Disabling musculoskeletal pain and its relation to somatization: a community-based postal survey

Efficacy of soothing cream gel in the range of motion and chronic pain at the shoulder and elbow: protocol of a double-blinded, randomised, placebo-controlled trial

INTRODUCTION

Upper limb problems have a significant impact on the global population leading to pain and restricted joint mobility, ultimately impacting their quality of life. Traditional treatments, such as non-steroidal anti-inflammatory drugs and corticosteroids, often come with undesirable side effects, prompting patients to seek alternative therapies. In this trial, we hypothesise that soothing cream gel (SCG) will improve range of motion and chronic pain in the shoulder and elbow. The objective of this trial is to evaluate the efficacy of SCG in improving the range of motion and chronic pain in the shoulder and elbow.

METHODS AND ANALYSIS

A double-blinded, randomised, placebo-controlled trial is conducted to compare the effects of SCG and placebo gel. SCG contains Vitis vinifera essence, Melaleuca viridiflora essential oil, etc, and is manufactured according to Good Manufacturing Practice standards. The placebo gel will be processed with similar appearance, texture and scent but will lack active ingredients. 70 participants with upper limb problems will be recruited from four study sites, including clinical centres and a sport department at the Chinese University of Hong Kong (CUHK). Participants will be randomly assigned to either treatment group or placebo group for 2 weeks. Primary outcome will be the range of motion in the upper limb, assessed by a goniometer, to measure active flexion and abduction for the shoulder, and active flexion and extension for the elbow. The primary efficacy analyses will be based on the full analysis set following the intention-to-treat principle.

ETHICS AND DISSEMINATION

The trial has obtained approval from the joint CUHK-New Territories East Cluster (CRE-2023.142), and the patient enrolment commenced in July 2023. Written informed consent will be obtained from all participants prior to participation. Study results will be disseminated through publication in peer-reviewed journals and presentations at conference.

TRIAL REGISTRATION NUMBER

NCT05799391.

Chronic Low Back Pain with and without Concomitant Osteoarthritis: A Retrospective, Longitudinal Cohort Study of Patients in England

Objective

Despite the high prevalence of chronic low back pain (CLBP) and osteoarthritis (OA), few estimates of the economic cost of these conditions in England have been published. The aim of the present analysis was to characterise the economic burden of moderate-to-severe pain associated with CLBP + OA and CLBP alone compared with general population-matched controls without CLBP or OA. The primary objective was to describe the total healthcare resource use (HCRU) and direct healthcare costs associated with the target patient populations. Secondary objectives were to describe treatment patterns and surgical procedures.

Methods

This was a retrospective, observational cohort study of patients receiving healthcare indicative of moderate-to-severe chronic pain associated with CLBP, with or without OA. We used linked longitudinal data from the Clinical Practice Research Datalink GOLD and Hospital Episode Statistics (HES). Patients (cases) were matched 1 : 1 with controls on age, sex, comorbidity burden, GP practice, and HES data availability.

Results

The CLBP-alone cohort comprised 13 554 cases with CLBP and 13 554 matched controls; the CLBP + OA cohort comprised 7803 cases with both OA and CLBP and 7803 matched controls. Across all follow-up periods, patients with CLBP alone and those with CLBP + OA had significantly more GP consultations, outpatient attendances, emergency department visits, and inpatient stays than controls (all p < 0.0001). By 36 months after indexing, the mean (SD) per-patient total direct healthcare cost in the CLBP-alone cohort was £5081 (£5905) for cases and £1809 (£4451) for controls (p < 0.0001); in the CLBP + OA cohort, the mean (SD) per-patient total direct healthcare cost was £8819 (£7143) for cases and £2428 (£4280) for controls (p < 0.0001).

Conclusion

Moderate-to-severe chronic pain associated with CLBP-with or without OA-has a substantial impact on patients and healthcare providers, leading to higher HCRU and costs versus controls among people with CLBP alone or together with OA.

Comparing the occurrence of chronic physical disorders in self-employed individuals with that of employees: A systematic review

BACKGROUND

A stringent systematic review of population-based observational studies focusing on the physical health of self-employed individuals as a basis for the development of targeted prevention strategies is lacking.

OBJECTIVE

We aimed to systematically evaluate all the studies of good quality that compared the occurrence of chronic physical disorders in self-employed individuals with that of employees.

METHODS

We searched three major medical databases (MEDLINE, Web of Science, Embase) following the Cochrane guidelines. The quality of the studies was rated based on the slightly modified validated assessment tool that was developed by Hoy et al.RESULTS:We included 16 population-based studies of good quality, with data from 15,369,964 participants in total. The two longitudinal evaluations of Swedish national registers with the longest follow-up periods showed increased cardiovascular mortality and incidence estimates of cardiovascular disease in self-employed individuals compared with those of white-collar (i.e., nonmanual) employees but decreased risk estimates compared with those of blue-collar (i.e., manual) workers. The results of the shorter cohort studies were heterogeneous. In cross-sectional studies, prevalence estimates for musculoskeletal, respiratory and malignant diseases were higher among self-employed individuals than among employees.

CONCLUSION

The long-term cardiovascular disease risk and mortality of self-employed individuals seemed to be higher than those of white-collar employees but lower than those of blue-collar employees. As a basis for targeted prevention strategies, further longitudinal studies in different settings are required to better understand the development of physical health disorders for specific self-employment categories such as sole proprietors, small entrepreneurs, family businesses and others.

Dor na coluna torácica e fatores associados em fumicultores

Resumo Introdução: dor na coluna torácica diz respeito a traumas cumulativos envolvendo má postura, movimentos repetitivos e longos períodos na mesma posição. Objetivo: avaliar a prevalência de dor na coluna torácica e fatores associados em fumicultores no sul do Brasil. Métodos: estudo transversal cuja associação entre o desfecho e os fatores sociodemográficos e comportamentais, atividades laborais, cargas de trabalho e comorbidades foram examinadas pelo teste de Wald para heterogeneidade e tendência linear. A análise multivariável foi realizada utilizando modelo hierárquico e regressão de Poisson com variância robusta. Resultados: o estudo envolveu 2.469 indivíduos de ambos os sexos. A prevalência de dor na coluna torácica foi de 21,2%. Limpar equipamento para aplicação de agrotóxico, número de episódios de Doença da Folha Verde, sintomas respiratórios e transtornos psiquiátricos menores foram positivamente associados ao desfecho em ambos os sexos. Tabagismo e intoxicação por agrotóxicos foram associados ao desfecho entre as mulheres, enquanto escolaridade e passar varas com folhas de tabaco foram associados aos homens. Conclusões: reestruturação ergonômica, redução das cargas de trabalho, trocas de posição durante o turno de trabalho e mecanização do processo de trabalho são estratégias importantes para reduzir a exposição à nicotina, agrotóxicos e carga de trabalho ergonômica.

Somatic symptoms in women with dysmenorrhea and noncyclic pelvic pain

Somatic symptoms are a robust, transdiagnostic risk factor for pain conditions. However, the extent to which somatic symptoms contribute to the manifestation of the women's pain syndromes, such as dysmenorrhea and noncyclic pelvic pain (NCPP), is unclear due to high rates of co-occurrence. Therefore, the present study investigated the primary hypothesis that somatic symptoms would be elevated in NCPP and distinctly influence the relationship between dysmenorrhea and co-occurring NCPP. A secondary analysis was performed on cross-sectional questionnaire data from 1012 nonpregnant reproductive-aged women. Eligible analyzed participants (n = 834) were categorized into four groups: healthy, dysmenorrhea, NCPP, and NCPP with co-occurring dysmenorrhea (NCPP+dysmenorrhea). A parallel mediation analysis was run to evaluate the primary hypothesis that somatic symptoms are the primary factor associated with increased NCPP accounting for dysmenorrhea. The NCPP+dysmenorrhea group had higher somatic, anxiety, and depression symptom T-scores (respectively 61, 61, 60) compared to the healthy controls (46, 51, 51; p's < .001) and the dysmenorrhea group (50, 53, 54; p's < .001). The pain and psychological symptoms were significantly correlated across the entire sample (r's = .29, - .64, p's < .01). Results from parallel mediation analysis showed that somatic symptoms were distinctly associated with NCPP+dysmenorrhea. Women with NCPP+dysmenorrhea have increased psychological and somatic symptoms compared to women with dysmenorrhea alone. Given that NCPP often co-occurs with dysmenorrhea, failure to account for comorbidity in previous studies has likely led to an overestimation of psychological symptoms in dysmenorrhea. Future studies should evaluate whether somatic sensitivity is a modifiable risk factor for NCPP.

