Chapter 4_PHN_Food and Nutrition Research

Research

Careful, diligent and exhaustive investigation of a specific subject matter

systematic - research process

logical - induction/deduction

empirical- evidence based

reductive - generalizable

replicable- methodology

key characteristics of research

science

from the latin word "scientia" which means knowledge

systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe

scientific method

tool that scientists use to answer questions involves, observation, identifying the question, stating a hypothesis, conducting an experiment, analysis and reaching a conclusion

Fundamental or Pure Research

type of research wherein the purpose is Dev't of theories by discovering broad generalizations or principles

Applied Research

type of research wherein the purpose is Testing theoretical concepts in actual problem situation; used to solve a specific practical situation

Action Research

type of research wherein the purpose is Focused on the immediate application, not on the development of theory, not upon general application; used to solve immediate specific problem

historical research

type of research that describes "what was"

descriptive research

type of research that describes "what is"

experimental research

type of research that describes "what will be" given a specific set of conditions

Upstream

Research implemented at national level

Midstream Research

Production of new materials based on gained knowledge for regional SCUs

Downstream Research

Technology dissemination/demo at provincial level

commodity research

research for the development of products

Problem, Lit review, hypothesis, research design, data collection, data analysis, writing report

Study design sequence

Theoretical Framework

Theory from which the research problem was derived or to which it is linked

Deductive Reasoning

Investigation aims to assess a pre-stated theory

Inductive Reasoning

Investigation aims to create novel theory

Ethnography

A research method that attempts to understand the beliefs, practices, and behaviors of the culture of study from the perspective of those living within the culture; researcher becomes an inherent part of the study

Quantitative Research

Type of research assessing a pre-stated theory (deductive reasoning); involves hypothesis testing; data infers statistics; data requires "closed responses"

Qualitative Research

Type of research strategy aiming to create a novel theory (inductive reasoning); data infers opinions; data collection permits "open" responses

Epistemology

Studying the potentiality of knowledge

Positivism

a paradigm that relies on measurement and reason, that knowledge is revealed from a neutral and measurable (quantifiable) observation of activity, action or reaction.

Interpretivism

Meanings are constructed by humans as they engage with the world they are interpreting. This is closely associated with qualitative methods of data collection.

Ontology

describes the nature of the data being studied

Ontology- Constructionism

believes that we come to "know" through our interactions

Objectivism

believes that knowledge exists whether we are conscious of it or not

Constructionism

Understand how social factors interact

Positivistic epistemology & objectivistic ontology

Research strategies required in the natural sciences

Interpretive epistemology & constructionist ontology

Research strategy required for social sciences

Reductionism

Describing a complex phenomenon that are held to represent a simpler or more fundamental level

Research Design

Also called plan of attack and study design, provides framework for data collection and analysis

Research Method

a technique for collecting data

Food and Nutrition Research

Integrate the effects of the physical and chem qualities of food on the totality of nutrient intake and promotion of well-being

Nutritional Epidemiology

Assessment of diet & its relationship to disease etiology in populations

to contribute to the prevention of disease and the improvement of public health through

1. monitoring the food consumption, nutri intake, nutri status of a pop

2. generate new hypotheses about diet and disease

3. produce evidence that supports or refutes existing hypotheses

4. assess strength of diet disease associations

goal of nutritional epidemiology

1. complex nature of diet

2. multiple determinants or causes

3. long latent periods of disease

4. occur with relatively low frequency despite a substantial cumulative lifetime risk

5. conditions not readily reversible

6. may result from excessive and or insufficient intake of dietary factors

challenges in investigating nutrition related disease

nutritional exposure

the thing/independent variable being investigated as the cause of a certain outcome/dependent variable

1. food

2. nutrient or non-nutrient component of food

3. anthrop(bmi, weight wtc)

4. biochem measure

5. clinical assessment

examples of nutritional exposures

research proposal

structured plan for a research cycle designed to investigate a specific phenomenon

1. defining a research problem

2. lit review

3. formulate hypo

4. preparing the research design

5. data collection

6. data processing & analysis

7. report writing, dissemination & utilization

steps in conducting research

resarch question

statement that identifies the phenomenon to be studied.

this could be gathered from theory, lit or exp

general objective

generic statement which describes in broad terms what the study wishes to accomplish

specific objective

identify in greater detail and in measurable terms the aims of the research project. it breaks down what needs to be accomplished

literature review

process of knowing more about previous studies done related to the research being conducted

- who have done work on the topic

- methods used

- results

- problems and how they were fixed

Theoretical Framework

A theory from which the research problem was derived; in formulating this framework, you may look at the various theories upon which you can base your study

Conceptual Framework

This presents the relationship between the concepts for study

hypothesis

states the researcher's true expectation of results, guiding the interpretation of outcomes and conclusion

Non directional H0/ two tailed

What type of hypothesis is this? Ho: there will be no significant diff vs Ha: there will be significant diff

Directional H1/ One-tailed Hypothesis

H0: mean score is ≤75%; Ha: mean score is >75%

Alternative Hypothesis (Ha)

Hypothesis that you support

Null Hypothesis (H0)

Statement of no relationship or the otherwise remaining outcome of the alternative hypothesis

simple hypothesis

predicts the relationship between a single dependent variable and a single independent variable.

complex hypothesis

predicts the relationship between two or more independent and dependent variables.

