Definitions Flashcards
(163 cards)
1
Q
What is an analytic cross-sectional study?
A
A cross-sectional study that tests a hypothesis.
2
Q
How is an analytic ecological study different from a descriptive ecological study?
A
Differs only from the descriptive ecologic study by its intent to test a hypothesis.
3
Q
Define the purpose of analytic epidemiology studies.
A
Analytic studies seek not only to describe, but also to test a hypothesis.
4
Q
What is animal model-based research?
A
The use of non-human animals in experiments to seek to control the variables that affect the behaviour or biological system under study.
5
Q
What does applicability mean in regard to research evaluation?
A
A criteria for evaluating research. Are you able to use results of the research in similar contexts with similar participants? In quantitative research, applicability is referred to as “external validity”; in qualitative research, it is referred to as “transferability”.
6
Q
What is basic research?
A
Discovery-based, and focuses on developing theories regarding natural phenomena and processes. The purpose of basic research is to enrich our scientific knowledge base; real-world applications are not involved at this stage.
7
Q
Explain the meaning of bias and its definition within quantitative research.
A
Refers to data being skewed in an unfair or inaccurate way. In quantitative research, bias is defined as a type of systematic (non-random) error in the design or conduct of a study that can lead to incorrect results.
8
Q
What is biochemistry research?
A
The study of the structure and function of biological molecules such as proteins, nucleic acids, carbohydrates, and lipids.
9
Q
Name and describe the technique used in experimental research to reduce bias.
A
Blinding: A technique used in experimental research to reduce bias by masking study information from researchers and/or experimental subjects.
10
Q
What is bracketing?
A
The act of suspending judgment about the natural world to instead focus on analysis of experience. Also called epoche.
11
Q
What is a case series?
A
A case series is composed of mulitple case studies. It describes the characteristics of a group or cluster of individuals with the same disease or symptoms (or condition/state) in an attempt to quantify various aspects of the group and thus present a relatively complete profile of the illness (condition/state).
12
Q
What are case studies?
A
An in-depth analysis of people, events, and relationships bound together by some unifying factor. The case study (also sometimes called case report) presents a detailed description of an individual patient in order to characterize and understand a specific disease or syndrome.
13
Q
Define case-control studies.
A
The study population is chosen based on their outcome status. Cases (those with the outcome) are compared to a group of controls (those without the outcome). Past exposure information is collected from both groups.
14
Q
What are causal associations?
A
When changes in the occurrence of the outcome can be shown to be the result of an exposure, the association is said to be causal. To determine if an association is likely causal, it is important to refer to Bradford Hill’s criteria for causation (Module 4).
15
Q
What is cell culture-based research?
A
The study of the behaviour of cells grown under controlled conditions.
16
Q
Describe clinical equipose.
A
Clinical equipoise means a genuine uncertainty exists on the part of the relevant expert community about what therapy or therapies are most effective for a given condition.
17
Q
What is a code?
A
A label meant to facilitate the grouping of data into meaningful categories. Codes are typically a single word or a short expression.
18
Q
What is a codebook?
A
Typically usd to document the codes used in the coding process. Researchers can compare identified codes to the codebook, and compare their own codes to those of other researchers (in the event that multiple investigators are coding the same data).
19
Q
What is a confounder?
A
Also called a confounding variable, a confounder is a third variable that affects, or is associated with, both the independent and dependent variables (exposure and outcome). Lack of control for confounding variables can result in misrepresented results.
There are three main criteria for a variable to be considered a confounder:
1) must be associated with the exposure
2) must be a risk factor for the outcome
3) must not be in causal chain linking exposure to outcome
20
Q
What are cohort studies?
A
In cohort studies, a group of people with different levels of exposure are selected and followed through time to see what happens to them. Participants must all be free of the outcome at the outset.
Cohort studies can be retrospective (i.e., the outcome has already occurred and we are looking backward in time, typically through the use of administrative data) or prospective (i.e., we are following participants forward in time to observe outcomes that have not yet occurred).
21
Q
What is a prospective cohort study?
A
In this design, a cohort is created based on current or past exposure and followed forward into the future to determine if an outcome develops.
22
Q
What is a retrospective cohort study?
