David McBride

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

&NA; Large international variation in the prevalence of disabling forearm and low back pain was only partially explained by established personal and socioeconomic risk factors. &NA; 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.

Evaluating the impact of wind turbine noise on health-related quality of life

We report a cross-sectional study comparing the health-related quality of life (HRQOL) of individuals residing in the proximity of a wind farm to those residing in a demographically matched area sufficiently displaced from wind turbines. The study employed a nonequivalent comparison group posttest-only design. Self-administered questionnaires, which included the brief version of the World Health Organization quality of life scale, were delivered to residents in two adjacent areas in semirural New Zealand. Participants were also asked to identify annoying noises, indicate their degree of noise sensitivity, and rate amenity. Statistically significant differences were noted in some HRQOL domain scores, with residents living within 2 km of a turbine installation reporting lower overall quality of life, physical quality of life, and environmental quality of life. Those exposed to turbine noise also reported significantly lower sleep quality, and rated their environment as less restful. Our data suggest that wind farm noise can negatively impact facets of HRQOL.

Physical and psychosocial risk factors for musculoskeletal disorders in New Zealand nurses, postal workers and office workers

Objective To investigate the association of physical and psychosocial risk factors with musculoskeletal disorders (MSDs) in New Zealand nurses, postal workers and office workers. Design A cross-sectional postal survey asking about demographic, physical and psychosocial factors and MSDs. Participants A total of 911 participants was randomly selected; nurses from the Nursing Council of New Zealand database (n=280), postal workers from their employers database (n=280) and office workers from the 2005 electoral roll (n=351). Outcome Measures Self-reported pain in the low back, neck, shoulder, elbow, wrist/hand or knee lasting more than 1 day in the month before the survey. Results The response rate was 58%, 443 from 770 potential participants. 70% (n=310) reported at least one MSDs. Physical work tasks were associated with low back (odds ratio (OR) 1.35, 95% CI 1.14 to 1.6), shoulder (OR 1.41, 95% CI 1.17 to 1.69), elbow (OR 1.14, 95% CI 1.13 to 1.83) and wrist/hand pain (OR 1.39, 95% CI 1.15 to 1.69). Job strain had the strongest association with neck pain (OR 3.46, 95% CI 1.30 to 9.21) and wrist/hand pain. Somatisation was weakly associated with MSDs at most sites. Better general and mental health status were weakly associated with lower odds of MSDs. Conclusions In injury prevention and rehabilitation the physical nature of the work needs to be addressed for most MSDs, with modest decreases in risk seemingly possible. Addressing job strain could provide significant benefit for those with neck and wrist/hand pain, while the effects of somatisation and the promotion of good mental health may provide smaller but global benefits.

Noise exposure and hearing loss in agriculture: a survey of farmers and farm workers in the Southland region of New Zealand.

Farmers are known to be exposed to intermittent intense noise from a variety of sources, but long-term exposure and the resulting risk of hearing loss have not been well characterized. We studied a cross-sectional random sample of farms on which agricultural workers completed an audiometric test and questionnaire, and performed noise dosimetry on a subsample. Sixty-five percent of farms and a total of 586 workers participated. Noise on the subsample of 60 farms lay in a range between 84.8 to 86.8 dB(A) and hearing losses were consistent with this level of exposure. Age, driving tractors without cabs, and working with metal were important risk factors. Reported compliance with hearing protection was higher than that actually observed. The majority of farmers have a moderate risk of hearing loss, but a significant minority is at high risk. Elimination and isolation of noise sources are the control methods of choice, and if residual hearing protection is required, compliance must be improved.

Prevalence and impact of musculoskeletal disorders in New Zealand nurses, postal workers and office workers.

Objectives: To describe the prevalence, characteristics and impact of musculoskeletal disorders (MSDs) in New Zealand nurses, postal workers and office workers.

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.

Patterns of multisite pain and associations with risk factors

Summary 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. ABSTRACT 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.

Occupational exposure to magnetic fields in relation to mortality from brain cancer among electricity generation and transmission workers.

OBJECTIVE: To investigate whether the risks of mortality from brain cancer are related to occupational exposure to magnetic fields. METHODS: A total of 112 cases of primary brain cancer (1972-91) were identified from a cohort of 84,018 male and female employees of the (then) Central Electricity Generating Board and its privatised successor companies. Individual cumulative occupational exposures to magnetic fields were estimated by linking available computerised job history data with magnetic field measurements collected over 675 person-workshifts. Estimated exposure histories of the case workers were compared with those of 654 control workers drawn from the cohort (nested case-control study), by means of conditional logistic regression. RESULTS: For exposure assessments based on arithmetic means, the risk of mortality from brain cancer for subjects with an estimated cumulative exposure to magnetic fields of 5.4-13.4 microT.y v subjects with lower exposures (0.0-5.3 microT.y) was 1.04 (95% confidence interval (95% CI) 0.60 to 1.80). The corresponding relative risk in subjects with higher exposures (> or = 13.5 microT.y) was 0.95 (95% CI 0.54 to 1.69). There was no indication of a positive trend for cumulative exposure and risk of mortality from brain cancer either when the analysis used exposure assessments based on geometric means or when the analysis was restricted to exposures received within five years of the case diagnosis (or corresponding period for controls). CONCLUSIONS: Although the exposure categorisation was based solely on recent observations, the study findings do not support the hypothesis that the risk of brain cancer is associated with occupational exposure to magnetic fields.

Noise and the classical musician.

OBJECTIVES--To test the hypothesis that noise exposure may cause hearing loss in classical musicians. DESIGN--Comparison of hearing levels between two risk groups identified during the study by measuring sound levels. SETTING--Symphony orchestra and occupational health department in the west Midlands. MAIN OUTCOME MEASURES--Hearing level as measured by clinical pure tone audiometry. RESULTS--Trumpet and piccolo players received a noise dose of 160% and 124%, respectively, over mean levels during part of the study. Comparison of the hearing levels of 18 woodwind and brass musicians with 18 string musicians matched for age and sex did not show a significant difference in hearing, the mean difference in the hearing levels at the high (2, 4, and 8 KHz) audiometric frequencies being 1.02 dB (95% confidence interval -2.39 to 4.43). CONCLUSIONS--This study showed that there is a potential for occupational hearing loss in classical orchestral musicians.

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.