Neuropathic pain in low back-related leg pain patients: What is the evidence of prevalence, characteristics, and prognosis in primary care? A systematic review of the literature.

This systematic review synthesizes literature describing prevalence, characteristics and prognosis of low back-related leg pain (LBLP) patients with neuropathic pain in primary care and/or similar settings. Inclusion and exclusion criteria were developed and used by independent reviewers to screen citations for eligibility. The initial search yielded 24,948 citations; after screening 12 studies were included. Neuropathic pain was identified by case ascertainment tools (n=5), by clinical history with examination (n=4), and by LBLP samples assumed neuropathic (n=3). Neuropathic pain prevalence varied from 19% to 80%. There was consistent evidence for higher back-related disability (n=3), poorer health-related quality of life (n=2) and some evidence for more severe depression (n=2), anxiety (n=3) and pain intensity (n=4) in patients with neuropathic pain. Results were less consistent when cases were identified through clinical history plus examination than those identified using case ascertainment tools. Prognosis (n=1) of LBLP patients with neuropathic pain was worse compared to those without, in all outcomes (leg pain intensity, leg and back-related disability, self-reported general health) except back pain intensity. No studies described prognostic factors. This systematic review highlights the evidence gap in neuropathic pain in LBLP in primary care, especially with respect to prognosis. PERSPECTIVE: Patients with low back-related leg pain may have neuropathic pain. This systematic review emphasises the paucity of evidence describing the characteristics and prognosis of neuropathic pain in this patient population. Future research investigating prognosis of these patients with neuropathic pain is likely to contribute to better understanding and management

Identifying Treatment Effect Modifiers in the STarT Back Trial: A Secondary Analysis

Identification of patient characteristics influencing treatment outcomes is a top low back pain (LBP) research priority. Results from the STarT Back Trial support the effectiveness of prognostic stratified care for LBP compared to current best care, however patient characteristics associated with treatment response have not yet been explored. The purpose of this secondary analysis was to identify treatment-effect modifiers within the STarT Back Trial at 4 months follow-up (n=688). Treatment response was dichotomized using back-specific physical disability measured by the Roland-Morris Disability Questionnaire (≥7). Candidate modifiers were identified using previous literature and evaluated using logistic regression with statistical interaction terms to provide preliminary evidence of treatment-effect modification. Socioeconomic status (SES) was identified as an effect modifier for disability outcomes (OR = 1.71, P=.028). High SES patients receiving prognostic stratified care were 2.5 times less likely to have a poor outcome compared to low SES patients receiving best current care (OR = 0.40, P=.006). Education level (OR = 1.33, P=.109) and number of pain medications (OR = 0.64, P=.140) met our criteria for effect modification with weaker evidence (0.20>P≥0.05). These findings provide preliminary evidence for SES, education, and number of pain medications as treatment-effect modifiers of prognostic stratified care delivered in the STarT Back Trial

Does a modified STarT Back Tool predict outcome with a broader group of musculoskeletal patients than back pain? A secondary analysis of cohort data.

OBJECTIVES: The STarT Back Tool has good predictive performance for non-specific low back pain in primary care. We therefore aimed to investigate whether a modified STarT Back Tool predicted outcome with a broader group of musculoskeletal patients, and assessed the consequences of using existing risk-group cut-points across different pain regions. SETTING: Secondary analysis of prospective data from 2 cohorts: (1) outpatient musculoskeletal physiotherapy services (PhysioDirect trial n=1887) and (2) musculoskeletal primary-secondary care interface services (SAMBA study n=1082). PARTICIPANTS: Patients with back, neck, upper limb, lower limb or multisite pain with a completed modified STarT Back Tool (baseline) and 6-month physical health outcome (Short Form 36 (SF-36)). OUTCOMES: Area under the receiving operator curve (AUCs) tested discriminative abilities of the tool's baseline score for identifying poor 6-month outcome (SF-36 lower tertile Physical Component Score). Risk-group cut-points were tested using sensitivity and specificity for identifying poor outcome using (1) Youden's J statistic and (2) a clinically determined rule that specificity should not fall below 0.7 (false-positive rate <30%). RESULTS: In PhysioDirect and SAMBA, poor 6-month physical health was 18.5% and 28.2%, respectively. Modified STarT Back Tool score AUCs for predicting outcome in back pain were 0.72 and 0.79, neck 0.82 and 0.88, upper limb 0.79 and 0.86, lower limb 0.77 and 0.83, and multisite pain 0.83 and 0.82 in PhysioDirect and SAMBA, respectively. Differences between pain region AUCs were non-significant. Optimal cut-points to discriminate low-risk and medium-risk/high-risk groups depended on pain region and clinical services. CONCLUSIONS: A modified STarT Back Tool similarly predicts 6-month physical health outcome across 5 musculoskeletal pain regions. However, the use of consistent risk-group cut-points was not possible and resulted in poor sensitivity (too many with long-term disability being missed) or specificity (too many with good outcome inaccurately classified as 'at risk') for some pain regions. The draft tool is now being refined and validated within a new programme of research for a broader musculoskeletal population. TRIAL REGISTRATION NUMBER: ISRCTN55666618; Post results

Preface: proceedings of the 13th IASWS international conference

This short article forms the preface to the Proceedings of the 13th IASWS conference held in Grahamstown in July 2014. It provides a background to the conference, a synthesis of the 15 published papers published in the special issue of JSS and a poem - written and read by Harry Owen on the opening night of the conference

Consenting to health record linkage: evidence from a multi-purpose longitudinal survey of a general population