A
Also called a historical cohort, this cohort study design is constructed using past administrative records. Exposure status is assigned based on information recorded in the past. The cohort is “followed” into the present (or sometime in the more recent past) to determine outcome status.
23
Q
Describe the concurrent nested design of mixed method research.
A
In a concurrent nested design, one paradigm takes priority over the other. This study is used when the two methods answer different questions or the same question at different levels (e.g., individual vs. community perceptions).
24
Q
What is concurrent triangulation?
A
In this mixed methods research design, both qualitative and quantitaive data collection are conducted simultaneously. The interpretatino of the data is doen together and no one aspect takes priority over the other. This type of study is used to confirm, cross-validate, or corroborate the findings from each paradigm of the study.
25
What is a confidence interval?
Confidence intevals define a range of plausible values for true population parameters, based on a desired level of confidence (90%, 95%, or 99%). A confidence interval consists of two numbers called confidence limits. A confidence interval allows the researcher to determine the precision of an estimate - a wide confidence interval indicates that the estimate is imprecise, while a shorter confidence interval indicates greater precision.
26
What does confirmability refer to in the context of evaluating research?
Refers to the degree to which the results of a qualitative research study align with the observation and/or interview data. Documentation of decisions made throughout the study (an audit trail) is key to enhancing confirmability.
27
What is a confirmability audit?
A confirmability audit focuses on data interpretation. The reviewer judges whether findings are grounded in the data and the inferences made by the researchers are logical.
28
What is a consensus statement?
A document devleoped by an independent panel of experts, usually multidisciplinary, convened to review the research literature in health and biomedical sciences, permitting searches at various levels of specificity.
29
What does consistency mean in research evaluation?
A criteria for evaluating research. Can you follow the reseach steps of the study and come to similar conclusions? In quantitative research, consistency is referred to as "reliability"; in qualitative research, it is referred to as "dependability".
30
Define the constructivist paradigm.
A constructivist paradigm leads a researcher to believe that reality is constructed inter-subjectively through the meanings and understandings developed socially and experientially (a relativist ontology). As such, we cannot separate ourselves from what we know. Constructivists favour qualitative methodology.
31
What does content analysis refer to? Is it used in quantitative, qualitative, or mixed methods research designs?
An umbrella term to refer to different techniques to retrieve meaningful information from text.
Qualitative and mixed methods research designs use this (use of words as data).
32
What is a control group?
A control group is the subset of participants in experimental research that is not exposed to the independent variable (or exposure, treatment, or intervention). Control groups provide a baseline measurement that can be compared to the experimental group.
33
What is convenience sampling?
A process of selecting subjects or units for examination and analysis that is based on accessibility, ease, speed, and low cost.
34
Define credibility in relation to research evaluation.
Refers to how believable the findings of a qualitative study are. It is based on an assessment of the design features adopted by the researcher to verify findings. Techniques such as triangulation and member checking enahnce the credibility of qualitative study results.
35
What is a critical discourse analysis?
The study of a group of ideas or patterned way of thinking, which can be identified in textual and verbal communications, and can be located in wider social structures.
36
Explain deductive reasoning.
This type of analysis is guided by a priori hypotheses or objectives (or theories), and is the approach used in quantitative research.
37
Describe dependability in the context of evaluating research.
Dependability refers to the stability or consistency of the research processes throughout the course of the qualitative study. A review of the activities of the researcher by an independent person is needed to assess dependability (i.e., a "dependability audit"). Dependability can be thought of as being akin to the transparency of the research process.
38
What is a dependability audit?
A review of the activities of the researcher by an independent person. This is only possible if the researcher has clearly documented how the study was conceptualized, how particiapnts were selected, how data were collected, and how the interpretation of the data evolved. The documentation must also idenify any changes that occurred in the setting.
39
Define the purpose/meaning of a dependent variable.
The variable that is changed as a result of manipulation of the independent variable. Also referred to as outcome or endpoint.
40
What are descriptive cross-sectional studies?
An exploratory study where exposure and outcome for each individual under study are measured at the same point in time. It is difficult to determine causation through the use of cross-sectional studies as a result of this design feature.
