Pain Intensity Numerical Rating Scale Research Articles

Validation of the Critical-Care Pain Observation Tool in Adult Critically Ill Patients

Effective management of pain begins with accurate assessment of its presence and severity, which is difficult in critically ill patients. The Critical-Care Pain Observation Tool (CPOT) was developed to evaluate behaviors associated with pain and validated primarily with cardiac surgical patients. The purpose of this study was to examine reliability and validity of the CPOT in a general population of adult, critically ill patients. Using a sample of 75 patients from critical care units of a community hospital, pain was evaluated at 3 times (prerepositioning, during repositioning, and postrepositioning) by 2 evaluators, using 3 different pain scales: CPOT; Faces, Legs, Activity, Cry, and Consolability (FLACC) scale; and Pain Intensity Numeric Rating Scale. Results indicated that reliability and validity of the CPOT were acceptable. Interrater reliability was supported by strong intraclass correlations (ranging from 0.74 to 0.91). For criterion-related validity, significant associations were found between CPOT scores and both FLACC (0.87-0.92) and Pain Intensity Numeric Rating Scale (0.50-0.69) scores. Discriminant validity was supported by significantly higher scores during repositioning (mean, 1.85) versus at rest (pre mean, 0.60; post mean, 0.65). The CPOT is an acceptable behavioral pain assessment scale for use in the general critical care patient population and is more appropriate for use with adults than the FLACC.

Place of neurocryostimulation in the treatment of post-traumatic pain in Emergency Department

ObjectiveThis work was designed to assess the antalgic effect of neurocryostimulation on traumatic pain in the emergency room.MethodsThis prospective cohort study was conducted in an emergency room during 12 days. Patients who were more than 12-year-old and admitted to the emergency room for up to 24 h for trauma pain were included. After pain assessment by a pain intensity numeric rating scale (PRS; score 0 to 100) during the first medical contact (t0), the patients received a single neurocryostimulation session. Pain intensity was re-evaluated just after the cryotherapy session (t1), and when the patients went out of the emergency room (t2). Results: Forty-nine patients were included in this study. During the first medical contact (t0), the average pain intensity was about 63 ± 16. The pain score rapidly decreased to 46 ± 23 (27% of reduction, P < 0.05) after the neurocryostimulation session (t1). Pain decrease was constant: the value of pain intensity at the release of the patients from the emergency room was 34 ± 20 (46% of reduction, P < 0.05). The decrease of pain intensity tends to be more important for patients with a PRS ≥ 70 (49% of reduction, P < 0.05).ConclusionNeurocryostimulation is an effective antalgic technique for emergency trauma for mild and major pains, as a supplement to usual antalgic treatments.

Percutaneous dorsal root ganglion lysis with phenol for the treatment of pain associated with thoracic compression fracture

Symptomatic thoracic compression fracture is one of the most common causes of back pain in elderly. Although vertebroplasty is widely utilized in patients when conservative treatment fails, we introduced an alternative percutaneous technique for the treatment of thoracic compression pain. This in a retrospective study. The analysis was performed on 28 consecutive patients who underwent undergoing percutaneous dorsal root ganglion lysis with phenol for the treatment of pain associated with thoracic compression fracture. An acceptable treatment outcome was operationally defined as a pain intensity numerical rating scale (NRS) score of 3 or lower or EQ-5D index of 0.672 or higher. The primary outcome was pain relief and acceptable treatment outcome at 1 day, 1 week, 1 month, and 1 year. Of the 28 cases treated with our procedures, the change in mean NRS score between baseline and one day was -2.5 (95 % CI -1.6 ~ -3.4, p < 0.001), between baseline and one week was -4.7 (-4.1 to -5.3, p < 0.001), between baseline and one month was -5.8 (-5.2 to -6.5, p < 0.001), and between baseline and one year was -6.3 (-5.6 to -7.1, p < 0.001). An acceptable treatment outcome was 14 % one day after the procedure, 46 % at one week, 72 % at one month, and 84 % at one year. Complication rate was 3.6 %. For thoracic compression fracture patients, percutaneous dorsal root ganglion lysis with phenol is an effective, and safe alternative treatment method worth considering. Pain relief is fast and persists for one year.