Individual and work-related risk factors for musculoskeletal pain among computer workers in Nigeria

We investigated the prevalence of musculoskeletal pain (MSP) and the association of 1-month prevalence with individual and work-related factors among commercial typists in Enugu. Participants responded to a questionnaire about occurrences of MSP and a 75.6% (242/320) response rate was achieved. Prevalence was summarized in frequencies and percentages while associations between MSPs and risk factors were explored using chi-square. MSP was most common in the low back (58.3%), and low back pain limited 51.7% from activities between 1 and 30 days. Advancing age was significantly associated with MSP in the low back (x² = 19.885; p = .001), neck (x² = 28.309; p < .001), shoulder (x² = 13.122; p = .011), but not wrist/hand (p = .075). Working 1-5 years in this job was associated with increasing prevalence of MSP in all body regions studied. Lesser job control was associated with increased prevalence of wrist/hand pain. Prevalence of MSDs among computer operators in Enugu, Nigeria, is high and highlights the importance of workplace intervention.

Disability due to knee pain and somatising tendency in Japanese adults

BACKGROUND

Knee pain is common and related to knee osteoarthritis. However, there is a discrepancy between knee pain and radiographic osteoarthritis. In the general population, knee pain is associated with psychological and cognitive factors, which would be one explanation for the discrepancy. Limited evidence demonstrates that somatization is associated with knee pain. This study examined the association between disability due to knee pain and a high somatising tendency.

METHODS

Japanese adults (aged 20-64 years) who had experienced knee pain in the past four weeks were included in this study (n = 14,695, 50% women). Data were extracted from a large internet survey. Somatising tendency was assessed using the Somatic Symptom Scale-8 (SSS-8). Disability due to knee pain was categorized into three levels: 1) knee pain without difficulty with activities of daily living (ADL), 2) knee pain with ADL difficulty but without requiring sick leave, and 3) knee pain requiring sick leave. The association between ≥ high somatising tendency (SSS-8 score ≥ 12) as well as very high somatising tendency (SSS-8 score ≥ 16) and disability due to knee pain was examined using logistic regression models adjusted for age, sex, body mass index, depressive symptoms, education level, regular exercise, chronicity of knee pain (≥3 months), osteoarthritis, rheumatoid arthritis, and fibromyalgia.

RESULTS

Greater disability due to knee pain was associated with a higher odds ratio for ≥ high somatising tendency (adjusted odds ratio (aOR) = 2.36 [2.10-2.66] in group 2 vs. group 1, aOR = 3.23 [2.66-3.92] in group 3 vs. group 1). Stronger associations were found for a very high somatising tendency (aOR = 2.80 [2.42-3.23] in group 2 vs. group 1, aOR = 4.51 [3.64-5.58] in group 3 vs. group 1).

CONCLUSIONS

Somatization may play a role in disability due to knee pain in the general adult population with knee pain, similar to the role of somatization in low back pain.

Predictors of low back pain in a longitudinal study of Iranian nurses and office workers

BACKGROUND

A previous survey had indicated high rates of low back pain (LBP) in Iranian nurses and office workers.

OBJECTIVE

To explore possible risk factors, we carried out a longitudinal study of the same subjects.

METHODS

Baseline information about risk factors and recent history of LBP was collected by self-administered questionnaire from 246 nurses and 182 office workers. Approximately 12 months later, 385 (90%) answered a second questionnaire about LBP in the past month. Predictors of LBP at follow-up were assessed by Poisson regression and summarised by prevalence rate ratios (PRRs) with 95% confidence intervals (CIs).

RESULTS

In a regression model that included all risk factors, the strongest predictor of LBP at follow-up was report of recent LBP at baseline. In addition, LBP was associated with older age, adverse beliefs about the work-relatedness of LBP (PRR 1.3, 95%CI 1.0-1.5), and incentives from piecework or bonuses (PRR 1.4, 95%CI 1.1-1.6). When baseline report of LBP was omitted from the model, associations were also observed with tendency to somatise, poor mental health and time pressures at work.

CONCLUSIONS

Our findings support the importance of psychosocial risk factors for LBP, including adverse health beliefs and working conditions that encourage higher output.

Are determinants for new and persistent upper limb pain different? An analysis based on anatomical sites

BACKGROUND

Only few longitudinal studies have explored separately predictors of pain incidence and persistence.

OBJECTIVE

To investigate whether biological, lifestyle, occupational and psychological risk factors for the development of new episodes of upper limb pain (ULP) differ from those for its persistence.

METHODS

Spanish nurses and office workers (1105) were asked at baseline about biological, lifestyle, occupational and psychological risk factors and pain in the past month at six anatomical sites in the upper limb (left and right shoulder, elbow and wrist/hand). At follow up, 12 months later, pain in the past month was again ascertained. Analysis was based on anatomical sites clustered by person. Associations were assessed by multilevel logistic regression models.

RESULTS

Nine hundred and seventy-one participants (87.9%) completed follow-up. Job dissatisfaction and older age carried higher risk of new ULP. Somatising tendency (OR 2.2, 95% CI 1.6-3.1) was the strongest predictor of new ULP, with a risk estimate which differed significantly from that for the same exposure and persistence of ULP. Having adverse beliefs about the work-relatedness of ULP carried a significantly reduced risk for persistence of ULP.

CONCLUSION

Our study provides only limited evidence that risk factors predicting new ULP differ from those predicting its persistence.

Descriptive Epidemiology of Somatising Tendency: Findings from the CUPID Study

Somatising tendency, defined as a predisposition to worry about common somatic symptoms, is importantly associated with various aspects of health and health-related behaviour, including musculoskeletal pain and associated disability. To explore its epidemiological characteristics, and how it can be specified most efficiently, we analysed data from an international longitudinal study. A baseline questionnaire, which included questions from the Brief Symptom Inventory about seven common symptoms, was completed by 12,072 participants aged 20-59 from 46 occupational groups in 18 countries (response rate 70%). The seven symptoms were all mutually associated (odds ratios for pairwise associations 3.4 to 9.3), and each contributed to a measure of somatising tendency that exhibited an exposure-response relationship both with multi-site pain (prevalence rate ratios up to six), and also with sickness absence for non-musculoskeletal reasons. In most participants, the level of somatising tendency was little changed when reassessed after a mean interval of 14 months (75% having a change of 0 or 1 in their symptom count), although the specific symptoms reported at follow-up often differed from those at baseline. Somatising tendency was more common in women than men, especially at older ages, and varied markedly across the 46 occupational groups studied, with higher rates in South and Central America. It was weakly associated with smoking, but not with level of education. Our study supports the use of questions from the Brief Symptom Inventory as a method for measuring somatising tendency, and suggests that in adults of working age, it is a fairly stable trait.

Influence of work-related psychosocial factors on the prevalence of chronic pain and quality of life in patients with chronic pain

OBJECTIVES

Working is a common cause of chronic pain for workers. However, most of them need to continue working despite the pain in order to make a living unless they get a sick leave or retirement. We hypothesised that the therapeutic effect of vocational rehabilitation may depend on psychosocial factors related to the workplace. To test this hypothesis, we examined the association of work-related psychosocial factors with the prevalence of chronic pain or health-related quality of life (HRQoL) among workers with chronic pain.