41
Define descriptive ecological studies.
An exploratory study where exposure and outcome for each individual under study are measured at the same point in time. It is difficult to determine causation through the use of cross-sectional studies as a result of this design feature.
42
What are descriptive ecological studies?
The units of analysis are groups (not individuals). Summary measures (average or proportions) of exposure and outcome for the groups are analyzed.
43
Define descriptive epidemiology.
Descriptive observational studies in epidemiology describe the occurrence of an exposure and/or outcome in a population. Investigators look for patterns of health/disease by answering the questions: Who? What? When?
44
What is a descriptive question?
These questions focus on the who, what, when, and where.
45
What is detection bias?
This type of information bias is present when the outcome status (in a case-control study) or the exposure status (in a cohort study) influences data collection and recording.
46
What are determinants?
Factors that contribute to morbidity and mortality in human populations.
47
What are deterrants?
Factors that prevent or reduce morbidity and premature mortality in human populations.
48
What does diagnostic suspicion bias refer to?
A bias that may occur when knowledge of the subject’s prior exposure to a putative cause (ethnicity, drug intake, a second disorder, an environmental exposure) influences both the intensity and the outcome of the diagnostic process.
49
What does distribution refer to?
The frequency and patterns of morbidity and mortality in a given population or community.
50
Define epidemiology.
The 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.
51
What is epistemology?
A branch of philosophy concerned with determining what can be known and how it can be known.
52
Define ethics in relation to study design.
Was the study conducted in compliance with standards of research ethics? The three core ethics principles are justice, concern for welfare, and respect for persons.
53
Explain the qualitative study tradition of ethnography.
The systematic study of the shared patterns of groups of people located in the same place or in frequent contact. The ethnographer’s subject is the group or its culture. He/she observes society from the point of view of the group.
54
What does etiology refer to?
The cause of a disease or condition.
55
What is exclusion criteria?
The bases on which a person would be excluded from participating in a study. Typically include factors such as: pre-existing conditions that may complicate study findings, previous or current medications, or patients that are too ill to participate.
56
What is an experimental group?
Also called the "treatment group", this is the subset of participants in experimental research that are exposed to the independent variable (or exposure, treatment, or intervention).
57
What are experimental units?
The who or what being randomized or analyzed, for example: cells, animals, participants.
58
What is an explanatory question?
These questions focus on the why and how.
59
What does exposure mean in the context of epidemiological research?
In epidemiology, the exposure (or treatment/intervention) is the independent variable that exerts influence on the dependent variable (or outcome). Exposures are usually risk factors, but are more broadly understood as any factor that might influence health, positively or negatively.
60
Define external validity in relation to evaluating research.
Also called generalizability, external validity refers to the degree to which the results of a study are likely to be true for populations other than the sample studied.
61
What are extraneous variables?
Variables outside of the main exposure-outcome relationship being studied.
62
Define focus groups.
Group interviews, usually with three to five groups of 6-12 participants.
63
Describe grounded theory studies.
In a grounded theory study, the researcher goes back and forth between data collection and analysis such that interpretations are continually derived from raw data. The intent is to collect and analyze data to develop or generate an initial theory that informs the subsequent data collection and analysis.
64
What is a group trial?
An intervention study in which groups of individuals are assigned to one of several interventions. This design is used when the intervention to be evaluated operates at a group level, manipulates the physical or social environment, or cannot be delivered to individuals.
65
What is a hazard rate?
The speed at which the outcome is observed. It is calculated by dividing the number of events (outcomes) observed by the sum of time each unit is observed (i.e., person-time). Hazard rate may also be referred to as incidence density or incidence rate.
66
A rate ratio is...
...the speed at which units in the treatment group develop the outcome divided by the speed at which units in the control group develop the outcome.
67
What is a hazard ratio?
A hazard ratio is a relative measure of survival and tells us nothing about risk. A hazard ratio of 1 indicates no difference between treatment and control groups
68
What does the healthy worker effect refer to?
The potential bias caused by the phenomenon that sicker individuals may choose work environments in which exposures are low; they may be excluded from being hired; or once hired, they may seek transfer to less exposed jobs or leave work.
69
What is a hypothesis?