Pregabalin beneficial effects on sleep quality or health-related quality of life are poorly correlated with reduction on pain intensity

Pregabalin beneficial effects on sleep quality or health-related quality of life are poorly correlated with reduction on pain intensity

Low Pain Intensity After Opioid Withdrawal as a First Step of a Comprehensive Pain Rehabilitation Program Predicts Long-term Nonuse of Opioids in Chronic Noncancer Pain

In specialized pain clinics there is an increasing number of patients with severe chronic noncancer pain (CNCP) despite long-term opioid medication. Few clinical studies show short-term pain relief after opioid withdrawal (OW). We have evaluated the relation between pain intensity after OW and long-term opioid nonuse. One hundred two consecutive patients with severe CNCP despite opioid medication (mean treatment duration, 43 mo) reported pain intensity (numerical rating scale, 0 to 10), Pain Disability Index, mood (CES-D), and quality of life (Short Form 36) before, shortly, and 12 to 24 months after inpatient OW. Total opioid withdrawal (n = 78) or significant dose reduction (DR; n = 24, mean reduction, 82%) was performed after individual decision. Opioid intake 12 to 24 months later, respectively dose increase ≥ 100% (DR group), was considered relapse. T tests, multivariable analysis of variance, logistic regression. After OW current pain intensity significantly decreased on an average by 41% (6.4 ± 2.4 vs. 3.8 ± 2.5), maximal and average pain by 18% and 24%, respectively. Twelve to 24 months later 42 patients (41%) relapsed (31 of the total opioid withdrawal group, 6 of the DR group, 5 lost). Patients without later relapse showed significantly lower pain scores than the later relapsed patients already shortly after OW (5.0 ± 2.2 vs. 5.9 ± 2.1) and 12 to 24 months later (5.5 ± 2.4 vs. 6.5 ± 2.0). There was a significant relation between relapse probability and pain intensity immediately after OW. In many patients with severe CNCP, despite opioid medication, sustainable pain relief can be achieved if OW is included in the rehabilitation program. Consequently, we recommend OW for opioid-resistant CNCP before any opioid escalation. Lower pain intensity shortly after OW may predict the long-term opioid nonuse probability.

Electroacupuncture to treat painful diabetic neuropathy: study protocol for a three-armed, randomized, controlled pilot trial

BackgroundThe purpose of this study is to conduct a basic analysis of the effectiveness and safety of electroacupuncture in the treatment of painful diabetic neuropathy (PDN) as compared to placebo and usual care and to evaluate the feasibility of large-scale clinical research.Methods/designThis study is a protocol for a three-armed, randomized, patient-assessor-blinded (to the type of treatment), controlled pilot trial. Forty-five participants with a ≥ six month history of PDN and a mean weekly pain score of ≥ 4 on the 11-point Pain Intensity Numerical Rating Scale (PI-NRS) will be assigned to the electroacupuncture group (n = 15), sham group (n = 15) or usual care group (n = 15). The participants assigned to the electroacupuncture group will receive electroacupuncture (remaining for 30 minutes with a mixed current of 2 Hz/120 Hz and 80% of the bearable intensity) at 12 standard acupuncture points (bilateral ST36, GB39, SP9, SP6, LR3 and GB41) twice per week for eight weeks (a total of 16 sessions) as well as the usual care. The participants in the sham group will receive sham electroacupuncture (no electrical current will be passed to the needle, but the light will be seen, and the sound of the pulse generator will be heard by the participants) at non-acupuncture points as well as the usual care. The participants in the usual care group will not receive electroacupuncture treatment during the study period and will receive only the usual care. The follow-up will be in the 5th, 9th and 17th weeks after random allocation. The PI-NRS score assessed at the ninth week will be the primary outcome measurement used in this study. The Short-Form McGill Pain Questionnaire (SF-MPQ), a sleep disturbance score (11-point Likert scale), the Short-Form 36v2 Health Survey (SF-36), the Beck Depression Inventory (BDI) and the Patient Global Impression of Change (PGIC) will be used as outcome variables to evaluate the effectiveness of the acupuncture. Safety will be assessed at every visit.DiscussionThe result of this trial will provide a basis for the effectiveness and safety of electroacupuncture for PDN.Trial registrationClinical Research information Service. Unique identifier: KCT0000466.

