Characterizing the Course of Low Back Pain: A Latent Class Analysis

Primary Care Sciences Research Centre, Keele University, Keele, United Kingdom.
American Journal of Epidemiology (Impact Factor: 5.23). 05/2006; 163(8):754-61. DOI: 10.1093/aje/kwj100
Source: PubMed


Understanding the course of back pain is important for clinicians and researchers, but analyses of longitudinal data from multiple time points are lacking. A prospective cohort study of consecutive back pain consulters from five general practices in the United Kingdom was carried out between 2001 and 2003 to identify groups defined by their pain pathways. Patients were sent monthly questionnaires for a year. Longitudinal latent class analysis was performed by using pain intensity scores for 342 consulters. Analysis yielded four clusters representing different pathways of back pain. Cluster 1 ("persistent mild"; n = 122) patients had stable, low levels of pain. Patients in cluster 2 ("recovering"; n = 104) started with mild pain, progressing quickly to no pain. Cluster 3 ("severe chronic"; n = 71) patients had permanently high pain. For patients in cluster 4 ("fluctuating"; n = 45), pain varied between mild and high levels. Distinctive patterns for each cluster were maintained throughout follow-up. Clusters showed statistically significant differences in disability, psychological status, and work absence (p < 0.001). This is the first time, to the authors' knowledge, that latent class analysis has been applied to longitudinal data on back pain patients. Identification of four distinct groups of patients improves understanding of the course of back pain and may provide a basis of classification for intervention.

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    • "LCGA assumes that the heterogeneity in a single outcome repeatedly assessed can be summarized by a certain number of clusters with distinct cluster-specific trajectories [9]. Quadratic growth models were applied that allow for one inflexion point, as the course of musculoskeletal pain is often non-linear and is known to be associated with depression and anxiety [18] [34]. This method requires a minimum of four time points. "
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    ABSTRACT: Distinguishing transient from persistent anxiety and depression symptoms in older people presenting to general practice with musculoskeletal pain is potentially important for effective management. This study sought to identify distinct post-consultation depression and anxiety symptom trajectories in adults aged over 50years consulting general practice for non-inflammatory musculoskeletal pain. Self-completion questionnaires, containing measures of anxiety and depressive symptoms, age, gender, pain status, coping and social status were mailed within 1week of the consultation and at 3, 6 and 12months. Latent class growth analysis was used to identify anxiety and depression symptoms trajectories, which were ascertained with cut-off score ≥8 on Hospital Anxiety and Depression Scale subscales. Associations between baseline characteristics and cluster membership were examined using multivariate multinomial logistic regression analysis (the 3-step approach). Latent class growth analyses determined a 3-cluster anxiety model (n=499) and a 3-cluster depression model (n=501). Clusters identified were: no anxiety problem (44.1%), persistent anxiety problem (33.9%) and transient anxiety symptoms (22.2%); no depression problem (74.1%), persistent depression problem (22.0%) and gradual depression symptom recovery (4.0%). Widespread pain, interference with valued activities, coping by increased behavioral activities, catastrophizing, perceived lack of instrumental support, age ≥70years, being female, and performing manual/routine work were associated with anxiety and/or depression clusters. Older people with non-inflammatory musculoskeletal pain are at high risk of persistent anxiety and/or depression problems. Biopsychosocial factors, such as pain status, coping strategies, instrumental support, performing manual/routine work, being female and age ≥70years, may help identify patients with persistent anxiety and/or depression. Copyright © 2015 Elsevier Inc. All rights reserved.
    Full-text · Article · Jun 2015 · Journal of Psychosomatic Research
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    • "In our study, the pain measurements and classifications were to a great extent different and the follow-up longer. Dunn et al. (2006) concluded that the optimal number of trajectories is either four or six for longitudinal latent class analysis. We also tried a two-step cluster analysis, which is available in SPSS, and this gave two different classifications: four and five clusters. "
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    ABSTRACT: Purpose To investigate the prevalence of low back pain among Finnish firefighters and to examine whether sleep disturbances predict membership of low back pain trajectories. Methods In this prospective study, 360 actively working firefighters responded to a questionnaire in 1996, 1999 and 2009. The outcome variables were radiating and local low back pain during the preceding year. Using logistic regression modeling, the likelihood of membership of pain trajectories was predicted by sleep disturbances at baseline. Results During the 13-year follow-up, the prevalence of radiating low back pain increased from 16 to 29 % (p < 0.0001) and that of local low back pain from 28 to 40 % (p < 0.001). The following trajectories were identified: “pain free,” “recovering,” “new pain,” “fluctuating” and “chronic.” More than one-fifth of the participants belonged to the new pain trajectory as regards both pain types, 6 % of the participants belonged to the chronic radiating and 12 % to the chronic local low back pain trajectory. Those with sleep disturbances at baseline had a 2.4-fold risk (adjusted OR 2.4; 95 % CI 1.2–4.7) of belonging to the new pain or chronic radiating pain cluster compared to pain-free participants. Conclusions This is the first prospective study to show that low back symptoms are common and persistent among firefighters and that sleep disturbances strongly predict membership of a radiating pain trajectory. Occupational health and safety personnel, as well as the firefighters themselves, should recognize sleep problems early enough in order to prevent back pain and its development into chronic pain.
    Full-text · Article · Aug 2014 · International Archives of Occupational and Environmental Health
    • "Chronic low back pain (CLBP) is a primary public health concern globally.[1] Four categories were proposed by Dunn et al.[2] to classify CLBP patients representing diverse paths over time: Persistent mild, recovering, severe chronic and fluctuating type.[3] CLBP has turned out to be the cause for approximately 6-9% of middle-aged people to consult their family physician every year.[4] "
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    ABSTRACT: Background:Studies have shown that Integrated Yoga reduces pain, disability, anxiety and depression and increases spinal flexibility and quality-of-life in chronic low back pain (CLBP) patients.Objective:The objective of this study was to compare the effect of two yoga practices namely laghu shankha prakshalana (LSP) kriya, a yogic colon cleansing technique and back pain specific asanas (Back pain special technique [BST]) on pain, disability, spinal flexibility and state anxiety in patients with CLBP.Materials and Methods:In this randomized control (self as control) study, 40 in-patients (25 were males, 15 were females) between 25 and 70 years (44.05 ± 13.27) with CLBP were randomly assigned to receive LSP or BST sessions. The measurements were taken immediately before and after each session of either of the practices (30 min) in the same participant. Randomization was used to decide the day of the session (3rd or 5th day after admission) to ensure random distribution of the hang over effect of the two practices. Statistical analysis was performed using the repeated measures analysis of variance.Results:Significant group * time interaction (P < 0.001) was observed in 11 point numerical rating scale, spinal flexibility (on Leighton type Goniometer) and (straight leg raise test in both legs), Oswestry Disability Index, State Anxiety (XI component of Spieldberger's state and trait anxiety inventory. There was significantly (P < 0.001, between groups) better reduction in LSP than BST group on all variables. No adverse effects were reported by any participant.Conclusion:Clearing the bowel by yoga based colon cleansing technique (LSP) is safe and offers immediate analgesic effect with reduced disability, anxiety and improved spinal flexibility in patients with CLBP.
    No preview · Article · Jul 2014 · International Journal of Yoga
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