METHODS

We examined 1764 workers aged 20-59 years in the pain-associated cross-sectional epidemiological survey in Japan. The outcomes were (1) chronic pain prevalence among all workers and (2) low Euro QoL (EQ-5D <0.76; mean value of the current study) prevalence among workers with chronic pain according to the degree of workplace social support and job satisfaction. Workplace social support and job satisfaction were measured using the Brief Job Stress Questionnaire. Multivariable-adjusted ORs were calculated using a logistic regression model including age, sex, smoking, exercise, sleep time, work hours, body mass index, personal consumption expenditure, intensity of pain and the presence of severe depressive symptoms.

RESULTS

Chronic pain prevalence was higher among males reporting job dissatisfaction compared with those reporting job satisfaction. No difference was observed among women. Chronic pain prevalence did not differ between workers of either sex reporting poor workplace social support compared with those reporting sufficient support. Among workers with chronic pain, low HRQoL was more frequent in those reporting job dissatisfaction. Similarly, low HRQoL was more frequent in patients with chronic pain reporting poor social support from supervisors or co-workers compared with patients reporting sufficient support.

CONCLUSIONS

Work-related psychosocial factors are critical for HRQoL in patients with chronic pain.

A systematic review of prognostic factors for distal upper limb pain

BACKGROUND

Musculoskeletal pain in the distal upper limb is relatively common, can be a cause of disability, presents a high cost to society and is clinically important. Previous reviews of prognostic factors have focused on pain in the proximal upper limb, whole upper extremity or isolated regions of the distal upper limb.

AIM

To identify factors that predict outcome of distal upper limb pain.

STUDY DESIGN

Systematic review.

METHOD

Eight bibliographic databases were searched from inception to March 2014. Eligible articles included adults with pain anywhere in the distal upper limb at baseline from randomised controlled trials with a waiting list, expectant policy or usual care group, or observational studies where no treatment or usual care was provided. Data describing the association between a putative prognostic factor and pain or functional outcome at follow-up were required. Quality was assessed using the Quality in Prognostic Studies tool.

RESULTS

Seven articles reporting on six studies were identified. Heterogeneity of study populations and outcome measures prevented a meta-analysis so a narrative synthesis of results was undertaken. Three factors (being female, a longer duration of the complaint at initial presentation and having musculoskeletal pain in multiple locations) were significantly associated with poor pain outcome in more than one study. Being female was the only factor significantly associated with poor functional outcome in more than one study.

CONCLUSIONS

A range of sociodemographic, pain-related, occupational and psychosocial prognostic factors for distal upper limb pain outcomes were investigated in studies included in the review. However, due to the lack of commonality of factors investigated and lack of consistency of results across studies, there is limited evidence for predictors of distal upper limb pain outcomes. Further research is required to identify prognostic factors of distal upper limb pain, particularly modifiable factors that may influence management.

Prevalence of chronic low back pain: systematic review

OBJECTIVE

To estimate worldwide prevalence of chronic low back pain according to age and sex.

METHODS

We consulted Medline (PubMed), LILACS and EMBASE electronic databases. The search strategy used the following descriptors and combinations: back pain, prevalence, musculoskeletal diseases, chronic musculoskeletal pain, rheumatic, low back pain, musculoskeletal disorders and chronic low back pain. We selected cross-sectional population-based or cohort studies that assessed chronic low back pain as an outcome. We also assessed the quality of the selected studies as well as the chronic low back pain prevalence according to age and sex.

RESULTS

The review included 28 studies. Based on our qualitative evaluation, around one third of the studies had low scores, mainly due to high non-response rates. Chronic low back pain prevalence was 4.2% in individuals aged between 24 and 39 years old and 19.6% in those aged between 20 and 59. Of nine studies with individuals aged 18 and above, six reported chronic low back pain between 3.9% and 10.2% and three, prevalence between 13.1% and 20.3%. In the Brazilian older population, chronic low back pain prevalence was 25.4%.

CONCLUSIONS

Chronic low back pain prevalence increases linearly from the third decade of life on, until the 60 years of age, being more prevalent in women. Methodological approaches aiming to reduce high heterogeneity in case definitions of chronic low back pain are essential to consistency and comparative analysis between studies. A standard chronic low back pain definition should include the precise description of the anatomical area, pain duration and limitation level.

Psychological and psychosocial determinants of musculoskeletal pain and associated disability

Although much attention has been given to the physical determinants of common musculoskeletal complaints such as back and arm pain, research points to a stronger influence of psychological factors. Multiple studies have implicated poor mental health and somatisation (a tendency to worry about the common somatic symptoms) in the incidence and chronicity of musculoskeletal pain and associated disability. Also important are adverse beliefs about the prognosis of such disorders, and about the role of physical activity in their development and persistence. Differences in societal beliefs may have contributed to major variation in the prevalence of disabling musculoskeletal pain that has been observed between countries and in the same countries over time. Psychosocial aspects of work have also been linked with musculoskeletal pain, although relative risks have generally been smaller. There is a need to take account of psychological factors in the clinical management of patients with back, neck and arm pain.

Combined musculoskeletal pain in the upper and lower body: associations with occupational mechanical and psychosocial exposures

PURPOSE

Pain in more than one site is common in working populations. We aimed to characterise combined pain (pain in the upper and lower body) and to evaluate whether the prevalence of combined pain is positively related to combined occupational mechanical exposures to the upper and lower body and to high psychosocial job strain.

METHODS

This cross-sectional study was based on questionnaire data from the Musculoskeletal Research Database at the Danish Ramazzini Centre. The study included 14,081 men and 20,173 women. Occupational exposures were assessed by job exposure matrices. We analysed the prevalence of pain limited to the upper body, pain limited to the lower body, and combined pain in relation to occupational exposures using Poisson regression.

RESULTS

During the last year, 23.2 % of the men and 33.9 % of the women reported combined pain, which was characterised by somatisation, illness worrying, and low SF-36 scores. For men, the adjusted prevalence ratio for combined pain was 1.51 [95 % confidence interval (95 % CI) 1.40-1.64] in relation to exposures limited to the upper body and 2.24 (95 % CI 2.11-2.39) in relation to combined exposures. For women, the corresponding adjusted prevalence ratios were 1.56 (95 % CI 1.50-1.63) and 1.55 (95 % CI 1.50-1.61). High job strain was related to pain among men, only.

CONCLUSION

Combined pain may in part be explained by local effects of occupational mechanical exposures acting at more than one site.

Chronic low back pain among tobacco farmers in southern Brazil

BACKGROUND

Despite tobacco farming involving intensive manual labor, chronic low back pain (CLBP) prevalence and associated factors are unknown among this occupational group.

METHODS

This was a cross-sectional study conducted in southern Brazil. A random sample of tobacco farmers was interviewed. Socioeconomic and individual characteristics, occupational tasks, workloads, and comorbidities were investigated. Chronic low back pain prevalence was described in relation to independent variables, and associations were examined with Poisson regression.

RESULTS

Chronic low back pain prevalence was 8·4%. Increasing age, rearing two or more species of livestock (PR 1·65), exposure to tasks that require heavy physical exertion (PR 2·00), working in awkward postures (PR 1·36), green tobacco sickness (GTS) (PR 1·63), pesticide poisoning (PR 2·37), and minor psychiatric disorders (PR 2·55) were associated with CLBP.

CONCLUSIONS

This study found that CLBP is a relevant health problem among tobacco farmers and highlights understudied risk factors such as pesticide poisoning and GTS. Policies to minimize exposure to physiological and chemical workloads in tobacco planting to prevent CLBP are needed. Health professionals should be trained to diagnose and prevent acute low back pain episodes and thus prevent/minimize limitations and disabilities due to CLBP.