A Double-Blind, Placebo-Controlled, Crossover Pilot Trial With Extension Using an Oral Mucosal Cannabinoid Extract for Treatment of Chemotherapy-Induced Neuropathic Pain

ContextNeuropathic pain caused by chemotherapy limits dosing and duration of potentially life-saving anti-cancer treatment and impairs quality of life. Chemotherapeutic neuropathy responds poorly to conventional treatments, and there is an urgent medical need for new treatments. Recent preclinical studies demonstrate that cannabinoid agonists suppress established chemotherapy-evoked neuropathy. ObjectivesThis was a pilot trial to begin to investigate a currently available cannabinoid agent, nabiximols (oral mucosal spray containing cannabinoids), in the treatment of chemotherapy-induced neuropathic pain. MethodsA randomized, placebo-controlled crossover pilot study was done in 16 patients with established chemotherapy-induced neuropathic pain. A 0–10 point numeric rating scale for pain intensity (NRS-PI) was used as the primary outcome measure. ResultsWhen examining the whole group, there was no statistically significant difference between the treatment and the placebo groups on the NRS-PI. A responder analysis demonstrated that there were five participants who reported a two-point or greater reduction in pain that trended toward statistical significance and the number needed to treat was five. ConclusionChemotherapy-induced neuropathic pain is particularly resistant to currently available treatments. This pilot trial found a number needed to treat of five and an average decrease of 2.6 on an 11-point NRS-PI in five “responders” (as compared with a decrease of 0.6 with placebo) and supports that it is worthwhile to study nabiximols in a full randomized, placebo-controlled trial of chemotherapy-induced neuropathic pain.

THU0356 Benefits of a multidisciplinary treatment in women with fibromyalgia and obesity

BackgroundFibromyalgia (FM) is a musculoskeletal chronic pain condition with low response to pharmacological conventional treatment (CPhT). Multidisciplinary treatment (MT) has showed efficacy in improving FM symptoms. Nevertheless, MT has not...

AB1099 Obesity and fibromyalgia: Relationship between body mass index and severity of the symptoms

BackgroundFibromyalgia (FM) is a prevalent musculoskeletal chronic pain condition. Obesity is frequent in patients with FM. Several studies suggests that body mass index (BMI) is related with pain intensity and...

Rasch-built Overall Disability Scale for patients with chemotherapy-induced peripheral neuropathy (CIPN-R-ODS)

Chemotherapy-induced peripheral neuropathy (CIPN) is a common neurological side-effect of cancer treatment and may lead to declines in patients’ daily functioning and quality of life. To date, there are no modern clinimetrically well-evaluated outcome measures available to assess disability in CIPN patients. The objective of the study was to develop an interval-weighted scale to capture activity limitations and participation restrictions in CIPN patients using the Rasch methodology and to determine its validity and reliability properties. A preliminary Rasch-built Overall Disability Scale (pre-R-ODS) comprising 146 items was assessed twice (interval: 2–3weeks; test–retest reliability) in 281 CIPN patients with a stable clinical condition. The obtained data were subjected to Rasch analyses to determine whether model expectations would be met, and if necessarily, adaptations were made to obtain proper model fit (internal validity). External validity was obtained by correlating the CIPN-R-ODS with the National Cancer Institute-Common Toxicity Criteria (NCI-CTC) neuropathy scales and the Pain-Intensity Numeric-Rating-Scale (PI-NRS).The preliminary R-ODS did not meet Rasch model’s expectations. Items displaying misfit statistics, disordered thresholds, item bias or local dependency were systematically removed. The final CIPN-R-ODS consisting of 28 items fulfilled all the model’s expectations with proper validity and reliability, and was unidimensional.The final CIPN-R-ODS is a Rasch-built disease-specific, interval measure suitable to detect disability in CIPN patients and bypasses the shortcomings of classical test theory ordinal-based measures. Its use is recommended in future clinical trials in CIPN.

