Which type of variable represents the outcome of the intervention in the study?

Appeared in: KPSC Staff Nurse - 2021

Explanation

The dependent variable is defined as the presumed effect or outcome of an intervention in a research study.
Its value is observed and measured to determine the effectiveness of the independent variable.
In a cause-and-effect relationship, the dependent variable is the 'effect' that 'depends' on the 'cause' (the independent variable).
In non-experimental research, this is often called the 'outcome variable'.

Option A: The independent variable is the intervention or presumed cause that is manipulated by the researcher, not the outcome.
Option B: A discrete variable refers to a type of data that can only take on a finite number of values (e.g., number of falls, number of children). It describes the nature of the measurement, not the variable's role as an outcome.
Option C: An extraneous (or confounding) variable is an external factor that can unintentionally influence the outcome of the study, potentially leading to incorrect conclusions. It is not the intended outcome.

Clinical Relevance

Nursing practice connection: Knowing Types of variables in research methodology helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Understanding the difference between independent and dependent variables is fundamental for nurses to critically appraise research articles and apply evidence-based practice (EBP) effectively.
When reading a study about a new treatment, a nurse must be able to identify what intervention was tested (independent variable) and what outcome was measured (dependent variable) to judge the study's relevance to their patients.
What if? If a study investigates the effect of a new pain medication on patient-reported pain scores, the medication is the independent variable, and the pain score is the dependent variable. The patient's age or other medical conditions would be extraneous variables that researchers must account for.

How to Approach the Question

First, identify the key terms in the question: 'outcome' and 'intervention'.
Recall the basic structure of an experimental study, which is based on a cause-and-effect relationship.
Associate 'intervention' with the 'cause' that the researcher manipulates. This is the independent variable.
Associate 'outcome' with the 'effect' that is measured. This is the dependent variable, as it 'depends' on the intervention.
Evaluate the options based on these definitions. 'Dependent' is the only term that means 'outcome' or 'effect' in a research context.

Concept Tested & Keywords

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E6 NursingResearch Suresh Sharma 5e Part 1 pp. 87-89, 86-88

E6 NursingResearch Polit 11e Part 1 p. 58-60

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Attempt every question from this paper in a timed mock, then review the full solution for each one.