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Biomedical subjects

L Punnett

Publications and source records attributed to L Punnett.

At least 37 records · Page 2Linked to original sources

Prevalence and predictors of long-term work disability due to carpal tunnel syndrome.

The objective of this study was to describe patterns and predictors of work absence in the prospective, community-based Maine Carpal Tunnel Study. Three hundred fifteen patients with carpal tunnel syndrome (CTS) were recruited from physicians' offices throughout Maine. The patients completed questionnaires at entry and after 6, 18, and 30 months. The questionnaires included scales measuring symptom severity, functional status, general and mental health status, exposure to physical stressors, work status, and other indicators. The analyses examined univariate and multivariate correlates of work absence. The mean age was 43, 72% of subjects were female, 71% underwent carpal tunnel release, and 45% were receiving Workers' Compensation. Fifty-two percent worked in managerial or technical occupations, 15% in service occupations, and 13% in heavy labor or machine operation. Forty-five percent of patients changed jobs or were absent from work (aside from postoperative recovery) during the 30-month follow-up. In multivariate logistic regression models, correlates of work absence at 18 months included worse functional status of the hand at study entry and at 6-month follow-up, involvement of an attorney at the time of enrollment (P < 0.002 for each), and work absence at 6 months (P = 0.03). Worse upper extremity functional status and having a contested Workers' Compensation claim are critical predictors of work absence and should be principal targets of interventions to reduce work disability in CTS.

Absenteeism↗

Ergonomic stressors and upper extremity disorders in vehicle manufacturing: cross sectional exposure-response trends.

OBJECTIVE: To evaluate the association between upper extremity soft tissue disorders and exposure to preventable ergonomic stressors in vehicle manufacturing operations. METHODS: A cross sectional study was conducted in one vehicle stamping plant and one engine assembly plant. A standardised physical examination of the upper extremities was performed on all subjects. An interviewer administered questionnaire obtained data on demographics, work history, musculoskeletal symptoms, non-occupational covariates, and psycho-physical (relative intensity) ratings of ergonomic stressors. The primary exposure score was computed by summing the responses to the psychophysical exposure items. Multivariate regression analysis was used to model the prevalence of disorders of the shoulders or upper arms, wrists or hands, and all upper extremity regions (each defined both by symptoms and by physical examination plus symptoms) as a function of exposure quartile. RESULTS: A total of 1315 workers (85% of the target population) was examined. The prevalence of symptom disorders was 22% for the wrists or hands and 15% for the shoulders or upper arms; cases defined on the basis of a physical examination were about 80% as frequent. Disorders of the upper extremities, shoulders, and wrists or hands all increased markedly with exposure score, after adjustment for plant, acute injury, sex, body mass index, systemic disease, and seniority. CONCLUSIONS: Musculoskeletal disorders of the upper extremities were strongly associated with exposure to combined ergonomic stressors. The exposure-response trend was very similar for symptom cases and for physical examination cases. It is important to evaluate all dimensions of ergonomic exposure in epidemiological studies, as exposures often occur in combination in actual workplaces.

Adult↗

Predictors of return to work following carpal tunnel release.

Little is known about factors that predict return to work following carpal tunnel release. Patients enrolled in a prospective, community-based study of carpal tunnel syndrome in Maine were evaluated with standardized questionnaires preoperatively and 6 months following carpal tunnel release. Univariate and multivariate analyses were performed to identify baseline factors associated with work disability 6 months following surgery. Thirty-one of 135 patients (23%) were out of work because of CTS 6 months following surgery. The predominant preoperative variables associated with work absence due to CTS 6 months postoperatively in logistic regression analyses were Workers' Compensation, work absence preoperatively, and worse mental health status (p < or = 0.01 for each). In analyses that considered postoperative as well as preoperative variables, persistence of symptoms following surgery was the most striking predictor of failure to return to work due to CTS (p < 0.0001). Preoperative correlates of less complete relief of symptoms in multivariate models included involvement of an attorney, milder preoperative symptom severity, preoperative work absence (p < 0.005 for each) and exposure to hand intensive work (p = 0.04). These data indicate that economic and psychosocial variables have a strong influence upon both return to work and the extent of symptom relief 6 months following surgery for carpal tunnel syndrome.

Adult↗

Back to the future: sweatshop conditions on the Mexico-U.S. border. II. Occupational health impact of maquiladora industrial activity.

