NUTR Capstone - Exam #1 Flashcards Preview

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Flashcards in NUTR Capstone - Exam #1 Deck (150)
1

What is the AND Code of Ethics?

-American Dietetic Association updated the 1999 code of ethics in 2009;
-“19 principles to guide dietetics professionals in their conduct, commitments and obligations to self, client, society, and the profession.”

2

What are the AND (ADA) values for the Code of Ethics?

1. Customer Focus;
2. Integrity;
3. Innovation;
4. Social Responsibility

3

What is Customer Focus?

-Meets the needs and exceeds expectations of internal and external customers;
-Principles 5, 9

4

What is Integrity?

-Acts ethically with accountability for life-long learning and commitment to excellence;
-Principles 1,2,4,5,6,7,10,11,12,13,17,18

5

What is Innovation?

Embraces change with creativity and strategic thinking

6

What is Social Responsibility?

-Makes decisions with consideration for inclusivity as well as environmental, economic and social implication;
-Principles 3, 8, 9, 11, 13, 14, 15, 16, 17, 18, 19

7

When does an ethical researcher practice ethical behavior?

-An ethical researcher practices ethical behavior from the beginning to the end of the study;
1. Design of a study;
2. Collection of data;
3. Analysis of data;
4. Publication of the findings

8

What are possible Errors in Research?

- Human errors → Honest mistakes;
- Fraud → Intentional deception or misrepresentation

9

What is good ethical design, conduct and analysis of a research study?

-A well-crafted research design minimizes errors;
-Confidentiality of medical and personal information is essential;
-The protocol should be carefully followed by all members of the research team and the data carefully collected, recorded, and stored.

10

What makes an Ethical Presentation and Interpretation of Research?

-Practice honesty, truthfulness and full disclosure.;
-Present the “truth, the whole truth and nothing but the truth.”;
-Use the best statistical technique to answer the question (driven by the original research question and hypothesis).;
-Present the study limitations.

11

What makes Ethics in Publication?

-Peer review helps prevent poor research and fraudulent information from being published;
-All listed authors are expected to have contributed to the publication;
-An author’s conflict of interest must be disclosed.

12

What are Common Research Errors?

1. Sampling;
2. Non-coverage;
3. Nonresponse;
4. Measurement;
5. Errors of data distortion and overgeneralization;
6. Errors in authorship and conflict of interest

13

What are Sampling Errors?

Study sample does not represent the actual sample

14

What are Non-Coverage Errors?

A sample that excludes some individuals

15

What are Nonresponse Errors?

A sample with a low response rate or loss of subjects to follow-up

16

What are Measurement Errors?

Use of slanted questions and/or use of instruments that lack reliability and validity

17

What is the Nuremberg Code of 1947?

-10 principles that must be followed in human experimentation;
-First established the requirement for INFORMED CONSENT.

18

What is the Declaration of Helsinki?

-12 basic principles to use when submitting experimental protocols;
-This idea lead to the genesis of the INSTITUTIONAL REVIEW BOARD (IRB).

19

What is the Belmont Report?

-Issued by the National Commission for the Protection of Human Subjects of Biomedical and Behavioral Research (President’s commission formed in 1974);
-Three basic principles upheld in the Belmont Report are:
1. Respect for persons,
2. Beneficence, and
3. Justice

20

What is the Belmont Report establish are the roles of the IRB?

-Protect rights of subjects;
-Demand non-coerced consent, confidentiality, protection of privacy, equity in subject selection, autonomous right of free choice including right of subject to terminate participation without penalty and termination of the research project at any point if the data warrants such action

21

What US Legislation

-IRBs are governed by TITLE 45 CODE OF FEDERAL REGULATIONS PART 46;
-Included in the National Research Act of 1974.

22

What is the National Research Act of 1974?

The Act defined IRBs and put the regulation of the IRB under the Office of Human Research Protection within the Department of Health and Human Services.

23

What is the Institutional Review Board (IRB)?

-The IRB is an independent ethics committee or ethical review board.;
-Made up of a variety of members from different backgrounds;
-This committee is formally designated to approve, monitor, and review biomedical and behavioral research involving humans;
-Their number one priority is to protect human subjects from physical or psychological harm.

24

What types of studies are reviewed by the IRB?

1. Exempted
2. Expedited
3. Full Review

25

What are the LSU IRBs?

Both LSU and the LSU AgCenter have IRB committees;

26

What makes up the LSU AgCenter IRB?