Effectiveness and gastrointestinal tolerability during conversion and titration with once-daily OROS&amp;reg; hydromorphone extended release in opioid-tolerant patients with chronic low back pain

PurposeTo describe the efficacy and safety of hydromorphone extended-release tablets (OROS hydromorphone ER) during dose conversion and titration.Patients and methodsA total of 459 opioid-tolerant adults with chronic moderate to severe low back pain participated in an open-label, 2- to 4-week conversion/titration phase of a double-blind, placebo-controlled, randomized withdrawal trial, conducted at 70 centers in the United States. Patients were converted to once-daily OROS hydromorphone ER at 75% of the equianalgesic dose of their prior total daily opioid dose (5:1 conversion ratio), and titrated as frequently as every 3 days to a maximum dose of 64 mg/day. The primary outcome measure was change in pain intensity numeric rating scale; additional assessments included the Patient Global Assessment and the Roland–Morris Disability Questionnaire scores. Safety assessments were performed at each visit and consisted of recording and monitoring all adverse events (AEs) and serious AEs.ResultsMean (standard deviation) final daily dose of OROS hydromorphone ER was 37.5 (17.8) mg. Mean (standard error of the mean [SEM]) numeric rating scale scores decreased from 6.6 (0.1) at screening to 4.3 (0.1) at the final titration visit (mean [SEM] change, −2.3 [0.1], representing a 34.8% reduction). Mean (SEM) change in Patient Global Assessment was −0.6 (0.1), and mean change (SEM) in the Roland–Morris Disability Questionnaire was −2.8 (0.3). Patients achieving a stable dose showed greater improvement than patients who discontinued during titration for each of these measures (P < 0.001). Almost 80% of patients achieving a stable dose (213/268) had a ≥30% reduction in pain. Commonly reported AEs were constipation (15.4%), nausea (11.9%), somnolence (8.7%), headache (7.8%), and vomiting (6.5%); 13.0% discontinued from the study due to AEs.ConclusionThe majority of opioid-tolerant patients with chronic low back pain were successfully converted to effective doses of OROS hydromorphone ER within 2 to 4 weeks.

Bilateral Thoracic Splanchnic Nerve Radiofrequency Thermocoagulation for the Management of End-Stage Pancreatic Abdominal Cancer Pain

Background: Pancreatic cancer pain is often severe and refractory to conservative therapies. Several interventional techniques have been described for the management of end-stage pancreatic cancer pain, with variable results and complications. Objectives: The aim of this study was to assess the efficacy of bilateral radiofrequency thermocoagulation of splanchnic nerves for pain relief, the consumption of opioids, and the quality of life in patients suffering from severe pain due to pancreatic malignancies. Study Design: A retrospective observational design. Setting: The study includes patients with end-stage pancreatic abdominal cancer pain, which is refractory to conservative treatment. Methods: Thirty-five patients were studied. They were evaluated prior to and after the radiofrequency thermocoagulation of both splanchnic nerves under fluoroscopic guidance. The assessment included the pain intensity (Numeric Rating Scale 0 – 10), quality of life (selfreported quality of life score 0 – 10), and 24-hour consumption of opioids with monthly follow-up visits until the end of life. Results: Follow-up was completed 6 months after the intervention. The pain scores, quality of life, and consumption of opioids were significantly improved during the entire follow-up period. A slight deterioration was noticed during the fifth month because of malignancy progression. No complications that could be attributed to the technique were observed. Limitations: The study was not prospective and does not have a control group with a different intervention for comparisons. Conclusion: Radiofrequency thermocoagulation of both splanchnic nerves may offer a safe and effective technique for pain management and quality of life improvement in patients with end-stage pancreatic cancer towards the end of life. Key words: Splanchnic nerves, radiofrequency thermocoagulation, pancreatic cancer, pain

Identification of pain-related psychological risk factors for the development and maintenance of pediatric chronic postsurgical pain