Present working conditions in one of the most active areas of the maquiladora system along the Mexico-U.S. border are reminiscent of nineteenth-century U.S. sweatshops. The organization of production is Tayloristic and authoritarian, with detailed division of labor, repetitive simple tasks, and piecework wages. Modern participative management styles are not apparent in the maquiladora setting. This study consists of two separate but interrelated surveys conducted in 1992, one of community leaders and this one of workers in maquiladora enterprises in the towns of Matamoros and Reynosa, Mexico. The community survey evaluated the economic and psychosocial impact of the maquiladora enterprise and was conducted simultaneously to the workers' survey and in the same Mexican towns where the workers lived and worked. The community leaders acknowledged the employment opportunities that maquiladora factories had brought to the region but believed them to have high environmental and psychosocial costs. For the occupational component, a community-based survey of 267 maquiladora workers was conducted. participants were chosen with more than a year seniority in the industry and living in the two Mexican cities surveyed. They responded to an extensive questionnaire given by trained canvassers. The workers' survey found evidence that maquiladora workers (81% female) report symptoms from musculoskeletal disorders related to working conditions. Acute health effects compatible with chemical exposures were also identified. Prevalence of symptoms was correlated with increasing duration of exposure to ergonomic risk factors and qualitative chemical exposure indexes. Other chronic disease was not apparent. The survey demonstrated inequalities in salary, working hours, and safety training between the two communities. Matamoros workers are substantially better paid and work fewer hours per week than Reynosa workers. Most hazards reported in the worker's survey have been well studied in the general occupational health literature with respect to adverse health effects. Therefore, it is recommended that hazard surveillance studies would be more useful towards the goal of prevention than further etiologic studies. Specific recommendations on policy and remediation interventions are also made.

Adult↗

PATH: a work sampling-based approach to ergonomic job analysis for construction and other non-repetitive work.

A high prevalence and incidence of work-related musculoskeletal disorders have been reported in construction work. Unlike industrial production-line activity, construction work, as well as work in many other occupations (e.g. agriculture, mining), is non-repetitive in nature; job tasks are non-cyclic, or consist of long or irregular cycles. PATH (Posture, Activity, Tools and Handling), a work sampling-based approach, was developed to characterize the ergonomic hazards of construction and other non-repetitive work. The posture codes in the PATH method are based on the Ovako Work Posture Analysing System (OWAS), with other codes included for describing worker activity, tool use, loads handled and grasp type. For heavy highway construction, observations are stratified by construction stage and operation, using a taxonomy developed specifically for this purpose. Observers can code the physical characteristics of the job reliably after about 30 h of training. A pilot study of six construction laborers during four road construction operations suggests that laborers spend large proportions of time in nonneutral trunk postures and spend approximately 20% of their time performing manual material handling tasks. These results demonstrate how the PATH method can be used to identify specific construction operations and tasks that are ergonomically hazardous.

Journal Article↗

Adjusting for the healthy worker selection effect in cross-sectional studies.

BACKGROUND: In a cross-sectional study of musculoskeletal disorders, women employed in highly repetitive manual work (garment assembly) were found to have approximately double the risk observed in a population with more varied tasks (hospital work). It was suspected that this estimate might be biased if garment workers with musculoskeletal pain were more likely than others to leave employment. METHODS: Retrospective information on date of first onset of symptoms and years employed to date of pain onset, or to survey date (whichever was earlier), was used to calculate age and calendar period-specific rates of onset, conditional on remaining employed until the survey. RESULTS: These rates, and the relative risk for garment work, increased over the 20-year period preceding the year of the survey. The trend was not explained by age or length of employment, or by any known changes in work demands that might have caused a true increase in incidence density. CONCLUSIONS: In the absence of longitudinal cohort data, alternative explanations for these results cannot be excluded. However, with specified assumptions, the most plausible appears to be a healthy worker selection effect acting differentially between high and low exposure groups. This effect would have caused the smallest bias in the prevalence in the year immediately before the survey, and a better estimate of the true relative risk would be approximately five. Where date of onset has been obtained, this method may be used in other cross-sectional studies to estimate and reduce the magnitude of selection bias in a survivor population, if longitudinal data cannot be collected.

Bias↗

Musculoskeletal Disorders: Work-related Risk Factors and Prevention.

Work-related musculoskeletal disorders cause chronic pain and functional impairment, impose heavy costs on society, and reduce productivity. In this position paper from the Scientific Committee for Musculoskeletal Disorders of the ICOH, the most important risk factors at work are described. Work-related musculoskeletal disorders have high incidences and prevalences among workers who are exposed to manual handling, repetitive and static work, vibrations, and poor psychological and social conditions. The application of ergonomic principles in the workplace is the best method for prevention. International organizations should develop standards, common classifications, and terminologies. Surveillance systems should be further developed nationally and in workplaces, and more effort should be directed to information dissemination, education, and training.

Journal Article↗

Workers' compensation recipients with carpal tunnel syndrome: the validity of self-reported health measures.

