certain time interval {divided by} # of live births during that same time
A
postneonatal mortality rate
13
Q
of deaths among children < 1 year during a given time interval / # of live births during that time
A
infant mortality rate
14
Q
of deaths assigned to pregnancy-related causes during a given time interval / # of live births during that time
A
maternal mortality rate
15
Q
of deaths in a particular age group / total # of people in the age group
A
age-specific mortality rate
16
Q
of deaths males OR females / total # of males OR females
A
sex-specific mortality rate
17
Q
of people infected / # of people exposed
A
infectivity
18
Q
of people who develop clinically apparent disease / # of people infected
A
pathogenicity
19
Q
of people who die / # of people who develop clinically apparent disease
A
virulence
20
Q
(# case in exposed/total # exposed) - (#cases unexposed/total # unexposed)
A
Attributable Risk % (AKA attributable risk reduction ARR)
21
Q
of events in control group/total # of control participants
A
Control Group Rate/Risk (CGR)
22
Q
of events in experimental group/total # of experimental participants
A
Experimental Group Rate/Risk (EGR)
23
Q
Control Group Rate (CGR) - Experimental Group Rate (EGR)
A
Attributable Risk Reduction
24
Q
EGR/CGR
A
Relative Risk
25
1) (CGR-EGR)/CGR
2) 1-(EGR/CGR)
3) 1-RR
*Note: all 3 formulas should give you the same result
Relative Risk Reduction (RRR)
26
The study of the distribution and determinants of health-related states or events in specified populations and the application of this study to control of health problems
Epidemiology
27
The cause of a disease
Etiology
28
Action taken to prevent the development of a disease in people who do not have the disease Examples: Vaccines, healthy behaviors, etc.
Primary Prevention
29
Identifying people in whom a disease process has already begun but who have not yet developed clinical signs or symptoms of the disease (preclinical phase) Examples: Cancer screening, mammograms, etc.
Secondary Prevention
30
Preventing complications in those who have already developed signs and symptoms of an illness and have been diagnosed (those in the clinical phase of illness) Examples: Cancer treatment, physical therapy, etc.
Tertiary Prevention
31
form of disease characterized by signs and symptoms
Clinical disease
32
Signs and symptoms have not developed. Includes preclinical, subclinical, persistent, and latent disease.
Nonclinical (inapparent) disease
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Disease is not clinically apparent but is destined to progress to clinical disease
Preclinical disease
34
Disease is not clinically apparent and is not destined to become clinically apparent. Diagnosed by serologic response or culture of the organism
Subclinical disease
35
The habitual presence of a disease within a given geographic area
Endemic
36
The occurrence in a community or region of a group of illnesses of similar nature, clearly in excess of normal expectancy and derived from a common or a propagated source
Epidemic
37
type of exposure where cases arise from the same exposure; Example: food poisoning outbreak from bad chicken at a buffet
Common-vehicle exposure
38
The resistance of a group of people to an attack by a disease to which a large proportion of the members of the group are immune
Herd immunity
39
The interval from infection to the time of onset of clinical illness. Often measured as the time from exposure until the onset of clinical disease as it is difficult to determine the exact time of infection.
Incubation period
40
A graph used to characterized the two primary types of outbreaks (common source and propagated). The y-axis is the number of cases and the x-axis is the date of onset each case patient. Note not all epidemics are common source or propagated- for example with some zoonotic or vector borne diseases.
Epidemic curve
41
The ongoing systematic collection, analysis, and interpretation of health data essential to the planning, implementation, and evaluation of public health practice closely integrated with the timely dissemination of these data to those who need to know
Epidemiologic surveillance
42
Surveillance in which available data on reportable disease are used, or in which disease reporting is mandated or requested by the government or the local health authority, with the responsibility for the reporting often falling on the health care provider or district health officer. Provider initiated; less resource intensive. Also known as 'passive reporting'
Passive surveillance
43
Who initiates passive surveillance?
providers
44
A system in which staff are specifically contact providers or others to carry out a surveillance program. Often more accurate than passive. Health-department initiated; more resource intensive
Active surveillance
45
Who initiates active surveillance?
Health departments
46
Incidence calculated using a period of time during which all of the individuals in the population are considered to be at risk for the outcome.
Cumulative incidence proportion
47
The sum of the units of time that each individual was at risk and was observed. Often expressed in person-months or person-years.
