Health Research week 6

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Questions and Answers

What is the primary purpose of descriptive studies in health research?

To evaluate hypotheses about the causes of disease

To develop new experimental treatment protocols

To monitor the public's health by identifying and counting cases of disease (correct)

To conduct randomized controlled trials

Which type of study is characterized by collecting data at a single point in time?

Case-control study

Ecological study

Cohort study

Cross-sectional study (correct)

In the context of health research, what does the term 'ecological study' refer to?

A method examining relationships between variables at the group level (correct)

A descriptive analysis of the population's health trends

A study focusing on individual-level exposure and outcomes

A controlled trial conducted in community settings

What step follows hypothesis generation in the health research process?

Identifying subjects and variables Signup and view all the answers

What is the main difference between case reports and case series in epidemiology?

Case reports are studies of a single individual, whereas case series involve multiple individuals Signup and view all the answers

What is the primary goal of identifying potential confounders in a study?

To minimize errors and distortions in associations between exposure and disease Signup and view all the answers

Which of the following describes a case definition?

A specific description of the event being studied, such as a disease or state Signup and view all the answers

What type of analysis is performed when confounding is suspected in a study?

Standardization and multivariate analysis to adjust for confounding Signup and view all the answers

Which of the following options best describes exposure in an epidemiological study?

The determinant of interest upon which an outcome depends Signup and view all the answers

How should researchers communicate their findings if no association is found in their study?

Report results through scientific journals and public media, regardless of the outcome Signup and view all the answers

What type of study examines a group of people at one specific point in time?

Cross-sectional Study Signup and view all the answers

Which term describes the percentage of a population with a health issue at a specific moment?

Point Prevalence Signup and view all the answers

In a clinical trial, what does an investigator primarily do?

Manipulates variables Signup and view all the answers

What type of study involves comparing individuals with a condition to those without it, often retrospectively?

Case-Control Study Signup and view all the answers

What is the primary method of exposure assessment in observational studies?

Inquiry Signup and view all the answers

What is a characteristic of period prevalence?

It counts cases over a defined time period. Signup and view all the answers

What is the primary focus of a cohort study?

Following a group over a period of time Signup and view all the answers

What is the primary purpose of a case report?

To report a health issue in one patient Signup and view all the answers

Which statement is true regarding case series?

Their goal is to report health issues in a group with the same condition. Signup and view all the answers

What distinguishes a sign from a symptom in medical reporting?

Signs are objectively observable indications of disease. Signup and view all the answers

What ethical consideration is important when conducting case reports or series?

Maintaining patient privacy Signup and view all the answers

How are inclusion and exclusion criteria utilized in case reports and series?

To classify individuals as diagnosed cases. Signup and view all the answers

Which of the following study types primarily describes health statuses without a hypothesis?

Case reports and case series Signup and view all the answers

What is a common coding system mentioned for classifying health issues?

Diagnostic and Statistical Manual of Mental Disorders (DSM) Signup and view all the answers

What is a characteristic of observational studies compared to experimental studies?

They do not involve intervention from the researchers. Signup and view all the answers

Study Notes

Session Information

Session: 6
Date: October 25, 2024
Course: HS2801A: Research Methods in Health Sciences
Instructor: Dr. Afshin Vafaei
Course year: Fall 2024

Today's Class Topics

Idea of Design
Research process (Session 1)
Case report, case series
Cross-sectional studies
Ecological (correlational) studies
Specific quantitative design measures
Perinent biases in associations

Health Research Process

Research Question
Hypothesis
Collect Data
Sample population
Analyze Data
Describe data
Interpret findings
Communicate
Causation
Bias
Confounding

Health Research Studies

Biological studies (basic medical)
Physiological studies (direct cell observation)
Test tube studies
Observational studies (epidemiologic, population health and clinical studies)
- Descriptive studies
  - Case reports
  - Case series
  - Ecological studies
  - Cross-sectional
- Analytic studies
  - Ecological
  - Cross-sectional
  - Case-control
  - Cohort
Experimental studies
- Randomized controlled trial
- Community trial