A hypothesis states the predicted research outcome. The hypothesis must by testable; the null hypothesis (the opposite of what is predicted) is what the researcher hopes to reject as a result of their research findings. Hypotheses guide research objectives.
70
What are in vitro studies?
These studies are conducted on components of an organism that have been isolated from their usual biological surroundings (i.e., cell culture and biochemical research).
71
What are in vivo studies?
These studies are conducted on components of an organism while those components reside within a living system (i.e., animal models).
72
What does incidence mean?
The number of new or incident cases of the specific outcome in a population during a specified time period. Where prevalence tells us who already has the outcome of interest, incidence tells us who is developing the outcome of interest over a period of time.
73
Define incidence proportion.
The proportion of an initially outcome-free population that develops the specified outcome during a specified period of time. Referred to as 'risk' in Module 4.
74
What does incidence rate refer to?
The speed at which the outcome is observed. It is a measure of incidence that directly incorporates time, and is measured by dividing the number of incident (new) cases by person-time. Referred to as 'hazard rate' in Module 4.
75
Describe the meaning of inclusion criteria.
The bases on which a participant would be included in a study, typically include factors such as: age, sex, ethnicity, and health status.
76
What is the independent variable?
The variable that is controlled or manipulated by the researcher in order to observe an effect on the depenent variable. Also referred to as exposure, treatment, or intervention.
77
What does induction refer to?
Time from exposure to the initiation of disease.
78
Define inductive reasoning.
This type of analysis is guided by observations leading to theory, and is the approach used in qualitative research.
79
What does inference mean?
Describes the process of gaining information about a population based on data collected from a sample.
80
What is information bias?
An error in measurement whereby the exposure and outcome are classified differently in the groups being compared. If the error is the same across exposure groups, the bias will be non-differential (the association will be underestimated). If the error is different across comparison groups, the bias will be differential (the association may be over or underestimated). Common sources of information bias include: recall bias, detection bias, or lack of accuracy in the tools used.
81
What does intention-to-treat analysis refer to?
In experimental research, this method of analysis includes all randomized patients in the groups to which they were randomly assigned, regardless of their adherence with the entry criteria, regardless of the treatment they actually received, and regardless of subsequent withdrawal from treatment or deviation from the protocol.
82
What is internal validity in the context of research evaluation?
The extent to which the researcher can show that the information collected accurately answers the research question. Internal validity is threatened by bias in the selection of observations or participants, in the information collected, or in the failure to control for extraneous factors in the analysis.
83
Describe a Kaplan-Meier plot and explain its purpose.
These plots are used to depict survival data, with the proportion of participants without the outcome represented on the vertical axis, and time represented on the horizontal axis. These plots are often referred to as survival curves, as the outcome is commonly death.
84
What does latency period refer to?
Time from disease initiation to detection.
85
What does local control mean?
Refers to practices and techniques used to ensure the intervention is applied uniformly and under standard conditions.
86
Define loss to follow-up bias and include which type of study this is primarily prevalent in.
During cohort studies, loss to follow-up occurs when participants can no longer be located or when they choose to no longer participate in the study. This will introduce bias in the measure of association if those who are lost to follow-up are systematically different from those who remain in the study with regard to their risk.
87
Describe a matched pairs design.
In a matched pairs, same experimental units design, each experimental unit is given both treatments in a random order, with each unit serving as its internal control. In a matched pairs, similar experimental units design, similar experimental units are paired together, and then each member of the pair is randomly given one of the two treatments.
88
What are measures of association?
Methods of quantifying the relationship or association between an exposure and an outcome. Relative risk (RRs) and odds ratios (ORs) are commonly used measures of association in epidemiology.
89
What does medical trial mean?
A research study that prospectively assigns human participants or groups to health-related interventions intended to evaluate the effects on health outcomes.
90
Define methodology.
Our strategic approach to the production of data; how we gain knowledge of what exists.
91
What does member checking mean?
Asking participants in a qualitative study to confirm that their words as transcribed match what they intended to say, and/or that the researcher's understanding reflects the study participants' experiences or perceptions.
92
What does neutrality refer to in the context of evaluating research?