An assessment of the relationships between overweight, obesity, related chronic health conditions and worker absenteeism

INTRODUCTION

Worker absenteeism is an important area of study within the field of occupational health. Prior studies have linked the presence of obesity to higher rates of absenteeism, but have not examined whether or not the relationship is moderated by the presence of other chronic health conditions or whether or not the relationships have been stable over time.

METHODS

Data from the 2000 and 2010 National Health Interview Survey, a nationally representative sample of the US population, were analyzed to determine the extent to which the presence of 5 obesity-related chronic health conditions moderates the relationship between overweight/obesity and worker absenteeism, and whether or not these relationships are stable over time. Logistic regression was used to examine the relationships between overweight/obesity, the obesity-related chronic health conditions and worker absenteeism, while controlling for demographic, socio-economic, occupational, health related and behavioral variables.

RESULTS

The findings suggest that obesity (p < 0.01) is related to higher rates of worker illness absence, and that the presence of diabetes positively moderates this relationship (p < 0.05) within the severely obese population (class III -€“ BMI ‰≥ 40). Other health conditions, including hypertension, coronary heart disease, other heart disease and stroke, were not found to have significant moderating effects.

CONCLUSION

The evidence suggests that obesity is associated with a higher likelihood of worker illness absenteeism, and that the effect is doubled for those with both class III obesity (BMI ≥ 40) and diabetes. The moderating effect between class III obesity and diabetes was observed only in 2010, indicating that this may be a relatively new phenomenon.

Is musculoskeletal pain a consequence or a cause of occupational stress? A longitudinal study

OBJECTIVES

Longitudinal studies have linked stress at work with a higher incidence of musculoskeletal pain. We aimed to explore the extent to which musculoskeletal pain is a cause as opposed to a consequence of perceived occupational stress.

METHODS

As part of the international cultural and psychosocial influences on disability study, we collected information from 305 Italian nurses, at baseline and again after 12 months, about pain during the past month in the low-back and neck/shoulder, and about effort-reward imbalance (ERI) (assessed by Siegrist's ERI questionnaire). Poisson regression was used to assess the RR of ERI >1 at follow-up according to the report of pain and of ERI >1 at baseline.

RESULTS

Among nurses with ERI ≤1 at baseline, ERI >1 at follow-up was associated with baseline report of pain in the low-back (RR 2.7, 95 % CI 1.4-5.0) and neck/shoulder (RR 2.6, 95 % CI 1.3-5.1). However, there was no corresponding association with persistence of ERI in nurses who already had ERI >1 at baseline. Associations of ERI at baseline with pain at follow-up were weak.

CONCLUSION

Our results suggest that the well-documented association between job stress and musculoskeletal pain is not explained entirely by an effect of stress on reporting of pain. It appears also that workers who report musculoskeletal pain are more likely to develop subsequent perceptions of stress. This may be because pain renders people less tolerant of the psychological demands of work. Another possibility is that reports of pain and stress are both manifestations of a general tendency to be aware of and complain about symptoms and difficulties.

Prevalence comparisons of somatic and psychiatric symptoms between community nonpatients without pain, acute pain patients, and chronic pain patients

OBJECTIVES

Somatic/psychiatric symptoms are frequently found in chronic pain patients (CPPs). The objectives of this study were to determine 1) which somatic/psychiatric symptoms are more commonly found in acute pain patients (APPs) and CPPs vs community nonpatients without pain (CNPWPs) and 2) if somatic/psychiatric symptom prevalence differs between APPs and CPPs.

DESIGN

The above groups were compared statistically for endorsement of 15 symptoms: fatigue, numbness/tingling, dizziness, difficulty opening/closing mouth, muscle weakness, difficulty staying asleep, depression, muscle tightness, nervousness, irritability, memory, falling, nausea, concentration, and headaches.

RESULTS

After controlling for age, gender, and level of pain, APPs and CPPs had a statistically significantly greater prevalence (at a P < 0.01 level) for 11 and 13 symptoms, respectively, vs CNPWPs. After controlling for age, gender, and level of pain, CPPs had a statistically significantly greater prevalence (at a P < 0.01 level) for eight symptoms vs APPs. Symptoms were highly correlated in both APPs and CPPs.

CONCLUSIONS

CPPs are characterized to a significantly greater extent than comparison groups by somatic/psychiatric symptoms that are highly intercorrelated. This has implications for clinical practice and future research.

Individual and work-related risk factors for musculoskeletal pain: a cross-sectional study among Estonian computer users

Background

Occupational use of computers has increased rapidly over recent decades, and has been linked with various musculoskeletal disorders, which are now the most commonly diagnosed occupational diseases in Estonia. The aim of this study was to assess the prevalence of musculoskeletal pain (MSP) by anatomical region during the past 12 months and to investigate its association with personal characteristics and work-related risk factors among Estonian office workers using computers.

Methods

In a cross-sectional survey, the questionnaires were sent to the 415 computer users. Data were collected by self-administered questionnaire from 202 computer users at two universities in Estonia. The questionnaire asked about MSP at different anatomical sites, and potential individual and work related risk factors. Associations with risk factors were assessed by logistic regression.

Results

Most respondents (77%) reported MSP in at least one anatomical region during the past 12 months. Most prevalent was pain in the neck (51%), followed by low back pain (42%), wrist/hand pain (35%) and shoulder pain (30%). Older age, right-handedness, not currently smoking, emotional exhaustion, belief that musculoskeletal problems are commonly caused by work, and low job security were the statistically significant risk factors for MSP in different anatomical sites.

Conclusions

A high prevalence of MSP in the neck, low back, wrist/arm and shoulder was observed among Estonian computer users. Psychosocial risk factors were broadly consistent with those reported from elsewhere. While computer users should be aware of ergonomic techniques that can make their work easier and more comfortable, presenting computer use as a serious health hazard may modify health beliefs in a way that is unhelpful.

Self-reported pain severity is associated with a history of coronary heart disease

BACKGROUND

Previous studies have found an association between chronic pain and cardiovascular (CV) mortality.

OBJECTIVE

To explore the relationship between the severity of pain and non-fatal CV disease.

METHODS

A total of 45,994 adults randomly selected from general practice registers in Manchester and Aberdeen were posted a survey, which included a Chronic Pain Grade questionnaire, pain manikin and questions about lifestyle and medical history. A single component measuring pain severity was extracted using factor analysis. Logistic regression was used to test for an association between quintiles of pain severity and a history of CV disease, adjusting for confounders.

RESULTS

Of the 15,288 responders, 61% (n = 9357) reported pain for ≥ 1 day in the past month. Compared with the first (lowest) pain severity quintile, the fully adjusted odds ratio for heart attack in the second severity quintile was 1.25 (95% confidence interval 0.68, 2.30); third quintile: 1.65 (0.93, 2.94); fourth quintile: 1.76 (1.00, 3.11) and fifth (highest) quintile 2.47 (1.43, 4.28). Corresponding figures for angina (excluding heart attack) were: 1.79 (0.93, 3.45), 1.91 (1.00, 3.62), 1.03 (0.50, 2.11) and 3.17 (1.71, 5.85).

CONCLUSION

A history of CV disease is reported more often in those with severe pain than would be expected by chance, even when adjusting for shared risk factors.

Multiple somatic symptoms predict impaired health status in functional somatic syndromes

BACKGROUND

The relationship between functional somatic syndromes and multiple somatic symptoms is unclear.

PURPOSE

We assessed whether the number of somatic symptoms is a predictor of health status in three functional somatic syndromes (FSS).

METHODS

In a population-based study of 990 UK adults we assessed chronic widespread pain (CWP), chronic fatigue (CF) and irritable bowel syndrome (IBS) by questionnaire and medical record data. We assessed health status (Short Form 12 and EQ-5D), number of somatic symptoms (Somatic Symptom Inventory) and anxiety/depression (Hospital Anxiety and Depression Scale) both at baseline and at follow-up 1 year later.

