Different types of low back pain in relation to pre- and post-natal maternal depressive symptoms.

BACKGROUND: Low back pain (LBP) is a common musculoskeletal problem during pregnancy, with an estimated prevalence ranging from 30-78% (Mota MJ et al. J Back Musculoskelet Rehabil 28(2):351-7,2015 and Abebe E et al. J Med Sc Tech 3(3). 37-44,2014). Women reporting LBP are at increased risk of developing perinatal depression. Pregnancy-related LBP is highly heterogeneous and can be divided into lumbar pain (LP), posterior pelvic pain (PPP), and combined pain (CP). Therefore, the purpose of this study was to investigate the associations between LBP and perinatal depressive symptoms. METHODS: This was a retrospective case-control study conducted from January 2016 to April 2019. A total of 484 pregnant women were enrolled in this study: a case group of 242 pregnant women who were diagnosed with LBP and an age-matched control group of 242 pregnant women without LBP. The Edinburgh Postnatal Depression Scale (EPDS), LBP characteristics, and questionnaires about pregnancy that included demographic, parity, work, comorbidity, and previous pregnancy data were completed and compared between the case group and the control group. RESULTS: A total of 68 of 242 (28.1%) women experienced PPP, 142 (58.7%) had lumbar pain(LP), and 32 (13.2%) had combined pain. Furthermore, 26.5% of women with prenatal depression in the LP subgroup remained depressed 6 months postnatally, while the percentages for women in the PPP subgroup and CP subgroup were just 10.6% and 15.6%, respectively. The percentage of women who recovered anytime between delivery and six months postnatally in the PPP subgroup was significantly higher than that in the LP subgroup (31.7% vs. 14.7%, P < 0.001). CONCLUSIONS: There is a difference in the prevalence of prenatal, postnatal, and perinatal depressive symptoms among pregnant women with different types of LBP. It is necessary to screen prenatal and postnatal depression separately and differentiate the types of LBP during pregnancy. Attention to these factors may help to outline better management strategies to improve maternal health.

Initial classification of low back and leg pain based on objective functional testing: a pilot study of machine learning applied to diagnostics.

OBJECTIVE: The five-repetition sit-to-stand (5R-STS) test was designed to capture objective functional impairment and thus provided an adjunctive dimension in patient assessment. The clinical interpretability and confounders of the 5R-STS remain poorly understood. In clinical use, it became apparent that 5R-STS performance may differ between patients with lumbar disk herniation (LDH), lumbar spinal stenosis (LSS) with or without low-grade spondylolisthesis, and chronic low back pain (CLBP). We seek to evaluate the extent of diagnostic information contained within 5R-STS testing. METHODS: Patients were classified into gold standard diagnostic categories based on history, physical examination, and imaging. Crude and adjusted comparisons of 5R-STS performance were carried out among the three diagnostic categories. Subsequently, a machine learning algorithm was trained to classify patients into the three categories using only 5R-STS test time and patient age, gender, height, and weight. RESULTS: From two prospective studies, 262 patients were included. Significant differences in crude and adjusted test times were observed among the three diagnostic categories. At internal validation, classification accuracy was 96.2% (95% CI 87.099.5%). Classification sensitivity was 95.7%, 100%, and 100% for LDH, LSS, and CLBP, respectively. Similarly, classification specificity was 100%, 95.7%, and 100% for the three diagnostic categories. CONCLUSION: 5R-STS performance differs according to the etiology of back and leg pain, even after adjustment for demographic covariates. In combination with machine learning algorithms, OFI can be used to infer the etiology of spinal back and leg pain with accuracy comparable to other diagnostic tests used in clinical examination. These slides can be retrieved under Electronic Supplementary Material.

A classification-based approach to low back pain in primary care - protocol for a benchmarking controlled trial.

