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Methods of Assessing Pain and Associated Conditions in Dementia: Self-report Pain Scales
Sophie Pautex and Stefan Lautenbacher
The application of self-report scales is limited due to the cognitive and linguistic impairments in patients with dementia. Dementia of mild to moderate degrees may still allow the necessary functional prerequisites for successful completion of self-report scales. The chapter will alert how it can be verified that these prerequisites are met. Furthermore, it will inform the readers about the cognitive challenges that are associated with the valid self-report of pain. Finally, the available scales will be reviewed and solutions for best practice will be recommended.
INTRODUCTION ABOUT THE IMPORTANCE OF SELF-ASSESSMENT
Pain is a subjective, complex, and multidimensional experience, for which there are no objective biological markers. Despite decades of effort, there is no neurophysiologic or chemical test that can measure pain in individual patients. Various studies have demonstrated that health-care professionals tend to underestimate a patient’s pain intensity, while family caregivers tend to the opposite and overestimate the intensity of pain [10, 42, 46, 47, 53, 62, 65, 72, 76]. To compensate for such evaluation biases, self-report tools should always be used in patients with dementia who can still communicate. Besides these considerations, self-report opens the realm of internal and private states and gains access to information never accessible by observers, making it always a first-choice approach [15, 37, 63].
Furthermore, we cannot assume that older patients automatically report pain, even to health professionals. Many older adults do not report pain for various reasons, including the belief that pain is regular and must be endured, not wanting be a bother, expecting that the health-care provider will anyhow know when pain is present, and fearing of the meaning of pain . Indeed, attitudes of stoicism and cautiousness may contribute to the underreporting of pain symptoms in older people as demonstrated by Yong . Given the higher prevalence of chronic pain with increasing age, older adults may also show more acceptance of chronic pain and may perceive mild aches and pain as normal part of aging. Kamel and colleagues  demonstrated in a study conducted in two nursing homes that the systematic use of three pain assessment scales (the visual analog scale [VAS], faces scale, and pain descriptive scale) increased the detection of pain (from 15% to 30%) among nursing home residents.
In conclusion, when an elder patient with dementia presents for an initial evaluation, then a quantitative and qualitative assessment for persistent pain including self-report measures should be performed; thereafter, the patient should be screened for persistent pain at a regular basis .
BARRIERS AGAINST AND PREREQUISITES FOR THE SUCCESSFUL COMPLETION OF SELF-REPORT
Dementia is not a single disease but a complex of different signs and symptoms that often overlap. For example, Alzheimer-type dementia is often characterized predominantly by memory loss, accompanied by impairment in other cognitive functions or “domains,” such as language function (aphasia), fine motor functions (apraxia), or recognition (agnosia). Especially cognitive impairments in memory may hinder a person’s ability to consider what pain has been during the course of a day, when it started, whether it was related to something, and what its cause might have been. The inability to concentrate and maintain attention can also affect participation in pain assessment. Loss of language (aphasia) and disturbances in visual-spatial skills can further limit the ability to provide detailed information. Visual agnosia, when people with dementia can no longer recognize everyday items, can also affect assessment when visual means become relevant.
Before assessing the pain of the patients, cognitive impairment but also cognitive resources of the patients should be identified. The mini-mental state examination (MMSE), although far from being a perfect tool, is still the most commonly administered psychometric screening assessment of cognitive functioning . The MMSE can be used to screen patients for cognitive impairment, to track changes in cognitive functioning over time, and oftentimes to assess the effects of therapeutic agents on cognitive function. If available, further neuropsychological examination should be used to identify the resources of the patient and to adapt the pain assessment to the patient’s capacities. Pain assessment can be a challenging procedure in patients with moderate to strong degrees of cognitive impairment. Accurate self-reporting of pain requires the ability to understand the question posed by a pain rating, to accurately interpret the experience of noxious stimuli as sources of pain, to correctly recall the pain, and to adequately express pain by verbal means.
