Research Basics for Nutrition Science Flashcards
Levels of Evidence
By examining the amount and types of studies on a topic you can judge the quality and the strength of evidence.
Helps critical consumers avoid the knee-jerk reaction to a single study in the media.
Tool for judging the quality and strength of research on a particular topic
Not all types of scientific research provide the same quality of evidence.
-sometimes not so great studies that are higher ranked on quality of evidence are not always better.
Single studies should almost never be considered as enough evidence.
Multiple quality studies reporting similar results increases the strength of evidence.
Research Approaches
Observational
Experimental
Critical Evaluation
Observational
No intervention given for any of those approaches.
Case reports, case studies, case series, descriptive studies, epidemiological studies.
Case reports and case studies/series involve observing what’s going on with people. Both have low level of evidence because low level of validity (can’t generalize findings).
Case Reports
Examining one case
Case Studies
More than report.
Affiliated with organization and have in-depth report on person like what occurs in case report.
Case Series
Multiple cases that you create reports on for a specific topic/interest.
Descriptive Studies/Research
Concerned with the state of things.
Looking at amounts and types of behaviours, attitudes, knowledge, and health status.
Many places to find research data.
Correlation research and longitudinal designs.
Correlation Research
Measure some things and see correlation between them.
Correlate variables.
Not limit on how many things are measured.
Often collect data at a single point in time.
-these snapshots are also referred to as cross-sectional designs.
-no intervention, just looking.
Longitudinal Designs
Follow people over time and observe change.
Strength = observe change over time.
More expensive.
Cross-sectional studies do not observe change over time.
-only look at single point in time.
Epidemiological Studies
Estimates the risks of behaviour in health.
Also referred to as a natural experiment.
Uncontrolled settings (don’t intervene).
Two types include case control and cohort designs.
Case Control
Weaker of the two.
Cases and controls used to gather data retrospectively with participants recalling dietary behaviours (higher error due to recall).
Gather people with (cases) and without (controls) disease
Look back at behaviours using self-reported measures.
Match cases and controls as closely as possible.
Cohort Designs
Stronger of the two.
Cohort created to gather data prospectively with data being subjective/objective and followed for period to see who gets disease and who doesn’t.
Follow people for a period and gather data on behaviour(s).
When disease emerges compare behaviours between groups.
Objective Measures
Unbiased
Not open for interpretation.
Usually gathered using instruments.
Subjective Measures
Biased.
Open to interpretation.
Usually gathered using questionnaires.
Self-reported measures are common.
What are some issues with subjective measures?
Recall bias, rounding errors, response bias.