BACKGROUND: Guidelines recommend a biopsychosocial framework for low back pain (LBP) management and the avoidance of inappropriate imaging. In clinical practice, care strategies are often inconsistent with evidence and guidelines, even though LBP is the most common disabling health condition worldwide. Unhelpful beliefs, attitudes and inappropriate imaging are common. LBP is understood to be a complex biopsychosocial phenomenon with many known multidimensional risk factors (symptom- and lifestyle-related, psychological and social) for persistent or prolonged disability, which should be identified and addressed by treatment. The STarT Back Tool (SBT) was developed for early identification of individual risk factors of LBP to enable targeted care. Stratified care according SBT has been shown to improve the effectiveness of care in a primary care setting. A biopsychosocially-oriented patient education booklet, which includes imaging guidelines and information, is one possible way to increase patients' understanding of LBP and to reduce inappropriate imaging. Premeditated pathways, education of professionals, written material, and electronic patient registry support in health care organizations could help implement evidence-based care. METHODS: We will use a Benchmarking Controlled Trial (BCT) design in our study. We will prospectively collect data from three health care regions before and after the implementation of a classification-based approach to LBP in primary care. The primary outcome will be change in PROMIS (Patient-Reported Outcomes Measurement Information System) (short form 20a) over 12-month follow-up. DISCUSSION: The implementation of a classification-based biopsychosocial approach can potentially improve the care of LBP patients, reduce inappropriate imaging without increasing health-care costs, and decrease indirect costs by reducing work disability. Using the BCT we will be able to evaluate the effectiveness of the improvement strategy for the entire care pathway. TRIAL REGISTRATION: ISRCTN,ISRCTN13273552, retrospectively registered 13/05/2019.

Characteristics of Low Back Pain in Pregnancy, Risk Factors, and Its Effects on Quality of Life.

BACKGROUND: Low back pain is a common problem experienced during pregnancy, negatively affecting quality of life. AIMS: The study aimed to determine the prevalence and risk factors of low back pain during pregnancy and its effects on the quality of life. DESIGN: This was a descriptive and cross-sectional study. SETTINGS: Its setting was the Kastamonu State Hospital Obstetrics and Gynecology clinics. PARTICIPANTS/SUBJECTS: The study consisted of 400 pregnant women. METHODS: The sample consisted of 400 pregnant women. Data were collected using an introductory information form, a back pain evaluation form, the Visual Analog Scale (VAS), and the Oswestry Disability Index (ODI). RESULTS: In terms of back pain, 75.3% of the participants experienced back pain during their current pregnancy. The mean VAS score for back pain during their current pregnancy was 4.91±1.88. Low back pain was generally experienced in the third trimester (85.5%) and in the lumbar area (45.5%). Factors associated with low back pain included income status, trimester, gestational weight gain, frequent urinary tract infections, a hunchback posture, having experienced low back pain during previous pregnancies, and a history of low back pain. The mean percentage score on the ODI, which assesses the effect of low back pain on functional status, was 31.87% ± 15.56%, and for the majority of the participants (45.7%), low back pain was found to slightly limit their activities of daily living. CONCLUSIONS: The prevalence of low back pain in pregnancy is quite high, and low back pain slightly limits women's activities of daily living.

A Practical Sensor-Based Methodology for the Quantitative Assessment and Classification of Chronic Non Specific Low Back Patients (NSLBP) in Clinical Settings.

The successful clinical application of patient-specific personalized medicine for the management of low back patients remains elusive. This study aimed to classify chronic nonspecific low back pain (NSLBP) patients using our previously developed and validated wearable inertial sensor (SHARIF-HMIS) for the assessment of trunk kinematic parameters. One hundred NSLBP patients consented to perform repetitive flexural movements in five different planes of motion (PLM): 0° in the sagittal plane, as well as 15° and 30° lateral rotation to the right and left, respectively. They were divided into three subgroups based on the STarT Back Screening Tool. The sensor was placed on the trunk of each patient. An ANOVA mixed model was conducted on the maximum and average angular velocity, linear acceleration and maximum jerk, respectively. The effect of the three-way interaction of Subgroup by direction by PLM on the mean trunk acceleration was significant. Subgrouping by STarT had no main effect on the kinematic indices in the sagittal plane, although significant effects were observed in the asymmetric directions. A significant difference was also identified during pre-rotation in the transverse plane, where the velocity and acceleration decreased while the jerk increased with increasing asymmetry. The acceleration during trunk flexion was significantly higher than that during extension, in contrast to the velocity, which was higher in extension. A Linear Discriminant Analysis, utilized for classification purposes, demonstrated that 51% of the total performance classifying the three STarT subgroups (65% for high risk) occurred at a position of 15° of rotation to the right during extension. Greater discrimination (67%) was obtained in the classification of the high risk vs. low-medium risk. This study provided a smart "sensor-based" practical methodology for quantitatively assessing and classifying NSLBP patients in clinical settings. The outcomes may also be utilized by leveraging cost-effective inertial sensors, already available in today's smartphones, as objective tools for various health applications towards personalized precision medicine.

Current Evidence for Diagnosis of Common Conditions Causing Low Back Pain: Systematic Review and Standardized Terminology Recommendations.

