Candidate risk factors for idiopathic rhegmatogenous retinal detachment (RRD) include heavy manual handling (requiring Valsalva’s maneuver). We assessed incidence rates of surgically treated idiopathic RRD among manual workers, non-manual workers and housewives resident in Tuscany, Italy.
We retrieved all hospital discharge records bearing a principal diagnosis corresponding to RRD coupled with retinal surgery for any resident of Tuscany during 1997-2009. After elimination of repeated admissions and patients with coexistent, associated conditions (including recent trauma), subjects aged 25–59 years were classified as manual workers, non-manual workers or housewives. Population data were extracted from the 2001 census.
We identified 1,946 eligible cases (1,142 men). Among men, manual workers experienced a 1.8-fold higher age-standardized rate per 100,000 person-years than non-manual workers (17.4 [95% CI, 16.1–18.7] vs. 9.8 [95% CI, 8.8–10.8]). Age-standardized rates among women were 1.9-fold higher for manual workers (11.1 [95% CI, 9.8–12.3]) and 1.7-fold higher for housewives (9.5 [95% CI, 8.3–10.8]) than in non-manual workers (5.7 [95% CI, 4.8–6.6]).
This large population-based study suggests that manual workers are affected by idiopathic RRD requiring surgical treatment more often than non-manual workers. The higher rates of surgically treated RRD experienced by manual workers accord with the hypothesis that heavy manual handling may have a causal role.
manual work; retinal surgery; patient discharge; incidence study
The International Agency for Research on Cancer controversially has classified formaldehyde as causing nasopharyngeal carcinoma and myeloid leukaemia. To provide further information on this question, we extended follow-up of 14,008 chemical workers at six factories in England and Wales, covering the period 1941-2012. Mortality was compared with national death rates, and associations with incident upper airways cancer and leukaemia were explored in nested case-control analyses. Excess deaths were observed from cancers of the oesophagus (100 v 93.1 expected), stomach (182 v 141.4), rectum (107 v 86.8), liver (35 v 26.9) and lung (813 v 645.8), but none of these tumours exhibited a clear exposure-response relationship. Nested case-control analyses of 115 men with upper airways cancer (including one nasopharyngeal cancer), 92 with leukaemia, and 45 with myeloid leukaemia indicated no elevations of risk in the highest exposure category (high exposure for ≥1 year). When the two highest exposure categories were combined the odds ratio for myeloid leukaemia was 1.26 (95%confidence interval: 0.39, 4.08). Our results provide no support for a hazard of myeloid leukaemia, nasopharyngeal carcinoma or other upper airways tumours from formaldehyde, and indicate that any excess risk of these cancers, even from relatively high exposures, is at most small.
Cancer; chemical industry; formaldehyde; mortality; myeloid leukaemia; nasopharyngeal cancer
Mental illness and psychotropic drugs have been linked with workplace injury, but few studies have measured exposures and outcomes independently or established their relative timings. To address this shortcoming, we conducted a case-control study nested within a database prospectively recording injury consultations, diagnoses and drug prescriptions.
The Clinical Practice Research Datalink logs primary care data for 6% of the British population, coding all consultations (by the Read system) and drug prescriptions. We identified 1,348 patients aged 16-64 years from this database who had consulted a family doctor or hospital over a 20-year period for workplace injury (cases, 479 diagnostic codes) and 6,652 age, sex, and practice-matched controls with no such consultation. Groups were compared in terms of consultations for mental health problems (1,328 codes) and prescription of psychotropic drugs prior to the case’s injury consultation, using conditional logistic regression.
In total, 1,846 (23%) subjects had at least one psychiatric consultation before the index date and 1,682 (21%) had been prescribed a psychotropic drug. The odds ratio for prior mental health consultation was 1.44 (P<0.001) and that for psychotropic drug treatment was 1.57 (P<0.001). Risks were significantly elevated for several subclasses of mental health diagnosis (e.g. psychosis, neurosis) and for each of the drug classes analysed. Assuming causal relationships, about 9-10% of all workplace injuries leading to medical consultation were attributable to mental illness or psychotropic medication.
Mental health problems and psychotropic treatments may account for an important minority of workplace injuries.