1. IRB Forms =
-Application for Exemption;
-Regular application (Expedited or Full Review)
2. IRB members

27

What is the required NIH certification regarding human research studies?

"Protecting Human Research Participants Certificate"

28

What are 3 Guiding Principles used in Human Research?

1. Respect for persons
2. Beneficence
3. Justice

29

Why is research needed?

1. Objectively measure complex environments
2. Rigorously test hypotheses and compare and evaluate of the outcome of procedures, treatments, and protocols
3. Carefully examine associations/relationships
→ “Generates New Information or Knowledge

30

How do you ensure that you are interpreting nutrition-related research carefully?

-Think critically and carefully when interpreting nutrition research findings.;
-Consider the type of research design and what can be concluded.

31

What are the 2 broad categories of research?

1. Descriptive research
2. Analytical research

32

What is Descriptive Research?

-Describes the state or characteristic at a specific point in time;
-Useful for generating hypotheses;
-Provide baseline data (monitor over time)
-Includes:
--qualitative research (Dr. Marks research)
--surveys (cross-sectional information) ****
--case reports
**** Our class project will be this type of research

33

What is Analytical Research?

-Analytical research (Inferential) → “This happens because of this”;
-Either EXPERIMENTAL;
-or Analytical but NOT experimental = Cohort (prospective or case-control)

34

What is a Prospective Cohort Study?

Prospective cohort (epidemiology study) → Enroll a whole bunch of people and then follow them FORWARD and see who gets sick or develops a condition

35

What is a Case-Control Study?

Case-control studies (epidemiology study) → Find people who already have a disease and those who don’t, and look BACK determine the differences in their lives that might have lead to the disease

36

What makes a experimental study?

*Randomized!!;
-Most rigorous study design =
1. Subjects are informed about the study.
2. After consenting to participate, subjects are randomized to one or more treatment or intervention groups (with minors, parents provide consent for their children to participate and children agree or “assent” to participate).
3. Participants are observed for the occurrence of particular outcomes or end points.
4. The design can be a group comparison or cross-over.
5. Causal inferences can be defended.

37

What are the characteristics of an experimental study?

*Randomized;
-Most rigorous design;
-Have a hypothesis or multiple hypotheses;
-Have dependent and independent variables

38

What is an dependent variable?

-outcome variable of interest;
-“Main character of a story (research)”

39

What is an independent variable?

- factor(s) thought to influence the dependent variable and is manipulated in the experimental design;
-“All of the other characters that influence the main character, good or bad”

40

What are the characteristics of Prospective Cohort Studies? (Epidemiological)

-The design is not experimental but it is analytic;
-A cohort is a group of people who are followed over time and while watching a common characteristic or factor of interest (usually a disease or condition);
-The cohort is followed forward in time to observe its experiences;
-The possible causal factor under investigation is called the exposure;
-It is assumed that the cohorts are comparable in all relevant factors other than the exposure.

41

What are the characteristics of Case-Control Studies (Epidemiological)?

-The design is not experimental but it is analytic.;
-These studies are retrospective and historically oriented.;
-Exposure status is assessed after disease status is known. ;
-Comparison groups are formed on the basis of disease or outcome status, either with disease diagnosis (cases) or without disease diagnosis (controls).

42

What is the Hierarchy of Evidence?

Broad to Specific:
1. Expert Opinion;
2. Case Report;
3. Case-Control;
4. Cross-Sectional;
5. Prospective Cohort;
6. Clinical Study;
7. Double Blinded;
8. Randomized control trial

43

What is a Confidence Interval?

Ratio of where answer actually lies;
-Greater than 1 means greater risk;
-Less than 1 means less risk associated;
-Equal to 1 means that it is not technically statistically significant

44

What is out class research study?

-The HUEC 4110 Research Project will be a descriptive, cross-sectional study;
-The project will have an OBJECTIVE or PURPOSE (not a hypothesis);
-Subject information will be collected using a survey-type instrument (pictures) and from a consent form;
-This study will provide descriptive information and will make inferences;
-It will describe and quantify characteristics of a defined population;
-It will NOT be an experimental study = no randomization

45

What are the steps in Designing a Research Study?

1. Select a research topic that is meaningful,expands current knowledge, and enhances practice;
2. Prepare for the research project by:
-reviewing the literature,
-solidifying the topic,
-addressing the issues, and
-identifying resources

46

What is the next step after designing the study?

