Chronic Low Back Pain Intensity Research Articles

Effectiveness of biobehavioral therapeutic education in chronic low back pain intensity and disability: a systematic review

Background: Chronic low back pain (CLBP) is a prevalent musculoskeletal issue that could lead to significant disability. CLBP involves persistent pain and psychological factors contributing to its complexity. Therapeutic education combining cognitive-behavioral approaches may aid in managing CLBP. Objectives: This systematic review evaluates the efficacy of therapeutic education based on a biobehavioral approach in modifying beliefs and promoting active coping strategies in CLBP patients. Methods: Following PRISMA guidelines, we searched PubMed, EBSCO host, and Google Scholar for randomized controlled trials (RCTs) and quasi-experimental studies from March 27 to April 16, 2022, with an update on June 15, 2024. Inclusion criteria focused on adults with CLBP undergoing therapeutic education aimed at behavioral modification. Methodological quality was assessed using the PEDro scale, and risk of bias was evaluated using RoB 2.0. Results: Out of 532 studies, four met the inclusion criteria. The interventions combined therapeutic education with therapeutic exercise or conventional physical therapy. Pain intensity and disability were the main outcomes measured. One study found significant improvements in pain and disability, while others showed trends towards improvement without statistical significance. The quality of evidence was very low. Conclusion: Combining therapeutic education with active coping strategies and other therapies may reduce pain intensity and disability in CLBP patients. However, the evidence quality is very low, highlighting the need for further research.

Associations between Combined Psychological and Lifestyle Factors with Pain Intensity and/or Disability in Patients with Chronic Low Back Pain: A Cross-Sectional Study.

Chronic low back pain (CLBP) is common in primary care, causing disability and economic burden globally. We aimed to compare socio-demographic, health, lifestyle, and psychological factors in people with and without CLBP and correlate them with clinical outcomes in people with CLBP. A total of 253 volunteers with and 116 without CLBP provided sociodemographic information, daily habits, medical history, subjective sleep complaints (Penn State Sleep Questionnaire), low back pain intensity, and disability (Quebec Back Pain Disability Scale), as well as the Zung Self-Rating Scale for self-assessment of depression and Self-Rating Anxiety Scale. CLBP diagnosis was linked with female gender and older age, as well as a higher level of sleep complaints such as sleepiness, OSA and insomnia symptoms, and a higher prevalence of moderate to severe depressive symptoms. The combination of moderate to severe depressive symptoms with obstructive sleep apnea or insomnia symptoms was the most important predictive factor for functional disability in CBLP patients (OR 13.686, 95% CI 4.581-40.885; p < 0.001). In conclusion, depressive symptoms and subjective sleep complaints appear to relate to greater CLBP intensity and/or CLBP-related disability in people with CLBP. A holistic approach is crucial for treating chronic CLBP patients, including psychological and sleep issue assessment and management, to improve their quality of life.

Development of a tool for objectively measuring somatic pain in the low back region based on a longitudinal diagnostic study conducted in Karachi, Pakistan

ObjectivesThis study aimed at devising an objective method for quantifying pain in the low back region using pressure pain threshold (PPT) and demographic factors as predictive variables.MethodsThe research was conducted...

Chronic low back pain prevalence in Federal Highway Police Officers: A cross-sectional study.

Police officers are exposed to specific occupational tasks, which require lifting, trunk flexion and rotation, carrying weight, and frequent standing periods, which may be associated with an increased risk of experiencing low back pain (LBP). To describe the prevalence and intensity of chronic LBP (CLBP) in Brazilian Federal Highway Police officers (FHPO) from the Rio Grande do Sul state and evaluate its associated factors. A total of 208 FHPOs participated in this study. The participants answered an electronic questionnaire containing sociodemographic, behavioral, and occupational questions, and CLBP history. Data analysis comprises descriptive statistics and Poisson regression models. Most of the FHPO were male, aged 41 or more, lived with a partner and were physically active. Sixty-seven percent of FHPO had CLBP, and the median pain intensity was 3.0 (IQR = 0- 5). Participants who lived with a partner were less likely to report CLBP (PR = 0.80; 95% CI = 0.64; 0.99). On the other hand, those who worked as FHPO for more than 11 years were more likely to report CLPB (PR = 1.32; 95% CI = 1.06; 1.63), and high pain intensity (β= 0.95; 95% CI = 0.19; 1.71). The high CLBP prevalence among FHPO from Rio Grande do Sul state indicates a need to highlight the importance for police organizations to promote CLBP prevention and implement workplace management programs.

