W5: Design 1 Flashcards
Today’s class
-the idea of design
-how it fits the research process (week 1)
-case report, case series
-cross-sectional studies
-ecological (correlational) studies
In all 3 design sessions specific measures of events and associations, and most pertinent biases will be reviewed
Health Research Process
Health Research Studies
Two types of Population/Clincial Health research
-Descriptive
-Analytic
Goals and Design Decisions
6 components of a study
- Population
- Exposure
- Outcome
- Potential Confounders
- Analysis
- Communication of Findings
1.Population
- Exposure
- Outcome
- Potential Confounders
- Analysis
- Analysis
- Communication of findings
Hierachy of Evidence
There is no good or bad TYPE of design but poorly vs. properly conducted studies
Case Report and Case Series
Case report: a report of a helath issue in ONE patient
- a disease, a disorder, or undergoing a procedure
Case series: a report that describes a group of individuals who have the SAME HEALTH ISSUE
Case Report and Case Series
No theory, no research question, goal is not research, only REPORTING
–may..
-The main scientific part: _____ __ ____
–sign..
–Symptom
-Several coding systmes
–ICD
–DSM
–may generate ideas for research questions
-The main scientific part: defining the case
-based on a list of the inclusion and xclusion criteria individuals will be classified as a case (diagnosed)
–sign: an objective indication of disease that can be clinically OBSERVED, such as a rash, cough, fever, or elevated blood pressure
–symptom: a subjective indication of illness that is EXPERIENCED by an individual but cannot be directly observed by others
-several coding systems
–international classification diseases (ICD)
–Diagnostic and Statistical Manual of Mental Disorders (DSM)
Case Report and Case Series
-Where do they occur and how is data usually collected?
-What two ethical issues should be respected?
-How much data analysis is required?
-What type of discussions dominate the report?
-Mostly in medical settings but data collection usually with standard QUESTIONNAIRES
-ethical issues should be respected
–privacy
–sometimes a group will be labeled unjustly because of the original case series
-few or no data analysis is required
-clinical discussion dominates the report
How to decide on study design?
Types of Analytic studies: Experimental and Observational
Example: Impact of Statins on lowering cholesterol
Cross-sectional (Prevalence) Studies
In this type of study a group of people is examined at ___ POINT IN ___
Prevalence:
-Point prevalence
-Period prevalence
Cross-sectional (Prevalence) Studies
In this type of study a group of people is examined at ONE POINT IN TIME
Prevalence: the percentage of members of a population who have a given health issue at the time of a study
-Point prevalence: the proportion of a population with a particular characteristic at one point in time
-Period prevalence: the proportion of a population with a particular characteristic during a defined time period, such as several weeks or several months
Point Prevalence of Arthritis in Postmenopausal Women
Period Prevalence of COVID19 in Sept 2022, City A
Prevalence (rate) ratio relative risk in cross-sectional studies
Cross-sectional Studies Example
Results
Your turn, a practice for Relative Risk
try it and then go back to slide and insert your answer here
Your turn, a practice for Relative Risk
try it and then go back to slide and insert your answer here
Misclassification-1
fill in answer
Misclassification-2
fill in answer
Limitations of Cross-sectional studies
Correlational (Ecological) Studies
- in these studies the UNIT OF ANALYSIS IS THE GROUP, NOT THE INDIVIDUAL. The group, or ECOLOGICAL UNIT, represents an AGGREGATE of individuals
Terminology:
-correlational studies
-Ecological studies
-aggregate studies (the same)
Example of Correlational Studies: Global, regional, and national burden of Alzheimer’s disease and other dementias, 1990-2016
The variables in the correlational studies are usually aggregate (grouped) statistics such as the PROPORTION OF A POPULATION with a particular characteristic or the average value of the variable in a population
Example #2: Mortality by class of street and house in Manchester,1844 (from the work of F. Engels)
Example 3: Correlational Studies
Results: Scatter Plot
- a positive correlation was found
Ecological Fallacy
The results of ecological studies should be interpreted with