Background: The British Household Panel Survey (BHPS) is the first long-running UK longitudinal survey with a non-medical focus and a sample covering the whole age range to have asked for permission to link to a range of administrative health records. This study determines whether informed consent led to selection bias and reflects on the value of the BHPS linked with health records for epidemiological research. Methods. Multivariate logistical regression is used, with whether the respondent gave consent to data linkage or not as the dependent variable. Independent variables were entered as four blocks; (i) a set of standard demographics likely to be found in most health registration data, (ii) a broader set of socio-economic characteristics, (iii) a set of indicators of health conditions and (iv) information about the use of health services. Results: Participants aged 16-24, males and those living in England were more likely to consent. Consent is not biased with respect to socio-economic characteristics or health. Recent users of GP services are underrepresented among consenters. Conclusions: Whilst data could only be linked for a minority of BHPS participants, the BHPS offers a great range of information on people's life histories, their attitudes and behaviours making it an invaluable source for epidemiological research. © 2012 Knies et al; licensee BioMed Central Ltd

Prevalence, Characteristics and Clinical Course of Neuropathic Pain in Primary Care Patients Consulting with Low Back-related Leg Pain.

OBJECTIVES: Little is known about the epidemiology of neuropathic pain in primary care patients consulting with low back-related leg pain. We aimed to describe prevalence, characteristics and clinical course of low back-related leg pain patients with and without neuropathic pain, consulting with their family doctor in the UK. METHODS: This was a prospective cohort study. Data were collected using a standardised baseline clinical examination and self-report questionnaires at baseline, 4, 12 and 36-months. We identified cases of neuropathic pain using three definitions: two based on clinical diagnosis (sciatica, with and without evidence of nerve root compression on MRI), one on the self-report version of Leeds Assessment for Neurological Symptoms and Signs (S-LANSS). Differences between patients with and without neuropathic pain were analysed comparing each definition. Clinical course (mean pain intensity measured as the highest of leg or back pain intensity: mean of three Numerical Rating Scales, each 0-10) was investigated using linear mixed models over 36-months. RESULTS: Prevalence of neuropathic pain varied from 48% to 74% according to definition used. At baseline, patients with neuropathic pain had more severe leg pain intensity, lower pain self-efficacy, more patients had sensory loss than those without. Distinct profiles were apparent depending on neuropathic pain definition. Mean pain intensity reduced after 4-months (6.1 to 3.9 (sciatica)), most rapidly in cases defined by clinical diagnosis. DISCUSSION: This research provides new information on the clinical course of neuropathic pain and a better understanding of neuropathic pain in low back-related leg pain patients consulting in primary care

Trajectories and predictors of the long-term course of low back pain: cohort study with 5-year follow-up

Low back pain (LBP) is a major health challenge globally. Research has identified common trajectories of pain over time. We aimed to investigate whether trajectories described in one primary care cohort can be confirmed in another, and to determine the prognostic value of factors collected 5 years prior to the identification of the trajectory. The study was carried out on 281 patients who had consulted primary care for LBP, at that point completed a baseline questionnaire, and then returned a questionnaire at 5-years follow-up plus at least 3 (of 6) subsequent monthly questionnaires. Baseline factors were measured using validated tools. Pain intensity scores from the 5-year follow-up and monthly questionnaires were used to assign participants into 4 previously derived pain trajectories (no or occasional mild, persistent mild, fluctuating, persistent severe), using latent class analysis. Posterior probabilities of belonging to each cluster were estimated for each participant. The posterior probabilities for the assigned clusters were very high (>0.90) for each cluster except for the smallest 'fluctuating' cluster (0.74). Lower social class and higher pain intensity were significantly associated with a more severe trajectory 5-years later, as were patients' perceptions of the greater consequences and longer duration of pain, and greater passive behavioural coping. LBP trajectories identified previously appear generalizable. These allow better understanding of the long-term course of LBP and effective management tailored to individual trajectories needs to be identified

Keele Aches and Pains Study Protocol: validity, acceptability and feasibility of the Keele STarT MSK Tool for subgrouping musculoskeletal patients in primary care

Musculoskeletal conditions represent a considerable burden worldwide, and are predominantly managed in primary care. Evidence suggests that many musculoskeletal conditions share similar prognostic factors. Systematically assessing patient’s prognosis, and matching treatments based on prognostic subgroups (stratified care), has been shown to be clinically and cost effective. This study (Keele Aches and Pains Study: KAPS) aims to refine and examine the validity of a brief questionnaire (Keele STarT MSK Tool), designed to enable risk-stratification of primary care patients with the five most common musculoskeletal pain presentations. We will also describe the subgroups of patients, and explore the acceptability and feasibility of using the tool, and how the tool is best implemented in clinical practice. The study design is mixed methods: a prospective, quantitative observational cohort study with a linked qualitative focus group and interview study. Patients who have consulted their General Practitioner or Healthcare Practitioner (GP/HCP) about a relevant musculoskeletal condition will be recruited from General practice. Participating patients will complete a baseline questionnaire (shortly after consultation), plus questionnaires 2 and 6 months later. A sub-sample of patients, along with participating GPs and HCPs, will be invited to take part in qualitative focus groups and interviews. The Keele STarT MSK Tool will be refined based on face, discriminant, construct and predictive validity at baseline and 2 months, and validated using data from 6 month follow-up. Patient and clinician perspectives about using the tool will be explored. This study will provide a validated prognostic tool (the Keele STarT MSK Tool) with established cut-points to stratify patients with the five most common musculoskeletal presentations into low, medium and high risk subgroups. The qualitative analysis of patient and healthcare perspectives will inform how to embed the tool into clinical practice using established general practice IT systems and clinician support packages