ESP: Emerging Solutions in Pain

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Introduction

Chronic pain directly affects a patient’s health-related quality of life. Whether these effects change in tandem with age has been the focus of relatively few formal studies, despite the abundance of chronic pain investigations. A recent study comparing quality of life in older and younger adult chronic pain patients may be able to answer this question, and potentially help clinicians’ better tailor pain management programs for different age groups of patients.¹    

Interview

Q: Dr. McCarberg, your experience working with chronic pain patients spans both the pain management and primary care settings. Why did you participate in a study comparing quality of life indicators between populations of older and younger chronic pain patients?

Dr. McCarberg: The more we understand the unique profiles of physical and psychological traits that characterize the different populations of patients we treat, the better equipped we are to treat individuals who present to us from those populations.  At the present time, most of our knowledge about pain comes from patients participating in clinical trials.  As the American Geriatrics Society (AGS) pointed out in their guidelines for managing chronic pain, the majority of these study populations have been restricted to younger adults, those below age 60.² Older adults also appear to be disproportionately underrepresented in many pain management programs.^3-5 In a way, this seems counterintuitive since we know that older adults experience painful conditions commonly associated with aging, such as osteoarthritis and lower back pain. In fact, the prevalence of pain in ambulatory older adults is estimated to be between 18% and 50%, and is even higher in nursing home residents.^1,6-10 And as people age, the number of chronic conditions they have increases, such that by age 65, 20% of individuals have at least five chronic conditions.¹¹ This paradox may speak to the heart of the problem. 

There have been several reports that pain in older adults is often unrecognized and undertreated.^1,6,10,12 This doesn’t necessarily mean that older people don’t have pain; they may just not complain about it. Even worse, approximately 40% of primary care physicians underestimate the extent of their patients’ pain.¹³ At the same time, quality of life is a key issue for pain patients, and a central focus of pain management. Pain can have a detrimental impact on quality of life. Yet, very few studies have compared how quality of life indicators differ with age in subpopulations of chronic pain patients.    

This scenario is rapidly changing. Older adults are the fastest growing segment of the American population. The graying of the baby boom generation is estimated to more than double the size of the elderly population over the next half century, growing from 35 million in 2000 to 78 million in 2050.¹⁴ The more we understand about the ramifications of pain in this population, the better prepared we will be to help them. A recent article in the New York Times highlighted how ill-informed health care practitioners from all medical specialties are about the unique traits of the geriatric population, and how this has led to inadequate care.¹⁵ The result is that pain management in older adults is a growing burden on the health care system. As an example, the aging process invokes a constellation of changes that can profoundly affect pain management. General physiological changes, such as decreased body mass and diminished organ function, can alter drug metabolism and sensitivity and interfere with pain control.^1,16 Other physiologic changes may specifically affect the mechanics or perception of pain, such as the loss of nerve cells or their dendrites, altered nerve fiber transmission, and reductions in the number and affinity of drug receptors.¹⁷ Knowledge of these changes, and how treatment can be tailored to compensate for them, is one of the keys to successful pain management in older adults with chronic pain.

Q: What was the purpose of the study?

Dr. McCarberg: We really had dual purposes in mind. First, we wanted to compare the health status of two populations of chronic pain patients, older patients aged 60 and above, and younger patients below age 60, with existing data for normative adults in each of the two corresponding age brackets. Secondly, we wanted to directly compare the health status of the two chronic pain populations we were studying. We included patients from multidisciplinary pain management programs at three regional locations in the US, in order to determine if there was geographic variation. So, we compared the composite older and younger populations from all three sites, as well as the older and younger populations at each of these sites. We used 60 as the age cutoff, because reports in the literature indicate relatively few patients over 60 are included in many pain management programs.^4,5

Q: How did you compare the different populations?