RESULTS

The proportion of people with an FSS who also have multiple somatic symptoms (52-55 %) was similar in the three functional syndromes. The presence of multiple somatic symptoms was associated with more impaired health status both at baseline and at follow-up. This finding was not explained by severity of FSS. In the absence of multiple somatic symptoms, the health status of the FSS was fair or good. In multiple regression analysis, the number of somatic symptoms, the presence of a functional syndrome (CWP or CF) and anxiety/depression were predictors of EQ-5D thermometer at follow-up after adjustment for confounders.

CONCLUSIONS

Multiple somatic symptoms in people with an FSS are associated with impaired health status and this cannot be explained by more severe functional syndrome or the presence of anxiety and depression.

Maintained physical activity and physiotherapy in the management of distal upper limb pain - a protocol for a randomised controlled trial (the arm pain trial)

Background

Distal upper limb pain (pain affecting the elbow, forearm, wrist, or hand) can be non-specific, or can arise from specific musculoskeletal disorders. It is clinically important and costly, the best approach to clinical management is unclear. Physiotherapy is the standard treatment and, while awaiting treatment, advice is often given to rest and avoid strenuous activities, but there is no evidence base to support these strategies. This paper describes the protocol of a randomised controlled trial to determine, among patients awaiting physiotherapy for distal arm pain, (a) whether advice to remain active and maintain usual activities results in a long-term reduction in arm pain and disability, compared with advice to rest; and (b) whether immediate physiotherapy results in a long-term reduction in arm pain and disability, compared with physiotherapy delivered after a seven week waiting list period.

Methods/Design

Between January 2012 and January 2014, new referrals to 14 out-patient physiotherapy departments were screened for potential eligibility. Eligible and consenting patients were randomly allocated to one of the following three groups in equal numbers: 1) advice to remain active, 2) advice to rest, 3) immediate physiotherapy. Patients were and followed up at 6, 13, and 26 weeks post-randomisation by self-complete postal questionnaire and, at six weeks, patients who had not received physiotherapy were offered it at this time. The primary outcome is the proportion of patients free of disability at 26 weeks, as determined by the modified DASH (Disabilities of the Arm, Shoulder and Hand) questionnaire.

We hypothesise (a) that advice to maintain usual activities while awaiting physiotherapy will be superior than advice to rest the arm; and (b) that fast-track physiotherapy will be superior to normal (waiting list) physiotherapy. These hypotheses will be examined using an intention-to-treat analysis.

Discussion

Results from this trial will contribute to the evidence base underpinning the clinical management of patients with distal upper limb pain, and in particular, will provide guidance on whether they should be advised to rest the arm or remain active within the limits imposed by their symptoms.

Trial registration

Registered on http://www.controlled-trials.com (reference number: ISRCTN79085082).

Do Psychological Factors Increase the Risk for Low Back Pain Among Nurses? A Comparing According to Cross-sectional and Prospective Analysis

Background

This study assesses influences of baseline psychological risk factors on prevalence of low back pain (LBP) at baseline and follow-up among nurses.

Methods

A prospective longitudinal study was performed at two phases, baseline and 1-year follow-up among 246 nurses of university hospitals in Shahroud, Iran. A standardized Cultural and Psychosocial Influences on Disability questionnaire was used for data collection. Logistic regression was performed for analysis.

Results

At the baseline of the study, 58.9% of nurses reported back pain in the previous 12 months. Age (p = 0.001), belief that work causes pain (p = 0.022), and somatization tendency (p = 0.002) significantly increased risk of LBP. At 1-year follow-up, prevalence of LBP was 45.7% and expectation of back pain at baseline (p = 0.016) significantly increased risk of LBP in this phase (p < 0.05).

Conclusion

Results indicate that risk factors for prevalence of back pain at baseline and 1-year follow-up are different. At baseline, the risk factors are age, belief that work causes pain, and somatization tendency, and at follow-up, expectation of pain is the major risk factor.

Disabling musculoskeletal pain in working populations: is it the job, the person, or the culture?

To compare the prevalence of disabling low back pain (DLBP) and disabling wrist/hand pain (DWHP) among groups of workers carrying out similar physical activities in different cultural environments, and to explore explanations for observed differences, we conducted a cross-sectional survey in 18 countries. Standardised questionnaires were used to ascertain pain that interfered with everyday activities and exposure to possible risk factors in 12,426 participants from 47 occupational groups (mostly nurses and office workers). Associations with risk factors were assessed by Poisson regression. The 1-month prevalence of DLBP in nurses varied from 9.6% to 42.6%, and that of DWHP in office workers from 2.2% to 31.6%. Rates of disabling pain at the 2 anatomical sites covaried (r = 0.76), but DLBP tended to be relatively more common in nurses and DWHP in office workers. Established risk factors such as occupational physical activities, psychosocial aspects of work, and tendency to somatise were confirmed, and associations were found also with adverse health beliefs and group awareness of people outside work with musculoskeletal pain. However, after allowance for these risk factors, an up-to 8-fold difference in prevalence remained. Systems of compensation for work-related illness and financial support for health-related incapacity for work appeared to have little influence on the occurrence of symptoms. Our findings indicate large international variation in the prevalence of disabling forearm and back pain among occupational groups carrying out similar tasks, which is only partially explained by the personal and socioeconomic risk factors that were analysed.

Musculoskeletal pain in Europe: the role of personal, occupational, and social risk factors

OBJECTIVES

The prevalence of musculoskeletal pain in European countries varies considerably. We analyzed data from the fifth European Working Conditions Survey (EWCS) to explore the role of personal, occupational, and social risk factors in determining the national prevalence of musculoskeletal pain.

METHODS

Over the course of 2010, 43 816 subjects from 34 countries were interviewed. We analyzed the one-year prevalence of back and neck/upper-limb pain. Individual-level risk factors studied included: sex; age; educational level; socioeconomic status; housework or cooking; gardening and repairs; somatizing tendency; job demand-control; six physical occupational exposures; and occupational group. Data on national socioeconomic variables were obtained from Eurostat and were available for 28 countries. We fitted Poisson regression models with random intercept by country.

RESULTS

The main analysis comprised 35 550 workers. Among individual-level risk factors, somatizing tendency was the strongest predictor of the symptoms. Major differences were observed by country with back pain more than twice as common in Portugal (63.8%) than Ireland (25.7%), and prevalence rates of neck/upper-limb pain ranging from 26.6% in Ireland to 67.7% in Finland. Adjustment for individual-level risk factors slightly reduced the large variation in prevalence between countries. For back pain, the rates were more homogenous after adjustment for national socioeconomic variables.

CONCLUSIONS

Our analysis indicates substantial variation between European countries in the prevalence of back and neck/upper-limb pain. This variation is unexplained by established individual risk factors. It may be attributable in part to socioeconomic differences between countries, with higher prevalence where there is less risk of poverty or social exclusion.

Health beliefs, low mood, and somatizing tendency: contribution to incidence and persistence of musculoskeletal pain with and without reported disability

OBJECTIVE

This study aims to investigate whether associations of psychological risk factors with the incidence and persistence of disabling musculoskeletal pain differ from those for non-disabling musculoskeletal pain.

METHODS

As part of the international Cultural and Psychosocial Influences in Disability (CUPID) study, 1105 Spanish nurses and office workers were asked at baseline about health beliefs concerning pain, mental health, and somatizing tendency. Musculoskeletal pain in the past months at ten anatomical sites (back, neck, and left and right shoulder, elbow, wrist/hand, and knee) was ascertained at baseline and one year later. Pain was classed as disabling if it made ≥1 specified everyday activities difficult or impossible. Multilevel multinomial logistic regression modeling was used to explore associations of baseline risk factors with pain outcomes at follow-up, conditioned on pain status at baseline.

