Predicting the transition from acute to persistent low back pain

BACKGROUND: Most people experience low back pain (LBP) at least once in their lifetime. Only a minority of them go on to develop persistent LBP. However, the socioeconomic costs of persistent LBP significantly exceed the costs of the initial acute LBP episode. AIMS: To identify factors that influence the progression of acute LBP to the persistent state at an early stage. METHODS: Prospective inception cohort study of patients attending a health practitioner for their first episode of acute LBP or recurrent LBP after a pain free period of at least 6 months. Patients were assessed at baseline addressing occupational and psychological factors as well as pain, disability, quality of life and physical activity and followed up at 3, 6, 12 weeks and 6 months. Variables were combined to the three indices 'working condition', 'depression and maladaptive cognitions' and 'pain and quality of life'. RESULTS: The index 'depression and maladaptive cognitions' was found to be a significant baseline predictor for persistent LBP up to 6 months (OR 5.1; 95% CI: 1.04-25.1). Overall predictive accuracy of the model was 81%. CONCLUSIONS: In this study of patients with acute LBP in a primary care setting psychological factors at baseline correlated with a progression to persistent LBP up to 6 months. The benefit of including factors such as 'depression and maladaptive cognition' in screening tools is that these factors can be addressed in primary and secondary prevention.

Acute life-threatening extrinsic allergic alveolitis in a paint controller

Occupational diisocyanate-induced extrinsic allergic alveolitis (EAA) is a rare and probably underestimated diagnosis. Two acute occupational EAA cases have been described in this context, but neither of them concerned hexamethylene diisocyanate (HDI) exposure.

Narrow band imaging (NBI) during medical thoracoscopy: first impressions

Background This is the first ever evaluation of narrow band imaging (NBI), an innovative endoscopic imaging procedure, for the visualisation of pleural processes. Methods The pleural cavity was examined in 26 patients with pleural effusions using both white light and narrow band imaging during thoracoscopy under local anaesthesia. Results In the great majority of the patients narrow band imaging depicted the blood vessels more clearly than white light, but failed to reveal any differences in number, shape or size. Only in a single case with pleura thickened by chronic inflammation and metastatic spread of lung cancer did narrow band imaging show vessels that were not detectable under white light. Conclusion It is not yet possible to assess to what extent the evidence provided by NBI is superior to that achieved with white light. Further studies are required, particularly in the early stages of pleural processes.

Occupational role stress is associated with higher cortisol reactivity to acute stress

We investigated whether occupational role stress is associated with differential levels of the stress hormone cortisol in response to acute psychosocial stress. Forty-three medication-free nonsmoking men aged between 22 and 65 years (mean ± SEM: 44.5 ± 2) underwent an acute standardized psychosocial stress task combining public speaking and mental arithmetic in front of an audience. We assessed occupational role stress in terms of role conflict and role ambiguity (combined into a measure of role uncertainty) as well as further work characteristics and psychological control variables including time pressure, overcommitment, perfectionism, and stress appraisal. Moreover, we repeatedly measured salivary cortisol and blood pressure levels before and after stress exposure, and several times up to 60 min thereafter. Higher role uncertainty was associated with a more pronounced cortisol stress reactivity (p = .016), even when controlling for the full set of potential confounders (p < .001). Blood pressure stress reactivity was not associated with role uncertainty. Our findings suggest that occupational role stress in terms of role uncertainty acts as a background stressor that is associated with increased HPA-axis reactivity to acute stress. This finding may represent a potential mechanism regarding how occupational role stress may precipitate adverse health outcomes.