Person-time
48
The number of affected persons present in the population at a specific time divided by the number of persons in the population at that time, aka proportion of the population is affected by the disease at that time
Prevalence
49
Percentage of people who have a certain disease die within a certain time after the disease was diagnosed
Case fatality
50
A standard population is used in order to eliminate the effects of any differences in age between two or more populations being compared. Most commonly used method.
Direct age adjustment
51
Used when numbers of deaths for each age-specific stratum are not available or in an occupationally exposed population.
Indirect age adjustment
52
Changes seen are attributable to the characteristics of the particular 'cohort' under study, not the variable being studied.
Cohort effect
53
Any empirical observation, whether systematically collected or not.
Evidence
54
A theory of knowledge that holds that the justification or reason of a belief is determined by the quality of the believer's evidence for the belief
Evidentialism
55
System of rating the quality of evidence and strength of recommendations that is explicit, comprehensive, and increasingly adopted by guideline organizations. Four levels (very low-high).
GRADE (Grading of Recommendations Assessment, development, and Evaluation)
56
These clinical questions are about physiology, pathology, epidemiology, and general management and are often asked by clinicians in training. The answers to background questions are often best found in textbooks or narrative review articles.
Background questions
57
These clinical questions are more commonly asked by seasoned clinicians. They are questions asked when browsing the literature (e.g., what important new information should I know to optimally treat my patients?) or when problem solving (e.g., defining specific questions raised in caring for patients and then consulting the literature to resolve these problems)
Foreground questions
58
Patient, Intervention, Comparison, Outcome. A method for answering clinical questions
PICO framework
59
Determining the effect of interventions on patient-important outcomes (symptoms, function, morbidity, mortality, and costs)
Therapy (foreground clinical questions)
60
Ascertaining the effects of potentially harmful agents (including therapies from the first type of question) on patient-important outcomes
Harm (foreground clinical questions)
61
In patients with a particular clinical presentation, establishing the frequency of the underlying disorders
Differential diagnosis (foreground clinical questions)
62
Establishing the power of a test to differentiate between those with and without a target condition or disease
Diagnosis (foreground clinical questions)
63
includes many study designs that are not randomized such as cohort or case control studies where the exposure to the intervention or disease is not controlled by the researcher
Observational studies
64
A method having established or widely accepted accuracy for determining a diagnosis that provides a standard to which a new screening or diagnostic test can be compared
Reference standard/Criterion Standard
65
The extent to which study results are subject to systematic error.
Risk of bias
66
Studies that find patterns among populations among person, place, and time and are used to develop hypotheses to test
Descriptive studies
67
Hypothesis-testing studies- answer the how and why
Analytic studies
68
Descriptive study- a comprehensive, detailed description of one case under observation
Case reports
69
Descriptive study- a comprehensive, detailed description of two or more cases under observation
Case series
70
Descriptive study- A study of group characteristics; Studying a group of people (for example, everybody in Texas) rather than individuals
Ecological studies
71
Descriptive study- one person trial; using the same person and comparing the outcome for the person before and after the intervention
N=1 studies
72
Observational study- Two groups, one with the exposure and one without the exposure, are followed over time to determine the occurrence of disease in each group; can be prospective or retrospective. Exposure is measured BEFORE the outcome
Cohort study
73
Observational study- Study involves two groups, one with the disease (cases) and one without the disease (controls), and compares the two groups in respect to previous exposures. Disease is measured BEFORE exposure
Case-control study
74
Observational study- prevalence surveys in which exposure and disease status are assessed simultaneously among individuals in a well defined population
Cross-sectional study
75
Experimental study- an experiment where the subjects are non-randomly assigned to (or offered) the exposure
Quasi-experimental study
76
Categorical(qualitative)-Different categories with no specific rank or significance in rank; dichotomous (only two possible answers)
Nominal
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Categorical(qualitative)-Different categories with specific ranks or significance in rank/levels
Ordinal
78
Continuous(quantitative)- numerical scale with a true zero point
Ratio
79
Describe the characteristics of the sample of individuals that represent the population from which they came from; ratios, mean, standard deviation, etc.
Descriptive statistics
80
Make inferences or predictions about the whole population from the sample taken of that population; p-values, confidence intervals, point estimates, etc.
Inferential statistics
81
generating a hypothesis about a population parameter and then using sample statistics to assess the likelihood the hypothesis is true
Hypothesis (significance) testing
82
What is the probability that the difference observed is due to chance?