OBJECTIVE: The purpose of this systematic review is to evaluate and summarize current evidence for diagnosis of common conditions causing low back pain and to propose standardized terminology use. METHODS: A systematic review of the scientific literature was conducted from inception through December 2018. Electronic databases searched included PubMed, MEDLINE, CINAHL, Cochrane, and Index to Chiropractic Literature. Methodological quality was assessed with the Scottish Intercollegiate Guidelines Network checklists. RESULTS: Of the 3995 articles screened, 36 (8 systematic reviews and 28 individual studies) met final eligibility criteria. Diagnostic criteria for identifying likely discogenic, sacroiliac joint, and zygapophyseal (facet) joint pain are supported by clinical studies using injection-confirmed tissue provocation or anesthetic procedures. Diagnostic criteria for myofascial pain, sensitization (central and peripheral), and radicular pain are supported by expert consensus-level evidence. Criteria for radiculopathy and neurogenic claudication are supported by studies using combined expert-level consensus and imaging findings. CONCLUSION: The absence of high-quality, objective, gold-standard diagnostic methods limits the accuracy of current evidence-based criteria and results in few high-quality studies with a low risk of bias in patient selection and reference standard diagnosis. These limitations suggest practitioners should use evidence-based criteria to inform working diagnoses rather than definitive diagnoses for low back pain. To avoid the unnecessary complexity and confusion created by multiple overlapping and nonspecific terms, adopting International Association for the Study of Pain terminology and definitions is recommended.

Can Primary Care for Back and/or Neck Pain in the Netherlands Benefit From Stratification for Risk Groups According to the STarT Back Tool Classification?

OBJECTIVE: To evaluate whether current Dutch primary care clinicians offer tailored treatment to patients with low back pain (LBP) or neck pain (NP) according to their risk stratification, based on the Keele STarT (Subgroup Targeted Treatment) Back-Screening Tool (SBT). DESIGN: Prospective cohort study with 3-month follow-up. SETTING: Primary care. PARTICIPANTS: General practitioners (GPs) and physiotherapists included patients (N=284) with nonspecific LBP, NP, or both. INTERVENTIONS: Patients completed a baseline questionnaire, including the Dutch SBT, for either LBP or NP. A follow-up measurement was conducted after 3 months to determine recovery (using Global Perceived Effect Scale), pain (using Numeric Pain Rating Scale), and function (using Roland Disability Questionnaire or Neck Disability Index). A questionnaire was sent to the GPs and physiotherapists to evaluate the provided treatment. MAIN OUTCOME MEASURES: Prevalence of patients' risk profile and clinicians' applied care, and the percentage of patients with persisting disability at follow-up. A distinction was made between patients receiving the recommended treatment and those receiving the nonrecommended treatment. RESULTS: In total, 12 GPs and 33 physiotherapists included patients. After 3 months, we analyzed 184 patients with LBP and 100 patients with NP. In the LBP group, 52.2% of the patients were at low risk for persisting disability, 38.0% were at medium risk, and 9.8% were at high risk. Overall, 24.5% of the patients with LBP received a low-risk treatment approach, 73.5% a medium-risk, and 2.0% a high-risk treatment approach. The specific agreement between the risk profile and the received treatment for patients with LBP was poor for the low-risk and high-risk patients (21.1% and 10.0%, respectively), and fair for medium-risk patients (51.4%). In the NP group, 58.0% of the patients were at low risk for persisting disability, 37.0% were at medium risk, and 5.0% were at high risk. Only 6.1% of the patients with NP received the low-risk treatment approach. The medium-risk treatment approach was offered the most (90.8%), and the high-risk approach was applied in only 3.1% of the patients. The specific agreement between the risk profile and received treatment for patients with NP was poor for low-risk and medium-risk patients (6.3% and 48.0%, respectively); agreement for high-risk patients could not be calculated. CONCLUSIONS: Current Dutch primary care for patients with nonspecific LBP, NP, or both does not correspond to the recommended stratified-care approach based on the SBT, as most patients receive medium-risk treatment. Most low-risk patients are overtreated, and most high-risk patients are undertreated. Although the stratified-care approach has not yet been validated in Dutch primary care, these results indicate there may be substantial room for improvement.

Validation of the Croatian version of the Oswestry Disability Index.