The relation between Dupuytren’s contracture and occupational exposure to hand-transmitted vibration (HTV) has frequently been debated. We explored associations in a representative national sample of workers with well-characterised exposure to HTV.
We mailed a questionnaire to 21,201 subjects aged 16 – 64 years, selected at random from the age-sex registers of 34 general practices in Great Britain and to 993 subjects chosen randomly from military pay records, asking about occupational exposure to 39 sources of HTV and about fixed flexion contracture of the little or ring finger. Analysis was restricted to men at work in the previous week. Estimates were made of average daily vibration dose (A(8) r.m.s.) over that week. Associations with Dupuytren’s contracture were estimated by Poisson regression, both for lifetime exposure to HTV and for exposures in the past week >A(8) of 2.8 ms−2 r.m.s.. Estimates of relative risk (Prevalence Ratio (PR)) were adjusted for age, smoking status, social class and certain manual activities at work.
In all 4,969 eligible male respondents supplied full information on the study variables. These included 72 men with Dupuytren’s contracture, 2,287 with occupational exposure to HTV, and 409 with A(8)>2.8 ms−2 in the past week. PRs for occupational exposure to HTV were elevated 1.5-fold. For men with an A(8)>2.8 ms−2 in the past week, the adjusted PR was 2.85 (95% confidence interval 1.37 to 5.97).
Our findings suggest that risk of Dupuytren’s contracture is more than doubled in men with high levels of weekly exposure to HTV.
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.
During 2010, 43,816 subjects from 34 countries were interviewed. We analyzed the one-year prevalence of back and neck/upper limb pain. Personal risk factors studied were: sex; age; educational level; socio-economic status; housework or cooking; gardening and repairs; somatising tendency; job demand-control; six physical occupational exposures; and occupational group. Data on national socio-economic risk factors were obtained from eurostat and were available for 29 countries. We fitted Poisson regression models with random intercept on country.
35,550 workers entered the main analysis. Among personal risk factors, somatising 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%) as Ireland (25.7%), and prevalence rates of neck/upper limb pain ranging from 26.6% in Ireland to 67.7% in Finland. Adjustment by personal risk factors slightly reduced the large variation of prevalence between countries. For back pain, the rates were more homogenous after adjustment for social risk factors.
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 socio-economic differences between countries, with higher prevalence where there is less poverty and more social support.
back pain; neck pain; upper limb pain; occupational exposures; risk factors; cross-sectional studies; population characteristics
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.
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.
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.
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.
Computer workers; Musculoskeletal pain; Risk factors; CUPID study
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.
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 one or more 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.
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.
Our findings suggest that established psychological risk factors relate principally to the disability that arises from musculoskeletal pain.
case definition; longitudinal study; musculoskeletal symptom; psychological risk factor
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.
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.
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.
Registered on http://www.controlled-trials.com (reference number: ISRCTN79085082).
Randomised controlled trial; Arm pain; Physiotherapy; Advice; Rest; Active; Pain management
To quantify the variation in rates of absence for musculoskeletal pain across 47 occupational groups (mostly nurses and office workers) from 18 countries, and to explore personal and group-level risk factors that might explain observed differences.
A standardised questionnaire was used to obtain information about musculoskeletal pain, sickness absence and possible risk factors in a cross-sectional survey of 12,416 workers (92 to 1017 per occupational group). In addition, group-level data on socioeconomic variables such as sick pay and unemployment rates were assembled by members of the study team in each country. Associations of sickness absence with risk factors were examined by Poisson regression.
Overall, there were more than 30-fold differences between occupational groups in the 12-month prevalence of prolonged musculoskeletal sickness absence, and even among office workers carrying out similar occupational tasks, the variation was more than ten-fold. Personal risk factors included older age, lower educational level, tendency to somatise, physical loading at work and prolonged absence for non-musculoskeletal illness. However, these explained little of the variation between occupational groups. After adjustment for individual characteristics, prolonged musculoskeletal sickness absence was more frequent in groups with greater time pressure at work, lower job control, and more adverse beliefs about the work-relatedness of musculoskeletal disorders.
Musculoskeletal sickness absence might be reduced by eliminating excessive time pressures in work, maximising employees’ responsibility and control, and providing flexibility of duties for those with disabling symptoms. Care should be taken not to overstate work as a cause of musculoskeletal injury.