P-value
83
Concluding that there is a difference between two groups when there is not; False Positive
Type 1 Error
84
Concluding that there is not a difference between two groups when there is a difference
Type 2 error
85
Probability of saying there is a difference when there is in fact a difference between two groups; the likelihood of making the right decision
power
86
What is the single value most likely to represent the true difference between experimental and control treatments?
point estimate
87
Given the observed difference between experimental and control groups, what is the plausible range of differences within which the true difference might actually lie?
Confidence interval
88
Assignment method which first stratifies the whole study population into subgroups with same attributes or characteristics then followed by simple random sampling from the stratified groups
Stratified randomization
89
Patients are first randomized into two groups and then switched between the groups after a certain time period and again observed for a given time period
planned crossover
90
In a planned crossover design, the effects from the first treatment the subjects are on may carry over and affect the subject during the second treatment
Carryover
91
During the course of the study, patients may unexpectedly crossover to a different treatment group
Unplanned Crossover
92
Examines how two or more variables (factors) predict or explain an outcome
Factorial Design
93
The absolute difference (risk difference) in risks of harmful outcomes between experimental groups (experimental group risk [EGR]) and control groups (control group risk [CGR]); calculated as the risk of harmful outcome in the control group minus the risk of harmful outcome sin the experimental group (CGR-EGR); Used to describe a harmful exposure or intervention
Absolute risk reduction (ARR)/risk difference
94
The degree to which the results of a study can be generalized to setting or samples other then the ones studied
Generalizable
95
the number of patients who must receive an intervention of therapy during a specific period to prevent 1 adverse outcome or produce 1 positive outcome
Number needed to treat (NNT)
96
Address whether the effect of an experimental intervention is not worse than a standard intervention by more than a specified margin
Noninferiority trials
97
Trials that estimate treatment effects that exclude any patient-important superiority of interventions under evaluation; helpful when determining if one intervention is neither better nor worse than another
Equivalence trials
98
The extent to which an instrument measures what it is intended to measure
validity
99
Trials stopped early due to apparent harm because the investigators have concluded that they will not be able to demonstrate a treatment effect or because of apparent benefit
Truncated RCTs
100
Experiment to determine the effect of an intervention or exposure on a single study participant; patient undergoes pairs of treatment periods organized so that 1 period involves the use of the experimental treatment and 1 period involves the use of an alternate treatment
N-of-1 Randomized Clinical Trials
101
Does the treatment work under ideal, controlled conditions?
Efficacy
102
Does the treatment work like it is supposed to in the real world?
Effectiveness
103
Is the benefit of the treatment worth the cost?
Efficiency
104
Proxy measures, outcomes that substitute for direct measures
Surrogate outcomes
105
Aggregate measures that used in combination to measure the effect of a treatment; combination of multiple end points
Composite end points
106
Determines the magnitude of increased benefit of the experimental intervention over the standard therapy on effectiveness outcomes
Superiority trial
107
What's the difference between descriptive and analytic epidemiology?
descriptive answers the WHO, WHAT, WHERE, WHEN, while analytic answers WHY and HOW
108
What does subclinical mean?
it's the same as asymptomatic- so there's stuff going on inside you but no signs or symptoms
109
What's the difference between virulence and pathogenicity?
virulence is proportion of people who have a disease and then die, while pathogenicity is the proportion of infected people who then become sick
110
What is surveillance (in the surveillance loop)
process of collecting data, analyzing the data, interpreting it, and disseminating the data
111
What are the 5 essential activities of surveillance?
public health surveillance, field investigation, analytic studies, evaluation, and linkages
112
Study of the distribution and determinants of health-related states or events in specified populations, and the application of this study to the control of health problems
epidemiology
113
What is the main purpose of epidemiology?
application of epidemiology to the control of health problems
114
What are health determinants in the context of the definition of epidemiology?
upstream factors that affect health status such as poverty, SES, and any other predisposing factors
115
Why is epidemiology important for healthcare providers?
Epi studies can help inform what we know about health issues, and what affects a population also affects an individual
116
Source of epidemic where people are exposed to the same source over a brief period of time; # of cases rises rapidly and falls gradually and usually only one incubation period (ex. food poisoning)
point source
117
Source of epidemic where people are exposed to the same source prolonged over a period of days, weeks, or longer; epidemic curve rises gradually and might plateau (ex. cholera in the Dr. John Snow case)
common continuous source
118
What epidemic source is when it spreads from person to person? The epidemic curve has multiple peaks all one incubation period apart (ex. most infectious diseases, like measles)
propagated source
119
What epidemic source is similar to common continuous source but the exposure is intermittent and the graph has multiple peaks? (ex. seen with contaminated food sold over a period of time)
common intermittent source
120
What are the 5 purposes of epi surveillance?