Physiotherapeutic treatment associated with the pain neuroscience education for patients with chronic non-specific low back pain-single-blind randomized pilot clinical trial.

Pain Neuroscience Education (PNE) shows improvement in pain and functional capacity in patients with chronic low back pain (CLBP). Therefore, the study aimed to verify if the physiotherapeutic treatment associated with PNE decreases the functional disability of patients with nonspecific CLBP. Forty patients were clinically evaluated and answered the following questionnaires: Brief pain inventory, Central Sensitization Inventory (CSI), Roland-Morris disability questionnaire, pain catastrophizing scale, Tampa scale of kinesiophobia, hospital anxiety, and depression scale, SF6D quality of life questionnaire and performed quantitative sensory tests (QSTs). Afterward, they were randomly divided into the intervention group (IG, n=20) and the control group (CG, n=20). Both performed kinesiotherapy exercises twice a week for 6 weeks. The IG received 3 individual PNE sessions and answered the pain neurophysiology questionnaire. IG showed significant improvement for all variables analyzed (p<0.001). The association decreased the kinesiophobia (estimated difference between CG-IG means: 7.6-95% CI: 2.3-12.9) (p=0.006). In the lumbar paravertebral region (CG and IG), there was a statistical difference in the intensity of CLBP in the QSTs (p<0.05). The association showed better results compared to only therapeutic exercises to reduce kinesiophobia and change the perception of pain intensity in the lumbar region.

Neurobiological substrates of chronic low back pain (CLBP): a brain [99mTc]Tc-ECD SPECT study

BackgroundRecent neuroimaging studies have demonstrated pathological mechanisms related to cerebral neuroplasticity in chronic low back pain (CLBP). Few studies have compared cerebral changes between patients with and without pain in the absence of an experimentally induced stimulus. We investigated the neurobiological substrates associated with chronic low back pain using [99mTc]Tc-ECD brain SPECT and correlated rCBF findings with the numeric rating scale (NRS) of pain and douleur neuropathique en 4 questions (DN4). Ten healthy control volunteers and fourteen patients with neuropathic CLBP due to lumbar disc herniation underwent cerebral SPECT scans. A quantitative comparison of rCBF findings between patients and controls was made using the Statistical Parametric Mapping (SPM), revealing clusters of voxels with a significant increase or decrease in rCBF. The intensity of CLBP was assessed by NRS and by DN4. RESULTS: The results demonstrated an rCBF increase in clusters A (occipital and posterior cingulate cortex) and B (right frontal) and a decrease in cluster C (superior parietal lobe and middle cingulate cortex). NRS scores were inversely and moderately correlated with the intensity of rCBF increase in cluster B, but not to rCBF changes in clusters A and C. DN4 scores did not correlate with rCBF changes in all three clusters. CONCLUSIONS: This study will be important for future therapeutic studies that aim to validate the association of rCBF findings with the pharmacokinetic and pharmacodynamic profiles of therapeutic challenges in pain.

Physical activity, fear avoidance beliefs and level of disability in a multi-ethnic female population with chronic low back pain in Suriname: A population-based study.