OBJECTIVES: This study compared the reliability, validity, and responsiveness of self-reported measures of health related quality of life in recipients and non-recipients of workers' compensation who have carpal tunnel syndrome. METHODS: Patients with carpal tunnel syndrome complete questionnaires at study enrollment and 6 months later scales measuring symptom severity functional status, and satisfaction were included. The scales internal consistency, validity, and responsiveness were assessed. RESULTS: The internal consistencies for each scale were high (Cronbach's alpha .88 to .96) and virtually identical in recipients and nonrecipients of workers' compensation. The correlations between self-reported and objectively measured grip strength were .32 in recipients and .30 in nonrecipients; these correlations were not influenced by whether workers' compensation recipients were out of work. Correlations between changes in scale scores and three indicators of perceived improvement were higher in recipients (.48 to .69) than in nonrecipients (.19 to .41) CONCLUSIONS: The reliability, validity, and responsiveness of these measures were comparable in nonrecipients and recipients of workers compensation, these data support the use of self-report measures in studies of workers.

Adolescent↗

Back to the future: sweatshop conditions on the Mexico-U.S. border. I. Community health impact of maquiladora industrial activity.

Present working conditions in one of the most active areas of the maquiladora system along the Mexico-U.S. border are reminiscent of nineteenth-century U.S. sweatshops. This conclusion was reached after evaluating two separate but interrelated surveys among Mexican nationals living near the Mexico-U.S. border, one of community leaders (Paper I), and one of workers in maquiladora enterprises in the towns of Matamoros and Reynosa, Mexico (Paper II). Paper I evaluates the results of the community leaders' survey. Criteria for selection of the leaders were: level of responsibility in the community; knowledge of the industry in the region, and length of residence in the area (more than 3 years). Representatives from government, maquiladora industry management, labor union leadership, labor union activists, and community improvement activists were interviewed. Structured questionnaires with opportunities for open-ended answers were used by trained Spanish speaking interviewers. The questions covered community demographics, health care structures, governance of the region, knowledge of working conditions, and knowledge of environmental impact on the region and the community. Community leaders were ambivalent on the purported benefits of the development of these types of industries in their communities. A substantial majority (21 of 25) thought that the maquiladoras brought few positive developments, other than creating jobs. Serious concerns about overextending weak social infrastructures and about environmental deterioration were voiced. Immediate (preventive) measures appear necessary to develop community infrastructures and to protect environmental health.

Community Health Services↗

A comparison of PMRs and SMRs as estimators of occupational mortality.

Standardized mortality ratios (SMRs) for occupational diseases are confounded by health differences between industrial and general populations. In 109 industrial cohorts largely free of work-related mortality, these selection effects were sizable for both malignant and nonmalignant outcomes. All-cancer SMRs were considerably less than 1.0 for many cohorts, and lung cancer was subject to almost as much selection-derived confounding as nonmalignant disease. Standardized proportional mortality ratios (PMRs) (approximated by relative SMRs (RSMRs] were less confounded than SMRs in estimating occupational risk. PMRs appeared to overestimate cancer mortality on average by 6%, while SMRs underestimated by 13%. PMRs underestimated nonmalignant respiratory disease by 16 percent but SMRs underestimated by 39 percent. The sources of confounding, in addition to selection on health status at hire, most likely include social class. SMRs, in the absence of internal population comparisons, would fail to detect both malignant and nonmalignant work-related mortality in many industrial cohorts.

Bias↗

Back disorders and nonneutral trunk postures of automobile assembly workers.

A case-referent study was conducted in an automobile assembly plant to evaluate the health effect of trunk postures, such as bending and twisting, that deviate from anatomically neutral. Cases of back disorders were all those of workers who reported back pain to the medical department in a ten-month period and met the severity criteria of an interview. The referents were randomly selected workers free of back pain according to medical department records, an interview, and an examination. For each of the final 95 cases and 124 referents, the job was analyzed for postural and lifting requirements with a video recording and software analysis system by analysts blinded to the case/referent status. Back disorders were associated with mild trunk flexion [odds ratio (OR) 4.9, 95% confidence interval (95% CI) 1.4-17.4], severe trunk flexion (OR 5.7, 95% CI 1.6-20.4), and trunk twist or lateral bend (OR 5.9, 95% CI 1.6-21.4). The risk increased with exposure to multiple postures and increasing duration of exposure.

Adult↗

Modernization and trends in occupational health and safety in the People's Republic of China 1981-1986.

Exchanges between U.S. and Chinese professionals have provided opportunities for observation of recent developments in occupational health in China. For the past decade, China has been committed to an unprecedented drive for economic modernization, including new policies on ownership, business management, employment, health care, and disability as well as increased activity in heavy, light, and service industries. Chinese occupational health professionals and labor organizations have set a goal of modernizing worker health along with the rest of society. Examples of advances in occupational health occurring since 1981 are the coordination of industrial hygiene and health research and services, an emphasis on epidemiology, interdisciplinary approaches to problem-solving, the pretesting of toxic substances, regulation and standard setting, and on-site workplace hazard prevention.

Accident Prevention↗