PURPOSE: To translate, cross-culturally adapt, and validate the Croatian version of the Oswestry Disability Index (ODI). METHODS: The original English-language ODI was cross-culturally adapted into Croatian and then evaluated in a group of 114 patients with chronic low back pain (LBP) at the Department of Neurosurgery, Zagreb University School of Medicine. Confirmatory factor analysis (CFA) was conducted with three models: two were theory driven (unidimensional and two dimensional-static and dynamic factors); the other was based on our exploratory factor analysis (EFA). Internal consistency and test-retest reliability were evaluated using Cronbach's α and the intraclass correlation coefficient (ICC), respectively. Construct validity was assessed by evaluating the correlation between the ODI and Visual Analogue Scale (VAS), and between the ODI and 36-item short form survey (SF-36) scores. RESULTS: The EFA-derived two-dimensional structure explained 82.7% of the total variance and was significantly better than the other models (P < 0.001); however, none of the models had acceptable fit. Internal consistency (Cronbach α = 0.84) and test-retest reliability (ICC = 0.94) were satisfactory. The ODI was positively correlated with VAS (rs = 0.54, P < 0.001) and negatively correlated with all of the SF-36 sections (rs = - 0.35 to - 0.64, P < 0.001, all), apart from the role-physical (rs = - 0.02, P = 0.767). CONCLUSIONS: The Croatian version of the ODI has acceptable psychometric properties. It appears to be suitable for assessment of LBP and treatment outcomes in Croatian-speaking patients. Overall, there was no evidence to reject the original unidimensional structure in favor of a two-factor solution. As such, the unidimensional structure should continue to be used in future studies. These slides can be retrieved under Electronic Supplementary Material.

The use of STarT BACK Screening Tool in emergency departments for patients with acute low back pain: a prospective inception cohort study.

PURPOSE: (1) To analyse the clinical utility of the STarT Back Screening Tool (SBST) in emergency departments by describing changes in classification over time and; (2) to identify what would be the best time to use the SBST to predict long-term clinical outcomes in patients with acute nonspecific low back pain (LBP) seeking emergency care. METHODS: A 6 months prospective inception cohort study was conducted. 200 participants with LBP seeking emergency medical treatment were included. Pain intensity, disability and SBST were collected at baseline, 6 and 26 weeks. Categories of improvement, clinical worsening, and stability were created to calculate the changes in the SBST subgroups. Linear regression models were built to analyse the predictive ability of SBST when applied at baseline, 6 weeks as well as changes in the subgroup from baseline to 6 weeks. These models were adjusted for potential confounders. RESULTS: 45% of patients were classified as high risk of chronicity at baseline. Most patients classified as medium (86.7%) or high (52.4%) risk changed their risk subgroup after 6 weeks and most of them improved. The SBST improved the prediction for all outcomes when applied at 6 weeks (R2 = 22.1% for disability and R2 = 15.6% for pain intensity), but not at baseline. CONCLUSION: Most of patients seeking care in emergency departments with a new episode of acute LBP improved after 6 weeks. The use of SBST to guide initial treatment and to predict clinical outcomes are most indicated when the instrument is applied after 6 weeks after presentation to emergency care. These slides can be retrieved under Electronic Supplementary material.

Subgroups of lumbo-pelvic flexion kinematics are present in people with and without persistent low back pain.

BACKGROUND: Movement dysfunctions have been associated with persistent low back pain (LBP) but optimal treatment remains unclear. One possibility is that subgroups of persistent LBP patients have differing movement characteristics and therefore different responses to interventions. This study examined if there were patterns of flexion-related lumbo-pelvic kinematic and EMG parameters that might define subgroups of movement. METHODS: This was a cross-sectional, observational study of 126 people without any history of significant LBP and 140 people with persistent LBP (n = 266). Wireless motion and surface EMG sensors collected lumbo-pelvic data on flexion parameters (range of motion (ROM) of trunk, lumbar, and pelvis), speed, sequence coordination and timing, and EMG extensor muscle activity in forward bending (flexion relaxation)), and sitting parameters (relative position, pelvic tilt range and tilt ratio). Latent class analysis was used to identify patterns in these parameters. RESULTS: Four subgroups with high probabilities of membership were found (mean 94.9%, SD10.1%). Subgroup 1 (n = 133 people, 26% LBP) had the greatest range of trunk flexion, fastest movement, full flexion relaxation, and synchronous lumbar versus pelvic movement. Subgroup 2 (n = 73, 71% LBP) had the greatest lumbar ROM, less flexion relaxation, and a 0.9 s lag of pelvic movement. Subgroup 3 (n = 41, 83% LBP) had the smallest lumbar ROM, a 0.6 s delay of lumbar movement (compared to pelvic movement), and less flexion relaxation than subgroup 2. Subgroup 4 (n = 19 people, 100% LBP) had the least flexion relaxation, slowest movement, greatest delay of pelvic movement and the smallest pelvic ROM. These patterns could be described as standard (subgroup 1), lumbar dominant (subgroup 2), pelvic dominant (subgroup 3) and guarded (subgroup 4). Significant post-hoc differences were seen between subgroups for most lumbo-pelvic kinematic and EMG parameters. There was greater direction-specific pain and activity limitation scores for subgroup 4 compared to other groups, and a greater percentage of people with leg pain in subgroups 2 and 4. CONCLUSION: Four subgroups of lumbo-pelvic flexion kinematics were revealed with an unequal distribution among people with and without a history of persistent LBP. Such subgroups may have implications for which patients are likely to respond to movement-based interventions.