Chronic low back pain (CLBP) is an important cause for reduced daily physical activity (PA) and loss of quality of life, especially in women. In Suriname, a middle-income country in South America, the relationship between PA and CLBP is still unknown. To assess the level of PA in women with CLBP of different ethnicity, and to identify whether fear avoidance beliefs (FAB), disability, co-occurring musculoskeletal pain sites and various sociodemographic and lifestyle factors were associated with self-reported PA. A cross-sectional community-based house-to-house survey was conducted between April 2016 and July 2017. The survey followed the Community Oriented Program for Control of Rheumatic Diseases methodology. Selection criteria were being female of Asian-Surinamese, African-Surinamese or of Mixed ethnicity and aged 18 or older, living in an urban area, and reporting CLBP. Data was collected on PA, FAB, disability, co-occurring musculoskeletal pain sites, CLBP intensity and sociodemographic and lifestyle factors. Urban adult women with current CLBP (N = 210) were selected. Nearly 57% of the population met the WHO recommendation on PA, with work-related PA as the largest contributor to total self-reported PA. Most women showed low FAB scores (FABQ-Work ≤34 (96.2%) and FABQ-PA ≤14 (57.6%)) and low disability levels (Oswestry Disability Index ≤20 (62.4%)). An inverse association between total PA and FABQ-Work (OR = 0.132, CI: 0.023; 0.750) was found. In contrast, total PA had a significant, positive association with disability (OR = 2.154, CI: 1.044; 4.447) and workload (OR = 2.224, CI: 1.561; 3.167). All other variables showed no association with total PA. This was the first study in Suriname reporting that 43.3% of urban adult women with CLBP were physically inactive. Total self-reported PA is influenced by FABQ-Work, average to heavy workload and moderate to severe disability. In this study, PA-Work was the major contributor to total PA. Therefore, future longitudinal studies should evaluate different types and aspects of PA in relation to CLBP management.

Postural sway does not differentiate individuals with chronic low back pain, single and multisite chronic musculoskeletal pain, or pain-free controls: a cross-sectional study of 229 subjects

BACKGROUND CONTEXTPhysical activity in its various forms are the most recommended prevention and treatment strategy for chronic low back pain (CLBP). Standing postural stability is a prerequisite for many types of physical activities. Systematic reviews have investigated the evidence for an association between CLBP and postural stability but results remain inconclusive. PURPOSEOur primary objective was to compare postural stability between pain-free controls and subjects with CLBP with or without leg pain and single and multisite chronic musculoskeletal pain subjects. The secondary objectives were to evaluate the association between postural stability with CLBP intensity and duration, demographics, physical characteristics and validated health and pain-related patient-reported outcome measures (PROMs). STUDY DESIGN/SETTINGCross-sectional study in a private chiropractic clinic setting PATIENT SAMPLESubjects included 42 pain-free controls and 187 patients with chronic musculoskeletal pain divided into CLBP with or without leg pain and single and multisite pain groups. OUTCOME MEASURESPain intensity was measured using the numerical pain rating scale, PROMs Central Sensitization Inventory, Tampa Scale of Kinesiophobia, The Depression Scale, EuroQol-5D, Roland-Morris Disability Questionnaire, and Pain and Sleep Questionnaire Three-Item Index disability. Group differences were measured using area and velocity of sway on the force plate. METHODSPostural stability was assessed using a force plate on four 60-second bipedal quiet stance tests: eyes open on a stable surface, eyes closed on a stable surface, eyes open on an unstable foam surface, eyes closed on an unstable foam surface. Following the clinic visit, subjects completed an online web-based data entry detailing pain history, demographic data, physical characteristics, pain intensity via the numerical pain rating scale, and PROMS. RESULTSPostural sway parameters did not differ between pain-free controls and subjects with CLBP with or without leg pain and single and multisite chronic musculoskeletal pain subjects. Furthermore, severity and duration of CLBP pain in addition to central sensitization, kinesiophobia, depression, quality of life, disability, and effect of pain on sleep only had very weak associations with postural stability. CONCLUSIONSChronic musculoskeletal pain appears not to influence bipedal postural stability.

Aberrant functional connectivity and temporal variability of the dynamic pain connectome in patients with low back related leg pain

Neuroimaging studies have suggested a link between the intensity of chronic low back pain intensity and structural and functional brain alterations. However, chronic pain results from the coordination and dynamics among several brain networks that comprise the dynamic pain connectome. Here, we use resting-state functional magnetic resonance imaging and measures of static (sFC) and dynamic functional connectivity (dFC) variability in the typical (0.01–0.1 Hz) and five specific (slow-6 to slow-2) frequency bands to test hypotheses regarding disruption in this variability in low back-related leg pain (LBLP) patients who experience chronic pain and numbness. Twenty-four LBLP patients and 23 healthy controls completed clinical assessments, and partial correlational analyses between altered sFC and dFC variability and clinical measures were conducted. We found a lower within-network sFC in the ascending nociceptive pathway (Asc) and a lower cross-network sFC between nodes of the salience network and the Asc in the typical frequency band. In the slow-5 frequency band, a lower within-network sFC was found in the Asc. Abnormal cross-network sFC was found between nodes of the salience network-Asc (slow-5 and slow-6) and the default mode network-Asc (slow-4 and slow-6). Furthermore, cross-network abnormalities in the typical and certain specific frequency bands were linked to clinical assessments. These findings indicate that frequency-related within- and cross-network communication among the nodes in the dynamic pain connectome is dysfunctional in LBLP patients and that selecting specific frequencies may be potentially useful for detecting LBLP-related brain activity.

