Development of a metric for a day of manageable pain control: derivation of pain severity cut-points for low back pain and osteoarthritis

Staging joint pain and disability: a brief method using persistence and global severity

OBJECTIVE

Joint pain in older adults is a problem commonly presented to primary care. In contrast to methods for defining and staging the most likely underlying disease (osteoarthritis), clinically practicable methods for staging pain and associated disability are lacking. Our objective was to test a method of brief pain assessment and clinical staging based on recognized focal features of chronic pain and preexisting measurement tools.

METHODS

A total of 781 adults ages > or =50 years who were registered with 3 general practices and were experiencing knee pain within the previous 6 months attended research clinics between August 2002 and September 2003. Pain and associated disability were staged on the basis of self-completed questions on knee pain persistence and global severity (Chronic Pain Grade). These were then compared with participants' appraisals of their knee problem, its perceived importance, negative health states, and consultation behavior.

RESULTS

Knee pain global severity was associated with symptom dissatisfaction, patient prioritizing, oral analgesic intake, mood, mobility limitation, poorer general health, and consultation behavior. Fewer independent associations were found with knee pain persistence. Staging could be performed using only 4 simple questions.

CONCLUSION

Although the usefulness of this approach still needs to be determined in routine clinical settings and across other joint pain sites, our findings suggest that focal characteristics of chronic pain (persistence, global severity) can be used as the basis of brief, simple assessment and staging of joint pain in older adults.

A study of the noninstrumented physical examination of the knee found high observer variability

OBJECTIVE

This study estimated the inter- and intraobserver reliability of a set of noninstrumented physical examination measures for knee pain in older adults.

STUDY DESIGN AND SETTING

Forty-five patients from primary care, and 13 patients from secondary care, were each examined by two out of a team of three physical therapists, and were reexamined by one of these observers 1 month later. The examination items were standardized and included dichotomous, ordinal and continuous variables considered relevant to a primary care context.

RESULTS

For individual dichotomous items, median interobserver and intraobserver agreement (kappa) was 0.22 (interquartile range IQR=0.12-0.35) and 0.41 (IQR=0.28-0.56) respectively. For ordinally rated variables, weighted kappa ranged from -0.08 to 0.43 for interobserver agreement, and from 0.00 to 0.79 for intraobserver agreement. The median intraclass correlation coefficient for continuous examination variables was 0.80 (range 0.68-0.89) for interobserver agreement, and 0.84 (range 0.67-0.95) for intraobserver agreement.

CONCLUSION

For trained but nonexpert examiners, agreement was generally poor for dichotomous and ordinal examination items; however, kappa-values are liable to be depressed by the low prevalence of clinical signs in this sample. Agreement on continuous variables was notably better.

The Prevalence and Occurrence of Diabetic Foot Ulcer Pain and Its Impact on Health-Related Quality of Life

This study describes the prevalence and occurrence of diabetic foot ulcer (DFU) pain and the impact of DFU pain on health-related quality of life (HRQL) using generic and disease specific instruments. Data were obtained from 127 patients with DFU who were recruited from 6 hospital-based diabetic outpatient clinics. HRQL was measured using the Medical Outcome Study-Short Form (SF-36) and the Diabetes Foot Ulcer Scale (DFS). Occurrence of pain was assessed using 2 items from the DFS (ie, pain while walking and/or standing and pain during the night related to foot ulcer problems). Seventy-five percent reported some pain related to DFU and 57% reported DFU pain while walking and/or standing and also during the night. Twenty-five percent reported pain none of the time. A higher percentage of patients with pain reported having a prescription for an analgesic medication than those without pain. Patients who reported pain most or all of the time had statistically and clinically significantly poorer HRQL than those who did not report pain. These findings suggest that pain associated with DFU is a significant clinical problem. Additional research is warranted to further characterize the pain associated with DFU and its impact on patient outcomes and HRQL.

PERSPECTIVE

Numerous basic and clinical studies have focused on pain associated with diabetic peripheral neuropathy. Findings from this study suggest a new pain problem in patients with diabetes, namely, pain associated with foot ulcers, that warrants further investigation.