RESULTS

A total of 971 participants (87.9%) completed follow-up. Among anatomical sites that were pain-free at baseline, the development of disabling musculoskeletal pain was predicted by pessimistic beliefs about pain prognosis [odds ratio (OR) 1.5, 95% confidence interval (95% CI) 1.0-2.1], poor mental health (OR 2.0, 95% CI 1.3-3.0), and somatizing tendency (OR 4.0, 95% CI 2.5-6.4). Adverse beliefs about prognosis were also associated with the transition from non-disabling to disabling musculoskeletal pain (OR 3.7, 95% CI 1.1-12.5) and the persistence of disabling musculoskeletal pain (OR 2.5, 95% CI 1.2-5.5), which was already present at baseline. Associations with non-disabling musculoskeletal pain were weaker and less consistent.

CONCLUSION

Our findings suggest that established psychological risk factors relate principally to the disability that arises from musculoskeletal pain.

Differences in risk factors for neurophysiologically confirmed carpal tunnel syndrome and illness with similar symptoms but normal median nerve function: a case-control study

BACKGROUND

To explore whether risk factors for neurophysiologically confirmed carpal tunnel syndrome (CTS) differ from those for sensory symptoms with normal median nerve conduction, and to test the validity and practical utility of a proposed definition for impaired median nerve conduction, we carried out a case-control study of patients referred for investigation of suspected CTS.

METHODS

We compared 475 patients with neurophysiological abnormality (NP+ve) according to the definition, 409 patients investigated for CTS but classed as negative on neurophysiological testing (NP-ve), and 799 controls. Exposures to risk factors were ascertained by self-administered questionnaire. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were estimated by logistic regression.

RESULTS

NP+ve disease was associated with obesity, use of vibratory tools, repetitive movement of the wrist or fingers, poor mental health and workplace psychosocial stressors. NP-ve illness was also related to poor mental health and occupational psychosocial stressors, but differed from NP+ve disease in showing associations also with prolonged use of computer keyboards and tendency to somatise, and no relation to obesity. In direct comparison of NP+ve and NP-ve patients (the latter being taken as the reference category), the most notable differences were for obesity (OR 2.7, 95 % CI 1.9-3.9), somatising tendency (OR 0.6, 95% CI 0.4-0.9), diabetes (OR 1.6, 95% CI 0.9-3.1) and work with vibratory tools (OR 1.4, 95% CI 0.9-2.2).

CONCLUSIONS

When viewed in the context of earlier research, our findings suggest that obesity, diabetes, use of hand-held vibratory tools, and repeated forceful movements of the wrist and hand are causes of impaired median nerve function. In addition, sensory symptoms in the hand, whether from identifiable pathology or non-specific in origin, may be rendered more prominent and distressing by hand activity, low mood, tendency to somatise, and psychosocial stressors at work. These differences in associations with risk factors support the validity of our definition of impaired median nerve conduction.

Physical and psychosocial risk factors for musculoskeletal disorders in Brazilian and Italian nurses

As part of the international CUPID investigation, we compared physical and psychosocial risk factors for musculoskeletal disorders among nurses in Brazil and Italy. Using questionnaires, we collected information on musculoskeletal disorders and potential risk factors from 751 nurses employed in public hospitals. By fitting countryspecific multiple logistic regression models, we investigated the association of stressful physical activities and psychosocial characteristics with site-specific and multisite pain, and associated sickness absence. We found no clear relationship between low back pain and occupational lifting, but neck and shoulder pain were more common among nurses who reported prolonged work with the arms in an elevated position. After adjustment for potential confounding variables, pain in the low back, neck and shoulder, multisite pain, and sickness absence were all associated with somatizing tendency in both countries. Our findings support a role of somatizing tendency in predisposition to musculoskeletal disorders, acting as an important mediator of the individual response to triggering exposures, such as workload.

Low back pain among textile workers: a cross-sectional study

BACKGROUND

Low back pain (LBP) is one of the most prevalent occupational health problems in industrialized countries. Little is known about the epidemiology of LBP in developing countries.

AIMS

To determine the prevalence of LBP among Nepalese textile workers and to investigate the influence of exposure to mechanical and other factors on LBP reporting.

METHODS

Interviewers completed questionnaires with study subjects, and work-related mechanical exposures were measured by self-completed questionnaires. Associations of LBP with mechanical factors and somatic symptoms were determined by logistic regression and reported as odds ratios (ORs) with 95% confidence intervals (CI).

RESULTS

Nine hundred and thirty-eight workers took part, a participation rate of 92%. The 1 month period prevalence of LBP was 35% (n = 324), being higher in females than males (45% versus 28%; P < 0.001). Several work-related mechanical factors were associated with increased odds of reporting LBP: lifting heavy weights with one hand (OR 1.7; 95% CI 1.1-2.8), pushing weights (OR 1.6; 95% CI 1.2-2.3 and pulling weights (OR 1.6; 95% CI 1.1-2.1). No association was found with working posture. Strong associations were found for reporting one (OR 2.4; 95% CI 1.7-3.4) or two somatic symptoms (OR 2.7; 95% CI 1.4-5.1). On multivariable analysis, reporting of somatic symptoms (OR 2.8; 95% CI 1.5-5.4), female gender (OR 2.2; 95% CI 1.5-3.1) and increasing age were significantly associated with increased risk of reporting LBP (OR 1.7; 95% CI 1.2-2.5), but no associations were found with mechanical factors.

CONCLUSIONS

This study suggests that mechanical load may not be the leading cause of LBP and adds to evidence that psychological factors play an important role in LBP in non-industrialized countries.

Increased BMP expression in arthrofibrosis after TKA

PURPOSE

Because of the multiple possible aetiologies of painful total knee arthroplasty (TKA), the diagnosis and treatment of such patients are challenging. In a considerable number of patients, an intraarticular pathology is present, although not verifiable with clinical and diagnostic imaging techniques as in cases of primary arthrofibrosis. In these patients, the differentiation between intra- and extraarticular causes of pain remains difficult. Until now, little attention has been paid to changes of the synovial fluid and tissue in these knees. The objective of this study was to analyse the changes of the synovial environment in patients suffering from arthrofibrosis after TKA in comparison with knees with referred pain suffering from hip arthritis. The changes of the synovial environment probably provide additional diagnostic information to verify an intraarticular pathology.

METHODS

The synovial fluid of 10 consecutive knees in 10 patients presenting with a primary arthrofibrosis after TKA without signs of infection, instability, malalignment, or loosening was analysed and compared to the synovial fluid of 10 knees with referred pain serving as controls. The BMP-2 concentration was measured in the synovial fluid, and the presence of cytokines leading to an overexpression of BMP-2 was detected by measuring the change of BMP-2 expression in a synoviocyte cell line following exposing to the synovial fluid of the patients.

RESULTS

The concentration of BMP-2 in the synovial fluid was significantly higher in arthrofibrotic TKA knees (24.3 ± 6.9 pg/mL), compared with the control group 5.9 ± 4.8 pg/mL (P < 0.001). Corresponding to this finding, BMP-2 expression in synoviocytes was upregulated 11.5-fold (P < 0.05) by synovial fluid of patients suffering from arthrofibrosis after TKA, compared with the control group with referred pain.

CONCLUSION

BMP-2 is overexpressed and its concentrations are consequently higher in patients suffering from arthrofibrosis after TKA. The synovial BMP-2 concentration may be a potential marker for differentiating between intra- and extraarticular causes of pain.

LEVEL OF EVIDENCE

II.

Risk factors for new onset and persistence of multi-site musculoskeletal pain in a longitudinal study of workers in Crete

OBJECTIVES

To explore occupational and psychological risk factors for the incidence and persistence of multi-site musculoskeletal pain.

METHODS

We conducted a longitudinal investigation of three occupational groups in Crete, Greece. Baseline information was obtained at interview about pain in the past year at each of six anatomical sites, and about possible risk factors for subsequent symptoms. Twelve months later, subjects were re-interviewed about pain at the same anatomical sites in the past month. Pain at two or more sites was classed as multi-site. Associations with new development and persistence of multi-site pain at follow-up were assessed by logistic regression.