Two Types of Population/Clinical Health Research

Descriptive research:
- Monitors public health
- Evaluates intervention program success
- Generates hypotheses about disease causes
- Identifies and counts disease cases in populations
- Examines disease according to person, place, and time
- Conducts simple studies
Analytic research:
- Evaluates hypotheses regarding disease causes
- Evaluates intervention program success
- Compares groups to determine associations

Goals and Design Decisions

Conduct health research to determine relationship between exposure & disease
Define exposure & disease clearly
Validity and precision in study design

Components of a Study

Population
Exposure
Outcome
Potential confounders
Analysis
Communication of findings

Population

Source Population: The group with information of interest
Study Population: The group participating in the study
Generalizability: Assesment of how widely the study's findings apply to larger population

Outcome

Case definition: Detailed description of the health event
Examples (Disease, defect, injury, event, state)
- Cardiovascular disease
- Breast cancer
- Structural heart abnormality in infants

Exposure

Determinant of interest where outcome depends on.
Examples (Constitutional, environmental, behavioral)
- Genetic polymorphism
- Environmental factors (e.g., water, air pollution)
- Behavioral factors (e.g., smoking, diet)

Potential Confounders

Extraneous risk factor for an outcome
Examples:
- Pesticide level
- Age

Analysis

Examination of study data
Estimation of disease frequency and associations
Describe study population
Crude estimates (no confounding)
Adjusted estimates (confounding present)
Standardization
Stratified analysis
Multivariate analysis

Communication of Findings

Tell appropriate persons or community, even if no association found
Peer-reviewed journals
Conferences and meetings
Government reports
Popular and social media

Hierarchy of Evidence (Importance Ranking)

Randomized controlled double blind studies
Systematic reviews and meta-analyses
Cohort studies
Case-control studies
Case series
Case reports
Ideas, editorials, and opinions
Animal research
In vitro (test tube) research

Case Report and Case Series

Report of a health issue in one patient
Reports on a group of individuals with same health issue
Not research, but reporting.
Main scientific part: defining the case
- Inclusion and exclusion criteria
Uses coding systems (e.g., ICD, DSM)
Data collection using questionnaires
Privacy issues are important.
Fewer/no analysis often but clinical discussion is prominent

Cross-sectional Studies (Prevalence)

Examines a group at one point in time
Prevalence: Percentage of population with a given health issue at the study's time
- Point prevalence: Proportion with characteristic at one particular time.
- Period prevalence: Proportion in a population during a defined time period

Point Prevalence of Arthritis in Postmenopausal Women

Data from a cross-sectional study.
3,276 postmenopausal women participated in a study.
597 had arthritis (18.2%).

Period Prevalence of COVID-19

Data from a cross-sectional study
Collected data for a specific time period.
Calculated prevalence rates.

Prevalence Ratio (Relative Risk) in Cross-Sectional Studies

Comparison of characteristics in populations
Measure of risk.
Prevalence in exposed group / prevalence in unexposed group

Cross-sectional Studies Example:

Information on Canadian workers
Data from the Canadian Community Health Survey.
Study of social support in the workplace
- Examining association with work-related injuries.

Correlational (Ecological) Studies

The unit of analysis is a group, not an individual.
Represents an aggregated group or ecological unit.
Statistics used are often grouped statistics like proportion of a population, average, etc.
Can illustrate associations but cannot prove causality

Ecological Fallacy

Incorrectly assuming individual behavior follows population-level trends.

Next Week (Nov. 1, 2024)

Introductions to Case-control studies
Cohort studies
Prospective and Retrospective designs
Study of Chapters 10 & 11

Studying That Suits You

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Description

Test your knowledge on descriptive studies, case definitions, and the health research process with this comprehensive quiz. Understand the critical differences between various study types and the importance of confounding factors in health research. Perfect for students and professionals in the field of epidemiology and public health.