Categorising the severity of neck pain: Establishment of cut-points for use in clinical and epidemiological research

Grading pain intensity scales into simple categories provides useful information for both clinicians and epidemiologists and methods to classify pain severity for numerical rating scales have been recommended. However, the establishment of cut-points is still in its infancy and little is known as to whether cut-points are affected by age or gender. The objectives of this paper were to establish optimal cut-points in pain severity in individuals with neck pain (NP) and to investigate if the cut-points were influenced by gender, age, and NP duration. Data from the population-based ;Funen Neck and Chest Pain Study' was used. Univariate and multivariate analyses of variance were performed to calculate optimal single and double cut-points for three different pain intensity scores within the past 2 weeks relative to two neck disability scales (;global assessment of NP' and the ;Copenhagen Neck Functional Disability Scale'). The two disability scales showed small differences in optimal cut-points. Furthermore, cut-points changed for each of the three pain intensity scales. Only small gender differences in cut-points were seen and no specific trend was noted in either single or double cut-points in different age groups. The cut-points were almost identical for acute, subacute, and chronic NP. This paper has implications for understanding the impact of using different pain intensity scales and provides reference cut-points in NP for use in future clinical and epidemiological research.

Pain severity in diabetic peripheral neuropathy is associated with patient functioning, symptom levels of anxiety and depression, and sleep

Our goal was to evaluate pain severity, pain-related interference with function, sleep impairment, symptom levels of anxiety and depression, and quality of life among patients with painful diabetic peripheral neuropathy (DPN). Participants in a burden of illness survey (n = 255) completed the modified Brief Pain Inventory-DPN (BPI-DPN), MOS Sleep Scale, Hospital Anxiety and Depression Scale (HADS), Short Form Health Survey-12v2 (SF-12v2), and the EuroQoL (EQ-5D). Patients were 61 +/- 12.8 years old (51.4% female), had diabetes for 12 +/- 10.3 years and painful DPN for 6.4 +/- 6.4 years. Average and Worst Pain scores (BPI-DPN, 0-10 scales) were 5.0 +/- 2.5 and 5.6 +/- 2.8. Pain substantially interfered (>or=4 on 0-10 scales) with walking ability, normal work, sleep, enjoyment of life, mood, and general activity. Moderate to severe symptom levels of anxiety and depression (HADS-A and HADS-D scores >or=11 on 0-21 scales) occurred in 35% and 28% of patients, respectively. Patients reported greater sleep problems compared with the general U.S. population and significant impairment in both physical and mental functioning (SF-12v2) compared with subjects with diabetes. The mean EQ-5D utility score was 0.5 +/- 0.3. Greater pain levels in DPN (mild to moderate to severe) corresponded with higher symptom levels of anxiety and depression, more sleep problems, and lower utility ratings and physical and mental functioning, (all Ps < 0.01). Painful DPN is associated with decrements in many aspects of patients' lives: physical and emotional functioning, affective symptoms, and sleep problems. The negative impact is higher in patients with greater pain severity.

Safety and effectiveness of topiramate for the management of painful diabetic peripheral neuropathy in an open-label extension study

OBJECTIVE

The aim of this study was to further assess the long-term safety and effectiveness of open-label topiramate therapy in subjects with moderately to severely painful diabetic peripheral neuropathy (DPN).

METHODS

Adults aged 18 to 75 years received open-label topiramate (25-600 mg/d for 26 weeks) in an extension of a previously published randomized, double-blind trial comparing topiramate with placebo. Safety analyses included adverse event (AE) reports and clinical laboratory tests. Metabolic end points included body weight and glycosylated hemoglobin (HbA(1c)). Effectiveness analyses included a 100-mm pain visual analog (PVA) scale, worst and current pain severity, and sleep disruption.

