Lentis/Pain Scales

Introduction
Pain Scales are a measurement which assess the severity of a patient's pain level. Pain scales are also a typical medical communication tool that may be utilized in a number of circumstances, so patients can report their pain level depending on different pain scales.

Categories
There are three major categories of unidimensional pain scales.


 * Numerical Rating Scales (NRS)
 * Visual Analog Scales (VAS)
 * Categorical Scales (CS)

Numerical Rating Scales
Numerical Rating Scales (NRS) are scales that utilize a number to indicate pain experienced. The most basic and common form of a NRS is the simple 0-10 pain scale, where 0 is no pain and 10 signifies unbearable pain. This form of a NRS is most common due to its ability to stretch across languages and the speed and accuracy if a patient is conscious and able. Other NRS also exist for children and adults who are unable to quantify their pain. The FLACC scale is an example for children and babies and is further expanded in the next section. Other scales also apply numerical ratings for different categories where each number has a specific requirement prior to its use in that category.

FLACC Scale
The FLACC (Face, Legs, Activity, Cry, Consolability) scale uses different categories in order to quantify pain within children who are too young to cooperate. Each category is rated from 0-2 and the scores are then summed for a total pain score. An example is to score a 1 in the Activity category, the child's legs must be deemed "uneasy, restless, tense". Other scales that are similarly formatted include the CRIES, used for infants, and the COMFORT which is used for in-depth pain analysis on uncooperative adults.

Visual Analog Scales
The Visual Analog Scales(VAS) is one of the most commonly used measurement in pain scales. VAS method can be used in measurement for subjective characteristics which can't be directly measured. Patients or respondents can define their pain level by indicating a position between two end-points in a line. The line usually is in fixed length of 10 cm. At one end of the line, the endpoint is "No Pain", and at the other end is "Worst Pain" or "Extreme Pain". It is easy to operate by using a VAS method, and it tends to be less expensive than other pain scales due to its relative simplicity

Categorical Scales
Categorical Scales (CS) utilize different tiers of pain that patients or respondents can select from in order to best describe their pan level. There are usually 5-6 different tiers to select from, with the left-most tier in the scale representing the smallest amount of pain (no pain) and the right-most tier representing the highest amount of pain possible. Categorical scales can be separated further into two types, depending on how the different tiers in the pain scale are represented. Those types are the Verbal Pain Intensity Scale and the Visual Pain Intensity Scale.

Verbal Pain Intensity Scale
Verbal Pain Intensity Scales represent the different tiers of pain using words. These types of categorical scales use easy to understand, simple words to describe the pain tiers. The left-most (least painful) tier of the pain scale is usually labelled as 'no pain' or 'little pain,' while the right-most tier usually has the label 'worst possible pain' or 'very severe pain'. An example of a verbal pain intensity scale could be: No Pain Mild Pain  Moderate Pain  Severe Pain  Very Severe Pain  Worst Possible Pain Verbal Pain Intensity Scales commonly use the words 'mild,' 'moderate', and 'severe' among all variations for ease of use. Patients choose the words that best describe their pain level.

Visual Pain Intensity Scale
Visual Pain Intensity Scales usually still have words describing the different tiers of pain. However, in addition to those words, visual pain intensity scales' tiers are accompanied with picture descriptors. The most common visual pain intensity scale is the Wong-Baker FACES pain rating scale. The Wong-Baker FACES scale presents patients with 6-8 different pictures of facial expressions, ranging from a pleasant face on the left of the scale, a neutral face around the middle of the scale, and a crying face on the right of the scale. Patients choose the face that best represents their internal pain level.

Because visual pain intensity scales use pictures of faces to distinguish pain levels, this type of scale is very popular with diagnosing pain in children, the mentally challenged, and with patients that do not speak the same language as their doctors. However, there have been some occasions where patients misinterpret the meaning of the faces on the scale. Patients may believe that they are supposed to choose the face that represents their overall emotion with their pain, and not their actual internal pain level itself. This can lead to a different tier of the pain scale being chosen than the real level of pain that a patient is feeling, which can cause a misunderstanding with their doctor.

Doctors
When doctors are trying to diagnose patients that cannot describe their symptoms/pain in detail, pain scales become very useful for accurately measuring the patient's pain. Many different doctors will choose to perform a set of different pain scales on the patient in order to gain a precise understanding of that patient's pain. Doing so will help the doctor: (1) diagnose the severity of the injury, (2) choose the correct treatment procedure and determine how to proceed with that treatment in order to minimize pain, and (3) evaluate the effectiveness of that treatment over time by administering pain scale tests to patients before, during, and after treatment.