**State the Research Question
3. Formulate the research question and evaluate its feasibility.
-Use words such as: identify, compare, differentiate, assess, and describe;
-Describe: who, what, and how assessed;
4. Design the research project (Choose the best research design)

47

What is the difference in a Research Objective or Hypothesis?

-Descriptive studies state an objective or purpose = Define distribution of disease and health-related characteristics of the population;
-Analytical studies, particularly experimental studies, state a hypothesis

48

What are the essential characteristics of a HYPOTHESIS?

-Measurable;
-Specifies the population being studied;
-Identifies a time frame;
-Specifies the type of relationship being examined;
-Defines the variables being studied;
-States the level of statistical significance

49

What are the types of DESCRIPTIVE research designs?

1. Qualitative;
2. Surveys

50

What is Qualitative Research?

*Descriptive Design;
-Explores the phenomenon of interest as a prelude to theory development;
-Data is collected via observation, interviews and questionnaires.

51

What is Survey Research?

-Describe and quantify characteristics of a population;
-Research using a survey has a research objective not a research hypothesis

52

What is QUASI EXPERIMENTAL (Partially Controlled) Design?

-Experiments that compare groups that have not been randomized;
-Causal inferences are difficult to defend.

53

What is EXPERIMENTAL Design?

-Have a hypothesis or many hypotheses;
-Have dependent and independent variables
--Dependent variable – outcome variable of interest
--Independent variable – factor(s) thought to influence the dependent variable and is manipulated in the experimental design

54

What is the best source for examining nutrition literature?

USDA Nutrition-Evidence Library

55

What must be remembered with research design?

-It is important to understand the types of research design and recognize the strengths and weakness of each.;
-Formulate your conclusions carefully after considering the type of research.

56

What determines the type of dietary assessment used in a research study?

-Purpose of the investigation;
-Necessary precision;
-Particular population;
-Time period of interest;
-Available resources

63

What is VALID data?

-Is the data TRUTHFUL?;
-Was the instrument used appropriate for the population?;
-Compared to biomarkers or doubly labeled water

64

What is RELIABLE data?

-Can it be REPRODUCED by another group of investigators or at another time by the same investigators?

65

How common is underreporting of dietary intake?

Common → 10% to 45% of individuals underreport

66

Who tends to underreport?

-Obese;
-Women vs. men;
-People of low socioeconomic status

67

How are underreports identified?

Identify cutoff points (how far your reported intake can differ from the estimated energy needs based upon your gender, height, weight and age).

68

How is underreporting handled DURING the study?

-Please emphasize that you are not judging your participant for what they do or do not eat;
-Emphasize that you just want to know how often and what people of different ages eat.;
-When you see that subjects are not sending data contact them as soon as possible.;
-If subjects become uncooperative then just dismiss them from the study and recruit someone else.

69

How is underreporting handled AFTER the data is collected?

-Exclude data from under-reporters from the analysis;
-Statistically adjustment the data to remove data from under-reporters

70

What is the purpose of qualitative research?

-Development of a concept or model;
-Description of a situation or process;
-Evaluation of a program or practice;
-Identification of policy issues

71

What are the time requirements in qualitative research?

-Every question = ~6-8 hours transcription time, then added evaluation and interpretation;
-Average qualitative piece ~1000 hour time estimate before 1st submission

72

What is Epidemiology?

-Epidemiology is “the study of the distribution and determinants of disease frequency.”;
-Epidemiology is always looking at diseases and conditions.

73

What are Descriptive Epidemiological Studies?

-QUANTIFY the extent and location of nutrition problems within a population and SUGGEST ASSOCIATIONS between DIET and DISEASE that can subsequently be evaluated in analytical research

74

What is Distribution?

who gets the disease, where it’s found, when did it occur, etc… (person, place & time)

75

What are the Determinants of Distribution?

1. Host factors: age, sex, race, genetic makeup, physiological status, etc…
2. Environmental factors: living conditions, occupation, geographical location (i.e. rural vs. urban), lifestyle, etc…
3. Time factors: seasonal and inter-annual fluctuations

76

What is Disease Frequency?

-Measures the amount of disease or mortality in a population and is expressed as incidence or prevalence;
-Translates into “risk of disease.” (Relative Risk or RR)

77

What is Incidence of Disease?

-Cumulative incidence or incidence rate – the number of NEW cases of a disease that occur in a population at risk within a specified time interval (frequently within 1 year of time)

78

What is the Prevalence of Disease?