RESULTS

Two hundred five subjects participated in this open-label extension study (118 formerly treated with topiramate and 87 who formerly received placebo). The groups did not differ in baseline demographics or disease characteristics. One hundred twenty-four (60.5%) subjects (68.6% of former topiramate recipients and 49.4% of former placebo recipients) completed the extension study; the most common reason for discontinuation was an AE (27.3% of subjects). AEs among subjects who received > or =1 dose of topiramate (n = 298) included upper respiratory tract infection (16.1%), anorexia (15.1%), diarrhea (12.8%), nausea (12.8%), paresthesia (10.7%), and headache (10.1%). Baseline pain scores were lower in those formerly treated with topiramate (n = 117) than in the former placebo group (n = 86) (PVA: 43.3 vs 52.5, P = 0.014; worst pain: 1.9 vs 2.5, P < 0.001; current pain: 1.6 vs 1.9, P = 0.026; sleep disruption: 3.6 vs 4.6, P = 0.021). At the final visit, PVA, current pain, and sleep disruption scores were not significantly different between the former topiramate and former placebo groups, but worst pain differed significantly (1.4 vs 1.8; P = 0.025). Mean weight loss from the start of topiramate therapy was 5.2 and 5.3 kg in the former topiramate and former placebo groups, respectively (P < 0.001 vs baseline). Mean HbA(1c) values before and after topiramate treatment were 7.7% and 7.4%, respectively, in the former topiramate group (P = 0.004 vs baseline), and 7.6% and 7.1%, respectively, in the former placebo group (P < 0.001 vs baseline).

CONCLUSION

Although 39.5% of subjects discontinued, most often due to AEs, the results of this 26-week, open-label extension study with topiramate (up to 600 mg/d) in subjects with moderately to severely painful DPN suggest that pain relief was effective and durable.

The Burden of Pain on Employee Health and Productivity at a Major Provider of Business Services

OBJECTIVE

The objective of this study was to examine the burden of pain on employee health and productivity at a Fortune 100 company headquartered in the northeastern United States to prioritize target areas for reducing this burden.

METHODS

An electronic survey was conducted in late 2004, which produced a reasonably representative national sample of 1039 active employee respondents.

RESULTS

A total of 28.6% of respondents met the study definition for pain. Pain was linked to: 1) drops of more than 45% and 23%, respectively, in Overall Physical and Mental Health; 2) a fivefold increase in health-induced limitations in work performance; and 3) nearly three and two thirds workdays lost to presenteeism and absenteeism over a 4-week period. Afflicted workers displayed considerable room for improvement in their capacity for pain control and management.

CONCLUSIONS

The prevalence of pain and its impact on those with the condition combine to make it an area of much opportunity for improving workforce health and productivity. Musculoskeletal diseases offer a promising initial target for corporate intervention.

The association between pain and disability

A clearer understanding of how pain intensity relates to disability could have important implications for pain treatment goals and definitions of treatment success. The objectives of this study were to determine the optimal pain intensity rating (0-10 scale) cutpoints for discriminating disability levels among individuals with work-related carpal tunnel syndrome (CTS) and low back (LB) injuries, whether these cutpoints differed for these conditions and for different disability measures, and whether the relationship between pain intensity and disability was linear in each injury group. Approximately 3 weeks after filing work injury claims, 2183 workers (1059 CTS; 1124 LB) who still had pain completed pain and disability measures. In the LB group, pain intensity rating categories of 1-4, 5-6, and 7-10 optimally discriminated disability levels for all four disability measures examined. In the CTS group, no pain intensity rating categorization scheme proved superior across all disability measures. For all disability measures examined, the relationship between pain intensity and disability level was linear in the CTS group, but nonlinear in the LB group. Among study participants with work-related back injuries, when pain level was 1-4, a decrease in pain of more than 1-point corresponded to clinically meaningful improvement in functioning, but when pain was rated as 5-10, a 2-point decrease was necessary for clinically meaningful improvement in functioning. The findings indicate that classifying numerical pain ratings into categories corresponding to levels of disability may be useful in establishing treatment goals, but that classification schemes must be validated separately for different pain conditions.

Identification of cut-points for mild, moderate and severe pain due to diabetic peripheral neuropathy

This study identified discrete categories of pain severity in a sample of patients with painful diabetic peripheral neuropathy (DPN), through derivation of cut-points on a 0-10 scale of pain severity (Brief Pain Inventory-DPN, BPI-DPN). Subjects were participants in a burden of illness survey (N=255). Serlin and colleagues' method establishing cut-points for cancer pain was adapted, considering all possible cut-points between 4 and 8. Optimal cut-points were those that created three pain severity categories producing maximum between-category differences on the seven BPI-DPN Interference items, using MANOVA. Cut-points of 4 and 7 optimally classified the sample for both Worst Pain and Average Pain, creating categories of mild, 0-3; moderate, 4-6; severe, 7 and higher (Hotelling's T(2)=22.95 and 16.20 for Worst and Average Pain, P<0.0001). Mean BPI-DPN Interference was 2.1 (SD=2.1), 4.9 (SD=1.9) and 7.4 (SD=1.6) for the mild, moderate and severe pain categories. Patients in the three categories differed significantly on patient-rated outcomes (Medical Outcomes Study Short Form-12v2 Mental and Physical Component Summaries and EuroQOL utility score), and on DPN-related healthcare visits (P<0.001). The labels 'mild, moderate and severe' Worst and Average Pain corresponded with patients' ratings of their pain using a verbal rating scale. This research shows that three categories of DPN pain severity can be identified based on interference with daily function, and that these categories are associated with patient outcomes and medical utilization.