BackgroundThe goals of this study were to examine the trajectory of pediatric chronic postsurgical pain (CPSP) over the first year after surgery and to identify acute postsurgical predictors of CPSP.MethodsEighty-three children aged 8–18 years (mean 13.8, standard deviation 2.4) who underwent major orthopedic or general surgery completed pain and pain-related psychological measures at 48–72 hours, 2 weeks (pain anxiety and pain measures only), and 6 and 12 months after surgery.ResultsResults showed that 1 year after surgery, 22% of children developed moderate to severe CPSP with minimal functional disability. Children who reported a Numeric Rating Scale pain-intensity score ≥ 3 out of 10 two weeks after discharge were more than three times as likely to develop moderate/severe CPSP at 6 months and more than twice as likely to develop moderate/severe CPSP at 12 months than those who reported a Numeric Rating Scale pain score < 3 (6-month relative risk 3.3, 95% confidence interval 1.2–9.0 and 12-month relative risk 2.5, 95% confidence interval 0.9–7.5). Pain unpleasantness predicted the transition from acute to moderate/severe CPSP, whereas anxiety sensitivity predicted the maintenance of moderate/severe CPSP from 6 to 12 months after surgery.ConclusionsThis study highlights the prevalence of pediatric CPSP and the role played by psychological variables in its development/maintenance. Risk factors that are associated with the development of CPSP are different from those that maintain it.

Preliminary Validation of the Defense and Veterans Pain Rating Scale (DVPRS) in a Military Population

The Army Surgeon General released the Pain Management Task Force final report in May 2010. Among military providers, concerns were raised that the standard numeric rating scale (NRS) for pain was inconsistently administered and of questionable clinical value. In response, the Defense and Veterans Pain Rating Scale (DVPRS) was developed. The instrument design integrates pain rating scale features to improve interpretability of incremental pain intensity levels, and to improve communication and documentation across all transitions of care. A convenience sample of 350 inpatient and outpatient active duty or retired military service members participated in the study at Walter Reed Army Medical Center. Participants completed the five-item DVPRS-one pain intensity NRS with and without word descriptors presented in random order and four supplemental items measuring general activity, sleep, mood, and level of stress and the Brief Pain Inventory seven interference items. Using systematic sampling, a random sample was selected for a word descriptor validation procedure matching word phases to corresponding pain intensity on the NRS. Parallel forms reliability and concurrent validity testing demonstrated a robust correlation. When the DVPRS was presented with the word descriptors first, the correlation between the two ratings was slightly higher, r = 0.929 (N = 171; P < 0.001), than ordering first without the descriptors, r = 0.882 (N = 177; P < 0.001). Intraclass correlation coefficient was 0.943 showing excellent alignment of word descriptors by respondents (N = 42), matching them correctly with pain level. The DVPRS tool demonstrated acceptable psychometric properties in a military population.

Analgesic efficacy and safety of the novel p38 MAP kinase inhibitor, losmapimod, in patients with neuropathic pain following peripheral nerve injury: a double‐blind, placebo‐controlled study

Inhibitors of p38 mitogen-activated protein kinase are undergoing evaluation as a novel class of anti-rheumatic drugs, by virtue of their ability to suppress the production of pro-inflammatory cytokines. Emerging data suggests that they may also attenuate peripheral or central sensitization in neuropathic pain. A double-blind, placebo-controlled study was undertaken to evaluate the analgesic efficacy of losmapimod (GW856553), a novel p38α/β inhibitor, in subjects with neuropathic pain following traumatic peripheral nerve injury. One hundred and sixty-eight subjects with pain of at least moderate intensity (average daily score ≥4 on an 11-point pain intensity numeric rating scale; PI-NRS) at baseline were randomized to receive oral losmapimod, 7.5 mg BID or placebo for 28 days. Efficacy and safety assessments were undertaken at weekly clinic visits. The mean treatment difference for the change in average daily pain score from baseline to week 4 of treatment based on the PI-NRS was -0.22 (95% CI -0.73, 0.28) in favour of losmapimod over placebo (p = 0.39). There were no statistically significant or clinically meaningful differences between the treatment groups over the 4-week dosing period for either the primary or secondary efficacy variables. There were no unexpected safety or tolerability findings following dosing with losmapimod. Losmapimod could not be differentiated from placebo in terms of a primary analgesia response in patients with pain following peripheral nerve injury. The lack of response could reflect inadequate exposure at central sites of action or differences between rodent and human with respect to the target or neuropathic pain mechanisms.