Sickness absence; musculoskeletal; international; risk factors; time pressure; job control
Routine statistics indicate a high frequency of work-related musculoskeletal disorders in Estonia. We aimed to describe the prevalence of musculoskeletal pain (MSP) amongst Estonian nurses, and to explore associations with personal characteristics and occupational risk factors.
As a part of an international investigation (the Cultural and Psychosocial Influences on Disability (CUPID) study), a cross-sectional survey was carried out amongst registered nurses at Tartu University Hospital, focusing on pain at six anatomical sites (low back, neck, shoulder, elbow, wrist/hand and knee) lasting for more than a day during the past year and past month. Associations with regional and multi-site (≥2 anatomical sites) pain were analysed by logistic regression.
Analysis was based on 221 female nurses (response rate 57%). The overall prevalence of MSP was 84% in the past year and 69% in the past month. The prevalence of multi-site pain was 60% in the past year and 40% in the past month. Low back, neck and knee were the sites most commonly painful. Pain in the past year tended to be more frequent at older ages, and with higher emotional exhaustion, and at most sites, with poor self-rated health, and reported distress from somatic symptoms. Multi-site pain was also significantly associated with older age and tendency to somatise.
The prevalence of MSP among Estonian nurses is high. Psychological risk factors such as somatising tendency have an important impact. However, none of the risk factors examined seems likely to explain the high frequency of work-related musculoskeletal disorders in Estonia.
It is unclear whether and to what extent intensive case management is more effective than standard occupational health services in reducing sickness absence in the healthcare sector.
To evaluate a new return to work service at an English hospital trust.
The new service entailed intensive case management for staff who had been absent sick for longer than four weeks, aiming to restore function through a goal-directed and enabling approach based on a bio-psycho-social model. Assessment of the intervention was by controlled before and after comparison with a neighbouring hospital trust at which there were no major changes in the management of sickness absence. Data on outcome measures were abstracted from electronic databases held by the two trusts.
At the intervention trust, the proportion of 4-week absences which continued beyond 8 weeks fell from 51.7% in 2008 to 49.1% in 2009 and 45.9% in 2010. The reduction from 2008 to 2010 contrasted with an increase at the control trust from 51.2% to 56.1% – a difference in change of 10.7% (95%CI 1.5% to 20.0%). There was also a differential improvement in mean days of absence beyond four weeks, but this was not statistically significant (1.6 days per absence, 95%CI −7.2 to 10.3 days).
Our findings suggest that the intervention was effective, and calculations based on an annual running cost of £57,000 suggest that it was also cost-effective. A similar intervention should now be evaluated at a larger number of hospital trusts.
Sickness absence; case management; intervention; evaluation; cost-effectiveness; healthcare
To explore definitions for multi-site pain, and compare associations with risk factors for different patterns of musculoskeletal pain, we analysed cross-sectional data from the Cultural and Psychosocial Influences on Disability (CUPID) study. The study sample comprised 12,410 adults aged 20-59 years from 47 occupational groups in 18 countries. A standardised questionnaire was used to collect information about pain in the past month at each of 10 anatomical sites, and about potential risk factors. Associations with pain outcomes were assessed by Poisson regression, and characterised by prevalence rate ratios (PRRs). Extensive pain, affecting 6-10 anatomical sites, was reported much more frequently than would be expected if the occurrence of pain at each site were independent (674 participants v 41.9 expected). In comparison with pain involving only 1-3 sites, it showed much stronger associations (relative to no pain) with risk factors such as female sex (PRR 1.6 v 1.1), older age (PRR 2.6 v 1.1), somatising tendency (PRR 4.6 v 1.3) and exposure to multiple physically stressing occupational activities (PRR 5.0 v 1.4). After adjustment for number of sites with pain, these risk factors showed no additional association with a distribution of pain that was widespread according to the frequently used American College of Rheumatology (ACR) criteria. Our analysis supports the classification of pain at multiple anatomical sites simply by the number of sites affected, and suggests that extensive pain differs importantly in its associations with risk factors from pain that is limited to only a small number of anatomical sites.
In a large cross-sectional survey, pain affecting 6–10 anatomical sites showed substantially different associations with risk factors from pain limited to 1–3 sites.
