Pain Assessment Tools

Pain is inherently subjective and influenced by a complex combination of biological, psychological and social factors. Incorporating all the aspects of a person’s experience to effectively assess pain is challenging, especially in cases where someone can’t verbalise or reliably report their pain.

Pain scale assessment tools have been developed to aid healthcare professionals and carers in accurately evaluating pain. Below, we explore the role of these tools in assessing pain and designing an appropriate pain management plan.

The purpose of pain scales

Pain assessment is a critical initial step towards providing comprehensive and effective pain treatment. According to Pain Australia, a significant proportion of people living with chronic pain reported clinically meaningful improvement in depression (57%) and anxiety (41%) following multidisciplinary pain assessment and treatment. This approach also led to a 35% reduction in healthcare utilisation, including hospitalisation and allied health visits.

Self-reporting is the gold standard of pain assessment. However, pain is difficult to explain, and the use of qualitative analogies – for example, “The pain is killing me” – is common2. Assessing pain is increasingly challenging in circumstances where people can’t easily vocalise their experience.

Pain scales help standardise pain assessment by producing a quantitative, consistent measure of a person’s experience. This makes it easier to reliably assess pain and develop a treatment plan appropriate to a person’s level of pain.

Types of pain scales

There are several types of pain scales used by clinicians and carers. These can be broken down into two broad categories:

Unidimensional pain scales

Unidimensional pain scales use numbers, words, images or descriptors to measure a person’s level of pain. Common pain scales in this category include:

    • Numeric rating scales (NRS): A person rates their pain on a scale of 0 to 10 or 0 to 5.
    • Visual analogue scales (VAS): A person marks a spot on a line to show their pain intensity.
    • Categorical scales: Pain intensity is measured using a verbal or visual descriptor, such as words like “mild” or “distressing”, or images of faces with different expressions.

Multidimensional pain scales

As the name suggests, multidimensional pain scales utilise multiple factors to assess pain. Examples of multidimensional pain scales include:

    • Brief pain inventory (BPI): A person completes a questionnaire addressing various aspects of their pain, including a numerical assessment and information about the types of treatments or medications they’re receiving.
    • McGill pain questionnaire (MPQ): A person chooses descriptors that best match their experience of pain from a list of 78 words. The MPQ assesses both the quality and intensity of subjective pain and can be used for patients with several diagnoses.

Improving evaluation with a pain scale assessment tool

A common challenge associated with both categories of pain scales is that they rely on a person’s ability to self-report their level of pain, either through verbal or visual descriptors. This precludes many people living with acute or chronic pain – including those with dementia, cognitive or physical impairment and young children – from easily describing their experience of pain.

While experienced healthcare providers or carers may be able to pick up on cues that a person is in pain, reliably evaluating pain is complicated. Additionally, where someone suffers from chronic pain, these cues may be misread as normal behaviour for that person.

Pain scale assessment tools help overcome these challenges by enabling accurate evaluation of pain levels in all people, as opposed to only those who can self-report.

PainChek is one example of a pain scale assessment tool designed to identify the presence of pain when it’s not obvious. PainChek Universal utilises AI technology to recognise and document facial microexpressions, as well as a binary checklist covering observations of vocalisations, behaviour, and other factors indicative of pain, before calculating an overall pain score based on these inputs. An NRS self-report can be completed where appropriate, to add another data-point supporting clinical decision-making. This enables carers and clinicians to accurately evaluate and manage pain. Using PainChek on an ongoing basis also allows carers to monitor the effectiveness of their pain management interventions over time.

Ultimately, effective pain scale assessment tools not only help accurately identify and evaluate a person’s pain, but also assist in designing an appropriate long-term pain management framework.


1 Peters, ML 2015. Emotional and Cognitive Influences on Pain Experience. Modern Trends in Pharmacopsychiatry, vol. 30, pp. 138-152. https://doi.org/10.1159/000435938
2 Schott, DG 2004. Communicating the experience of pain: the role of analogy. Pain, vol. 108(3), pp. 209–212. https://doi.org/10.1016/j.pain.2004.01.037

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