Efficacy of abdominal trunk muscles-strengthening exercise using an innovative device in treating chronic low back pain: a controlled clinical trial

Exercise is the most common conservative intervention for chronic low back pain (CLBP). We have developed an innovative exercise device for the abdominal trunk muscles that also measures muscle strength in a sitting position. The device, which is easy for patients with CLBP to use, allows for lumbar stabilization exercise under pressure. This study aimed to examine the efficacy of abdominal trunk muscle strengthening using the device in improving CLBP. We conducted a two-group non-randomized controlled clinical trial. CLBP patients were allocated into two groups. The strengthening group underwent a 12-week exercise program that included abdominal trunk muscle strengthening using our device and stretching exercises, while the control group received a 12-week stretching exercise program. The outcome measures included the improvement of the abdominal trunk muscle strength measured by the device, pain intensity of CLBP, physical function, and quality of life (QOL). A total of 40 participants (20 in each group) were analyzed. The strengthening group showed better improvement in the abdominal trunk muscle strength, CLBP, physical function, and QOL than in the control group. In conclusion, the strengthening exercise using the device with easy stretching was effective in improving the strength of the abdominal trunk muscles, pain intensity of CLBP, physical function, and QOL.

Genetic Contribution in Low Back Pain: A Prospective Genetic Association Study.

Chronic pain is one of the most common reasons individuals seek medical attention. It is a major issue because of the wide interindividual variability in the analgesic response. This might be partly explained by the presence of variants in genes encoding molecules involved in pharmacodynamics and pharmacokinetics. The aim was to analyze opioid effectiveness in chronic low back pain (CLBP) relief after opioid titration, unveiling the impact of pharmacogenetics. The study included 231 opioid-naïve patients from the Spine Unit; age 63±14years, 64% female, body mass index 29±6kg/m2 , visual analog scale pain intensity score 73±16mm. Clinical data were collected at baseline, 3months after opioid titration, and after 2 to 4years of follow-up concerning pain (intensity and relief), quality of life, disability, comorbidities, and drug prescription (opioid dose, rotations, and adverse events). The genotype influence of OPRM1, COMT, UGT2B7, ABCB1, KCNJ6, and CYP3A5*3A in analgesic response was analyzed by reverse-transcription polymerase chain reaction genotyping. Patients with the COMT G472A-AA genotype (rs4680) and KCNJ6 A1032G-A allele (rs2070995) CLBP responded differently to opioid titration, with higher pain intensity requiring higher dosing. Furthermore, GG- genotypes of A118G (OPRM1, rs1799971) and A854G (UGT2B7, rs776746) influenced the neuropathic component. After opioid titration, CLBP intensity, neuropathic component, low back pain disability, anxiety, and depression significantly decreased, while quality of life improved. Single-nucleotide polymorphisms in genes involved in pain transmission and opioid metabolism might predispose to exaggerated sensitivity and differences in the opioid analgesic effect in patients with CLBP. We encourage clinical trials for their clinical application in chronic pain management.

Relationship between the intensity of chronic low back pain and the generated limitations with depressive symptoms