Risk classification of patients referred to secondary care for low back pain.

BACKGROUND: Nonspecific low back pain is characterized by a wide range of possible triggering and conserving factors, and initial screening needs to scope widely with multilevel addressment of possible factors contributing to the pain experience. Screening tools for classification of patients have been developed to support clinicians. The primary aim of this study was to assess the criterion validity of STarT Back Screening Tool (STarT Back) against the more comprehensive Örebro Musculoskeletal Pain Questionnaire (ÖMPSQ), in a Norwegian sample of patients referred to secondary care for low back pain. Secondary aims were to assess risk classification of the patients, as indicated by both instruments, and to compare pain and work characteristics between patients in the different STarT Back risk categories. METHODS: An observational, cross-sectional survey among patients with low back pain referred to outpatient secondary care assessment at Trondheim University Hospital, Norway. Cohen's Kappa coefficient, Pearson's r and a Bland-Altman plot were used to assess criterion validity of STarT Back against ÖMPSQ. Furthermore, linear regression was used to estimate mean differences with 95% CI in pain and work related variables between the risk groups defined by the STarT Back tool. RESULTS: A total of 182 persons participated in the study. The Pearsons correlation coefficient for correspondence between scores on ÖMPSQ and STarT Back was 0.76. The Kappa value for classification agreement between the instruments was 0.35. Risk group classification according to STarT Back allocated 34.1% of the patients in the low risk group, 42.3% in the medium risk, and 23.6% in the high risk group. According to ÖMPSQ, 24.7% of the participants were allocated in the low risk group, 28.6% in the medium risk, and 46.7% in the high risk group. Patients classified with high risk according to Start Back showed a higher score on pain and work related characteristics as measured by ÖMPSQ. CONCLUSION: The correlation between score on the screening tools was good, while the classification agreement between the screening instruments was low. Screening for work factors may be important in patients referred to multidisciplinary management in secondary care.

The association between subgroups of MRI findings identified with latent class analysis and low back pain in 40-year-old Danes.

BACKGROUND: Research into the clinical importance of spinal MRI findings in patients with low back pain (LBP) has primarily focused on single imaging findings, such as Modic changes or disc degeneration, and found only weak associations with the presence of pain. However, numerous MRI findings almost always co-exist in the lumbar spine and are often present at more than one lumbar level. It is possible that multiple MRI findings are more strongly associated with LBP than single MRI findings. Latent Class Analysis is a statistical method that has recently been tested and found useful for identifying latent classes (subgroups) of MRI findings within multivariable datasets. The purpose of this study was to investigate the association between subgroups of MRI findings and the presence of LBP in people from the general population. METHODS: To identify subgroups of lumbar MRI findings with potential clinical relevance, Latent Class Analysis was initially performed on a clinical dataset of 631 patients seeking care for LBP. Subsequently, 412 participants in a general population cohort (the 'Backs on Funen' project) were statistically allocated to those existing subgroups by Latent Class Analysis, matching their MRI findings at a segmental level. The subgroups containing MRI findings from the general population were then organised into hypothetical pathways of degeneration and the association between subgroups in the pathways and the presence of LBP was tested using exact logistic regression. RESULTS: Six subgroups were identified in the clinical dataset and the data from the general population cohort fitted the subgroups well, with a median posterior probability of 93%-100%. These six subgroups described two pathways of increasing degeneration on upper (L1-L3) and lower (L4-L5) lumbar levels. An association with LBP was found for the subgroups describing severe and multiple degenerative MRI findings at the lower lumbar levels but none of the other subgroups were associated with LBP. CONCLUSION: Although MRI findings are common in asymptomatic people and the association between single MRI findings and LBP is often weak, our results suggest that subgroups of multiple and severe lumbar MRI findings have a stronger association with LBP than those with milder degrees of degeneration.