1. measurable/testable

2. based on sound rationale

3. specificies population being studied

4. identifies time frame

5. indicates type of relationship being examined

6. includes variables being studied

7. defines level of stat sig

essential characteristics of hypothesis

Quantitative Research

Used to generate numerical data or that can be transformed into usable stats

Descriptive epidemiology

Aims to describe the characteristics of the distribution of disease in relation to person, place, and time

who has the disease

where does it occur

when (seasonal?)

descriptive studies

describe the occurrence of outcome

analytical studies

describe association between exposure and outcome

Experimental Study Design

Researcher intervenes; clinical trials

Observational Study Design

Researcher observes; no individual intervention; treatment occur in a non- controlled environment

Cross sectional

Also called prevalence study; studying between exposure and disease at the same point in time; both exposure and (disease) outcome are determined simultaneously for each subj

prospective study

Data is collected from the cohort over time, usually starting with a baseline measurement and continuing into the future

also known as longitudinal or cohort studies. In these studies, researchers select a group of participants (cohort) and follow them over a specific period of time to observe and collect data on various variables. The key characteristics of prospective studies include

retrospective study

also known as case-control studies, involve selecting participants based on the presence or absence of an outcome (cases and controls) and then looking backward in time to assess past exposures or risk factors.

Case study

Empirical inquiry investigating a phenomenon within real life context providing detailed and intensive analysis of one case

External Validity

extent to which we can generalize findings to real-world settings

External Validity

Biggest issue concerning case studies because it is impossible to generalize findings; the the point is to examine particulars rather than attempt to generalize

Comparative Design

Two or more cross-sectional studies carried out at the same point in time. compares two or more cases which can show circumstances in which a particular theory will or will not hold.

Ecological studies

Aims to generate etiologic hypothesis and to evaluate effectives of population interventions

correlation coefficient

Quantifies extent to which there is a linear relationship b/w exposure and disease; used in ecologic comparison

Exploratory Ecological Studies

type of ecological study that Compares outcomes/disease among several grps within a grp at diff pts in time

ecological comparison

type of ecological study that looks at the frequencies of exposures and the outcomes per group and comparisons are made among several groups and uses correlation coefficients ????

Ecologic Trend (Time Series)

Assessment of trends over time; frequency of the exposure and/or outcome/disease at diff pts in time

Survey research

comprises a cross-sectional design in relation to which data are collected primarily by questionnaire or by structured interview on more than one case and at a single point in time in order to collect a body of quantitative or quantifiable data in connection with two or more variables which are then examined to detect patterns of association

longitudinal research

Status of a given group (same) at various pts in time or in more than one occasion

correlational research

Relationship b/w variables

Case report

Most elementary study design, describing experience of a single case with similar diagnosis based on sporadic discoveries; provides first clues in recognition of disease and id's risk factors or effects of exposure

Case series

Extension of case report, showing similar clinical observations sharing most of similarities

F. Temporal relationship between exposure and disease CANNOT be determined since exposure and outcome are measured simultaneously

T or F: In cross-sectional studies, temporal relationship between exposure and disease can be determined

Weak

Internal validity in Cross sectional study is ____ because correlations are much more likely to be found than causality

Random

External validity in cross sectional studies will be strong if the sample is truly _______

Case control

Retrospective observational study that compare the past exposure of people with the disease (cases) with the people without the disease (controls)

1. when disease is rare

2when the study population is dynamic

3. when disease has a long latency period

4. when studying multiple health effects(diseases) stemming from a single exposure

when to use case control study

Odds Ratio

a measure of the association between frequency of exposure and frequency of outcome; used in case-control studies

group matching

consists of selecting the controls in such a manner that the proportion of controls with a certain characteristic is identical to the proportion of cases with the same characteristic ex: frequency matching

individual matching

the pairing of one or more controls to each case based on similarity in sex, race, or other variables; preferred in hospital population

Cohort Study

Prospective observational study used to test hypothesis; long-term; waits for the dev't of disease;

e.g. Follow ups, incidence studies, and panel studies

True

True or False: In cohort studies, the temporal relationship between the exposure and the disease and the disease can be determined

Cohort

A well-defined grp of individuals who share a common characteristic or experience

Risk Ratio

A comparison of the risk of some health-related event such as disease or death in two groups; used in cohort studies

Cohort Study

Used when the exposure is rare, and the outcome (disease) is common ex: agri pesticide use and cancer events; to learn about multiple outcomes due to a single exposure

1. when the exposure is rare

2. to learn about multiple outcomes due to a single exposure

when to conduct a cohort study

developmental research

the systematic study of designing, developing and evaluating instructional programs, processes and products that must meet the criteria of internal consistency and effectiveness

general normative research

produces theory of practice for a professional activity, such as design, which can consist of recommendations, rules, standards, algorithms, advices or other tools for improving the object of study

methodological research

research designed to establish valid and reliable instrument to measure a specific concept. also called reliability and validity study

Cohort Bias

The type of bias where participants are Lost to follow up; misclassification

Qualitative Research

research that relies on what is seen in field or naturalistic settings more than on statistical data; provides insights and dive deeper into the problem or helps to develop ideas or hypothesis

Meta-analysis

a procedure for statistically combining the results of many different research studies of similar design to produce overall estimate of effects; most often used to assess the clinical effectiveness of health care interventions by combining data from ≥2 RCT

Systematic Review

summarized findings from multiple studies of a specific clinical practice question or topic that recommend practice changes and future directions for research; one of the strongest sources of evidence for evidence-based practice; critically appraise relevant primary research

Randomized Controlled Trial (RCT)

Thought to produce the most scientifically rigorous data of all study design; not always feasible due to difficulties in enrolling participants, high costs and ethical issues