Sensory Impairment: Assistive Devices
Given that sensory deficits are common in older persons, it is important to determine the presence of any deficit and to evaluate the patient’s sensory ability to use available pain scales. Sensory-assistive devices, for example glasses, should be checked to make sure they are working properly. Adjustments to the self-report tool should be made to accommodate patients with poor vision, such as using enlarged type and bold figures or using verbal communication with numerical or verbal scales [18, 30]. Written information should be provided for patients with auditory deficits.
Guidelines for Caregivers on How to Use and Explain the Scales to the Patients
It is important to take the time to find the most appropriate scale for each patient and ensure that they assimilate and respond adequately. Using the same scale over time in one patient is the best approach to track changes reliably. Furthermore, patients with dementia have often limited attention spans and are easily distracted . Therefore, it may be helpful to prepare these patients by limiting distractions in the room. If possible, pain assessment should be performed in a quiet room. It is also important to allow sufficient time for older adults to process and respond to the assessment task . A pain assessment scale should be explained to the patient using a standard text and the patient should demonstrate comprehension of the scales.
SELF-ASSESSMENT OF PAIN
A careful patient history that allows the patient to describe her or his pain is also essential for discriminating the types of pain, identifying the underlying cause and evaluating the impact of pain as well as the efficacy of our treatments. It is also crucial to acknowledge the pain of the patient and to reassure that the health-care professionals will take care of it.
A structured pain interview that includes simple questions related to the presence or absence of pain or discomfort, pain intensity, frequency, location, and impact on daily activities is a feasible approach to pain assessment even in the cognitively impaired patients [17, 50, 73]. This complete pain assessment must, of course, be followed by a complete physical examination focusing on the site of pain and referred pain and with some complementary examinations, if appropriate (for example, X-ray, computed-tomography [CT] scan, magnetic resonance imaging [MRI]).
Onset, Duration, Variations, Rhythms
Patients need to be asked when and how pain occurred. Duration and variations of pain should be assessed with some question such as “Is your pain always there, or does it come and go?” Transitory exacerbation of pain (breakthrough pain) should be assessed.
Exacerbating and Alleviating Factors
Asking the patient to describe the factors that exacerbate or alleviate the pain helps to plan interventions. A typical question might be “What makes the pain better or worse?” Analgesics, nonpharmacologic approaches (massage, relaxation, music or visualization therapy, heat or cold) are some interventions that may relieve the pain. Other factors (movement, physical therapy, activity) may intensify the pain.
Qualitative Description of Pain
Patients should also be encouraged to describe their pain with qualitative terms. For example, patients can describe nociceptive pain with terms that include “burning,” “searing,” “raw,” “numb,” “stabbing,” and “tingling.” Neuropathic pain is described as “electric shock,” or “pins and needles” . Some patients with dementia and aphasia do not understand anymore the term of pain but admit some discomfort or other unpleasant sensations such as aching.
Location of Pain
Most (74.9%) of older adults with pain endorsed multiple sites of pain . In this context, establishing the location and spatial extent of pain on a chart consisting of drawings of the human body or body parts, on which the patient maps the pain, can be a very useful approach. Pointing to the body part that hurts has also been shown to be an effective approach with cognitively impaired older adults .
Consequences of Pain
The extent to which pain interferes with daily activities increases exponentially with age. The consequences (for example, depression, anxiety, loss of appetite, sleep disturbance, functional disability, behavior trouble, and compromised quality of life) must regularly be assessed [4, 6, 11, 21, 27, 51, 60, 61, 64, 74].
Pain Intensity Scales
First, we have to determine which self-report pain scale is the most adequate for the particular patient. The ability to comprehend and use a self-report scale is closely related to the severity of dementia and, in particular, to the communication ability of the patient . However, scale comprehension is not related to the type of dementia. Patient’s failure to complete one type of self-report pain scale does not preclude success with other types of scale. There are several self-report scales, among which the VAS, the Numerical Rating Scale (NRS), the Verbal Rating or Descriptor Scale (VRS, VDS), the Pain Thermometer (PT), and the Faces Pain Scale (FPS) are the most frequently used .