Dr. McCarberg: Each of the 6,147 study subjects completed the Treatment Outcomes of Pain Survey (TOPS) at the start of treatment, and the survey results were tabulated and statistically compared between the two chronic pain populations. TOPS is an in depth validated questionnaire developed specifically for chronic pain patients from the Medical Outcomes Survey Short Form-36 (SF-36), one of the most commonly used generic health status assessments.^18,19 The SF-36 is a brief, 36-item questionnaire that evaluates eight health status domains: physical functioning, role limitations due to physical problems, bodily pain, general health, vitality, social functioning, role limitations due to emotional problems, and mental health.^18,20.21 Answers to SF-36 questions embedded in the TOPS were compared to available normative data for the SF-36.²² As I mentioned, our study population included patients being treated at three different pain management program sites: San Diego (1,731), Salt Lake City (2,698), and Boston (1,718).     

Q: How did the older and younger populations compare in other respects?

Dr. McCarberg: They were extremely similar, with a few exceptions. Patients at the San Diego site were older, less likely to have finished high school, and had a higher annual income ($40,000-$50,000) than patients at the other two sites ($30,000-$40,000).   The Hispanic or Latino population at the San Diego site (10%) was also more than twice that of the Boston or Salt Lake City sites.  In other respects, however, the three sites were comparable, and more similar to each other than they were to the younger populations at each of the sites. The younger group tended to be better educated than the older group and also had a lower percentage of Caucasians. In San Diego and Boston, they were less likely to be earning less than $10,000 per year compared with their older counterparts.

Table 1. Demographics for the Three Geographic Locations

	Pain Management Center Locations
	San Diego (N=1,731)		Salt Lake City (N=2,698)			Boston (N=1,718)
Age	>60 y.o.	≤60 y.o.	>60 y.o.		≤60 y.o.	>60 y.o.	≤60 y.o.
Number in each age group	1,325	406	2,199		499	1,409	309
Gender (% Female Sample)	58.4 %		62.2%			78.1%
Race
% Caucasian	78.7%	76%	92%	91.2%		84.8%	86%
% Hispanic/Latino	10%	10%	>5%	>5%		>5%	>5%
Marital Status
Live alone	16.3%	29.8%	11.2%	28%		16.3%	29.8%
Married	60.9%	62.9%	58.6%	65.4%		47.9%	56.4%
Work Status
Full-time	25.6%	7.6%	26.5%	7.2%		24.7%	8.6%
Part-time	6.8%	3.9%	6.3%	4.4%		8.2%	5.4%
Retired	1.0%	24.1%	1.3%	39.3%		0.7%	41.3%
Disabled	37.7%	20.1%	32.5%	22.6%		43.6%	33%
Education
Finished High School	35.6%	17.2%	27.3%	36.8%		30.4%	38.9%
Finished College	13.2%	9%	12.7	9.6%		15.6%	11.8%
Mean Income
<$10,000	6.9%	4.6%	15.2%	12.1%		17.5%	22.5%
$80,000 or more	15.9%	11.2%	12.4%	9.2%		18.5%	11.5%
Adapted from Wittink H, et al. Pain Med.2006;7(2):151-163.1

Q: How did the two chronic pain populations compare to their normal counterparts?

Dr. McCarberg: Compared to normative SF-36 data, both populations of chronic pain patients had a considerably inferior quality of life, across all eight domains. In this respect, both age groups of chronic pain patients were more similar to each other than to the normative population, although they differed in the extent to which they deviated from normal for some of the domains. The greatest spread among chronic pain subpopulations was in the domains for social functioning, role limitations due to emotional problems, and mental health. As shown in Figure 1, all the adjusted mean domain scores for the older and younger chronic pain subpopulations at each of the three study sites clustered together at scores well below those for their corresponding normal counterparts. The profiles of the chronic pain subpopulations more closely resembled the profile of the normal older adults, primarily because the normal younger adults had a higher role limitation due to physical problems (RP) score. All the chronic pain subpopulations scored very similarly in bodily pain and role limitation due to physical problems, indicating that they had similar levels of physical pain.