Has the researcher discussed all potential sources of bias? In quantitative research, neutrality is referred to as "objectivity"; in qualitative research, it is referred to as "confirmability".
93
What are non-causal associations?
These associations are real, in the sense that based on the data and sample population, the relationship exists. However, the relationship is due to other factors (e.g., confounders).
94
What do research objectives refer to?
Research objectives state the experiments or methods that will be undertaken to test the research hypothesis and define the specific aims of the study. Study objectives are focused on relevant outcomes.
95
What does objectivity mean in relation to evaluating research?
Relates to the researcher's neutrality. Objectivity reuquires that the researcher observe reality without "contamination" from his/her experience and values. This is achieved by standardizing measurements and protocols for data collection, coding, analysis, and reporting.
96
What is an observational study?
These studies test hypotheses but, in contrast to experimental research, the researcher does not control the study conditions.
97
What does an odds ratio measure?
The odds ratio measures relative odds - the odds that an outcome will occur given a particular exposure, compared to the odds of the outcome occurring without that exposure. As with relative risk, an OR>1 indicates that the exposed group has greater odds of developing the outcome compared to the non-exposed group, while an OR<1 indicates lower odds in the exposed group. An OR=1 indicates that both groups have equal odds of developing the outcome.
98
What does ontology mean?
The philosophy of existence and the assumptions and beliefs that we hold about the nature of being and existence.
99
What is an open-ended interview?
Also called unstructured interviews. The interviewer has clear goals for the interview but rather than relying on a structured interview guide, they build rapport allowing interviewees to open-up and express themselves in their own way.
100
What does outcome mean in relation to epidemiology?
In epidemiology, the outcome is the dependent variable that is influenced by the independent variable (or exposure). Outcomes are usually diseases, but are more broadly conceived of as any type of health state.
101
What is a paradigm?
Systems of beliefs and practices that influence how researchers select both the questions to study and the methods they use to study them. No paradigm is right or wrong - they serve different purposes.
102
What does participant observation mean?
The process of learning through exposure to or involvement in (collecting data on) the day-to-day or routine activities of participants in the research setting.
103
Define peer-review.
The process of subjecting research to scrutiny of others who are experts in the same field to evaluate quality and importance.
104
What is period prevalence?
A measure of the proportion of the population with the outcome of interest during a specific period of time (for example, between January and June 2019). It is the number of existing cases measured over a period of time and divided by the average population during that time period.
105
Define pharmacokinetic profile.
The time-course of drug action in the body: absorption, distribution, metabolism, and excretion.
106
What does phenomenology mean?
Phenomenology is concerned with investigating, describing and understanding phenomena as they are experienced by study participants. It requires that the researcher suspend his/her belief in the objective existence of the phenomenon.
107
What is a placebo?
A substance or procedure having no therapeutic effect.
108
What does point prevalence mean?
A measure of the proportion of the population with the outcome of interest at a specific point in time.
109
Describe the positivist paradigm.
A researcher working from this paradigm believes there is an objective reality (a realist ontology), and that symbols can be used to describe and explain reality. The preferred methodology for positivists is quantitative.
110
What does power refer to in the context of statistics?
Statistical power is affected by sample size, effect size/estimate, and alpha. Power is the probability of rejecting a null hypothesis when it is false. In other words, the power of a study is its ability to show what you're looking to find.
111
What does power relationship refer to?
The inevitable power differential between researcher and research participants.
112
What are preclinical studies?
These studies use cell cultures or animals to monitor the effects of an intervention or treatment before it is tested in humans. The focus is on evaluating the effectiveness and safety of a potential treatment for humans.
113
What does prevalence mean?
The numer of events (e.g., disease cases, deaths, etc.) in a population, reported as a proportion (number of events divided by the total size of the population or sample).
114
What is a prevention trial?
The goal of a prevention trial is to assess whether an intervention/treatment may reduce the occurrence of disease in healthy individuals or groups.
115
What is a primary outcome?
The objective measure that may provide the strongest evidence to support study hypotheses or objectives.
116
Define prognosis.
A medical term that describes the probable course and outcome of a disease, and the predicted chance of recovery from a disease.
117
What is a prognostic factor?
