Experimental Study Designs and Research Elements

Experimental Study Designs

• Experimental studies are used to determine cause-and-effect relationships.
• Classification of study designs is a crucial element for research.
• Evidence levels are important considerations in evaluating research.
• The difference between experimental and non-experimental studies is substantial.
• Types of experimental study designs include randomized controlled trials, cohort studies, case-control studies, and cross-sectional studies.
• Advantages and disadvantages of each design should be considered.

Elements of Research Design

• Purpose Statement: Defines the study's objectives.
• Techniques: Specific methods used in data collection.
• Methodology: Overall approach to the study.
• Objections: Potential limitations or biases.
• Elements: Key components of the design.
• Settings: Context of the study.
• Timeline: Duration and stages of the study.
• Measurement: Process of collecting data.
• Analysis Method: Statistical tools used to analyze information.

Types of Studies

• Experimental: Researcher assigns exposures.

  • Randomised controlled trials (RCTs): Random allocation to treatment or control groups.
    • Exposure → Outcome
    • Outcome → Exposure
  • Non-randomised controlled trials: Allocation isn't random.
  • Cohort study: Follow group over a defined period to observe outcomes related to exposure.
  • Case-control study: Compare individuals with and without a condition to identify risk factors.
  • Cross-sectional study: Assess exposure and outcome at the same point in time.

• Observational: Researcher doesn't assign exposures.

  • Cohort studies
  • Case-control studies
  • Cross-sectional studies

Analytical Studies

• Experimental:
  • Randomized Controlled Trial
  • Non-Randomized Controlled Trial
• Observational:
  • Cohort Study
  • Case-Control Study
  • Cross-Sectional Study

Clinical Trials

• Experimental Studies: Randomized Clinical Trials, these are considered "Gold Standard" for studying treatment or preventative interventions.
• Observational Studies: Cohort, Case-Control, Cross-Sectional, and Case Series. "Natural Conditions" (e.g., personal preferences, genetics, social determinants) are considered.

Types of Clinical Research

• Observational Studies: Cohort, Case-Control, Cross Sectional, Case Series/Report.
• Interventional Studies: Controlled Trial (Randomized, Non-randomized, Non-controlled).

Designs of Clinical Trials

• Non-Experimental: Measure outcomes before and after program only for the participants. No comparison group.

• Quasi-Experimental: Measure outcomes for program participants and non-participants without assigning randomly, often uses a "control" group to make comparisons.

• Experimental/RCT: Randomizes participants into treatment or control groups, often used in situations requiring a larger number of participants. Outcomes for both groups are measured.

Experimental Research Designs

• Pre-Experimental: Includes one-shot case study, one-group pretest-posttest, and static group design.

Validity

• Internal validity: How well a study establishes a causal relationship between the variables examined.

• External validity: How well the findings of a study can be generalized to other populations and settings.

Evidence Level

• A hierarchical system of classifying the strength of evidence related to a specific medical topic. Higher levels of evidence usually originate from randomized controlled trials (RCTs).

Intervention Trials

• Phases: Phase 1 (safety), Phase 2 (does it work), Phase 3 (is it better), Phase 4 (can it stay in the market).

Symbols

• O (Observation), X (Exposure), EG (Experimental Group), CG (Control Group), R (Random Assignment), M (Equal).

This quiz focuses on the essential aspects of experimental study designs and elements of research methodology. It covers various types of study designs, their advantages and disadvantages, and key components integral to research design. Test your understanding of how these elements contribute to determining cause-and-effect relationships in research.