Figure 1 Adjusted means of the Short Form-36 domains for older (O) and younger (Y) adults for each of the three sites.
PF = physical functioning; RP = role physical; BP = bodily pain; GH + general health;
VT = vitality; SF = social functioning; RE = role emotional; MH = mental health.

Adapted from Wittink H, et al. Pain Med.2006;7(2):151-163.¹

Q: How did the younger and older populations compare to each other?

Dr. McCarberg: The older and younger populations were compared directly using the mean values of the SF-36 and TOPS results at each study site. TOPS provided greater detail than the SF-36, although both survey results followed a similar pattern. Significant differences between the older and younger age groups were apparent for physical functioning of the lower body and for mental health variables. At all three study sites, the older adults had less work-related disability, fear avoidance, and passive coping than the younger adults, and they also had greater control over their lives. Pain intensity, as measured by pain symptoms on the TOPS and bodily pain on the SF-36, was similar between both age groups. Despite the comparable levels of pain intensity, multivariate analysis revealed that age was associated with profound limitations in lower body function, and this effect grew stronger with increasing age. Presumably, the diminished function of the lower body in older adults is caused by a combination of factors, including sarcopenia, stiffness, decreased range of motion, and immunologic, hormonal, and central nervous system changes that accompany aging.¹⁶ 

Another notable finding on the TOPS was that formal work disability, work limitations, fear avoidance, and passive coping were each inversely related to age. The effect of passive coping was the most significant, suggesting that older adults rely less on an external locus of control to manage their pain.

These results contrasted strongly with some of the psychological and social domains on the SF-36. Despite their similar levels of pain and worse physical functioning compared to the younger group, older chronic pain patients have better vitality, social functioning, and mental health than younger chronic pain patients. At two of the study sites, Boston and San Diego, patients in the older group also ranked higher in the role limitation due to emotional problems domain.

Q: Were you surprised by these results?

Dr. McCarberg: Most definitely. One of the most surprising findings of this study was that despite the comparable levels of pain intensity in both age groups at all three sites, and the more significant deficits in lower body functioning in the older adults, the older group of chronic pain patients had better mental health, vitality, social functioning, and life control than the younger group, and they also had lower levels of fear avoidance and passive coping. Together, this suggests that older adult chronic pain patients are better adjusted and have more psychosocial resources than younger adults with chronic pain. 

I would add, however, that these findings are not unique. Distinct differences between younger and older chronic pain patients have been evident in other studies as well, and are recommended to be taken into consideration when tailoring pain management programs to a patient’s age.^23,24

Q: Are your findings directly applicable to clinical practice?

Dr. McCarberg: As I mentioned, increased knowledge about the elderly chronic pain population can help practitioners treat individual older patients who present with pain. Perhaps the most valuable information revealed by the study was the difference between how younger and older adults perceive pain and quality of life. Despite their comparable levels of pain, the older patients had a better quality of life. Perceptual differences between the older patient and the physician undoubtedly also have an impact on treatment.¹³ As practitioners, we are constantly guilty of unwittingly passing judgments on our patients, rather than accepting their preferences and desires. When a younger patient presents, our highest priority in pain management is improving the patient’s health status to facilitate their return to work. However, there may be greater disparity between the practitioners’ and patients’ priorities and perceptions when an older adult presents. An older patient may have lower expectations for their physical functioning, and place greater importance on being able to return to what we consider to be a somewhat limited repertoire of activities. It is not our place to judge this, but rather to listen to and respect their choices and provide pain relief that helps them achieve their goals. This discordance can be minimized if practitioners use some of the excellent assessment tools now available to measure patient perception of pain and quality of life. Some examples of these are referenced in the Appendix. Although cognitive deficits and dementia may be present in some older adults, studies have shown that self-assessment of pain can still be reliably used in most patients.²⁵     

It is also true, however, that many older adults underreport their pain or their reports are cloaked in a different glossary of words.² They may substitute the terms “hurting” or “aching” for “pain.” Some may be afraid of the anticipated diagnostic tests or medications with their attendant side effects. Others may think of pain as a metaphor for impending death. It is therefore incumbent upon both primary care physicians and pain specialists to be vigilant about pain in older patients by listening carefully to their patients, asking questions, and inquiring at every visit about more generalized pain, rather than focusing merely on the presenting symptoms.²

Q: What role, if any, does physical exercise play in pain management?

