Keith T Palmer

Smoking and musculoskeletal disorders: findings from a British national survey

Objectives: To explore the relation between smoking habits and regional pain in the general population. Methods: A questionnaire was mailed to 21 201 adults, aged 16–64 years, selected at random from the registers of 34 British general practices, and to 993 members of the armed services, randomly selected from pay records. Questions were asked about pain in the low back, neck, and upper and lower limbs during the past 12 months; smoking habits; physical activities at work; headaches; and tiredness or stress. Associations were examined by logistic regression and expressed as prevalence ratios (PRs). Results: Questionnaires were completed by 12 907 (58%) subjects, including 6513 who had smoked at some time, among whom 3184 were current smokers. Smoking habits were related to age, social class, report of headaches, tiredness or stress, and manual activities at work. After adjustment for potential confounders, current and ex-smokers had higher risks than lifetime non-smokers for pain at all of the sites considered. This was especially so for pain reported as preventing normal activities (with PRs up to 1.6 in current v never smokers). Similar associations were found in both sexes, and when analysis was restricted to non-manual workers. Conclusions: There is an association between smoking and report of regional pain, which is apparent even in ex-smokers. This could arise from a pharmacological effect of tobacco smoke (for example, on neurological processing of sensory information or nutrition of peripheral tissues); another possibility is that people with a low threshold for reporting pain and disability are more likely to take up and continue smoking.

Risk of prematurity, low birthweight and pre‐eclampsia in relation to working hours and physical activities: a systematic review

Background: Occupational activities are suspected of having an adverse impact on outcomes of pregnancy. Aim: To assess the evidence relating three major adverse outcomes (preterm delivery, low birthweight (LBW) and pre-eclampsia/gestational hypertension) to five common occupational exposures (prolonged working hours, shift work, lifting, standing and heavy physical workload). Methods: A systematic search of Medline and Embase (1966–December 2005) using combinations of keywords and medical subject heading terms was conducted. For each relevant paper, standard details were abstracted that were then used to summarise the design features of studies, to rate their methodological quality (completeness of reporting and potential for important bias or confounding) and to provide estimates of effect. For studies with similar definitions of exposure and outcome, pooled estimates of relative risk (RR) in meta-analysis were calculated. Results: 53 reports were identified—35 on preterm delivery, 34 on birth weight and 9 on pre-eclampsia or gestational hypertension. These included 21 cohort investigations. For pre-term delivery, extensive evidence relating to each of the exposures of interest was found. Findings were generally consistent and tended to rule out a more than moderate effect size (RR >1.4). The larger and most complete studies were less positive, and pooled estimates of risk pointed to only modest or null effects. For small-for-gestational age, the position was similar, but the evidence base was more limited. For pre-eclampsia and gestational hypertension, it was too small to allow firm conclusions. Conclusions: The balance of evidence is not sufficiently compelling to justify mandatory restrictions on any of the activities considered in this review. However, given some uncertainties in the evidence base and the apparent absence of important beneficial effects, it may be prudent to advise against long working hours, prolonged standing and heavy physical work, particularly late in pregnancy. Our review identifies several priorities for future investigation.

Back pain in Britain: comparison of two prevalence surveys at an interval of 10 years

In Britain, as in many other countries, back pain is a major cause of disability, especially in adults of working age. During the decade to 1993, outpatient attendances for back pain rose fivefold, and the number of days of incapacity from back disorders for which social security benefits were paid more than doubled.1 It is unclear whether this represents an increase in the occurrence of diseases affecting the back or a change in peoples behaviour when they have symptoms. To address this question we compared the prevalence of low back pain and associated disability in two postal surveys 10 years apart.