Establishment of reference scores and interquartile ranges for the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) in patients with low back pain.

BACKGROUND: The Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) was developed in 2007, including the five domains of Pain-related disorder, Lumbar spine dysfunction, Gait disturbance, Social life disturbance, and Psychological disorder. It is used by physicians to evaluate treatment efficacy by comparing scores before and after treatment. However, the JOABPEQ does not allow evaluation of the severity of a patient's condition compared to the general population at a single time point. Given the unavailability of a standard measurement of back pain, we sought to establish reference scores and interquartile ranges using data obtained from a multicenter, cross-sectional survey taken in Japanese primary care settings. METHODS: The Lumbar Spinal Stenosis Diagnosis Support Tool project was conducted from 2011 to 2012 in 1657 hospitals in Japan to investigate the establishment of reference scores using JOABPEQ. Patients aged ≥ 20 years undergoing medical examinations by either non-orthopaedic primary care physicians or general orthopedists were considered for enrollment. RESULTS: A total of 10,651 consecutive low back pain patients (5331 men, 5320 women, 18 subjects with missing sex data) who had undergone a medical examination were included. Reference scores and interquartile ranges for each of the five domains of the JOABPEQ according to age and sex were recorded. The median score and interquartile range are the same in the domain of Pain-related disorder in all ages and sexes. The reference scores for Gait disturbance, Social life disturbance and Psychological disorder declined with increasing age in both age- and sex-stratified groups, while there was some different trend in Lumbar spine dysfunction between men and women. CONCLUSION: Reference scores and interquartile ranges for JOABPEQ were generated based on the data from the examination data. These provide a measurement standard to assess patient perceptions of low back pain at any time point during evaluation or therapy.

Respiratory characteristics of individuals with non-specific low back pain: A cross-sectional study.

Non-specific low back pain (NS-LBP) is known to cause respiratory dysfunction. In this study, we investigated alterations in breathing, respiratory strength and endurance, core stability, diaphragm mobility, and chest expansion among patients with NS-LBP and healthy individuals. The specific aim of the study was to correlate between respiratory function and other variables among NS-LBP patients. Thirty four patients with NS-LBP were matched with 34 healthy participants before undergoing total faulty breathing scale, spirometer, respiratory pressure meter, chest expansion, ultrasound, and pressure biofeedback measurements. There were signs of faulty breathing in the NS-LBP patients when compared to the healthy participants. Diaphragmatic mobility and respiratory muscle endurance were lower in the NS-LBP group. Chest expansion exhibited a significant decrease at the level of the fourth intercostal space in the NS-LBP group, but respiratory muscle strength and core stability were not significant between the two groups. Positive correlations were found to be fairly significant regarding respiratory muscle strength. The findings of this study indicated altered respiratory characteristics in the NS-LBP patients, and suggested that they would improve through respiratory exercises.

Multigroup latent class model of musculoskeletal pain combinations in children/adolescents: identifying high-risk groups by gender and age.

BACKGROUND: To investigate the combinations of Musculoskeletal pain (MSP) (neck, shoulder, upper and low back pain) among a sample of Iranian school children. METHODS: The MSP combinations was modeled by latent class analysis (LCA) to find the clusters of high-risk individuals and multigroup LCA taking into account the gender and age (≤ 13 years and ≥ 14 years of age categories). RESULTS: The lowest and highest prevalence of MSP was 14.2% (shoulder pain in boys aged ≥14 years) and 40.4% (low back pain in boys aged ≤13 years), respectively. The likelihood of synchronized neck and low back pain (9.4-17.7%) was highest, while synchronized shoulder and upper back pain (4.5-9.4%) had the lowest probability. The probability of pain at three and four locations was significantly lower in boys aged ≥14 years than in other gender-age categories. The LCA divided the children into minor, moderate, and major pain classes. The likelihood of shoulder and upper back pain in the major pain class was higher in boys than in girls, while the likelihood of neck pain in the moderate pain class and low back pain in the major pain class were higher in children aged ≥14 years than those aged ≤13 years. Gender-age specific clustering indicated a higher likelihood of experiencing major pain in children aged ≤13 years. CONCLUSIONS: The findings highlight the importance of gender- and age-specific data for a more detailed understanding of the MSP combinations in children and adolescents, and identifying high-risk clusters in this regard.

Identifying subgroups of patients using latent class analysis: should we use a single-stage or a two-stage approach? A methodological study using a cohort of patients with low back pain.