A Randomized, Controlled Trial of Gabapentin Enacarbil in Subjects with Neuropathic Pain Associated with Diabetic Peripheral Neuropathy

Gabapentin enacarbil (GEn), a transported prodrug of gabapentin, provides sustained, dose-proportional gabapentin exposure. The purpose of this study was to investigate the dose response of GEn to select the optimal dose(s) for clinical use in subsequent diabetic peripheral neuropathy (DPN) trials. This was a multicenter, randomized, double-blind, double-dummy, parallel group, placebo-controlled trial with a study duration of approximately 20weeks (Clinicaltrials.gov database, Identifier ! NCT00643760). Pregabalin (PGB) (Lyrica(®) ; Pfizer Inc.) was used as an active control to provide assay sensitivity of the trial. A total of 421 adult subjects with DPN were randomized in a ratio of 2:1:1:1:2 to receive oral GEn 3,600mg/day, GEn 2,400mg/day, GEn 1,200mg/day, PGB 300mg/day, or matching placebo, respectively. The primary efficacy endpoint was change from baseline to end of maintenance treatment with respect to the mean 24-hour average pain intensity score based on an 11-point Pain Intensity Numerical Rating Scale (PI-NRS). Safety and tolerability assessments included treatment-emergent adverse events (TEAEs), laboratory evaluations, vital signs, electrocardiograms (ECG), neurological examination, and pedal edema. The adjusted mean difference vs. placebo at the end of maintenance treatment with respect to the mean 24-hour average PI-NRS pain intensity score for GEn 1,200mg (-0.35; [95% CI: -1.02, 0.31]; P=0.295), GEn 2,400mg (-0.02; [95% CI: -0.71, 0.66]; P=0.946), and GEn 3,600mg (-0.55; [95% CI: -1.10, 0.01]; P=0.105) was not statistically significant. The active control, PGB (300mg/day), did not differentiate from placebo. Overall, none of the GEn treatment groups differentiated from placebo. Analyses of the secondary endpoints showed comparable results across treatment groups. However, the majority of the endpoints, including all of the pain endpoints, showed the largest numerical treatment difference was between GEn 3,600mg and placebo. The active control, PGB (300mg/day), did not differentiate from placebo.

Exploring the Causes of Neck Pain and Disability as Perceived by Those Who Experience the Condition: A Mixed-Methods Study

Designing effective treatment protocols for neck-related disability has proven difficult. Disability has been examined from structural, emotional, and cognitive perspectives, with evidence supporting a multidimensional nature. The patient’s perspective of their condition has found increasing value for patient-centred, evidence-informed care. This cross-sectional study utilized descriptive thematic analysis to examine perceptions of causation in 118 people with neck pain. The Brief Illness Perceptions Questionnaire was used to capture perceptions of causation for neck pain symptoms. The Neck Disability Index, the Pain Catastrophizing Scale, the Hospital Anxiety and Depression Scale, and the P4 pain intensity numeric rating scale were also collected. Eight main themes were found for the cause(s) of neck pain: posture and movement, structure and mechanism, emotions, predisposition and lifestyle, symptoms, fatigue and insomnia, treatment, and environment. A series of regression models stratified by perceived cause suggested that disability could be explained by different constructs across the larger of the main themes. The findings are discussed in terms of the false view that mechanical neck pain should be considered a homogenous condition and potential application to treatment decision making based on patient perspectives.

Intraoperative injection of bupivacaine‐adrenaline close to the fascia reduces morphine requirements after cesarean section: a randomized controlled trial

The purpose of this study was to investigate whether a single injection of bupivacaine with adrenaline close to the fascia could decrease opiate consumption and pain in patients undergoing cesarean section in spinal anesthesia. Randomized double-blind controlled study. Karolinska University Hospital, Huddinge, Sweden. 260 women scheduled for elective cesarean section were enrolled in the study. The treatment group (n= 130) received 40 mL bupivacaine (2.5 mg/mL) with adrenaline (5 μg/mL) (Marcain® adrenalin) and the control group (n= 130) received 40 mL saline solution (0.9%), which was, in both groups, injected close to the fascia before closure of the wound. Morphine consumption and mean resting pain intensity numerical rating scale at 12 and 24 hours were the primary outcome variables. Other assessments for pain as well as mobilization parameters were considered secondary. Morphine requirements were significantly less in the bupivacaine group, 19.0 mg/woman, compared with 24.0 mg/woman in the placebo group, during the first 12 postoperative hours. During this time period there was also a trend towards a difference between groups in mean pain intensity, but significant only during the first six hours. Over the whole first postoperative 24 hours, there were no differences in either morphine requirement or pain intensity between groups. A single injection of bupivacaine with adrenaline in the surgical wound decreases the need for morphine requirements for the first 12 postoperative hours and contributes to safe and effective pain management in women undergoing cesarean section.