RESULTS

Analysis was based on 518 subjects (87% of those originally selected for study). At follow-up, multi-site pain persisted in 217 (62%) of those who had experienced it in the year before baseline, and was newly developed in 27 (17%) of those who had not. Persistence of multi-site pain was significantly related to physical loading at work, somatising tendency and beliefs about work as a cause of musculoskeletal pain, with OR (95% CI) for the highest relative to the lowest exposure categories of 2.3 (1.0 to 5.6), 2.6 (1.5 to 4.6) and 1.9 (1.1 to 3.3) respectively. Development of new multi-site pain was most strongly associated with working for ≥40 h per week (OR 5.0, 95% CI 1.1 to 24.0).

CONCLUSIONS

Our findings confirm the importance of both physical loading at work and somatising tendency as risk factors for multi-site pain, and suggest that persistence of pain is also influenced by adverse beliefs about work causation.

The CUPID (Cultural and Psychosocial Influences on Disability) study: methods of data collection and characteristics of study sample

Background

The CUPID (Cultural and Psychosocial Influences on Disability) study was established to explore the hypothesis that common musculoskeletal disorders (MSDs) and associated disability are importantly influenced by culturally determined health beliefs and expectations. This paper describes the methods of data collection and various characteristics of the study sample.

Methods/Principal Findings

A standardised questionnaire covering musculoskeletal symptoms, disability and potential risk factors, was used to collect information from 47 samples of nurses, office workers, and other (mostly manual) workers in 18 countries from six continents. In addition, local investigators provided data on economic aspects of employment for each occupational group. Participation exceeded 80% in 33 of the 47 occupational groups, and after pre-specified exclusions, analysis was based on 12,426 subjects (92 to 1018 per occupational group). As expected, there was high usage of computer keyboards by office workers, while nurses had the highest prevalence of heavy manual lifting in all but one country. There was substantial heterogeneity between occupational groups in economic and psychosocial aspects of work; three- to five-fold variation in awareness of someone outside work with musculoskeletal pain; and more than ten-fold variation in the prevalence of adverse health beliefs about back and arm pain, and in awareness of terms such as “repetitive strain injury” (RSI).

Conclusions/Significance

The large differences in psychosocial risk factors (including knowledge and beliefs about MSDs) between occupational groups should allow the study hypothesis to be addressed effectively.

His-story or her-story: deconstruction of the concepts of somatization towards a new approach in advanced nursing practice care

PURPOSE

This article will endeavor to present an alternative view of somatoform disorders, assist in understanding the possible underlying comorbid psychiatric symptoms, and identify psychopharmacological options for treatment.

CONCLUSIONS

Recognizing symptom clusters is a useful strategy when considering psychotropic options for treatment and management.

PRACTICE IMPLICATIONS

The alternative strategies presented and discussed in this article can contribute to a useful and positive experience for both the clinician and the individual suffering from medically unexplained physical symptoms as they promote the care, health, and well-being of the individual rather than a cure, illness, and/or disease state that needs rendering, mending, and/or surgery.

Clinical presentation of low back pain and association with risk factors according to findings on magnetic resonance imaging

We hypothesised that the relative importance of physical and psychological risk factors for mechanical low back pain (LBP) might differ importantly according to whether there is underlying spinal pathology, psychological risk factors being more common in patients without demonstrable pathology. If so, epidemiological studies of LBP could benefit from tighter case definitions. To test the hypothesis, we used data from an earlier case-control study on patients with mechanical LBP who had undergone magnetic resonance imaging (MRI) of the lumbosacral spine. MRI scans were classified for the presence of high-intensity zone (HIZ), disc degeneration, disc herniation, and nerve root displacement/compression. Information about symptoms and risk factors was elicited by postal questionnaire. Logistic regression was used to assess associations of MRI abnormalities with symptoms and risk factors, which were characterised by odds ratios (ORs) and 95% confidence intervals (CIs). Among 354 patients (52% response), 306 (86.4%) had at least 1, and 63 (17.8%) had all 4 of the MRI abnormalities. Radiation of pain below the knee (280 patients) and weakness or numbness below the knee (257 patients) were both associated with nerve root deviation/compression (OR 2.5, 95% CI 1.4 to 4.5; and OR 1.8, 95% CI 1.1 to 3.1, respectively). However, we found no evidence for the hypothesised differences in risk factors between patients with and without demonstrable spinal pathology. This suggests that when researching the causes and primary prevention of mechanical LBP, there may be little value in distinguishing between cases according to the presence or absence of the more common forms of potentially underlying spinal pathology.

Occupational musculoskeletal and mental health: Significance of rationalization and opportunities to create sustainable production systems - A systematic review

This literature review aims to identify occupational musculoskeletal and mental health effects of production system rationalization as well as organizational-level measures that may improve health outcome ("modifiers" in this review). A short review of the effect of ergonomic interventions is included as background and rationalization is discussed as a theoretical concept. Indicator variables for occupational musculoskeletal and mental health and related risk factors are presented. Variables with a generalized format were allowed in the literature searches (e.g., job satisfaction and absenteeism were accepted as risk factor and health indicator, respectively), suitable for the research fields of work sociology, organization science, human resource management (HRM) and economics research. One hundred and sixty-two studies of rationalization effects on health and risk factors and 72 organization-level modifier results were accepted into the final database. Entries were sorted by rationalization strategy and work life sector, and trends in outcome (positive, mixed, no effect, or negative effect on health and risk factors) were determined. Rationalizations have a dominant negative effect on health and risk factors (57% negative, 19% positive); the most negative effects were found for downsizing and restructuring rationalizations in general (71 studies negative, 13 positive) and for the health care sector in particular (36 studies negative, 2 positive). The rationalization strategy High Performance Work System (HPWS) was associated with the highest fraction positive outcome studies (6 of 10 studies). Other rationalization strategies (lean practices, parallel vs. serial production and mechanization level) reported intermediate results, in part dependent on work life sector, but also on the year when studies were carried out. Worker participation, resonant management style, information, support, group autonomy and procedural justice were modifiers with favourable influence on outcome. It is concluded that production system rationalization represents a pervasive work life intervention without a primary occupational health focus. It has considerable and mostly negative influence on worker health, but this can be reduced by attention to modifiers. The results create a basis for new priorities in ergonomic intervention research.

Epidemiology of spine care: the back pain dilemma

In this article, the epidemiology of back pain and the use of a variety of treatments for back pain in the United States are reviewed. The dilemma faced by medical providers caring for patients with low back pain is examined in the context of epidemiologic data. Back pain is becoming increasingly common and a growing number of treatment options are being used with increasing frequency in clinical practice. However, limited evidence exists to demonstrate the effectiveness of these treatments. In addition, health-related quality of life for persons with back pain is not improving despite the availability and use of an expanding array of treatments. This dilemma poses a difficult challenge for medical providers treating individual patients who suffer from back pain.

Work-related and psychological determinants of multisite musculoskeletal pain

OBJECTIVE

Musculoskeletal pain is associated with occupational physical activities and psychosocial risk factors. We evaluated the relative importance of work-related and psychological determinants of the number of -anatomical sites affected by musculoskeletal pain in a cross-sectional survey.

METHODS

The survey focused on musculoskeletal pain in six body regions (low-back, neck, shoulder, elbow, wrist-hand, and knee) among 224 nurses, 200 office workers and 140 postal clerks in Crete, Greece (response rate 95%). Information was collected about demographic characteristics, occupational physical load, psycho-social aspects of work, perceptions about the causes of pain, mental health, somatization, and experience of pain in the past 12 months. We used Poisson regression to assess associations of risk factors with the number of painful anatomical sites and explored interactions using classification and regression trees (CART).

RESULTS

Two-thirds of the study sample reported pain in >or=2 body sites during the past 12 months, and in 23%, >3 sites were affected. The number of painful anatomical sites was strongly related to both physical load at work and somatization (with relative risks increased 5-fold or more for frequent and disabling multisite pain) and was also significantly associated with work-related psychosocial factors and beliefs about work causation. The CART analysis suggested that somatization was the leading determinant of the number of painful body sites.