Patients
Patients can express their direct feelings by using pain scales and self-reports their different pain levels by using a specially designed pain scale. Pain scales become an effective tool for patients who want to communicate with doctors, and so that patients can measure their pain level and receive necessary aids from doctors. By implementing and using VAS method, patients can be beneficial from its quickness and highly reliable results.

Pharmaceuticals
The approach to patients with different pain levels begins by identifying the underlying cause and a disease-specific treatment. Pharmaceutical companies are designed to provide adequate pain relief for patients by different pain levels. Therefore, pain scales provide enough and accurate information for these companies to develop and recommend medicines. The original recommendation consists of three parts:

(1) Mild Pain

(2) Moderate Pain

(3) Severe and Persistent Pain

There have been major controversies that relate pharmaceuticals to the opioid epidemic. In 2020, Purdue Pharma pleaded guilty to three opioid criminal charges and settled to pay over $600 million in damages. Purdue Pharma is viewed as a leader of the opioid addiction crisis as they downplayed the addictive nature and pushed physicians to prescribe larger doses for pain. Purdue Pharma attempted to influence government health agencies, healthcare, and academia to sell more of their drug OxyContin. Proper utilization of pain scales in such scenarios may help reduce the need of a opioid prescription, but corporate influence by pharmaceuticals have blurred the lines for physicians and patients.

Online Survey
Due to the simple operability of VAS method, it can be transformed into different formats. A good example is provided by online survey software. It allows people to choose a specific pain level by moving the mouse remotely which makes VAS method practically possible. Then the responses will be collected, and feedback will be given soon.

Children Pain Scale
It is commonly used in Categorical Scales with images of faces for children. Children can choose which face represents how they feel and the face will be the most consistent with the current pain level.

Challenges
There are many known challenges to accurately measuring pain. The reason why there exist so many pain scales is because pain is subjective and personal, making it a very social topic. Therefore, it is difficult to develop a technical scale that would work for all patients. A lot of the different pain scales were developed such that they covered each other's downsides, which is another reason why developing a single perfect pain scale is most likely not possible and why it is important to continue improving the existing pain scales and potentially developing new pain scales to complement the existing pain scales.

Language
Because the languages patients and doctors speak are a part of these pain scales, language barriers can make administering pain scales difficult. When patients and their doctors do not speak the same language, certain pain scales (like some numerical rating scales and the verbal pain intensity categorical scales) cannot be used to measure pain. Even when patients and doctors do speak the same language, misunderstandings of patient responses on the pain scales can still occur, since different words mean different things to different people. Pain that someone could think is "moderate" could be "severe" to someone else.

Gender
Studies have found that women feel less pain than their male counterparts. Those surveyed in a 2021 study were asked to survey other's pain; the study shown clear underestimations of the target when they were a female instead of a male. Survey participants were also asked to answer about best or suitable treatment and psychotherapy were prescribed to women more often as opposed to pain medicine for men. These underestimations of pain can result in mistreatment and ineffective care for pain for female patients. Although these biases exist, there are more physical correlation between the pain experienced between males and females which may also influence a physician's ability to gauge pain experienced by female patients.

Race
There is documented racial bias in pain assessment; black Americans are less likely to be believed than their white counterparts. According to a case study, black Americans were more likely to be incorrectly treated for their pain due to both implicit and explicit biases. These biases include believing black people to have "thicker skin" and higher pain tolerances than white people. The study also surveyed a group of participants who were not medically trained. They were asked to answer questions about how much pain a specific target (white or black) may feel in a scenario and were then asked about fake medical beliefs like "Blacks’ nerve endings are less sensitive than whites". They found that believing in fake beliefs correlated with a lower pain rating pain experienced by a black target compared to a white one.

This research helps illustrate the problem within healthcare, as doctors and physicians rely on pain assessments in order to properly diagnose and treat patients. According to a 2016 study in the Proceedings of the National Academies of Science, half of the first and second year medical students surveyed believed in at least one or two fake beliefs such as black people having thicker skin. To avoid mistreatment of patients, healthcare professionals must educate themselves and/or gather more research and evidence in order to explore assumptions. Actions like these will be more important in the goal of reducing the disparity in treatment of different races, for the the U.S. Department of Health and Human Services report that black and hispanic people receive worse care on 40% of the department’s care quality measures.