ABSTRACT BACKGROUND AND OBJECTIVES: Aging adds to the prevalence of chronic diseases and functional impairment. Depressive symptoms and chronic low back pain affect an increasing number of elderly people and become important research topics. This study aimed to identify the relationship between chronic low back pain intensity, its generated disability, and the presence of depressive symptoms in independent elderly people for basic daily activities. METHODS: The study is descriptive, quantitative, and cross-sectional. A sample of independent elderly patients with chronic low back pain (n=46) enrolled in the Family Health Units of the city of Sao Carlos, SP, Brazil, was analyzed. For collection, we used the Characterization Sheet, Multidimensional Pain Rating Scale, Roland-Morris Disability Questionnaire, and the Geriatric Depression Scale. The data obtained were input in the Statistical Package for Social Sciences software (SPSS) for Windows to perform the descriptive and Spearman correlational analysis. The ethical precepts for research with humans of the National Health Council were respected. RESULTS: The most frequent pain intensity perceived by the elderly was intense (43.5%, n=20), preceded by moderate pain (41.3%, n=19). Most of the elderly describe low back pain as persistent, painful, and uncomfortable. The mean total depression score was 4.37 points (Md=4.00, SD=2.67, xmin = 0.00, xmax = 11.00). CONCLUSION: Correlational analyses showed that there is a significant directly proportional relationship between the intensity of low back pain and the number of weak depressive symptoms, and a significant directly proportional relationship between the number of disabilities/limitations caused by low back pain and the number of moderate depressive symptoms.

Can Beta-Endorphin Be Used as a Biomarker for Chronic Low Back Pain? A Meta-analysis of Randomized Controlled Trials.

Chronic low back pain (CLBP) is usually quantified using the visual analog scale (VAS). However, the VAS is a subjective measure and prone to reporting bias, therefore making it difficult to differentiate patients with true pain from those seeking to obtain secondary gain. This study aimed to evaluate the feasibility of using plasma β-endorphin as an objective biomarker for CLBP. We searched PubMed, Embase, and the Cochrane Library for randomized trials that compared treatment vs sham procedures for patients with CLBP. Changes in VAS and β-endorphin levels between baseline and final evaluations were assessed for the treatment and control groups. A meta-regression model was developed to evaluate the association between the β-endorphin level and VAS. We included data from seven trials involving 375 patients. There was no significant difference in VAS scores and β-endorphin levels between both groups at baseline. At final evaluation, the treatment group demonstrated significantly greater improvements in VAS scores and an increased β-endorphin level compared with the control group. The change in the plasma β-endorphin level may be a surrogate marker of treatment response for patients with CLBP (explanatory power: 80%). The plasma β-endorphin level might be rarely affected by sham procedures. For patients with CLBP, the baseline β-endorphin level may reflect the intensity of CLBP (explanatory power: 66%). A change in plasma β-endorphin level may be a surrogate marker of the treatment response for patients with CLBP. Advancements in β-endorphin measurements may help us better quantify pain intensity.

Education, job position, income or multidimensional indices? Associations between different socioeconomic status indicators and chronic low back pain in a German sample: a longitudinal field study

ObjectiveTo investigate associations between socioeconomic status (SES) indicators (education, job position, income, multidimensional index) and the genesis of chronic low back pain (CLBP).DesignLongitudinal field study (baseline and 6-month follow-up).SettingFour medical...

Relationship Between Radiographic Lumbosacral Spine Mensuration and Chronic Low Back Pain Intensity: A Cross-sectional Study

ObjectiveThe purpose of this study was to investigate correlative factors affecting chronic low back pain (CLBP), with special emphasis on the radiographic postural findings in the sagittal lumbosacral spine. MethodsA cross-sectional study alongside a randomized trial was conducted. Standing lateral lumbar spine radiographs from 352 patients with CLBP enrolled in a randomized trial were analyzed and radiographic mensuration of lumbar lordosis, lumbosacral disc angle, and sacral inclination performed. These angles were correlated with baseline variables, including CLBP intensity, age, and sex. Multiple polynomial regressions were performed in which CLBP intensity was regressed on linear and quadratic terms of lumbar lordosis to investigate the possibility of greater pain with hypo- and/or hyperlordosis. ResultsThere was no significant correlation of the angles with pain and age (r ≤ 0.09, P > .05). Weak but statistically significant correlation was identified between all 3 measurements and sex (r = –0.12 to 0.21, P < .05). Greater pain was not noted for hypo- and hyperlordosis; regression coefficients for the linear and quadratic effects were approximately 0 (P > .05). ConclusionThis study determined that there was no correlation between lumbar lordosis and pain levels for people with CLBP; thus, use of lumbar spine radiographic mensuration in the management of pain for people with CLBP is not recommended.

