Evidence-Based Practice

Understand research design and methodology terminology 

• Research design refers to the overall plan that allows researchers to seek answers to study questions and test study hypotheses. 

• Each design has inherent strengths and limitations that make some more appropriate to answer a research question over others.

• Scientific inquiry: systematic process of asking questions and proposing explanations based on evidence acquired through validated methods 

Use of scientific inquiry is evidence-based practice 

• Objective evidence generation: standardized approaches for conducting experiments and collecting data in a way that minimizes bias

• Critical evaluation of information: requires critical thinking skills to evaluate the quality of scientific information, identify credible sources, and understand the limitation of research findings 

• Distinguishing credible evidence: the ability to discern good quality evidence from misinformation or weak arguments, ensuring that decisions are based on robust science (instead of “belief”) 

• Promoting best practices: provides the framework for finding, critiquing, and synthesizing that evidence to guide the development of best practice recommendations 

Describe the classification of research designs in clinical research: Order

Order 

• Scientific method is not common sense 

• Arrives at conclusions through organized observations of entities or events classified on the basis of common properties and behaviors 

• Organizing by shared properties/behaviors allows for predictions (inference)

Describe the classification of research designs in clinical research: Interference and Chance 

Interference and Chance 

• Reasoning, or inference, means that a statement or conclusion out to be accepted because the premise is true

• Always possibility conclusions are result of chance 

• Two distinct approaches or arguments have evolved in the development of inferences:

  • Deductive reasoning

  • Inductive reasoning 

• Deduction moved from the general to the specific → reasoning minimizes chance 

  • All A is B

  • All B is C, thus

  • All A is C

• Health research depends almost entirely upon inductive reasoning 

• Inductive reasoning moves from the specific to the general 

  • The conclusion does not necessarily follow from the premises or evidence (facts)

  • Increases the possibility that premises may be tru but the conclusions false 

Describe the classification of research designs in clinical research: Evaluation of probability 

Evaluation of probability 

• Probability measures how likely an event, outcome, or result will occur

• Used to

  • Test hypothesis

  • Determine how likely data patterns happen by random chance 

• Measures from 0-1, where 0 is impossible and 1 is total certainty 

Describe the classification of research designs in clinical research: Hypothesis testing 

Hypothesis testing 

• are carefully constructed predictions about characteristics of a population to answer a research question.

• Includes independent variables (cause) and dependent variables (effect)

• Testing looks for differences in effects between groups exposed to the cause (or not)

• Testing requires:

  • a null hypothesis (H0) there is no difference between groups = failure to reject the null hypothesis

  • alternative hypothesis (HA) there is a difference and we can reject the null hypothesis

Describe the classification of research designs in clinical research: Ethics 

Ethics 

• provide the moral societal standards for responsible research conduct

• These standards are based on respect, fairness, and well­being of research participants

Discuss common research methodologies in clinical research: Validity 

• Explain the importance of reliability and validity in research 

Validity: reflects accuracy of study results 

• Internal: extent to which the design of the study is likely to produce reliable and consistent results pertaining to the relationship between the dependent variable and the independent variable  

• External: extent to which results of a study can be generalized to other settings 

Discuss common research methodologies in clinical research: variables (relationship)

Relationship among variables:

Causality

• A relationship between variables where one event (the cause) directly leads to another event (the effect)

• relationship cannot be explained by a third event (confounder) this is known as spuriousness

Correlation: a statistical concept that implies only that a relationship exists but has zero implications on causation.

• There is no causation without correlation.

• Correlation does not imply causation. 

  • refers to the inability to legitimately deduce a cause-and-effect relationship between two events or variables solely on the basis of an observed association or correlation between them.

Discuss common research methodologies in clinical research: Variables

Variables: characteristics of pop or sample that are examined, measured, described, and interpreted 

• Independent variable is the cause

• Dependent variable is the effect 

• Confounding (unknown or known): variables that have an association with both the independent and dependent variable 

  • They distort the relationships between variables, leading to incorrect conclusions about causation 

Discuss common research methodologies in clinical research: Function of time 

• Prospective Analysis

• Retrospective Analysis

to be continued …