-Proportion of the population that is affected by a certain disease or condition AT A GIVEN TIME (includes both new and existing cases)

79

What is Point Prevalence?

at one point in time – cross-sectional survey → EX: NHANES

80

What is Period Prevalence?

cases during a period of time

81

What is Reliability?

→ reproducible

82

What is Validity?

→ measures what it is designed to measure

83

What is Sensitivity?

Proportion of persons who HAVE the condition who have a POSITIVE test result

84

What is Specificity?

Proportion of persons who do NOT have the condition who have a NEGATIVE test result

85

What is Predictive Value?

-The predictive value of a test is its ability to accurately distinguish people with or without the disease or condition;
— POSITIVE predictive value is the probability of disease given a positive test result.;
— NEGATIVE predictive value is the probability of not having disease given a negative test result.

86

What is Descriptive Research?

-Report characteristics of person, place, time related to disease or condition of interest;
-Used to identify patterns of disease or conditions, Identify potential association between risk factor and disease

87

What are the types of possible Descriptive Research Design?

-Ecological Studies
-Case Reports and Case Series
-Surveys
-Surveillance Systems

88

What are Ecological Studies?

-Examines patterns relating a possible risk or causative factor to a disease;
-Only show ASSOCIATIONS;
-CANNOT claim causation or;
-Effect of potential confounding factors or ;
-Biological processes involved with disease

89

What are Case Reports and Case Series?

→ Don’t utilize too much in nutrition ;
-Unique experiences with one patient or a small group of patients with a similar diagnosis;
-Never able to conclude “cause and effect”;
-Useful for initial description of a new disease or documenting biological processes of a disease or condition

90

What are Surveys?

-Gather a wide variety of DESCRIPTIVE information about a disease or condition;
-Offer a representative overview of the health of the population (cross-sectional: i.e. one point in time);
-National surveys =
1. National Health and Nutrition Examination Survey (NHANES) → ONE point in time;
2. Continuing Survey of Food Intake by Individuals (CSFII)*
**The CSFII was integrated into the NHANES survey in 2002

91

What is Surveillance?

-Systematic, ongoing survey designed to monitor specific health outcomes in a population over time. → Constantly adding to the database!;
EX:
-Pediatric Nutrition Surveillance System (PedNSS)
-Pregnancy Nutrition Surveillance System (PNSS)

92

What are Vital Stats?

Vital statistics are a type of surveillance data and include:
1. Birth certificates
2. Death certificates
3. Census data

93

What is Qualitative Research?

“Qualitative research is any data gathering technique that generates open-ended, narrative data or words rather than numerical data or numbers.”

94

Similarities b/w Qualitative and Quantitative Research

Similarities =
- Descriptive
- Evaluative
- Context-sensitive
- Viewed on continuum

95

Differences b/w Qualitative and Quantitative Research

Differences =
- Data
- Sample size
- Data collection techniques
- Terminology

96

What is Qualitative Inquiry?

-Qualitative inquiry is the art of learning to listen to others’ stories and to interpret and retell the account.

97

What are the point of “words” in qualitative research?

-Reflect the point of view of the SUBJECT not the researcher;
→ Can only go off of or use information that is TOLD by the subject; NO inferences, no filling gaps, no assumptions

98

What are Empirical Observations?

Based solely on verifiable observation, regardless of logic or theory)

99

What are the Assumptions of Empirical Observation?

-Reality is socially constructed;
-Variables are complex, interwoven, and difficult to measure

100

What is the Research Purpose of Empirical Observation?

- Contextualization
- Understanding
- Interpretation

101

What is the Research Approbate of Empirical Observation?

-May result in hypotheses and theory;
-Researcher as instrument;
-Naturalistic;
-Inductive;
-Searches for patterns;
-Seeks pluralism, complexity;
-Makes minor use of numerical indices;
-Descriptive write-up

102

What is the role of the researcher in Empirical Observations?

-Personal involvement
-Empathic understanding

103

What terminology is different between Qualitative (Empirical) and Quantitative Research?

-Participants/informants (not subjects);
-Meaningfulness (not validity);
-Inductive approach (not deductive)

104

What is INDUCTIVE Reasoning?

-“Bottom-up” logic;
-Constructs or evaluates general propositions that are derived from specific examples;
-Probabilistic ( it only states that, given the premise, the conclusion is probable)

105

What is DEDUCTIVE Reasoning?

-“Specific examples” are derived from general propositions.;
-“Top-down logic”;
-Process of reasoning from one or more general statements to reach a logical conclusion

106

What are the Data Collection methods in Qualitative Research?