BACKGROUND: Heterogeneity in patients with low back pain (LBP) is well recognised and different approaches to subgrouping have been proposed. Latent Class Analysis (LCA) is a statistical technique that is increasingly being used to identify subgroups based on patient characteristics. However, as LBP is a complex multi-domain condition, the optimal approach when using LCA is unknown. Therefore, this paper describes the exploration of two approaches to LCA that may help improve the identification of clinically relevant and interpretable LBP subgroups. METHODS: From 928 LBP patients consulting a chiropractor, baseline data were used as input to the statistical subgrouping. In a single-stage LCA, all variables were modelled simultaneously to identify patient subgroups. In a two-stage LCA, we used the latent class membership from our previously published LCA within each of six domains of health (activity, contextual factors, pain, participation, physical impairment and psychology) (first stage) as the variables entered into the second stage of the two-stage LCA to identify patient subgroups. The description of the results of the single-stage and two-stage LCA was based on a combination of statistical performance measures, qualitative evaluation of clinical interpretability (face validity) and a subgroup membership comparison. RESULTS: For the single-stage LCA, a model solution with seven patient subgroups was preferred, and for the two-stage LCA, a nine patient subgroup model. Both approaches identified similar, but not identical, patient subgroups characterised by (i) mild intermittent LBP, (ii) recent severe LBP and activity limitations, (iii) very recent severe LBP with both activity and participation limitations, (iv) work-related LBP, (v) LBP and several negative consequences and (vi) LBP with nerve root involvement. CONCLUSIONS: Both approaches identified clinically interpretable patient subgroups. The potential importance of these subgroups needs to be investigated by exploring whether they can be identified in other cohorts and by examining their possible association with patient outcomes. This may inform the selection of a preferred LCA approach.

Latent class analysis derived subgroups of low back pain patients - do they have prognostic capacity?

BACKGROUND: Heterogeneity in patients with low back pain is well recognised and different approaches to subgrouping have been proposed. One statistical technique that is increasingly being used is Latent Class Analysis as it performs subgrouping based on pattern recognition with high accuracy. Previously, we developed two novel suggestions for subgrouping patients with low back pain based on Latent Class Analysis of patient baseline characteristics (patient history and physical examination), which resulted in 7 subgroups when using a single-stage analysis, and 9 subgroups when using a two-stage approach. However, their prognostic capacity was unexplored. This study (i) determined whether the subgrouping approaches were associated with the future outcomes of pain intensity, pain frequency and disability, (ii) assessed whether one of these two approaches was more strongly or more consistently associated with these outcomes, and (iii) assessed the performance of the novel subgroupings as compared to the following variables: two existing subgrouping tools (STarT Back Tool and Quebec Task Force classification), four baseline characteristics and a group of previously identified domain-specific patient categorisations (collectively, the 'comparator variables'). METHODS: This was a longitudinal cohort study of 928 patients consulting for low back pain in primary care. The associations between each subgroup approach and outcomes at 2 weeks, 3 and 12 months, and with weekly SMS responses were tested in linear regression models, and their prognostic capacity (variance explained) was compared to that of the comparator variables listed above. RESULTS: The two previously identified subgroupings were similarly associated with all outcomes. The prognostic capacity of both subgroupings was better than that of the comparator variables, except for participants' recovery beliefs and the domain-specific categorisations, but was still limited. The explained variance ranged from 4.3%-6.9% for pain intensity and from 6.8%-20.3% for disability, and highest at the 2 weeks follow-up. CONCLUSIONS: Latent Class-derived subgroups provided additional prognostic information when compared to a range of variables, but the improvements were not substantial enough to warrant further development into a new prognostic tool. Further research could investigate if these novel subgrouping approaches may help to improve existing tools that subgroup low back pain patients.

Clinical classification in low back pain: best-evidence diagnostic rules based on systematic reviews.