To explore definitions for multisite pain, and compare associations with risk factors for different patterns of musculoskeletal pain, we analysed cross-sectional data from the Cultural and Psychosocial Influences on Disability (CUPID) study. The study sample comprised 12,410 adults aged 20–59 years from 47 occupational groups in 18 countries. A standardised questionnaire was used to collect information about pain in the past month at each of 10 anatomical sites, and about potential risk factors. Associations with pain outcomes were assessed by Poisson regression, and characterised by prevalence rate ratios (PRRs). Extensive pain, affecting 6–10 anatomical sites, was reported much more frequently than would be expected if the occurrence of pain at each site were independent (674 participants vs 41.9 expected). In comparison with pain involving only 1–3 sites, it showed much stronger associations (relative to no pain) with risk factors such as female sex (PRR 1.6 vs 1.1), older age (PRR 2.6 vs 1.1), somatising tendency (PRR 4.6 vs 1.3), and exposure to multiple physically stressing occupational activities (PRR 5.0 vs 1.4). After adjustment for number of sites with pain, these risk factors showed no additional association with a distribution of pain that was widespread according to the frequently used American College of Rheumatology criteria. Our analysis supports the classification of pain at multiple anatomical sites simply by the number of sites affected, and suggests that extensive pain differs importantly in its associations with risk factors from pain that is limited to only a small number of anatomical sites.
Pain; Multisite; Widespread; Definition; Risk factors
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.
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.
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).
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.
Carpal tunnel syndrome; Nerve conduction; Case–control; Obesity; Vibration; Occupation; Psychosocial; Somatising tendency; Upper limb disorders
We have previously proposed that sensory nerve conduction (SNC) in the median nerve should be classed as abnormal when the difference between conduction velocities in the little and index fingers is > 8 m/s. In a prospective longitudinal study, we investigated whether this case definition distinguished patients who were more likely to benefit from surgical treatment.
We followed up 394 patients (response rate 56%), who were investigated by a neurophysiology service for suspected carpal tunnel syndrome. Information about symptoms, treatment and other possible determinants of outcome was obtained through questionnaires at baseline and after follow-up for a mean of 19.2 months. Analysis focused on 656 hands with numbness, tingling or pain at baseline. Associations of surgical treatment with resolution of symptoms were assessed by Poisson regression, and summarised by prevalence rate ratios (PRRs) and associated 95% confidence intervals (95% CIs).
During follow-up, 154 hands (23%) were treated surgically, and sensory symptoms resolved in 241 hands (37%). In hands with abnormal median SNC, surgery was associated with resolution of numbness, tingling and pain (PRR 1.5, 95% CI 1.0-2.2), and of numbness and tingling specifically (PRR 1.8, 95% CI 1.3-2.6). In contrast, no association was apparent for either outcome when median SNC was classed as normal.
Our definition of abnormal median SNC distinguished a subset of patients who appeared to benefit from surgical treatment. This predictive capacity gives further support to its validity as a diagnostic criterion in epidemiological research.
Carpal tunnel syndrome; Neurophysiology; Case definition; Validity; Surgery; Outcome
To inform the clinical management of patients with suspected carpal tunnel syndrome (CTS) and case definition for CTS in epidemiological research, we explored the relation of symptoms and signs to sensory nerve conduction (SNC) measurements.
Patients aged 20–64 years who were referred to a neurophysiology service for investigation of suspected CTS, completed a symptom questionnaire (including hand diagrams) and physical examination (including Tinel’s and Phalen’s tests). Differences in SNC velocity between the little and index finger were compared according to the anatomical distribution of symptoms in the hand and findings on physical examination.
Analysis was based on 1806 hands in 908 patients (response rate 73%). In hands with numbness or tingling but negative on both Tinel’s and Phalen’s tests, the mean difference in SNC velocities was no higher than in hands with no numbness or tingling. The largest differences in SNC velocities occurred in hands with extensive numbness or tingling in the median nerve sensory distribution and both Tinel’s and Phalen’s tests positive (mean 13.8, 95% confidence interval (CI) 12.6-15.0 m/s). Hand pain and thumb weakness were unrelated to SNC velocity.