Occupational exposure to noise and the attributable burden of hearing difficulties in Great Britain

Aims: To determine the prevalence of self reported hearing difficulties and tinnitus in working aged people from the general population, and to estimate the risks from occupational exposure to noise and the number of attributable cases nationally. Methods: A questionnaire was mailed to 22 194 adults of working age selected at random from the age–sex registers of 34 British general practices (21 201 subjects) and from the central pay records of the British armed services (993 subjects). Information was collected on years of employment in a noisy job; and whether the respondent wore a hearing aid, had difficulty in hearing conversation, or had experienced persistent tinnitus over the past year. Associations of hearing difficulty and tinnitus with noise exposure were examined by logistic regression, with adjustment for age, sex, smoking habits, and frequent complaints of headaches, tiredness, or stress. The findings were expressed as prevalence ratios (PRs) with associated 95% confidence intervals (CIs). Attributable numbers were calculated from the relevant PRs and an estimate of the prevalence of occupational exposure to noise nationally. Results: Some 2% of subjects reported severe hearing difficulties (wearing a hearing aid or having great difficulty in both ears in hearing conversation in a quiet room). In men, the prevalence of this outcome rose steeply with age, from below 1% in those aged 16–24 years to 8% in those aged 55–64. The pattern was similar in women, but severe hearing loss was only about half as prevalent in the oldest age band. Tinnitus was far more common in subjects with hearing difficulties. In both sexes, after adjustment for age, the risk of severe hearing difficulty and persistent tinnitus rose with years spent in a noisy job. In men older than 35 years with 10 or more years of exposure, the PR for severe hearing difficulty was 3.8 (95% CI 2.4 to 6.2) and that for persistent tinnitus 2.6 (95% CI 2.0 to 3.4) in comparison with those who had never had a noisy job. Nationally, some 153 000 men and 26 000 women aged 35–64 years were estimated to have severe hearing difficulties attributable to noise at work. For persistent tinnitus the corresponding numbers were 266 000 and 84 000. Conclusions: Significant hearing difficulties and tinnitus are quite common in men from the older working age range. Both are strongly associated with years spent in a noisy occupation—a predominantly male exposure. The national burden of hearing difficulties attributable to noise at work is substantial.

The Southampton examination schedule for the diagnosis of musculoskeletal disorders of the upper limb

OBJECTIVES Following a consensus statement from a multidisciplinary UK workshop, a structured examination schedule was developed for the diagnosis and classification of musculoskeletal disorders of the upper limb. The aim of this study was to test the repeatability and the validity of the newly developed schedule in a hospital setting. METHOD 43 consecutive referrals to a soft tissue rheumatism clinic (group 1) and 45 subjects with one of a list of specific upper limb disorders (including shoulder capsulitis, rotator cuff tendinitis, lateral epicondylitis and tenosynovitis) (group 2), were recruited from hospital rheumatology and orthopaedic outpatient clinics. All 88 subjects were examined by a research nurse (blinded to diagnosis), and everyone from group 1 was independently examined by a rheumatologist. Between observer agreement was assessed among subjects from group 1 by calculating Cohens κ for dichotomous physical signs, and mean differences with limits of agreement for measured ranges of joint movement. To assess the validity of the examination, a pre-defined algorithm was applied to the nurses examination findings in patients from both groups, and the sensitivity and specificity of the derived diagnoses were determined in comparison with the clinics independent diagnosis as the reference standard. RESULTS The between observer repeatability of physical signs varied from good to excellent, with κ coefficients of 0.66 to 1.00 for most categorical observations, and mean absolute differences of 1.4°–11.9° for measurements of shoulder movement. The sensitivity of the schedule in comparison with the reference standard varied between diagnoses from 58%–100%, while the specificities ranged from 84%–100%. The nurse and the clinic physician generally agreed in their diagnoses, but in the presence of shoulder capsulitis the nurse usually also diagnosed shoulder tendinitis, whereas the clinic physician did not. CONCLUSION The new examination protocol is repeatable and gives acceptable diagnostic accuracy in a hospital setting. Examination can feasibly be delegated to a trained nurse, and the protocol has the benefit of face and construct validity as well as consensus backing. Its performance in the community, where disease is less clear cut, merits separate evaluation, and further refinement is needed to discriminate between discrete pathologies at the shoulder.

Potential of magnetic resonance imaging findings to refine case definition for mechanical low back pain in epidemiological studies: a systematic review.