A situation or condition, or a characteristic of a patient, that can be used to estimate the chance of recovery from a disease or the chance of the disease recurring.
118
What is purposeful sampling?
The researcher selects individual and sites for study because they are believed to be able to inform an understanding of the research problem and central phenomenon in the study.
119
What does randomisation mean?
Assignment of the exposure is a key aspect of experimental studies; it is usually done through randomization to either the intervention group or a control group. Randomization ensures that the intervention and control groups are as similar as possible at the start of the study. As such it accounts for unknown factors that may affect the outcome.
120
What is a randomised block design?
This type of randomization is performed when the researcher wishes to control for factors believed to affect the outcome. Homogenous subgroups are formed before participants are randomly assigned to experimental or control groups. This is sometimes also called stratified randomization.
121
What is a randomised control trial?
An intervention study where peple are allocated randomly to receive one of several clinical interventions (or to an intervention or control group).
122
Describe the realist paradigm.
The realist researcher believes that there is an objective reality but that our ability to know reality is imperfect; we can only know reality from our own perspective of it (a realist ontology). We cannot separate ourselvles from what we know, but objectivity remains the ideal. Realist researchers will often rely on mixed methodology (qualitative and quantitative).
123
What does recall bias refer to?
This type of information bias is present when one subset of the study participants is more likely to recall an exposure than another.
124
What is reflexivity?
The ongoing consideration of the context of research on knowledge creation, especially the effect of the researcher's knowledge, attitudes, and behaviours.
125
What does relative risk mean?
The ratio of the probability of the outcome occurring in the treatment group and the probability of it occurring in the control group. Also referred to as risk ratio, relative probability, or relative likelihood.
126
Define reliability in the context of research evaluation.
Refers to the consistency of a study's results. If findings are replicated consistently, they are said to be reliable.
127
What is replicability in relation to evaluating research?
The quality of being replicable (i.e., copied or recreated)
128
What does replication mean?
Repetition of the experiment on many experimental units is needed to provide an estimate of experimental error. The number of replications is the sample size.
129
What is a research question?
Forms the basis of the hypothesis/objectives for a study. It should address your population of interest, an exposure (or intervention), and an outcome of interest.
130
What is risk?
Also referred to as cumulative incidence or incidence proportion, risk is the probability of the outcome occurring over a defined period of time. It is calculated by dividing the number of units (participants) in which the outcome is observed by the number of units (participants) that were observed during the period of time.
131
Define risk difference.
The probability of the outcome occurring in the treatment group minus the probability of it occurring in the control group. Also referred to as absolute effect size or treatment effect.
132
What is a risk factor?
An exposure that increases the probability of developing a given outcome.
133
Define saturation.
The point at which additional data does not provide new information or produce new interpretations. Saturation is a function of both the 'richness' (number/variety of data sources used) and 'thickness' (depth of information) of the data. See also "Descriptive Saturation" and "Theoretical Saturation".
134
What is descriptive saturation?
No new codes, categories, or themes emerge from data analysis.
135
What is theoretical saturation?
Data fully explain how codes, categories and themes interconnect.
136
Describe a saturation table.
Displays the data in a grid listing major codes on the veritcal and interview on the horizontal to see if new topics are still emerging.
137
What is a scoping review?
Sets the scene for a future research agenda. This review documents what is already known in the literature, and using a ciritical analysis of gaps in knowledge helps to refine research questions, concepts, and theories to point the way to future research.
138
What is a secondary outcome?
These outcomes do not hold the same statistical authority as the primary outcomes for which the study was design, but may also provdie support for study hypotheses.
139
What is selection bias?
A systematic error that results from procedures used to select participants and from factors that influence participation in the study (i.e., those that are included in a study differ systematically from those who are not included in a study). Three common types of selection bias are: the healthy worker effect, volunteer bias, and loss to follow-up bias.
140
What are semi-structured interviews?
An interview where the interviewer relies on an interview guide - a list of questions and topics that need to be covered (usually in a particular order) – allowing for divergence on a topic when he or she feels this is appropriate.
A flexible qualitative method that allows the interviewer and interviewee to divert from and explore themes based on a structured set of questions.
141
Define the sequential explanatory design.
