- Rating Scales: Types, Benefits, and Applications
- Psychometric Properties of Numeric Rating Scales
- Rating Scales and Digital Health: Conclusion
- Rating Scales and Digital Health: Reference
Pain is a complex and internal phenomenon, the vast majority of pain experiences cannot be detected by standard observations or laboratory tests. Thus, only self-reports can help experts understand, evaluate, and treat both acute and chronic pain. Rating scales, such as the visual analog scale, the verbal rating scale, and the numeric rating scale, are reliable instruments in research and practice.
As pain is a major health concern worldwide, pain assessment becomes the main key to effective treatment. Acute pain, for instance, can be caused by an injury or disease and serves a biological purpose. In order to be reduced in an effective manner, evidence shows that acute pain should be documented within the first 20-25 minutes of the initial assessment in the emergency department. Note that treatment should tackle the underlying cause of a patient’s sensory experience (Karcioglu et al., 2018). Chronic pain, on the other hand, is defined as pain lasting more than 12 weeks with no-recognizable end-point. As chronic pain is perceived as a disease itself, treatment must embrace a multidisciplinary approach and multidimensional measures. Rating scales facilitate both the evaluation of pain and its comprehensive assessment.
Rating Scales: Types, Benefits, and Applications
Comprehensive pain assessment tackles the unidimensional evaluation of pain intensity and the multidimensional assessment of a patient’s pain perception. Rating scales, in particular, provide a quick and reliable way to assess the unidimensional pain intensity regarding the area of pain or specific circumstances (e.g., hip pain when sitting). Common rating scales include the visual analog scale, the verbal rating scale, the faces rating scale, and the numeric rating scale.
- Visual analog scales: The visual analog scale is one of the most popular tools, which allows patients to assess their pain experiences with high precision. Scores are ranked on a 10-cm line (either vertical or horizontal) that stretches between “no pain” and “worst pain” (Delgado et al., 2018). Note that mechanical, pen-and-paper and electronic formats of the test exist. The visual analog scale is simple to administer, and it’s able to identify cut-off scores of patients with clinically significant symptoms (Safikhani et al., 2018). Patients express preferences for this scale as it doesn’t restrict their ratings to a number of pain categories. The scale can be utilized to assess cancer pain, headaches, labor pain, fatigue, appetite, and health-related quality of life. In fact, quality of life is a vital part of digital health.
- Verbal rating scales: The verbal rating scale is a valid tool to assess pain experiences. Note that verbal rating scales are also known as verbal pain scores and verbal descriptor scales. These scales consist of a number of descriptors, or statements designed to describe pain intensity and quality (Karcioglu et al., 2018). One of the most popular sets of descriptors includes the following rankings: “None,” “mild,” “moderate,” “severe,” “very severe,” and “not at all.” Because participants have to read the descriptors to rate their pain, verbal rating scales reveal high compliance. Verbal rating scales have numerous applications, including in geriatric populations with high levels of cognitive impairment. Interestingly, data shows that patients who reported higher verbal rating scores were more likely to receive pain treatment in a timely and effective manner.
- Faces rating scales: The faces rating scales are also popular tools used in pain assessment. Faces scales are defined as graphical tools that employ pictures or photographs of facial expressions to help patients rate their pain experiences (Safikhani et al., 2018). The faces pain scale facilitates pain assessment and treatment in patients with low verbal skills and pediatric populations. In fact, the faces scale-revised (FPS-R) is one of the most valuable instruments designed specifically for children. Another pictorial scale is the Pain Thermometer scale.
- Numeric rating scales: The numeric rating scale is among the most popular rating scales, which reveals good psychometric properties and high compliance. The scale can include an 11-point scale (0-10) to help patients assess their pain. In addition, numeric assessments can consist of 21 points (0-20) and 101 points (0-100). The numeric rating scale requires minimal language skills and translation, which makes it a popular tool across cultures (Hjermstad et al., 2011). The scale can benefit patients with limited English proficiency, and it can erase discrepancies in pain management based on ethnicity and gender. Also, research shows that the scale has high discriminative power for cancer and chronic pain.
Psychometric Properties of Numeric Rating Scales
Given the multidimensional aspect of pain, each rating scale has various benefits in research and practice. Thus, rating scales cannot be replaced or used interchangeably. Rating scales such as the verbal rating scale, the numeric rating scale, and the visual analog scale reveal good psychometric properties and meet vital regulatory requirements for pain assessment. That said, although clear comparisons between these rating scales cannot be made, evidence suggests:
- Research shows that the numeric rating scale correlates well with other pain assessments. The scale shows good sensitivity and provides data which can be used for audit purposes. The verbal numeric rating scale, in particular, reveals high convergent validity, known-groups validity, responsivity, and reliability in children (6-17 years) (Tsze et al., 2018).
- Evidence shows that an 11-point numeric scale for assessing migraine is 55% more sensitive than a 4-point verbal rating scale (Kwong and Pathak, 2007). Yet, there’s a strong correlation between verbal rating scales and numeric rating scales, as well as an agreement regarding pain reduction in patients.
- Recent studies and review articles claim that the 11-point numeric rating scale is perhaps the optimal response scale to evaluate pain among adult patients without cognitive impairment (Safikhani et al., 2018). On the other hand, the faces rating scale-revised is a preferred scale in cognitively impaired individuals and children. As explained, above, pictorial scales are highly beneficial in children.