The relationship between chronic low back pain and fatigue: a systematic review

Background: Fatigue is a common non-specific symptom in the general population. The association between fatigue and pain is high and people with chronic conditions and/or pain report high prevalence of fatigue. Individuals with chronic low back pain (CLBP) often experience fatigue symptoms and those who experience fatigue are more likely to have restricted physical functioning. It is important to clarify the association between CLBP and fatigue in order to devise management strategies which alleviate and/or manage fatigue symptoms while improving physical functioning in individuals with CLBP.Objectives: The main aim of this systematic review is to determine the level of evidence supporting the association between self-reports of LBP and fatigue in individuals with CLBP.Methods: Major electronic databases were searched since inception till April 2016. Studies comparing the association between CLBP and general fatigue were included.Results: Considerable heterogeneity in the included studies precluded a meta-analysis. Five studies were included for final descriptive synthesis. There is very limited evidence to support the association between presence of CLBP and fatigue. There is moderate evidence to support the association between CLBP intensity and/or CLBP functional disability and fatigue.Conclusion: The association between fatigue and CLBP is under researched although there is moderate association between CLBP intensity and CLBP disability with fatigue. Fatigue is an important symptom that should be considered in the assessment and management of patients with CLBP.

Studying the Effect of Relaxation Training on Chronic Low Back Pain Intensity and Daily Functioning in the Elderly

Relaxation is a natural blessing & everyone can activate it. Medical science has recently linked psychological speculations with physiological & measurable information. The present research aims to analyze the effect of relaxation training on the intensity of chronic back pain & daily functioning of the elderly. This study is applied in terms of goal using semiexperimental (quasi-empirical) method with pre-test & post-test design. The statistical community consists of all old people staying in Sari-based Saraye Mehr nursing home in 2013 including 117 ones .To select the sample, simple random sampling method has been conducted. Thus one class has been chosen for performing the training method employing relaxation (30 individuals) & the other for performing traditional training (30 individuals).The measuring tool has been pain intensity standard scale (VAS) & health assessment questionnaire (HAQ).In order to analyze the data, descriptive statistics method (calculating mean & standard deviation) & inferential statistics (covariance analysis test) have been employed via SPSS software. The findings indicated that training relaxation results in reducing the orderly's chronic backache intensity. Also, training relaxation brings about increasing basic & average daily activities in the aged. Relaxation is of the methods used for lowering pain intensity & increasing the efficiency of the individuals in societies .Therefore, simultaneously using medical & pharmaceutical approaches, self-discovery, and mind-body interaction methods in treatment process can lead to optimal effects.

Associations between KCNJ6 (GIRK2) gene polymorphisms and pain-related phenotypes

G-protein coupled inwardly rectifying potassium (GIRK) channels are effectors determining degree of analgesia experienced upon opioid receptor activation by endogenous and exogenous opioids. The impact of GIRK-related genetic variation on human pain responses has received little research attention. We used a tag single nucleotide polymorphism (SNP) approach to comprehensively examine pain-related effects of KCNJ3 (GIRK1) and KCNJ6 (GIRK2) gene variation. Forty-one KCNJ3 and 69 KCNJ6 tag SNPs were selected, capturing the known variability in each gene. The primary sample included 311 white patients undergoing total knee arthroplasty in whom postsurgical oral opioid analgesic medication order data were available. Primary sample findings were then replicated in an independent white sample of 63 healthy pain-free individuals and 75 individuals with chronic low back pain (CLBP) who provided data regarding laboratory acute pain responsiveness (ischemic task) and chronic pain intensity and unpleasantness (CLBP only). Univariate quantitative trait analyses in the primary sample revealed that 8 KCNJ6 SNPs were significantly associated with the medication order phenotype (P<.05); overall effects of the KCNJ6 gene (gene set-based analysis) just failed to reach significance (P=.054). No significant KCNJ3 effects were observed. A continuous GIRK Related Risk Score (GRRS) was derived in the primary sample to summarize each individual’s number of KCNJ6 “pain risk” alleles. This GRRS was applied to the replication sample, which revealed significant associations (P<.05) between higher GRRS values and lower acute pain tolerance and higher CLBP intensity and unpleasantness. Results suggest further exploration of the impact of KCNJ6 genetic variation on pain outcomes is warranted.