Study Design. Systematic review and meta-analysis. Objective. To assess how confidently low back pain (LBP) can be attributed to abnormalities on magnetic resonance imaging (MRI), and thereby explore the potential value of MRI abnormalities in refining case definition for mechanical LBP in epidemiological research. Summary of Background Data. Most epidemiological studies of mechanical LBP have defined cases only by reported symptoms, but it is possible that the potency of causes differs depending on whether there is demonstrable underlying spinal pathology. Methods. We reviewed the published data on MRI abnormalities, looking for data on the repeatability of their assessment, their prevalence in people free from LBP, and their association with LBP. Where data were sufficient, we calculated a summary estimate of prevalence in people without LBP and a meta-estimate of the odds ratio for the association with LBP. A formula was then applied to estimate the corresponding prevalence rate ratio, assuming 3 possible prevalence rates for LBP in the general population. Results. Data were most extensive for disc protrusion, nerve root displacement or compression, disc degeneration, and high intensity zone, all of which could be assessed repeatedly. All were associated with LBP, meta-estimates of odds ratios ranging from 2.3 (nerve root displacement or compression) to 3.6 (disc protrusion). However, even for disc protrusion, estimates of the corresponding prevalence rate ratios were mostly less than 2. Conclusion. MRI findings of disc protrusion, nerve root displacement or compression, disc degeneration, and high intensity zone are all associated with LBP, but individually, none of these abnormalities provides a strong indication that LBP is attributable to underlying pathology. This limits their value in refining epidemiological case definitions for LBP.

Soft-Tissue Rheumatic Disorders of the Neck and Upper Limb: Prevalence and Risk Factors

OBJECTIVES To review the epidemiologic literature concerning the occurrence of and the risk factors for pain and specific soft-tissue rheumatic conditions that affect the neck and upper limbs. METHODS An extensive search of the literature, including a search of Medline and EMBASE, authoritative recent reviews, and relevant textbooks, was performed. Studies that furnished data about the occurrence of or risk factors for regional pain or specific soft-tissue entities were extracted. RESULTS Numerous epidemiologic studies among different populations suggest a high prevalence of pain in the neck (10% to 19%), shoulder (18% to 26%), elbow (8% to 12%), and wrist/hand (9% to 17%) at any point in time. Less clear is the proportion of pain caused by specific upper-limb disorders as compared with nonspecific pain; however, as many as 6% of adults may have carpal tunnel syndrome. Significant risk factors for these disorders include age, female gender, obesity, and association with mechanical exposures (eg, posture, force, repetition, vibration) in the workplace. Also implicated are psychologic well-being and psychosocial workplace factors such as high levels of demand, poor control, and poor support. CONCLUSION Pain and soft-tissue rheumatic disorders of the neck and upper limb are common. It appears that individual, mechanical, and psychosocial factors all contribute to upper-limb disorders, suggesting that future strategies for prevention will need to address each of these factors if they are to be successful.

Validity of self reported occupational exposures to hand transmitted and whole body vibration

OBJECTIVES To assess the accuracy with which workers report their exposure to occupational sources of hand transmitted (HTV) and whole body vibration (WBV). METHODS 179 Workers from various jobs involving exposure to HTV or WBV completed a self administered questionnaire about sources of occupational exposure to vibration in the past week. They were then observed at work over 1 hour, after which they completed a second questionnaire concerning their exposures during this observation period. The feasibility of reported sources of exposure during the past week was examined by questioning managers and by inspection of tools and machines in the workplace. The accuracy of reported sources and durations of exposure in the 1 hour period were assessed relative to what had been observed. RESULTS The feasibility of exposure in the previous week was confirmed for 97% of subjects who reported exposure to HTV, and for 93% of subjects who reported exposure to WBV. The individual sources of exposure reported were generally plausible, but occupational use of cars was substantially overreported, possibly because of confusion with their use in travel to and from work. The accuracy of exposures reported during the observation period was generally high, but some sources of HTV were confused—for example, nailing and stapling guns reported as riveting hammers, and hammer drills not distinguished from other sorts of drill. Workers overestimated their duration of exposure to HTV by a median factor of 2.5 (interquartile range (IQR) 1.6–5.9), but estimated durations of exposure were more accurate when the exposure was relatively continuous rather than for intermittent short periods. Reported durations of exposure to WBV were generally accurate (median ratio of reported to observed time 1.1, IQR 1.0–1.2). CONCLUSIONS Sources of recent occupational exposure to vibration seem to be reported with reasonable accuracy, but durations of exposure to HTV are systematically overestimated, particularly when the exposure is intermittent and for short periods. This raises the possibility that dose-response relations may have been biased in some of the studies on which exposure standards might be based, and that the levels in currently proposed standards may be too high. Future studies should pay attention to this source of error during data collection.