1. Observations = Field notes, Artifacts;
2. Interviews

107

Why use a Qualitative approach?

-Traditional quantitative research approach cannot answer the question.;
-Researchers are as interested in process variables as in outcome variables.;
-Evaluators want to know how and why a given outcome happens.

108

What are the theories behind Qualitative Research?

-Qualitative research can be theory-generated or atheoretical

(Atheoretical – NOT based on or concerned with theory)

109

What is the Study Design of Qualitative Research?

With qualitative research the investigator can modify the study design as needed to address the issues that become apparent (quantitative research is seldom if ever altered).

110

What is the data collection with Qualitative Research?

Participant selection (SAMPLING) should be determined by…
1. Appropriateness
2. Adequacy

111

What are the types of Sampling?

1. Selective;
2. Purposeful;
3. Theoretical

112

What is Selective Sampling?

– Researcher identifies the people, times, and places to be sampled in advance of study commencement

113

What is Purposeful Sampling?

– Similar to selective but occurs after initial data collection and analysis has begun

114

What is Theoretical Sampling?

– Similar to purposeful but focuses on filling in the gaps that hinder theory development

115

What are the Collection Techniques in Qualitative Research?

1. Observation;
2. Ethnography;
3. Case Studies;
4. Interviews

116

What is Observation in Qualitative?

observational forms, videotapes, field notes to record observations and researcher’s thoughts

117

What is Ethnography in Qualitative?

Participant observations in the social setting, field research, field studies

118

What are the different Interviews in Qualitative?

→ Individual or Group;
-Interviewing – “Process of getting words to fly”;
-Human interaction with all of its attendant uncertainties;
-Interviewer “pitches” the questions at the respondents with the intent of making words fly;
-Individual or group format

119

How is Understanding developed through interviewing?

-Develop a clearly defined topic.;
-Design interview questions that fit the topic.;
-Ask the questions with consummate skill.;
-Have ample time to “pitch” the questions to forthcoming and knowledgeable respondents

120

What are the attributes on the Interviewer (researcher)?

-Anticipatory
-Alert to establish rapport
-Naïve
-Analytic
-Nondirective and therapeutic
-Aware of status differences
-Patiently probing

121

What are the stages of Data Analysis in Qualitative?

1. Early Data Analysis;
2. Intercder Reliability;
3. Later Data Analysis - Entering the Code Mines;
4. Computer Analysis Software to Manage Data;
5. Displaying Data;
6. Determine Trustworthiness of Interpretation

122

Early Data Analysis

-Consistently reflect on your data, work to organize them and try to discover what they have to tell you.
-Write memos
-Build analytical files
-Develop rudimentary coding schemes

123

Intercoder Reliability

Members of the research team work together to assign codes to observations or verbalizations

124

Later Data Analysis: Entering the Code Mines

-Coding is a progressive process of sorting and defining and defining and sorting those scraps of collected data;
-By putting like-minded pieces together into data clumps your create an organizational framework.

125

Displaying Data

-Way to summarize data in a visual fashion to facilitate analysis and reporting’
-Examples
•Matrices,
•Diagrams,
•Flowcharts
•Concept maps

126

Trustworthiness of your interpretation

-Dependability
-Credibility
-Confirmability
-Transferability

127

What are the LIMITATION of Qualitative Research?

-Generalizations cannot be made from any one data set to a larger population.;
-It is difficult to compare studies because they are context bound.;
-Qualitative studies can’t be examined using meta-analysis.

128

Where does Qualitative Research take the investigator?

“Qualitative inquiry is a search that leads into other’s lives, your discipline, your practice, and yourself. You cannot be sure of what you will find, but you invariably get caught up in the search and made steps forward.”

141

What is a clinical nutrition research study?

-Research conducted with human participants;
-Evaluates the effects of a dietary modification on one or more end points.

142

What are the study designs of clinical nutrition research studies?

Experimental designs, participant populations and methods can vary.

143

How are the experimental food components or diets delivered?

Includes the “delivery of one or more specific nutrient(s) or diet(s).”

144

Do clinical nutrition research studies have hypotheses?

Hypothesis-driven (experimental)! =
- Hypothesis determines the:
1. Experimental design
2. Subject population
3. Methods to be implemented
4. Statistical analysis methods

145

What is considered in the study design of clinical nutrition research?