Influence of Time, Activities, and Memory on the Assessment of Chronic Low Back Pain Intensity

A prospective study. To identify factors potentially influencing patient self-evaluation of chronic low back pain (CLBP) and their interactions. The impact of the time, context, and/or recall on the self-assessment of chronic pain intensity remains poorly understood. A prospective study investigated patients' CLBP intensity over 29 days. Patients were evaluated on days 1 and 29 by the investigator with a pain intensity visual analog scale (0-100), and interviewed by phone on days 8, 15, and 22 to 28 to evaluate pain intensity with a numerical rating scale (0-10), either thrice daily (time-associated group), or during rest/activities (activity-associated group). Current and/or recalled pain intensities were also assessed. Means of recorded pain intensity and overall assessment of patient's pain intensity of the day were subjected to statistical analyses with analysis of variance and test of correlation. Among the 203 patients included, 194 (56.2% women; mean age: 47.5 +/- 12.1 year) were considered in the analysis (9 patients were not followed until day 24). Strong correlations were obtained between mean pain intensity (time-associated group = 44 patients) and overall assessment of pain intensity of the day. Strong correlations were also obtained between overall assessment of pain intensity of the day and intensity measured during each activity, but not between current pain intensity and remembered pain 24 of 48 hours earlier (activity-associated group = 150 patients). Recalled pain intensities for the last 7 or 28 days were strongly correlated with current pain intensity, but the correlations were markedly weaker after adjustment for day 29-pain intensity. For CLBP patients, overall assessment of pain intensity of the day at evening is accurate to assess pain on 1 day. Overall assessment of pain intensity of the day is very close with usual pain. Furthermore, 24 and 48 hours remembered pain intensity are not accurate measures. Recalls of pain on the 7 or 28 last days were very dependant of the pain intensity of the day of the assessment. These findings could contribute to improving pain intensity assessment in CLBP patients avoiding multiple assessments, especially during clinical trials.

(248) Analgesic efficacy and safety of controlled-release hydrocodone and acetaminophen tablets, dosed twice daily, for moderate to severe mechanical chronic low-back pain: A randomized, double-blind, placebo-controlled withdrawal trial

Analgesic efficacy and safety of hydrocodone/acetaminophen extended-release (HC/APAP CR) was assessed in subjects with moderate-to-severe chronic low-back pain (CLBP). Subjects with CLBP (n 773) were enrolled at 62 sites; study protocol and informed consent were IRB-approved. Study periods were: Washout/Screening, 3-week Active-Drug Open-Label, 12-week Double-Blind inwhichsubjectswererandomizedtoplacebo,1or2tabletsHC/APAPCRtwice daily, and Taper/Follow-up. Primary efficacy endpoint was mean change from double-blind baseline to final evaluation in Subject’s Assessment of CLBP Intensity (VAS). Safety was evaluated by adverse-event (AE) assessment. All results reported are from the Double-Blind period. 511 subjects were randomized and received °Ý1 dose of study drug; data for 507 were evaluated for efficacy. Most subjects were women (59%) and white (87%); mean age 48 years. Baseline variables were similar among the 3 groups. Mean change from baseline CLBP intensity was statistically significantly lower in subjects in the HC/APAP CR groups than in the placebo group (8.6, 2-tablet; 13.3, 1-tablet vs 22.2, placebo; p 0.05); no statistically significant difference was observed between HC/APAP CR groups. The superiority of treatment with both HC/APAP treatments compared to placebo treatment was consistent across multiple secondary efficacy endpoints. 89/169 (53%) subjects in the HC/APAP CR 2-tablet, 75/170 (44%) in the 1-tablet, and 79/172 (46%) in the placebo group reported °Ý1 AE. AEs in °Ý5% of subjects in any treatment group were nausea, constipation, diarrhea, and headache. Nine subjects reported serious AEs (2 in each HC/APAP CR group; 5 in placebo group); 28 subjects discontinued due to AEs (3% in placebo; 6% in 1-tablet; 7% in 2-tablet group). Both HC/APAP CR doses given twice daily were effective treatment for CLBP over the 12-week period.ThesafetyprofileofHC/APAPCRwasconsistentwithknownprofilesof mu-opioid receptor agonists. Funded by Abbott Laboratories.