Dr. McCarberg: Physical exercise plays a valuable role in the management of chronic pain. The AGS recommendation to include physical exercise in chronic pain management makes sense, particularly in light of our findings.²⁶ The older group of patients showed a significant decline in lower body function, although upper body function was not affected. Decline in lower body function was captured in the TOPS by questions about mobility and the ability to walk and climb stairs. Lower body function tends to decline with age, even in individuals without chronic pain, as a result of the physiological effects of aging, such as stiffness. Loss of muscle strength tends to impact the lower body more than the upper body, and may be accelerated in patients with chronic pain because they may be more sedentary.²⁷ Additional conditions, such as spinal stenosis and intermittent claudication, which are diagnoses seen more commonly in older adults, may further limit lower extremity function without causing pain. Once an older adult’s ability to carry out the activities of daily living is affected, it may usher in a cascade of declining function, leading to disability and dependence. Including physical exercise in the pain management program may delay or prevent this decline by improving muscle strength and mobility.

Q: Are there any other factors that affect quality of life in chronic pain patients?

Dr. McCarberg: There is a well-established relationship between chronic pain and depression. A score of 52 or less on the TOPS mental health domain is considered the cutoff for probable depression. Most of the TOPS scales assess dysfunction, in which case lower scores are desirable. In this case, however, for life control and satisfaction with outcomes, a higher score signifies better life control and more satisfaction. In our study, although the prevalence of probable depression was high in both age groups, the older adults fared much better, 39% of whom scored 52 or less compared to 47% of the younger adults. The prevalence of probable depression in our study is comparable to levels reported in the literature, although not all studies reported differences by age.^3,24,28,29  In another large study that examined age differences in chronic pain patients, Edwards also found that affective distress was much greater in younger than older patients.²⁴ One possible explanation for these findings is that many older people show a pragmatic resilience to stressors. As I mentioned, our results also suggest that older adults rely less on external control to manage their pain than younger patients, and they have higher life control. This higher life control, combined with their comparatively lower levels of fear avoidance and passive coping may indicate that older chronic pain patients living in the community may simply attribute their pain symptoms to the normal aging process, allowing them to more readily accept and adjust to their pain.

 Q: What other principles of pain management are important in the geriatric population?      

Dr. McCarberg: Many of the AGS recommendations reinforce the same principles used in pain management of other age groups. For example, the AGS recommends a thorough initial physical and psychological assessment to definitively identify the underlying cause of pain.²⁶ It emphasizes the importance of an interdisciplinary approach to pain assessment and management to identify all the potentially treatable contributors to the pain. Good communication and coordination among members of the interdisciplinary team help ensure successful outcomes. Tailoring the types of approaches to the needs of the patient is important, including the use of social or psychological interventions in those patients for whom it is warranted.³⁰

Pain is a very subjective experience. Consequently, it is extremely important to provide a patient-centric approach to pain assessment and management. Since the most reliable evidence regarding the presence of pain and its intensity is the patient, clinicians and caregivers are encouraged to believe patients’ reports of pain, and to take them seriously.  Patients should be queried carefully about symptoms indicative of pain, such as recent changes in activities or functional status, and they can be observed for the presence of verbal and nonverbal pain-related behaviors. Some common pain-related behaviors include facial grimaces or frowns, rigid body posture, fidgeting, rapid blinking, pacing or rocking, noisy breathing, sighing, and grunting or groaning.²⁶ As a matter of fact, the AGS recommends that all health care providers of older adults maintain a vigilant attitude toward pain, querying and assessing any older person who presents for evidence of persistent pain.