Our findings suggest that in the absence of other objective evidence of median nerve dysfunction, there is little value in referring patients of working age with suspected CTS for nerve conduction studies if they are negative on both Tinel’s and Phalen’s tests. Alternative case definitions for CTS in epidemiological research are proposed according to the extent of diagnostic information available and the relative importance of sensitivity and specificity.
Epidemiology; Evidence-based medicine; Hand; Nerve compression syndromes; Wrist
The paper describes the adaptation and testing of the Cultural and Psychosocial Influences on Disability Questionnaire for use in Portuguese. The cross-cultural adaptation followed the steps of translation, back-translation, evaluation of the translations by a committee of judges, and then piloting of the pre-final version. This was performed in a sample of 40 nursing staff from the Hospital at the University of São Paulo. Adjustments were made after review of the translations by the committee of judges (CVI≤ 80%). The pilot study was used to test whether questions could be satisfactorily understood and completed (≥ 85% of subjects). The Brazilian version of the Questionnaire is an adequate instrument for the ascertainment of occupational activities, psychosocial aspects of work, musculoskeletal symptoms and associated disabilities in nursing staff.
Translations; Validation Studies; Occupational Health; Cumulative Trauma Disorders
Candidate risk factors for idiopathic rhegmatogenous retinal detachment (RRD) include heavy manual handling (requiring Valsalva’s maneuver). We assessed incidence rates of surgically treated idiopathic RRD among manual workers, non-manual workers and housewives resident in Tuscany, Italy.
We retrieved all hospital discharge records bearing a principal diagnosis corresponding to RRD coupled with retinal surgery for any resident of Tuscany during 1997–2009. After elimination of repeated admissions and patients with coexistent, associated conditions (including recent trauma), subjects aged 25–59 years were classified as manual workers, non-manual workers or housewives. Population data were extracted from the 2001 census.
We identified 1,946 eligible cases (1,142 men). Among men, manual workers experienced a 1.8-fold higher age-standardized rate per 100,000 person-years than non-manual workers [17.4 (95 % confidence interval (CI) 16.1–18.7) vs. 9.8 (95 % CI 8.8–10.8)]. Age-standardized rates among women were 1.9-fold higher for manual workers [11.1 (95 % CI 9.8–12.3)] and 1.7-fold higher for housewives [9.5 (95 % CI 8.3–10.8)] than in non-manual workers [5.7 (95 % CI 4.8–6.6)].
This large population-based study suggests that manual workers are affected by idiopathic RRD requiring surgical treatment more often than non-manual workers. The higher rates of surgically treated RRD experienced by manual workers are in accord with the hypothesis that heavy manual handling may have a causal role.
Manual work; Retinal surgery; Patient discharge; Incidence study
Knee osteoarthritis (kOA) risk is increased by obesity and physical activities (PA) which mechanically stress the joint. We examined the associations of midlife kOA with body mass index (BMI) and activity exposure across adult life and their interaction.
Data are from a UK birth cohort of 2597 participants with a clinical assessment for kOA at age 53. At ages 36, 43 and 53 BMI (kg/m2), self-reported leisure-time PA, and occupational activity (kneeling/squatting; lifting; climbing; sitting; assigned using a job-exposure matrix) were ascertained. Associations were explored using the multiplicative logistic model.
BMI was strongly and positively associated with kOA in men and women. Men and women in manual occupations also had greater odds of kOA; there was a weak suggestion that kOA risk was higher among men exposed to lifting or kneeling at work. For men, the only evidence of a multiplicative interaction between BMI and activities was for lifting (p = 0.01) at age 43; BMI conferred higher kOA risk among those most-likely to lift at work (OR per increase in BMI z-score: 3.55, 95% CI: 1.72-7.33). For women, the only evidence of an interaction was between BMI and leisure-time PA (p = 0.005) at age 43; BMI conferred higher kOA risk among those at higher PA levels (OR per increase in BMI z-score: 1.59, 95% CI: 1.26-2.00 in inactive; 1.70, 95% CI: 1.14-2.55 (less-active); and 4.44; 95% CI: 2.26-8.36 (most-active).
At the very least, our study suggests that more active individuals (at work and in leisure) may see a greater reduction in risk of kOA from avoiding a high BMI than those less active.