- Hjermstad and colleagues conducted a systematic review and concluded that out of 19 studies, the numeric rating scales showed better compliance in 15 studies when compared to the visual analog scale and the verbal rating scale (Hjermstad et al., 2011). To increase compliance, digital scales are highly recommended.
- Demographic factors influence the interpretation of ratings. Cultural differences, for instance, affect the interpretation of verbal rating scales and descriptors. The orientation of the visual analog scale, on the other hand, influences the statistical distribution of the data. Interestingly, evidence shows that the reading tradition of the population affects visual analog ratings (Willimason and Hoggart, 2005).
Nevertheless, research proves that all rating scales work well. The selection of a tool depends on conditions, such as demographic factors, methods of administration, instructions, specific circumstances, and interpretation of clinical significance (Williamson and Hoggart, 2005). Note that using raw scores to assess pain reduction may lead to error. To set an example, a change from 51 to 48 mm on a 100-mm visual analog scale is a change of 6%. On a 0-10 numeric scale, this can be represented as a change from 5 to 4, which, however, is a change of 20%. Therefore, multidimensional assessments are also needed to evaluate one’s pain experience with all its psychological, social, and financial aspects. As pain management has a detrimental effect on one’s quality of life, health care providers must implement rating scales and reassessments as a key element in the effective treatment of both acute and chronic pain.
Pain Assessment: The Key to Effective Pain Treatment
Pain is a subjective experience, and as such, patient reports are the most valuable tools to obtain a complete understanding of pain. Rating scales are popular instruments in pain assessment, with verbal rating scales, visual analog scales, and numeric rating scales being valid and reliable tools in practice. Subjective measures can help experts evaluate factors, such as location and nature of pain. Note that pain is a complex experience and may be influenced by demographic factors and social pressure. In fact, beliefs, cultural differences, and expectations have an impact on pain. Fear and anxiety, for instance, may lead to an increase in pain intensity.
When assessing pain experiences, there are several major factors to consider:
- Pain intensity and severity (e.g., moderate pain): As pain is a subjective feeling, rating scales can help experts evaluate and treat pain. Note that pain intensity may be influenced by the meaning of the pain, previous experience, and expected duration. To assess pain intensity and severity, rating scales can be applied across different settings and populations, including pediatric populations.
- Pain duration: While acute pain may be severe, chronic pain is often considered a disease itself. As chronic pain may lead to numerous social and emotional problems, a multidisciplinary approach is needed. The McGill Pain Questionnaire, for instance, is one of the most powerful tests used in research and practice.
- Pain behavior (e.g., facial expressions): Although pain is a subjective experience, pain can lead to various behavioral and social changes. Note that nonverbal rating scales can be highly beneficial in vulnerable and nonverbal patients (e.g., intubated patients). Behavioral scales can assess factors, such as movement of limbs, physiological signs, and facial expressions.
- Pain quality: Pain is a complex phenomenon which consists of a wide range of qualities. Research shows that there are six main categories of pain quality: numbness, pulling pain, sharp pain, pulsing pain, dull pain, and affective pain. The effective evaluation of pain quality can improve pain treatment, with the sole purpose of increasing patients’ health-related quality of life.
- Pain location: Pain location can also improve pain treatment. Note that pain drawings are valuable tools in pain assessment. They can be used to differentiate between organic and functional pain; they can help health care professionals reach a correct diagnosis in the presence of comorbidity. Interestingly, research shows that people who report multiple areas of pain reveal a high psychological factor in their pain experiences, which requires complex pain management.
- Affective qualities of pain: Pain experience is a mixture of psychological, cultural, social, and physiological factors. Thus, the affective qualities of pain influence pain assessment and treatment. As explained above, personal, cultural and demographic differences may influence pain ratings. That said, research shows there are discrepancies in pain treatment based on race and gender.
Rating Scales and Digital Health: Conclusion
Pain, described as the fifth vital sign, is one of the biggest health concerns worldwide. It’s no surprise that rating scales must be employed alongside other multifaceted measurements. Rating scales are popular subjective instruments used to assess pain experiences and pain intensity, in particular. While there’s a potential for error within ratings, rating scales such as the verbal rating scale, the numeric rating scale, the visual analog scale, and the faces rating scale are valid and reliable tools in medical research and routine clinical care. Rating scales reveal numerous benefits and applications across a wide variety of settings and populations.
What’s more, with the leveraging role of health technologies in today’s health care industry, electronic rating scales are becoming more and more popular. Digital tools improve data collection and analysis, as well as interoperability. The use of electronic rating scales (delivered via a web-based platform, a mobile device or interactive voice record technology) results in high compliance and positive user experience. Rating scales are valuable tools in pain assessment and treatment. After all, patients are active participants in today’s digital health world – with the right to voice their experience and seek a pain-free.
Rating Scales and Digital Health: Reference
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Kwong, W., & Pathak, D. (2007). Validation of the Eleven-Point Pain Scale in the Measurement of Migraine Headache Pain.
Safikhani, S., Gries, K., Trudeau, J., Reasner, D., Rudell, K., Coons, S., Bush. E., Hanlon, J., Abraham, L., & Vernon, M. (2018). Response scale selection in adult pain measures: results from a literature review. Journal of Patient-Reported Outcomes.
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