Q: Are all older adult chronic pain patients candidates for pharmacologic therapy?

Dr. McCarberg: Yes, indeed they are. This is one of the most urgent messages of the AGS.²⁶ Chronic pain that impairs a patient’s ability to function or quality of life is considered a significant problem worthy of treatment. Patients of any age whose health status is impaired by chronic pain are entitled to have their pain treated with pharmacologic therapy, which is the most common treatment for pain in older adults. Even patients who have a history of substance abuse are entitled to receive pharmacologic therapy. This is, perhaps, one of the greatest misunderstandings in pain management. The only difference when treating patients with a history of substance abuse is that, regardless of age, they require greater precautionary measures and more vigilant monitoring.

Q: What common problems do physicians encounter when prescribing pharmacologic therapy to older adults?

Dr. McCarberg: Older adults require careful monitoring, and a good rule of thumb is to “start low and go slow.” In other words, whether it be an opioid, an anticonvulsant, or an antidepressant, start patients at a very conservative dose and titrate slowly because many older adults, especially women, may not require as high a dose to achieve adequate levels of analgesia.^31,32 It may also be helpful to lengthen the dosing interval. As with any other patient, dosing is very individualized, and older patients do not necessarily require less opioids than other patients. Older men, especially, have been shown to have increased sensitivity to pain.³² Patients should also be reevaluated frequently for drug efficacy and side effects, although older patients may be less likely to develop tolerance.³³ One clear challenge with this population, however, is the greater risk of medication-associated problems, due in part to the higher rate of polypharmacy and comorbidity.

 Q: Have any common misperceptions about this population interfered with physicians’ propensity to prescribe opioids to older adults?

Dr. McCarberg: Use of opioids in older adults has been a source of concern for many physicians. There seems to be a misperception that opioid abuse is far less common among older adults, perhaps because younger age is one of the many risk factors for potential opioid abuse.^34,35 However, reports in the literature indicate that older adults have the same potential for abuse as other age groups, and prior dependence on medications, alcohol, cigarettes, or illegal drugs are important predictors of risk.³² Societal biases may also mask the presence of late-onset alcohol abuse.³⁶ Other risk factors for opioid abuse include a family history of substance abuse, presence of mental disease, stress, and a history of preadolescent sexual abuse.³⁴ Consequently, the same good clinical practice that would be used with any other population of chronic pain patients should be used with older adults. 

 Q: Many physicians are reticent to prescribe opioids to patients of any age because they are afraid the patient may become addicted. Can a patient’s risk for opioid abuse be determined prior to beginning opioid therapy?  
 
Dr. McCarberg: The first step in the treatment process for any patient is conducting a comprehensive pain assessment.²⁶ This would include a thorough history to characterize the pain and determine when it began; a history of the effectiveness of past analgesia; a physical examination that focuses on the sites of reported and potentially referred pain, and the musculoskeletal and neurologic systems; pertinent laboratory and other diagnostic tests; an evaluation of the patient’s social support system; and an evaluation of psychological function, including depression. In older adults, it is important to also assess cognitive function, as this will determine which pain assessment methods and tools are most appropriate. 

It is equally important to assess a patient’s likelihood of abusing opioid therapy. Several excellent opioid risk assessment tools have been developed specifically for this purpose. They can be administered prior to beginning therapy to give the physician greater confidence in knowing which patients to monitor more carefully.

Q: Risk management is an essential component of treating chronic pain patients. Is this an area that clinicians also need to address with elderly patients?

Dr. McCarberg: Most definitely. As mentioned, there has been a tendency to minimize the risk of opioid abuse in older chronic pain patients. However, they are as susceptible to opioid abuse as chronic pain patients of any age. In general, the incidence of opioid abuse is 2% to 5% among chronic pain patients who do not have a history of substance abuse.³⁷ The AGS also notes that true addiction, characterized by drug craving and continued use despite awareness of harm, is probably rare in older patients with chronic pain when compared to the prevalence of undertreated debilitating pain. Just as in other populations, when aberrant drug-related behaviors are observed, it is important for physicians to be able to distinguish which patients are truly having a problem with opioid abuse and those who seek more drug because their pain is inadequately controlled, which is referred to as pseudoaddiction. Proactive management of substance abuse can best be achieved by initially assessing each patient for their potential risk of opioid abuse, and carefully monitoring for drug-related behaviors once pharmacotherapy has begun.