Estimating Preference-Based EQ-5D Health State Utilities or Item Responses from Neuropathic Pain Scores

Preference-based health state utilities are required for many health economic evaluations. When the direct evidence of such is lacking and only condition-specific scores are available, establishing a 'mapping' relationship between instruments can be useful. Our objective was to map the 11-point Pain Intensity Numerical Rating Scale (PI-NRS-11), a pain-specific instrument ranging from 0 ('no pain') to 10 ('pain as bad as you can imagine'), to the EQ-5D, a preference-based generic instrument. We used web survey data collected from adult US respondents who (i) had ≥ 3 months of neuropathic pain (NP), either painful diabetic peripheral neuropathy (pDPN) or post-herpetic neuralgia (PHN); (ii) were receiving medications treating NP; and (iii) had completed the EQ-5D and PI-NRS-11. We explored indirect and direct mapping approaches. The indirect method took a probabilistic approach using ordered logistic models (OLMs) predicting response levels for each EQ-5D item via repeated Monte Carlo simulations before computing utilities. The direct approach simply predicted EQ-5D utilities directly using ordinary least squares (OLS). Categorical scores of PI-NRS-11 were used as the predictors. Patient age, gender, and pain duration were additionally controlled in the full model specification. Seventy percent of the data were used for estimation and 30% for prediction. Mean square errors (MSEs) and 95% confidence intervals (CIs) of prediction errors were reported. A total of 2719 respondents were included. Mean (SD) age was 55.48 (10.65) years and 56.23% were female. Average NP duration was 61 months and 58% gave scores ≥ 6 on the PI-NRS-11. The clinical pain scores were significantly associated with all EQ-5D items, especially with the 'pain/discomfort' item (p < 0.001). The observed mean (SD) EQ-5D index was 0.594 (0.22). Predicted utilities and responses showed good representation of the observed ones. The reduced model showed comparable results with the full model while imposing minimum data collection burden. From the reduced model, the predicted mean (SD) EQ-5D index was 0.594 (0.11) from direct estimation and 0.588 (0.19) from indirect estimation. All estimated utilities discriminated health gains/losses along the PI-NRS-11. Lower MSEs and prediction errors were found for EQ-5D >0.2. Findings suggest that EQ-5D utilities or item responses could be estimated on the basis of NP scores. Independent testing of the external validity of the mapping algorithms developed herein is encouraged.

The relationship between pain and depressive symptoms after lumbar spine surgery

Although depressive symptoms are common among those living with back pain, there is limited information on the relationship between postsurgical pain reduction and changes in depressive symptoms. The objective of this prospective cohort study was to examine the change in pain and depressive symptoms and to characterize the relationship between pain and depressive symptoms after lumbar spine surgery. We assessed 260 individuals undergoing lumbar spine surgery preoperatively and postoperatively (3 and 6months) using a pain intensity numeric rating scale and the Patient Health Questionnaire depression scale. The relationship between change in pain (a 2-point decrease or 30% reduction from the preoperative level) and depressive symptoms was examined using standard regression methods. Preoperatively, the mean pain intensity was 5.2 (SD 2.4) points, and the mean depressive symptom score was 5.03 (SD 2.44) points. At 3months, individuals who experienced a reduction in pain (63%) were no more likely to experience a reduction in depressive symptoms (odds ratio 1.07, 95% confidence interval [CI] .58 to 1.98) than individuals who experienced no change from preoperative pain (34%). However, at 6months, individuals who experienced a reduction in pain (63%) were nearly twice as likely to experience a reduction in depressive symptoms (odds ratio 1.93, 95% CI 1.15 to 3.25) as those who experienced no change or an increase in pain (31%). We found that most individuals experienced clinically important reductions in pain after surgery. We concluded that those whose pain level was reduced at 6months were more likely to experience a reduction in depressive symptoms.