Categorizing the severity of cancer pain: further exploration of the establishment of cutpoints

Previous work by Serlin and colleagues [Serlin R C, Mendoza T R, Nakamura Y, Edwards K R, Cleeland C S. When is cancer pain mild, moderate, or severe? Grading pain severity by its interference with function. Pain 1995;61:277-84] established cutpoints for mild, moderate, and severe cancer pain based on the pain's level of interference with function. Recent work [Jensen M P, Smith D G, Ehde D M, Robinson L R. Pain site and the effects of amputation pain: further clarification of the meaning of mild, moderate, and severe pain. Pain 2001;91:317-22; Zelman D C, Hoffman D L, Seifeldin R, Dukes, E. Development of a metric for a day of manageable pain control: derivation of pain severity cutpoints for low back pain and osteoarthritis. Pain 2003;106(1/2):35-42]found differences in cutpoints for pain severity for different pain-related conditions. Reasons for these discrepancies may relate to the methods used to determine the cutpoints or to differences based on the type or the cause of the pain. The purposes of this study were to determine the optimal cutpoints for mild, moderate, and severe pain based on patients' ratings of average and worst pain severity, using a larger range of potential cutpoints, and to determine if those cutpoints distinguished among the three pain severity groups on several outcome measures. Results from a homogenous sample of oncology outpatients with pain from bone metastasis confirm a non-linear relationship between cancer pain severity and interference with function and also confirm that the boundary between a mild and a moderate level of cancer pain is at 4 on a 0-10 numeric rating scale. However, this analysis did not confirm the boundary between moderate and severe cancer pain previously described by Serlin and colleagues [Serlin R C, Mendoza T R, Nakamura Y, Edwards K R, Cleeland C S. When is cancer pain mild, moderate, or severe? Grading pain severity by its interference with function. Pain 1995;61:277-84]. In addition, these results were not consistent with the cutpoints that were found for back pain, phantom limb pain, pain 'in general', or osteoarthritis pain reported by Jensen and colleagues and Zelman and colleagues [Jensen M P, Smith D G, Ehde D M, Robinson L R. Pain site and the effects of amputation pain: further clarification of the meaning of mild, moderate, and severe pain. Pain 2001;91:317-22; Zelman D C, Hoffman D L, Seifeldin R, Dukes, E. Development of a metric for a day of manageable pain control: derivation of pain severity cutpoints for low back pain and osteoarthritis. Pain 2003;106(1/2):35-42]. Possible explanations for these differences are discussed, as well as implications for future research.

Acceptable, manageable, and tolerable days: patient daily goals for medication management of persistent pain

Although the construct of "a symptom-free day" has been widely applied in asthma and gastric reflux disease, there is no analogous concept in the field of pain management. This study represents the initial development of a "day of acceptable or manageable pain control," a construct which reflects patients' daily strategic use of pain medication in order to allow the accomplishment of desired activities while minimizing side effects. Focus group methodology was used to extract patient-generated themes of "an acceptable day of pain control." Fifty-three outpatients with persistent moderate to severe average pain intensity due to osteoarthritis (n=18), metastatic cancer (n=15), and low back pain (n=20) participated. Participants preferred the term "manageable" or "tolerable" to "acceptable." Thematic analysis revealed components of a manageable/tolerable day of pain control as including: 1) taking the edge off the pain, 2) performing valued activities; 3) relief from dysphoria and irritability; 4) reduced medication side effects; 5) feeling well enough to socialize. Additional cancer-specific themes included relief from fatigue and ability to have a positive day when one's future days were perceived as being limited. The set of themes is presented and their relevance for developing a measure of "a manageable day of pain control" discussed. Study findings identify a novel construct that can inform development of an outcome for evaluating the effectiveness of different pharmacotherapies for pain management.