Q: What types of assessment tools might you use to determine risk of opioid abuse?

Dr. McCarberg: A number of different assessment tools are available that are quick and easy to use in clinical practice. One of these, the Opioid Risk Tool (ORT), is applicable in a variety of clinical settings.³⁸ Of all the available assessments, it is the most predictive of the potential for aberrant behavior. Patients are evaluated for five parameters that predict risk: family history of substance abuse (alcohol, illegal drugs, and prescription drugs), personal history of substance abuse, age, history of preadolescent sexual abuse, and psychological disease. Each possible answer is assigned a numeric value, and the final score determines the likelihood of risk. 

The CAGE questionnaire, another simple assessment tool, is an acronym for Cutting down, Annoyance by criticism, Guilty feeling, and Eye-openers.³⁹ It is a brief four-question assessment that asks patients if they have ever felt the need to Cut down on their alcohol or drug use, been Annoyed by people who criticized their alcohol or drug use, felt bad or Guilty about their alcohol or drug use, or needed an Eye-opener to steady their nerves or get rid of the after effects of alcohol or drugs. At least two positive responses would be indicative of risk for developing a drug abuse problem.

A third assessment, the Screener and Opioid Assessment for Patients in Pain (SOAPP) tool, is a comparatively longer 24-item self-administered questionnaire that captures the key determinants of aberrant drug-related behavior.40 Patients rate questions such as, “How often have you felt a need for higher doses of medication to treat your pain?” Based on frequency, each possible choice is awarded a numerical value of 0 to 4, 0 being never. A total score of 7 or more identifies 91% of patients who are high risk

Really, the most important aspect of assessment is not about which assessment tool is ultimately selected, but about sitting down with the patient, asking the necessary questions, and listening carefully to their responses.

Also, as previously mentioned, if a patient is assessed at-risk for opioid misuse, the finding does not preclude appropriate treatment. The treatment design, however, may be stringent, closely monitored, and may include referral to a specialist, such as an addictionologist or psychologist specializing in patients at risk.

Q: Are there any other precautionary measures that can be taken to prevent opioid abuse?

Dr. McCarberg: Yes.  Another important element of proactive opioid abuse prevention is the use of a treatment or medication-use agreement. As recommended by the Federation of State Medical Boards (FSMB) guidelines, the purpose of a treatment agreement is to set boundaries for the patient and physician by clarifying the terms of treatment.⁴¹ Most treatment agreements stipulate that the patient will not obtain pain medication from any source other than that physician; sell or distribute their medication to anyone else; forge or alter a prescription; and designate the one pharmacy that will fill the opioid prescription.

Regular reevaluation of the patient for drug efficacy and side effects helps patients maintain optimal analgesia, reducing the risk of pseudoaddiction. Patients should also be continually monitored for dangerous or inappropriate drug abuse. This would include opioid use for depression or anxiety and requests for early refills. These precautionary measures have been shown to reduce the abuse rate by 50%.⁴² 

Q: Are there other risk factors that clinicians need to review with elderly patients when prescribing medications for chronic pain?

Dr. McCarberg: Patients should also be advised to be aware of safety issues when storing their medications so that medication is not diverted to other individuals such as caregivers, friends, or family members. 

Q: In conclusion, what are the key points that clinicians need to keep in mind when treating older adult chronic pain patients?

