Rating Scales and Digital Health: Introduction

With the increasing role of patient-reported outcome measures in today’s digital health industry, rating scales are among the most effective tools used to assess subjective experiences, such as pain, mood, appetite, and comfort with knowledge. Rating scales facilitate the collection of qualitative and quantitative data in research, which can be used to track the progression of a condition or response to treatment. In fact, subjective scales improve the diagnostic process in practice, as well as data interoperability.

Thus, rating scales become fundamental to data collection and patients’ health-related quality of life. Some of the most popular and reliable rating scales include the visual analog scale, the verbal rating scale, the faces rating scale, and the numeric rating scale. Moreover, the use of electronic rating scales (delivered via a web-based platform, mobile devices or interactive voice record technology) results in high compliance and a positive user experience.

Rating Scales: Types, Benefits, and Applications

Rating scales are valuable tools in digital health and routine clinical care, used to assess a variety of subjective phenomena, such as fatigue, user satisfaction, asthma, and even provider performance. Interestingly, such measurements are most often applicable to pain assessment and pain management. Common rating scales with high psychometric properties and a wide range of applications include the visual analog scale, the verbal rating scale, the faces rating scale, and the numeric rating scale, as well as their electronic versions:

• Visual analog scales: The visual analog scale is one of the most popular tools, which allows patients to assess various internal events with high precision. The scale can be utilized to assess asthma, user satisfaction, cancer pain, headaches, labor pain, fatigue, appetite, and health-related quality of life. 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). Note that mechanical, pen-and-paper and electronic formats of the instrument exist. Patients express preferences for this scale as it doesn’t restrict their ratings to a number of categories. For instance, when applied to pain assessment, visual analog scores are ranked on a 10-cm line (either vertical or horizontal) that stretches between “no pain” and “worst pain” (Delgado et al., 2018).
• Verbal rating scales: The verbal rating scale is a valid tool to assess abstract concepts, such as patients’ perceptions and provider performance. Furthermore, verbal scales are highly beneficial to assess pain experiences. Data shows that patients who reported higher verbal rating scores were more likely to receive pain treatment in a timely and effective manner. Note that such verbal rating scales are also known as verbal pain scores and verbal descriptor scales. Verbal rating 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. Consequently, these rankings have wide applications, including across geriatric populations with high levels of cognitive impairment.
• Faces rating scales: The faces rating scales are another well-accepted category of self-report tools applicable to different settings, such as user experience, mood, and patient satisfaction with the hospital stay. Faces scales are defined as graphical tools that employ pictures or photographs of facial expressions to help patients rate their subjective experiences (Safikhani et al., 2018). Because of their attractive interface, graphical tools are most often used in pain assessment. 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. Note that another popular 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 events, such as response to treatment, hedonic qualities of a product, and migraine. In fact, research shows that the scale has high discriminative power for cancer and chronic pain. The 11-point numeric rating scale requires minimal language skills and translation, which makes it a popular tool across cultures (Hjermstad et al., 2011). Additionally, numeric assessments can consist of 21 points (0-20) and 101 points (0-100). The scale can benefit patients with limited English proficiency, and it can erase discrepancies in pain management based on ethnicity and gender.

Comparison of Rating Scales in Digital Health Care

Rating scales, such as the verbal rating scale, the numeric rating scale, and the visual analog scale, reveal good psychometric properties and meet fundamental regulatory requirements for pain assessment. As rating scales cannot be replaced or used interchangeably, choosing the right measurement can be challenging. The selection of a tool depends on study conditions, such as demographic factors, methods of administration, instructions, specific circumstances, and interpretation of clinical significance (Williamson and Hoggart, 2005). That said, although clear comparisons between rating scales cannot be made, evidence suggests:

• Research in the field of pain assessment shows that the numeric rating scale correlates well with other pain instruments. The scale shows good sensitivity and provides data that 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.
• When it comes to vulnerable subjects, 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 for cognitively impaired individuals and children. As explained above, pictorial scales and emoji-based tools are highly beneficial in children.
• Demographic factors influence the understanding and 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).
• 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). Furthermore, to increase compliance, digital rating scales are highly recommended.

While research proves that all rating scales work well, the interpretation of patients’ scores is crucial. For instance, 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 a patient’s subjective experience with all its psychological, social, and financial aspects.

Rating Scales and Pain Assessment: The Key to Effective Pain Treatment

With their numerous applications in practice, rating scales are among the most popular subjective measures employed in pain assessment. Note that a 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). As 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.

Given the multidimensional aspect of pain, each rating scale has various benefits in pain assessment, which is 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 are popular instruments in pain assessment, with verbal rating scales, visual analog scales, and numeric rating scales being valid and reliable tools in health care. 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 patients’ experiences. Fear and anxiety, for instance, may lead to an increase in pain intensity. When assessing pain, there are several major factors to consider:

• Pain intensity and severity (e.g., moderate pain): Pain is a subjective experience, and as such, patient reports are the most valuable tools to obtain a complete understanding of patients’ sensory experiences. 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 that 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 effective 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 and 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 sensory 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. 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.

Rating Scales and Digital Health: Conclusion

Rating scales are popular subjective instruments used to assess abstract events and internal experiences, such as food intake, emotional arousal to daily activities, asthma, and service satisfaction. 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. Such measurements reveal numerous benefits and applications across a wide variety of settings and populations; particularly in pain assessment. As pain, described as the fifth vital sign, is one of the biggest health concerns worldwide, rating scales are commonly employed alongside other multifaceted patient-reported measurements.

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. After all, patients are active participants in today’s digital health world – with the right to voice their subjective experience and opt for high health-related quality of life.

Resources

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