Most of these scales have demonstrated an acceptable reliability and validity in older patients and in patients with cognitive impairment in different settings (acute care, pain clinic, nursing home, community dwelling) .
The VAS consists typically of a 10-cm line anchored by the two extremes of pain, for example, no pain, extreme pain. Patients are asked to position a sliding vertical marker or mark the position by a pen to indicate the level of pain they were experiencing, for example, currently; pain severity is then measured as the distance in millimeter between the zero position and the marked spot [35, 44, 59, 69]. The VAS is one of the most commonly used tools in the clinical setting due to its practicability and availability. However, elderly people can have problems of understanding the VAS; two studies demonstrated a significant correlation between age and incorrect responding to the VAS [35, 38]. The VAS has also been thought to become better intelligible by adding graded colors, usually red, symbolizing more pain, with a higher completion rate in patients with dementia .
The VRS originated by Melzack is a simple, commonly used pain rating scale . To complete it, subjects select one of six descriptors that represent pain of progressive intensity: none, mild, discomforting, distressing, horrible, or excruciating . It has demonstrated good reliability and validity with older adults and when compared with other pain intensity scales, is often the preferred tool for many older adults [31, 33]. Limitations include the possibility that the words may not have the same meaning for each individual, and the categories between words do not represent equal intervals on the scale . The PT, originally developed by Roland and Morris, is a variation of the VRS and has demonstrated some preferences in elderly patients with moderate to severe cognitive impairment .
The NRS with a 0–10, 0–20, or 0–100 point scale has wording such as “no pain” at one extreme and “worst pain possible” at the other . Often the value of “4” on a 0–10 point scale is used to confirm the need for further intervention or to document that the patient’s goals for analgesia have been achieved . Although validated for use with the elderly, a substantial portion of older adults have difficulty responding to this scale, particularly if administered verbally without showing the number [73, 75]. A similar scale is the modified 21-point box scale. It is a row of 21 boxes labeled from 0 to 100 in increments of five. The 0 anchor was labeled “no pain,” while the 100 anchor was labeled “pain as bad as it could be.” To complete the scale, respondents indicate the box that best represent their pain .
The FPS consists of a line drawing of seven faces which express increasing pain (no pain = 0, maximum pain = 6) . It has been adapted for older adults populations from similar pain scales used in pediatric settings . Herr et al.  found preliminary support for the construct validity, strong ordinal properties, and strong test–retest reliability of the FPS in a sample of white, elderly individuals in the community. Later, Stuppy evaluated the reliability and validity of the FPS using a sample of 60 patients older than 55. Findings revealed that the FPS was reliable, valid, and sensitive to change and was preferred to the NRS, VAS, and VDS by 53% of the subjects .
Different studies have attempted to determine the most appropriate scale for cognitively impaired elderly but report conflicting results. Ferrell and others found completion rates in 287 nursing homes residents that vary from 44% for the VAS to 65% for the present pain intensity subscale of the McGill questionnaire, a combined word and number scale . This is consistent with the findings of Krulewitch et al. , who reported the worst completion rate for a VAS (53%) and the faces scale (53%) compared to the pain intensity scale (62%), a combined visual and verbal scale. Scherder and others  described a very high completion rate for the CAS, a colored vertical VAS (100% in early AD and 80% in midstage AD). In comparison to NRS, VRS remained more stable as the degree of cognitive impairment increases. Pautex et al. [54, 55] was able to demonstrate that four pain self-assessment scales (verbal, horizontal visual, vertical visual, and FPS) possess high test–retest reliability in a population with dementia. Correlation between the four self-assessment scales was very strong. Correlations were slightly lower in patients with moderate than with mild dementia. The 5-point VRS appeared to perform slightly better in a more recent study among patients with severe cognitive deficits (respectively 57.5% and 95% for the NRS and 5-point VRS) .