Dr. McCarberg: Our research has shown that overall, older adults with chronic pain seem to be better adjusted, both psychologically and socially, than younger patients with chronic pain. Nevertheless, it is important that clinicians be alert to the presence of chronic pain in this population, since it is very common, although it is often overlooked and undertreated. One reason for this is that patients themselves tend to under report pain, attributing it to the natural process of aging. However, if the pain is interfering with a patient’s functional status and quality of life, it should definitely be assessed and treated. Older adults require the same precautionary measures if they are prescribed opioids, especially in light of the tendency to minimize their potential for addiction. Special attention must also be paid to the presence of polypharmacy and comorbidity in this population, and changes in drug metabolism that accompany aging. The axiom “start low and go slow” is a good rule of thumb.

     
Thank you, Dr. McCarberg. That was very enlightening.

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37. Fishbain DA, Rosomoff HL, Rosomoff RS. Drug abuse, dependence, and addiction in chronic pain patients. Clin J Pain. 1992;8(2):77-85.
38. Webster LR, Webster RM. Predicting aberrant behaviors in opioid-treated patients: validation of the opioid risk tool. Pain Med. 2005;6:432-442. Accessed November 8, 2006. Available at www.emergingsolutionsinpain.com
39. Ewing JA. Detecting alcoholism: The CAGE questionnaire. J Am Med Assoc. 1984;252(14):1905-1907.
40. Akbik H, Butler S, Budman S, et al. Validation and clinical assessment of the screener and opioid assessment for patients in pain. J Pain Symptom Manage.  2006;32:287-293.
41. Joranson DE, Gilson AM, Dahl JL, Haddox JD.  Pain management, controlled substances, and state medical board policy: a decade of change.  J Pain Symptom Manage. 2002;23:138-147.
42. Mancipant L, Manchukonda R, Damron KS, et al. Does adherence monitoring reduce controlled substance abuse in chronic pain patients?  Pain Physician.
    2006;9:57-60.

Appendix.  Assessment Tools for Use in Clinical Practice

1. Shelkey M, Wallace M. Katz Index of Independence in Activities of Daily Living (ADL). The Hartford Institute for Geriatric Nursing.  1998.  Assess the patient’s ability to provide self-care, including bathing, dressing, toileting, transferring, continence, and feeding. Accessed November 8, 2006. Available at www.hartfordign.org
2. Pollard CA. The Pain Disability Index. Percept Mot Skills. 1984;(59):974.  The Pain Disability Index measures 7 categories of life activity, including family/home responsibilities, recreation, social activity, occupation, sexual behavior, self-care, and life-support activity. 
3. Cowan P, Kelly N.  Quality of Life Scale. American Chronic Pain Association. Assesses patient on a 10-point scale from non-functioning to having a normal quality of life. Accessed November 8, 2006. Available at http://www.theacpa.org/managingyourrisk/Quality_of_Life_Scale.pdf
4. Akbik H, Butler S, Budman S, et al.  Validation and clinical assessment of the screener and opioid assessment for patients in pain. J Pain Symptom Manage.2006;32:287-293. A brief 14-question assessment for predicting opioid misuse. Accessed  November 8, 2006. Available at: www.emergingsolutionsinpain.com/opencms/esp/news/index.html
5. Webster LR, Webster RM. Opioid Risk Tool described in Determining the Risk of Opioid Abuse. Predicting aberrant behaviors in opioid-treated patients: validation of the opioid risk tool. Pain Med.2005. Two 5-item assessment tools, one for clinicians and one for patients, that assess opioid risk. Accessed November 8, 2006. Available at: www.emergingsolutionsinpain.com
6. Wu SM, Compton P, Bolus R, et al. The addiction behaviors checklist: validation of a new clinician-based measure of inappropriate opioid use in chronic pain. J Pain Symptom Manage. 2006;32(4):342-351.
7. The Screener and Opioid Assessment for Patients in Pain (SOAPP): Matrix PDF and brief tutorial. Accessed November 8, 2006. Available at: http://www.painedu.org/soap.asp
8. Four-question CAGE assessment tool. Accessed November 8, 2006. Available at: http://www.gpnotebook.co.uk/cache/-1389035520.htm