-Scope of the study = try to keep as narrow, yet inclusive as possible;
-Time needed to detect a meaningful difference
-Level of intensity or dietary control required (controlled vs. free-living)
-Demands placed on the participants enrolled in the study

146

What is the Gold-Standard design for Clinical Nutr Research?

Randomized Controlled Trial (RCT): BEST POSSIBLE Study Design =
-Employs a comparative design with an intervention with one or more treatments;
-Each participant is assigned to a group based upon a formal randomized procedure.

147

What are the two types of Randomized Control Trials?

1. Parallel Design→ Randomly assign and then follow two or more groups ;
2. Crossover Design → Control participant and washed out and then receive treatment so serve as his/her OWN CONTROL → Participants create their personal baseline

148

What is Parallel RCT Design?

Participants are randomly assigned to a particular treatment group and remain in that group throughout the study.

149

What is Crossover RCT Design?

-Each participant receives the intervention or control in the first period and the alternative treatment in the second period.
-There is a wash-out period between experimental periods.
-Each subject serves as his/her own control.

150

How are Clinical Nutrition Studies FACTORIAL?

-Allows the researcher to address multiple objectives within one study;
-The factor is the major independent variable with two or more levels as a subdivision of each factor;
-The more factors you put in, the more groups and controls required;
-Two factors with two subdivisions would have a 2 X 2 design and would require four intervention groups

151

What are FREE-LIVING Clinical Nutrition Studies used for?

Often used in long-term weight-loss trials

152

What are POSTPRANDIAL Clinical Nutrition Studies used for?

Evaluate acute effects of a specific nutrient, food or mixed meal on an end point of interest

153

What are DOSE-RESPONE Clinical Nutrition Studies used for?

Information used to establish the dietary recommendations

154

What are the budgetary considerations needed in Clinical Nutrition Research?

ANY possible resources =
-Personnel
-Supplies (food)
-Laboratory assays and procedures
-Equipment
-Participant stipends

155

Who are the the participants in clinical nutrition research?

-The HYPOTHESIS will drive subject recruitment;
-Identify the population from which subjects will be recruited;
-Identify the inclusion and exclusion criteria.;
-Estimate the sample size and recruit enough participants to account for subjects who are non-compliant or withdraw from the study (see chapter 27 for power calculation).

156

What is a Type 2 Error?

= Fail to Reject the null, but there IS a difference

157

What is a Type 1 Error?

= Reject the null, but there is NO difference

158

What does the NULL hypothesis state?

Says there is NO difference → Accepting the NULL states that the correlation is FALSE (you agree nothing happened)

159

Why would you set a very small P-Value?

→ A smaller p-value means you don’t want to be wrong

160

What are the relationships in P-values and determining causation?

Set base P-Value at 0.05 to determine relationship = can set your p-value at any level;
— GREATER than 0.05 (any p-value) FAIL to REJECT → NO Difference
— LESS than 0.05 (any p-value) REJECT → There IS DIFFERENCE
= P-Value – Less than .05 means things are related (CAUSE)

161

Why is the recruitment and screening in clinical nutr studies so important?

-The ability to recruit the proper subjects is a critical aspect of any project.;
-Screening is essential to ensure that participants meet the eligibility criteria and understand what is involved in participating;
-It is important to evaluate participant attitude, behavior, interest, commitment and maturity before enrolling them in a study.

162

What are the types of Participant Randomization?

1. Simple Random
2. Stratified
3. Constrained, or blocked
4. Nonrandomized concurrent control

163

Simple Randomization

Each participant is assigned to a treatment without regard for assignments made to other participants.

164

Stratified Randomization

Investigators construct strata based on variables of interest and perform randomization scheme separately within each stratum.

165

Constrained, or blocked, Randomization

A sequence of blocks contains a pre-specified number of treatments in random order.

166

Nonrandomized Concurrent Control

Control group and treatment group are not necessarily “treated” at the same time.

167

What are Participant Incentives of clinical nutrition studies?

- Help facilitate participant recruitment and retention;
-Should be age and gender-appropriate;
-Appropriate for the time and effort required to participate;
-Can be given throughout the study but the bulk should be reserved for participants who successfully complete the study.

168

What are some additional considerations with clinical nutrition studies?

1. Participant monitoring
2. Informed consent
3. Participant retention and compliance
— Protocol must define retention policies and activities
— Protocol must indicate how to deal with compliance issues, policies for acceptable deviations from study protocols, and criteria for participant dismissal (must be shared with study participant)