BACKGROUND: Clinical examination findings are used in primary care to give an initial diagnosis to patients with low back pain and related leg symptoms. The purpose of this study was to develop best evidence Clinical Diagnostic Rules (CDR] for the identification of the most common patho-anatomical disorders in the lumbar spine; i.e. intervertebral discs, sacroiliac joints, facet joints, bone, muscles, nerve roots, muscles, peripheral nerve tissue, and central nervous system sensitization. METHODS: A sensitive electronic search strategy using MEDLINE, EMBASE and CINAHL databases was combined with hand searching and citation tracking to identify eligible studies. Criteria for inclusion were: persons with low back pain with or without related leg symptoms, history or physical examination findings suitable for use in primary care, comparison with acceptable reference standards, and statistical reporting permitting calculation of diagnostic value. Quality assessments were made independently by two reviewers using the Quality Assessment of Diagnostic Accuracy Studies tool. Clinical examination findings that were investigated by at least two studies were included and results that met our predefined threshold of positive likelihood ratio ≥ 2 or negative likelihood ratio ≤ 0.5 were considered for the CDR. RESULTS: Sixty-four studies satisfied our eligible criteria. We were able to construct promising CDRs for symptomatic intervertebral disc, sacroiliac joint, spondylolisthesis, disc herniation with nerve root involvement, and spinal stenosis. Single clinical test appear not to be as useful as clusters of tests that are more closely in line with clinical decision making. CONCLUSIONS: This is the first comprehensive systematic review of diagnostic accuracy studies that evaluate clinical examination findings for their ability to identify the most common patho-anatomical disorders in the lumbar spine. In some diagnostic categories we have sufficient evidence to recommend a CDR. In others, we have only preliminary evidence that needs testing in future studies. Most findings were tested in secondary or tertiary care. Thus, the accuracy of the findings in a primary care setting has yet to be confirmed.

Reliability, Construct and Predictive Validity of the Hong Kong Chinese Orebro Musculoskeletal Pain Screening Questionnaire.

Purpose The aim of this study was to evaluate the reliability, construct validity and predictive validity of the Hong Kong Chinese version of the Orebro Musculoskeletal Pain Screening Questionnaire (COMPSQ-HK). Methods The COMPSQ-HK was developed using the forward-backward translation. Internal consistency was assessed using Cronbach's alpha and test-retest reliability was examined using intraclass correlation coefficient with one-way random-effects model (ICC1,1), minimum detectable change (MDC) and 95% limits of agreement (LoA). Construct validity was evaluated by correlating the COMPSQ-HK with the Numeric Pain Rating Scale, Roland-Morris Disability Questionnaire, Northwick Park Neck Pain Questionnaire, Tampa Scale for Kinesiophobia, and Medical Outcomes Study Short Form 12. The predictive validity was investigated using receiver operating characteristics (ROC) curve analyses with sick leave >60 days and return-to-work for ≥4 consecutive weeks as outcomes at 1 year follow-up. The areas under the curve (AUC) were calculated. Results The COMPSQ-HK was administered to 305 patients with acute/subacute low back pain and 160 patients with acute/subacute neck pain. The Cronbach's alphas and ICC1,1 ranged from 0.83 to 0.84 and 0.81 to 0.92 respectively. The MDC were 32.1 and 21.1. The 95% LoA were -32.4 to 31.8 and -15.4 to 26.7. The Pearson r ranged from 0.333 to 0.697 in absolute value. The AUC for the ROC curve analyses ranged from 0.59 to 0.71. Conclusions The COMPSQ-HK has good internal consistency, moderate test-retest reliability, satisfactory construct validity and predictive validity as a screening tool for patients with back and neck pain at risk of chronic disability.

Validity and responsiveness of the French version of the Örebro Musculoskeletal Pain Screening Questionnaire in chronic low back pain.

PURPOSE: The assessment of a broad range of biopsychosocial aspects is important in the rehabilitation of patients with chronic low back pain (CLBP) for the prediction of outcome as well as for evaluation. The objective of this study was to test the responsiveness, construct validity and predictive value of the Örebro Musculoskeletal Pain Screening Questionnaire (OMPSQ) compared to other instruments widely used to assess biopsychosocial aspects in patients with CLBP. METHODS: 111 patients with CLBP admitted to an inpatient rehabilitation completed a set of questionnaires on biopsychosocial aspects at baseline and at discharge. Ninety-eight patients responded at three months for an assessment of the return to work status. Responsiveness of the OMPSQ, the ability to detect change in the construct of interest, was investigated by a set of hypotheses on correlations with widely used questionnaires. We tested the hypothesis that the changes in the OMPSQ would vary along with the responses in the Patient's Global Impression of Change. Prediction of disability at discharge, work status at three months and time to return to work was evaluated with linear, logistic and cox regression models. RESULTS: The OMPSQ showed good predictive values for disability and return to work and construct validity of the instrument was corroborated. Seventy-nine percent of our hypotheses for responsiveness could be confirmed, with the OMPSQ showing the second highest change during the rehabilitation. CONCLUSIONS: The OMPSQ can also be applied in patients with CLBP, but for the assessment of change in psychosocial variables one should add specific questionnaires.