Musculoskeletal pain in elite professional musicians from British symphony orchestras

BACKGROUND Professional musicians have high rates of musculoskeletal pain, but few studies have analysed risks by work activities or the psychosocial work environment. AIMS To assess the prevalence and impact of musculoskeletal pain, and its relation to playing conditions, mental health and performance anxiety, in musicians from leading British symphony orchestras. METHODS Musicians from six professional orchestras completed a questionnaire concerning their orchestral duties and physical activities at work, mental health (somatizing tendency, mood, demand, support and control at work, performance anxiety) and regional pain in the past 4 weeks and past 12 months. Prevalence rates were estimated by anatomical site and associations with risk factors assessed by logistic regression. RESULTS Responses were received from 243 musicians (51% of those approached), among whom 210 (86%) reported regional pain in the past 12 months, mainly affecting the neck, low back and shoulders. Risks tended to be higher in women, in those with low mood, and especially in those with high somatizing scores. Only weak associations were found with psychosocial work stressors and performance anxiety. However, risks differed markedly by instrument category. Relative to string players, the odds of wrist/hand pain were raised 2.9-fold in wind players, but 60% lower in brass players, while the odds of elbow pain were 50% lower among wind and brass players. CONCLUSIONS Musculoskeletal pain is common in elite professional musicians. A major personal risk factor is somatizing tendency, but performance anxiety has less impact. Risks differ substantially by instrument played, offering pointers towards prevention.

Prevalence and pattern of occupational exposure to whole body vibration in Great Britain: findings from a national survey.

OBJECTIVES To estimate the number of workers in Great Britain with significant occupational exposure to whole body vibration (WBV) and to identify the common sources of exposure and the occupations and industries where such exposures arise. METHODS A postal questionnaire was posted to a random community sample of 22 194 men and women of working age. Among other things, the questionnaire asked about exposure to WBV in the past week, including occupational and common non-occupational sources. Responses were assessed by occupation and industry, and national prevalence estimates were derived from census information. Estimates were also made of the average estimated daily personal dose of vibration (eVDV). RESULTS From the 12 907 responses it was estimated that 7.2 million men and 1.8 million women in Great Britain are exposed to WBV at work in a 1 week period if the occupational use of cars, vans, buses, trains, and motor cycles is included within the definition of exposure. The eVDV of >374 000 men and 9000 women was estimated to exceed a proposed British Standard action level of 15 ms-1.75. Occupations in which the estimated exposures most often exceeded 15 ms-1.75 included forklift truck and mechanical truck drivers, farm owners and managers, farm workers, and drivers of road goods vehicles. These occupations also contributed the largest estimated numbers of workers in Great Britain with such levels of exposure. The highest estimated median occupational eVDVs were found in forklift truck drivers, drivers of road goods vehicles, bus and coach drivers, and technical and wholesale sales representatives, among whom a greater contribution to total dose was received from occupational exposures than from non-occupational ones; but in many other occupations the reverse applied. The most common sources of occupational exposure to WBV are cars, vans, forklift trucks, lorries, tractors, buses, and loaders. CONCLUSIONS Exposure to whole body vibration is common, but only a small proportion of exposures exceed the action level proposed in British standards, and in many occupations, non-occupational sources are more important than those at work. The commonest occupational sources of WBV and occupations with particularly high exposures have been identified, providing a basis for targeting future control activities.