1. track conditions of PH importance
2. Assess PH status
3. Define PH priorities
4. evaluate programs
5. develop PH research
121
What are the 4 types of PH surveillance?
active, passive, syndromic, and sentinel
122
What is sentinel surveillance?
pre-arranged sample of healthcare providers or others who agree to report cases of a certain disease
123
What is syndromic surveillance?
it's dependent on a constellation of signs and symptoms vs lab criteria
124
What is the most reliable type of surveillance?
active surveillance
125
In PH surveillance, is it better for a test to be more sensitive or more specific?
more sensitive
126
What is the application of test sensitivity?
SNout: if the test is highly SENSITIVE and the result is NEGATIVE, the disease can be ruled OUT
127
What is the application of test specificity?
SPin- if the test is highly SPECIFIC and the result is POSITIVE then the disease can be ruled IN
128
Incidence and prevalence are two measures of what?
frequency
129
Formula for incidence rate
Total # of new cases/ total population at risk
130
Formula for prevalence rate
all new and pre-existing cases/ total population
131
When can mortality be used as a measure of risk?
When case fatality is high and duration is short
132
What measure of mortality answers the question: What is the risk of death from disease X for this population?
Cause-specific mortality rate
133
What measure of mortality answers the question: What proportion of cases of disease X are fatal?
Case fatality
134
What measure of mortality answers the question: What proportion of all deaths is attributable to disease X?
Proportionate mortality rate
135
The conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients
Evidence-based medicine
136
5 steps of EBM
Ask, acquire, appraise, apply, act
| "Shakers and Quakers parked their ship at Plymouth, actually"
137
Errors in study design (bias and generalizability) can affect which steps of EBM?
appraisal and apply
138
What does PICO stand for?
Patient problem, intervention, comparison, outcome
139
What is part of primary research?
Studies
140
Synopses of studies, syntheses, synopses of syntheses, summaries, and systems are part of what kind of research?
secondary research
141
Study when you're just describing an interesting case or disease or presentation on a patient
case-report study
142
Case-reports, case-series, ecologic studies, and one-person trials are all what group of studies?
descriptive studies
143
study where participants are selected based on having an exposure or not, and then followed to see if they develop a certain outcome
prospective cohort study
144
Study where participants are selected whether or not they have an outcome and then see which had a common exposure
case-control study
145
Study where both the exposure and outcome are studied at the same time
cross-sectional study
146
Difference between estimation and significance testing
Estimation provides both magnitude and direction of a possible assn, while significance testing doesn't
147
Power is affected by which 3 things?
sample size, alpha value, true effect
148
testing where you're interested in a difference between groups in one direction
one-sided test
149
Does a one-sided or two-sided test need a larger sample size?
two-sided
150
How well the study is measuring what it's supposed to measure
validity
151
Type of cross-over where each person is their own control case
planned cross-over
152
Problems with planned cross-over
carry-over effect from the first treatment
153
Type of cross-over where a person in one treatment switches to the other treatment at some point in the study
unplanned cross-over
154
Treatment design to test the association between two or more treatments on an outcome
factorial design/multifactorial design
155
What happens in the preclinical phase?
animal trials, potential risks are identified
156
What happens in Phase 1 trials?
testing in small groups of humans, safety and dosage tested
157
What happens in phase 2 trials?
more people are added and takes longer time. Testing efficacy
158
What happens in phase 3 trials?
more people recruited, efficacy and side effects studied
159
When does FDA review happen in a clinical trial?
between phase 3 and 4
160
error due to the lack of precision in measuring an effect
random error
161
3 criteria for determining confounding variables
1. independent risk factor for the outcome
2. associated w the exposure in source population
3. the confounder is not an intermediate or in the causal pathway btw exposure and outcome
162
In interpreting sample size adequacy with confidence intervals for a positive study, look at what?
the lower boundary
163
In interpreting sample size adequacy with confidence intervals for a negative study, look at what?
the upper boundary
164
What are the 4 steps of the PH loop in order?
collect, analyze, interpret, disseminate