CONCLUSION

In the population studied, pain at multiple anatomical sites was common and strongly associated with somatization, which may have a more important influence on multisite pain than pain that is limited to a single anatomical site.

Is chronic pain associated with somatization/hypochondriasis? An evidence-based structured review

STUDY DESIGN

This is an evidence-based structured review.

OBJECTIVES

The objectives of this review were to answer the following questions: (1) Are somatization/hypochondriasis associated with chronic pain? (2) Is the degree of somatization/hypochondriasis related to pain levels? (3) Does pain treatment improve somatization/hypochondriasis? (4) Are some pain diagnoses differentially associated with somatization/hypochondriasis?

METHODS

Fifty-seven studies which fulfilled inclusion criteria and had high quality scores were sorted by the above-mentioned objectives. Agency for health care policy and research guidelines were utilized to type and characterize the strength/consistency of the study evidence within each objective.

RESULTS

Somatization and hypochondriasis were both consistently associated with chronic pain (consistency ratings B and A, respectively). Study evidence indicated a correlation between pain intensity and presence of somatization and hypochondriasis (consistency rating A and B, respectively). Pain treatment improved somatization and hypochondriasis (consistency rating B and A, respectively). Some chronic pain diagnostic groups somatized more (consistency rating B).

CONCLUSIONS

Somatization is commonly associated with chronic pain and may relate to pain levels.

Cultural differences in musculoskeletal symptoms and disability

OBJECTIVES

To test the hypothesis that cultural factors such as health beliefs and expectations have an important influence on common musculoskeletal symptoms and associated disability, we compared prevalence rates in groups of workers carrying out similar physical activities in different cultural settings.

METHODS

We conducted a cross-sectional survey at factories and offices in Mumbai, India and in the UK. A questionnaire about symptoms, disability and risk factors was administered at interview to six occupational groups: three groups of office workers who regularly used computer keyboards (165 Indian, 67 UK of Indian subcontinental origin and 172 UK white), and three groups of workers carrying out repetitive manual tasks with the hands or arms (178 Indian, 73 UK of Indian subcontinental origin and 159 UK white). Modified Cox regression was used to calculate hazard ratios (HRs) for the prevalence of symptoms and disability by occupational group, adjusted for differences in sex, age, mental health and job satisfaction.

RESULTS

Reported occupational activities were similar in the three groups of office workers (frequent use of keyboards) and in the three groups of manual workers (frequent movements of the wrist or fingers, bending of the elbow, work with the hands above shoulder height and work with the neck twisted). In comparison with the Indian manual workers, the prevalence of back, neck and arm pain was substantially higher in all of the other five occupational groups. The difference was greatest for arm pain lasting >30 days in the past year in UK white manual workers (HR 17.8, 95% CI 5.4-59.1) and UK manual workers of Indian subcontinental origin (HR 20.5, 95% CI 5.7-73.1). Office workers in India had lower rates of pain in the wrist and hand than office workers in the UK. Only 1% of the Indian manual workers and 16% of the Indian office workers had ever heard of 'RSI' or similar terms, as compared with 80% of the UK workers.

CONCLUSIONS

Our findings support the hypothesized impact of cultural factors on common musculoskeletal complaints. Current controls on hazardous physical activities in the workplace may not have the benefits that would be predicted from observational epidemiology.

How common is repetitive strain injury?

OBJECTIVE

Statistics from Labour Force Surveys are widely quoted as evidence for the scale of occupational illness in Europe. However, occupational attribution depends on whether participants believe their health problem is caused or aggravated by work, and personal beliefs may be unreliable. The authors assessed the potential for error for work-associated arm pain.

METHODS

A questionnaire was mailed [corrected] to working-aged adults, randomly chosen from five British general practices. They were asked about: occupational activities; mental health; self-rated health; arm pain; and beliefs about its causation. Those in work (n = 1769) were asked about activities likely to cause arm pain, from which the authors derived a variable for exposure to any "arm-straining" occupational activity. The authors estimated the relative risk (RR) from arm-straining activity, using a modified Cox model, and derived the population attributable fraction (PAF). They compared the proportion of arm pain cases reporting their symptom as caused or made worse by work with the calculated PAF, overall and for subsets defined by demographic and other characteristics.

RESULTS

Arm pain in the past year was more common in the 1143 subjects who reported exposure to arm-straining occupational activity (RR 1.2, 95% CI 1.1 to 1.5). In the study sample as a whole, 53.9% of 817 cases reported their arm pain as work-associated, whereas the PAF for arm-straining occupational activity was only 13.9%. The ratio of cases reported as work-related to the calculated attributable number was substantially higher below 50 years (5.4) than at older ages (3.0) and higher in those with worse self-rated and mental health.

CONCLUSIONS

Counting people with arm pain which they believe to be work-related can overestimate the number of cases attributable to work substantially. This casts doubt on the validity of a major source of information used by European governments to evaluate their occupational health strategies.

Total knee replacement: is it really an effective procedure for all?

Total knee replacement (TKR) is considered an effective intervention for the treatment of chronic knee pain and disability. Yet there is increasing evidence, based on research using patient-based outcome measures, that a significant proportion of patients experience chronic knee pain, functional disability, a poor quality of life and dissatisfaction after TKR. Although some poor outcomes after TKR are due to surgical technique and implant factors, much of the pain and disability after surgery is medically unexplained. A range of possible patient factors could contribute to a poor outcome after TKR. Socio-demographic factors that have been found to correlate with a poor outcome after TKR include female gender, older age and low socio-economical status. Medical factors that are highly predictive of pain and disability after TKR are a greater number of co-morbidities and a worse pre-operative status. A range of psychological factors could be predictive of a poor outcome after surgery including depression, low self-efficacy, poor pain coping strategies, somatization, low social support and patient expectations. It is also proposed that a biological explanation for continuing pain after TKR could involve central sensitisation, a dysfunction of pain modulation by the central nervous system. To improve patient selection for TKR, future research needs to focus on developing a pre-operative screening protocol to identify those patients at risk of medically unexplained pain and disability after TKR.

Reduction of pain-related disability in working populations: a randomized intervention study of the effects of an educational booklet addressing psychosocial risk factors and screening workplaces for physical health hazards

STUDY DESIGN

Cluster randomized controlled trial with 6 and 8 quarters of follow-up.

OBJECTIVE

To test the effects of giving evidence-based information addressing psychosocial risk factors for pain-related disability and of screening workplaces for physical health hazards at work on reducing new episodes and duration of pain-related and general absence taking.

SUMMARY OF BACKGROUND DATA

The "flag strategy" for handling low back pain problems is recommended in many Western countries but, so far, randomized intervention studies addressing psychosocial risk factors for disability related to low back pain show mixed results.

METHODS

We followed employees from 39 different work sites in western Denmark, who had received interventions consisting of either a carefully prepared booklet providing evidence-based information on common musculoskeletal pain problems alone or in combination with systematic workplace screening for physical work hazards. Absence due to pain for at least 7 days and the cumulative numbers of absence days were the main outcome measures. General absence taking was analyzed, too. Company registrations of sickness absence in combination with self-report on the cause of a given absence spell was used to inform absence spells.

RESULTS

A total of 3808 of 4006 eligible employees provided information. Among 1063 participants in the control arm, 1458 in the information arm, and 1287 in the information and workplace screening arm, 4.6%, 6.9%, and 4.6%, respectively, experienced pain-related absence, and 27.8%, 27.2%, and 24.0%, respectively, experienced general absence taking during follow-up. No positive effect on the risk of the 2 measures of absence or on the cumulative duration of absence among cases was seen.

CONCLUSION

Results did not support population-based interventions addressing psychosocial risk factors for pain-related disability alone or in combination with workplace screening as effective in reducing the risk of pain-related absence taking or the duration of absence.