Knee osteoarthritis; Body mass index; Physical activity; Occupational activity
To explore occupational and psychological risk factors for the incidence and persistence of multi-site musculoskeletal pain.
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.
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 ORs (95%CIs) for the highest relative to the lowest exposure categories of 2.3 (1.0-5.6), 2.6 (1.5-4.6) and 1.9 (1.1-3.3) respectively. Development of new multi-site pain was most strongly associated with working for ≥ 40 hours per week (OR 5.0, 95%CI 1.1-24.0).
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.
To assess the importance of psychological and culturally-influenced factors as predictors of incidence and persistence of LBP in a Spanish working population.
As part of the international CUPID study, 1105 Spanish nurses and office workers, aged 20-59 years, answered questions at baseline about LBP in the past month and past year, associated disability, occupational lifting, smoking habits, health beliefs, mental health, and distress from common somatic symptoms. At follow-up 12 months later, they were asked again about LBP and associated disability in the past month. Associations with the incidence and persistence of LBP were assessed by log binomial regression, and characterised by prevalence rate ratios (PRRs) with associated 95% confidence intervals (CIs).
971 participants (87.9%) completed follow-up. Among 579 with no LBP at baseline, 22.8% reported LBP at follow-up. After adjustment for sex, age and occupation, development of new LBP was predicted by poor mental health (PRR 1.5, 95%CI 1.0-2.2), somatising tendency (PRR 1.8, 95%CI 1.2-2.7), and presence of LBP for >1 month in the year before baseline (PRR 4.7, 95%CI 3.1-6.9). Among 392 subjects who had LBP at baseline, 59.4% reported persistence at follow-up. Persistence of LBP was associated with presence of symptoms for >1 month in the 12 months before baseline (PRR 1.4, 95%CI 1.2-1.7), and more weakly with somatising tendency, and with adverse beliefs about the work-relatedness and prognosis of LBP
In Spain, as in northern European countries, psychological and culturally-influenced factors have an important role in the development and persistence of LBP.
low back pain; health beliefs; mental health; somatising tendency
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. We assessed the potential for error for work-associated arm pain.
We mailed a questionnaire to working-aged adults, randomly chosen from five British general practices. We 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 we derived a variable for exposure to any ‘arm-straining’ occupational activity. We estimated the relative risk (RR) from arm-straining activity, using a modified Cox model, and derived the population attributable fraction (PAF). We 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.
Arm pain in the past year was more common in the 1,143 subjects who reported exposure to arm-straining occupational activity (RR 1.2, 95% confidence interval 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.
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.
Large international variation in the prevalence of disabling forearm and low back pain was only partially explained by established personal and socioeconomic risk factors.
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.
Low back; Forearm; Pain; International; Socioeconomic; Psychosocial
The aim of this study was to investigate whether whole-body vibration (WBV) is associated with prolapsed lumbar intervertebral disc (PID) and nerve root entrapment among patients with low-back pain (LBP) undergoing magnetic resonance imaging (MRI).
A consecutive series of patients referred for lumbar MRI because of LBP were compared with controls X-rayed for other reasons. Subjects were questioned about occupational activities loading the spine, psychosocial factors, driving, personal characteristics, mental health, and certain beliefs about LBP. Exposure to WBV was assessed by six measures, including weekly duration of professional driving, hours driven at a spell, and current 8-hour daily equivalent root-mean-square acceleration A(8). Cases were sub-classified according to whether or not PID/nerve root entrapment was present. Associations with WBV were examined separately for cases with and without these MRI findings, with adjustment for age, sex, and other potential confounders.
Altogether, 237 cases and 820 controls were studied, including 183 professional drivers and 176 cases with PID and/or nerve root entrapment. Risks associated with WBV tended to be lower for LBP with PID/nerve root entrapment but somewhat higher for risks of LBP without these abnormalities. However, associations with the six metrics of exposure were all weak and not statistically significant. Neither exposure–response relationships nor increased risk of PID/nerve root entrapment from professional driving or exposure at an A(8) above the European Union daily exposure action level were found.
WBV may be a cause of LBP but it was not associated with PID or nerve root entrapment in this study.
back pain; disc pathology; whole-body vibration