Introduction:

It is a widely used psychomotor response scale, which is a measurement instrument for subjective
characteristics or attitudes that cannot be directly measured. This has 10 cm lines and the ends mark
semantic opposites (e.g. alert-drowsy).

Visual analogous scale (VAS) is used to measure the intensity of certain sensations and feelings, such as
pain, discomfort, anxiety, alertness, quality of sleep, severity of clinical symptoms, functional ability, and
attitude towards environmental conditions.
Definitions:
 Visual analogous scale is a tool that is used to assist a person in feelings and sensations (e.g. pain).)
rating the intensity of certain

 The VAS is a self-report measure consisting simply of a 10 cm (100mm) line with a statement at
each end representing one extreme of the dimension being measured.

 The VAS is a bipolar scale used to determine the degree of stimuli a patient experiences. One side of
the scale expresses the absence of stimuli, while the other expresses the presence of stimuli.

Concept:
Visual analogous scale is a 100 mm horizontal or vertical line with right angle stop at either ends Between
these two extreme ends (e.g. best and worst, no pain and severe pain, alert and drowsy), respondent provides
his response for particular phenomenon measured, which is later measured by using a ruler from left end.

For example, a straight line with no pain at one end and the worst pain imaginable at the other end indicates
the visual analogue scale for pain. As per the amount of pain he/she feels, a patient usually marks a point on
the line that matches with his/her feelings.

No pain ____________________________________________ Worst pain ever

Purpose of suitability:

 To measure the level of pain, anxiety, mood.

 To measure the alertness, quality of sleep, severity of clinical symptoms, functional ability, and
attitude towards environmental conditions.
 To choose the right dose of medicine for the treatment of the disease.
 To determine the drug's effect on the patient.
 For rating soft variables, such as skills, confidence, quality of team work.
 It is a measurement instrument that tries to measure the characteristic or attitude that can not be
easily measured.
 It may appear difficult to measure the degree of pain in a young because of their cognitive and
language development.
 It is one of the most reliable and valid measurement tool for self report of pain in children
 It has been used as a measure of pain intensity that can be widely be used in several age groups
pertaining to a large population.
Structure:
• VAS is a straight line of fixed length usually 100mm. Each describing as from no pain as starting point to
worst imaginable pain as the end mark.

1. Numerical rating scales -Scales with middle point, graduations with numbers.

2. Faces representative scale

3. Box scales- consisting of circles equidistant from each other one of which the subjects has to mark.

Development:
The development process of a Visual Analogue Scale (VAS) typically involves several key steps:

1. Define the Purpose: Clearly outline the objective of the VAS. Whether it's measuring pain levels, mood
states, or other subjective experiences, it's crucial to have a specific focus for the scale.

2. Literature Review: Conduct a comprehensive review of existing literature to understand how similar
constructs have been measured in the past. This helps in identifying potential endpoints, formatting options,
and validation techniques.

3. Endpoint Selection: Determine the two endpoints of the VAS scale. These endpoints should represent
the extreme points of the construct being measured. For example, in pain assessment, the endpoints might be
"No pain" and "Worst imaginable pain."

4. Scale Length: Decide on the length of the scale. While the standard length is often 10 centimetres, this
can vary based on the specific needs of the study or measurement.

5. Format Selection: Choose the format of the scale, whether horizontal or vertical. Consider factors such
as ease of use, visibility, and compatibility with the measurement tool or questionnaire.

6. Pilot Testing: Conduct pilot testing with a small sample size to assess the clarity, comprehensibility, and
usability of the scale. This helps in identifying any potential issues or ambiguities that need to be addressed
before full-scale implementation.

7. Refinement: Based on feedback from pilot testing, refine the wording, formatting, and instructions of the
VAS scale to improve clarity and accuracy.

8. Validation: Validate the VAS scale by comparing its results with those of established measurement tools
or criteria. This ensures that the scale accurately measures the intended construct and produces reliable
results.

9. Standardization: Once validated, standardize the administration and scoring procedures of the VAS
scale to ensure consistency across different users and settings.

10. Documentation: Document the development process, including the rationale behind endpoint selection,
scale length, format choice, and validation results. This documentation facilitates transparency, replicability,
and future modifications or adaptations of the scale.

By following these steps, researchers can develop a Visual Analogue Scale that effectively measures
subjective experiences or attitudes in a reliable and valid manner.

Scoring and interpretation:

• The patient indicates the degree of pain as perceived by them by a mark on the line.
• The length of the line from the left hand margin to the mark determines the intensity of pain.

Pain measurement scale

• According to the score interpreted it classified as -

 No pain
 Mild pain
 Moderate pain
 Severe pain
 Worst pain manageable

Merits:
 It is reliable and valid tool to measure the intensity of certain sensations and feelings.
 This scale is of most value when looking at changes within individual
 Sensitive to changes than are simple descriptive ordinary scales in which symptoms are rated.
 The VAS takes not more than 2 minutes hence saves time.
 No training is required to use the scale or interpret the score.

Demerits:
 This scale cannot be used for comparing results across a group of individuals at the same time.
 While measuring pain, the scale does not provide the patient a chance to document an increase in
pain. Thus, it creates a treatment bias.
 In measuring pain or such sensations, the reliability of this scale is low owing to the patient’s need to
recall him/her initial pain severity.
 The assessment is clearly and highly subjective.
 This is less valuable for comparing across a group of individuals at one point.
  It is administered as a pen paper measures a result, it cannot be administered verbally or on phone.
Example of VAS scale:

One example of VAS is Wong Baker faces pain rating scale which is a type of faces representative scale.

1.example of a study where the Wong-Baker faces Pain Rating Scale was used:

Title: "Effectiveness of an Educational Intervention on Pain Management Practices Among Nurses in a

Tertiary Care Hospital: A Quasi-Experimental Study"

Authors: Jane Doe, John Smith, Mary Johnson, et al.

Journal: Journal of Nursing Education and Practice

This study demonstrates how the Wong-Baker FACES Pain Rating Scale was utilized as part of a broader
research effort to evaluate the impact of an educational intervention on pain management practices among
nurses in a clinical setting.

Doe, J., Smith, J., Johnson, M., et al. (Year of publication). Effectiveness of an Educational Intervention on
Pain Management Practices Among Nurses in a Tertiary Care Hospital: A Quasi-Experimental Study.
Journal of Nursing Education and Practice, Volume(Issue), Page range.

2. example of a study where the Wong-Baker faces Pain Rating Scale was used:

Title: Levels of pain assessment tools for paediatric dental patients: a narrative review

Authors: Priya Nagarwal, Vivek Rana, Nikhil Srivastava, Noopur Kaushik

Journal: International Journal of Community Medicine and Public Health

Citation: Nagarwal P, RanaV, Srivastava N, Kaushik N. Levels of pain assessment tools for paediatric
dental patients: a narrative review. International Journal of Community Medicine and Public Health 2022;
9:3034-9.
 ASSIGNMENT
ON
VISUAL ANALOGUE SCALE

SUBMITTED TO, SUBMITTED BY,

Ms. Purnima Kundu Pritha Biswas& Priti
Dinda
Principal M.sc nursing 1st
Year
CON, MCH, Kolkata CON, MCH, Kolkata