In this mixed methods research design, the quantitative research is completed first, followed by the qualitative. This design is used to provide context or more in-depth understanding of a quantitative study result.
142
Define the sequential exploratory design.
In this mixed methods research design, the qualitative research is completed first, followed by the quantitative. This design is used to explore a phenomenon.
143
What is a simple randomised design?
Participants are assigned to groups completely at random - for example, each participant has an equal chance of being selected for the experimental group. This method of randomization is analagous to tossing a coin repeatedly.
144
What is the SMART framework?
The SMART acronym is used to describe qualities of good study objectives. It stands for: specific, measurable, attainable, realistic, and time-bounded.
145
Define snowball sampling.
Snowball sampling occurs when a researcher begins with a small list of potential participants who subsequently provide contact information for additional potential participants. The researcher follows this chain of contacts in order to identify and accumulate participants. This sampling method is typically used with hard-to-reach populations (e.g., illicit drug users).
146
What is a spurious relationship?
This type of association is simply not true. It can be caused by random error (the role of chance) or by bias.
147
What does it mean when a result is statistically significant?
Meaning that a result is unlikely to be seen if the null hypothesis (no association) was true.
148
What does stratification refer to?
Presenting results for each level of the potential confounder will both reveal if confounding is present (the measures of association will be the same for each level but different from the overall estimate) and remove its effect if stratum-specific results are presented.
149
What is a study rationale?
Consists of an argument, or series of arguments, that convince a scientific audience that a particular research question needs to be addressed via a formal study.
150
Define the meaning of a surrogate endpoint.
Suppose a primary endpoint, such as patient survival, is not practical to measure due to its extended time scale. In this case, a surrogate enpoint (short-term outcome) may be used in its place (clinical practicality).
151
What is the survival proportion?
The proportion of units (participants) who survive (do not develop the outcome) over a defined period of time. Also referred to as probability of survival or survival.
152
What does target population refer to?
The population that an epidemiologist is trying to learn about when conducting a study. As it is usually not possible to measure everyone in a target population, investigators use samples to make inferences about the health-related characteristics of a population.
153
Define template analysis.
An approach to assigning themes to textual data using a scheme which starts with broad themes within which are successively narrower themes. A preliminary list of themes is identified a priori and revised as analysis progresses. Once all data is coded, the template serves as the basis for interpretation of the data.
154
What is a therapeutic trial?
The goal is to evaluate new treatments for existing disease. Such trials can randomize groups or individuals.
155
What is a thick description?
Refers to interpreted accounts resulting from qualitative research, as compared to factual accounts derived from quantitative research.
156
What does transferability refer to in the context of evaluating research?
The degree to which the results of a qualitative research study can inform understanding of other contexts or settings. It is a judgement made by the reader of the research by considering the specifics of the research context and comparing them to determine the extent to which the results obtained suggest further questions for study or directions for action. Note that transferability is not a necessity.
157
What does translational refer to in the context of health research?
Research is translational when findings in a laboratory setting can lead to applications to enhance human health.
158
What does transparency mean?
Requires that the researcher outline procedures used to collect, generate, or choose data, theory, or methods. The resulting documentation is referred to as an audit trail. Transparency required reflexivity on the part of the researcher.
159
Define triangulation.
Corroboration among findings from different data sources or methods to capture data. In mixed methods research, triangulation of quantitative and qualitative findings often occurs. There are four types of triangulation: method, investigator, theory, and data source. Types of triangulation can be combined in te same study, but not all types are required for each study.
160
Explain the meaning of truth value.
A criteria for evaluating research. Are the findings of the study believable? Are they legitimate given the research paradigm used? In quantitative research, the truth value is referred to as "internal validity"; in qualitative research, it is referred to as "credibility".
161
What is a type I error?
Rejecting the null hypothesis when it is in fact true. The probability of making this error is given by the p-value, also referred to as alpha.
162
What is a type II error?
Failing to reject the null hypothesis when it is in fact false. The probability of making this error is given by beta.
163
Describe volunteer bias.
Occurs when those who choose to participate are different from the source population with regard to their probability of exposure (in case-control studies) or outcome (in cohort studies).