Who is likely to develop persistent low back pain? A longitudinal analysis of prognostic occupational factors

OBJECTIVE: Occupational low back pain (LBP) is considered to be the most expensive form of work disability, with the socioeconomic costs of persistent LBP exceeding the costs of acute and subacute LBP by far. This makes the early identification of patients at risk of developing persistent LBP essential, especially in working populations. The aim of the study was to evaluate both risk factors (for the development of persistent LBP) and protective factors (preventing the development of persistent LBP) in the same cohort. PARTICIPANTS: An inception cohort of 315 patients with acute to subacute or with recurrent LBP was recruited from 14 health practitioners (twelve general practitioners and two physiotherapists) across New Zealand. METHODS: Patients with persistent LBP at six-month follow-up were compared to patients with non-persistent LBP looking at occupational, psychological, biomedical and demographic/lifestyle predictors at baseline using multiple logistic regression analyses. All significant variables from the different domains were combined into a one predictor model. RESULTS: A final two-predictor model with an overall predictive value of 78% included social support at work (OR 0.67; 95%CI 0.45 to 0.99) and somatization (OR 1.08; 95%CI 1.01 to 1.15). CONCLUSIONS: Social support at work should be considered as a resource preventing the development of persistent LBP whereas somatization should be considered as a risk factor for the development of persistent LBP. Further studies are needed to determine if addressing these factors in workplace interventions for patients suffering from acute, subacute or recurrent LBP prevents subsequent development of persistent LBP.

Occupational exposure to magnetic fields and electric shocks and risk of ALS: The Swiss National Cohort

Amyotrophic lateral sclerosis (ALS) has been associated with exposures in so-called 'electrical occupations'. It is unclear if this possible link may be explained by exposure to extremely low-frequency magnetic fields (ELF-MF) or by electrical shocks. We evaluated ALS mortality in 2000-2008 and exposure to ELF-MF and electrical shocks in the Swiss National Cohort, using job exposure matrices for occupations at censuses 1990 and 2000. We compared 2.2 million workers with high or medium vs. low exposure to ELF-MF and electrical shocks using Cox proportional hazard models. Results showed that mortality from ALS was higher in people who had medium or high ELF-MF exposure in both censuses (HR 1.55 (95% CI 1.11-2.15)), but closer to unity for electrical shocks (HR 1.17 (95% CI 0.83-1.65)). When both exposures were included in the same model, the HR for ELF-MF changed little (HR 1.56), but the HR for electric shocks was attenuated to 0.97. In conclusion, there was an association between exposure to ELF-MF and mortality from ALS among workers with a higher likelihood of long-term exposure.

Assessment of Functioning when Conducting Occupational Capacity Evaluations - What is "Evidence-Based"?

Aim: Occupational capacity evaluations have previously been subject to criticism for lacking in quality and consistency. To the authors' knowledge, there is no clear consensus on the best way to formally assess functioning within capacity evaluations. In this review we investigated different instruments that are used to assess functioning in occupational capacity evaluations. Methods: Systematic review of the literature. Results: Though several instruments that assess functional capacity were found in our search, a specific validated instrument assessing occupational capacity as part of a larger psychiatric evaluation was not found. The limitations of the existing instruments on assessing functional capacity are discussed. Conclusion: Medical experts relying on instruments to conduct functional capacity evaluations should be cognizant of their limitations. The findings call for the development and use of an instrument specifically designed to assess the functional and occupational capacity of psychiatric patients, which is also likely to improve the quality of these reports.

Feasibility study of a single-blind randomised controlled trial of an occupational therapy intervention.

BACKGROUND Several factors facilitate or hinder efficacy research in occupational therapy. Strategies are needed, therefore, to support the successful implementation of trials. AIM To assess the feasibility of conducting a randomised controlled trial (RCT). The main feasibility objectives of this study were to assess the process, resources, management, and scientific basis of a trial RCT. MATERIAL AND METHODS A total of 10 occupational therapists, between the ages of 30 and 55 (M 43.4; SD 8.3) with seven to 26 years' (M 14.3; SD 6.1) experience, participated in this study. Qualitative data collected included minutes of meetings, reports, and field notes. The data were analysed based on the principles of content analysis, using feasibility objectives as the main categories. RESULTS Data analysis revealed strengths in relation to retention and inclusion criteria of participants, the study protocol, study organisation, and the competence of researchers. Weaknesses were found related to recruitment, randomisation, data collection, time for training and communication, commitment, and design. CONCLUSION The findings indicated that there are several factors which had a considerable impact on the implementation of an RCT in practice. However, it was useful to assess methods and procedures of the trial RCT as a basis to refine research plans.