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Biomedical subjects

Alex Burdorf

Publications and source records attributed to Alex Burdorf.

At least 37 records · Page 2Linked to original sources

Reduced productivity after sickness absence due to musculoskeletal disorders and its relation to health outcomes.

OBJECTIVES: This prospective cohort study quantified the reduced productivity of workers on full duty after sickness absence from a musculoskeletal disorder and determined the effect of health parameters such as perceived pain, functional disability, and general health on reduced productivity. METHODS: Workers were included who were returning to work from 2- to 6-week sickness absence due to a musculoskeletal disorder. Self-administered questionnaires at baseline, after return to work, and at a 12-month follow-up were used to collect information on productivity and health status. Logistic regression analyses evaluated the determinants of reduced productivity and determined the level of productivity loss shortly after return to work. RESULTS: Reduced productivity was prevalent for 60% of the workers after they returned to work, and for 40% still at the 12-month follow-up. The initial musculoskeletal disorder caused 75% of the productivity loss shortly after return to work and 60% at the follow-up. Among those with productivity loss, the median loss for an 8-hour workday was 1.6 hours shortly after return to work and also at the follow-up. Worse physical health, more functional disability, and poorer relations with the supervisor were associated with productivity loss shortly after return to work, whereas recurrent sick leave was the greatest predictor of productivity loss at the follow-up. CONCLUSIONS: Reduced productivity was common among workers returning to full duty after sickness absence due to a musculoskeletal disorder. Productivity loss illustrates the importance of the timing of return to work, especially among workers with residual functional disability after return to work. Moreover, the supervisor should be engaged early in the return-to-work process to guarantee an early, sustainable, and productive return to work for the employee.

Adult↗

Development of a decision model to identify workers at risk of long-term disability in the construction industry.

OBJECTIVE: This study presents a decision model that predicts long-term disability among construction workers. METHODS: Risk factors were identified in two cohort studies among construction workers and evaluated in validation samples of smaller cohort studies among Dutch construction workers. The risk estimates (odds ratios) were used in a logistic regression model to calculate the probability of long-term disability in the next 4 years for a particular construction worker, subject to a specific combination of risk factors. The a priori probability was set equal to the overall long-term disability risk among the youngest construction workers (< 30 years) with a relatively short exposure history. RESULTS: According to literature findings, the risk estimate for work ability was set with the odds ratio at 2.0 for good work ability, 5.0 for moderate work ability, and 10.0 for bad work ability. Age-dependent risks were set at odds ratios of 1.5, 2.0, and 3.0 for the age groups of 30-34 years, 35-44 years, and 45-54 years, respectively. A sickness absence period of > or = 3 months had an odds ratio of 2.0, and severe musculoskeletal complaints had an odds ratio of 3.0. Since the number of construction workers older than 55 years was rather small and heavily biased by a healthy worker effect, it was decided to limit the applicability of the decision model to workers aged 20-55 years. The decision model used four risk factors and predicted a 40-fold difference in disability risk between construction workers with all four risk factors present (0.79) and those without any risk factor (0.02). CONCLUSIONS: The decision model presented the combined effect of different risk factors on the risk of an individual worker becoming disabled within 4 years. Evaluation studies will need to demonstrate whether the application of this decision model is helpful in identifying workers at risk for long-term disability and will facilitate appropriate intervention at the individual level.

Adult↗

Does this patient have an instability of the shoulder or a labrum lesion?

CONTEXT: History taking and clinical tests are commonly used to diagnose shoulder pain. Unclear is whether tests and history accurately diagnose instability or intra-articular pathology (IAP). OBJECTIVE: To analyze the accuracy of clinical tests and history taking for shoulder instability or IAP. DATA SOURCES: Relevant studies identified through PubMed, EMBASE, CINAHL, and bibliographies of known primary and review articles. STUDY SELECTION: Studies comparing the performance of history items or physical examination with a reference standard were included. Studies on fibromyalgia, fractures, or systemic disorders were excluded. Of 1449 articles, 35 were eligible, and 17 were selected. DATA EXTRACTION: Data were extracted on study population, clinical tests, reference tests, and outcome. The studies' methodological quality (patient spectrum, verification, blinding, and replication) was assessed with the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) checklist. DATA SYNTHESIS: Six tests showed positive likelihood ratios (LRs) and confidence intervals (CIs). Tests favoring the diagnosis for establishing instability included: relocation (LR, 6.5; 95% CI, 3.0-14.0) and anterior release (LR, 8.3; 95% CI, 3.6-19). Tests showing promise for establishing labral lesions included: the biceps load I and II (LR, 29; 95% CI, 7.3-115.0 and LR, 26; 95% CI, 8.6-80.0), respectively, pain provocation of Mimori (LR, 7.2; 95% CI, 1.6-32.0), and internal rotation resistance strength (LR, 25; 95% CI, 8.1-76.0). The apprehension, clunk, release, load and shift, and sulcus sign tests proved less useful. Results should be cautiously interpreted because studies were completed in select populations in orthopedic practice, mostly assessed by the test designers, and evaluated in single studies only. No accuracy studies were found for history taking or for clinical tests in primary care. CONCLUSIONS: Shoulder complaints are frequently recurrent. Instability might cause some of these complaints. Best evidence supports the value of the relocation and anterior release tests. Symptoms related to IAP (labral tears) remain unclear. Most promising for establishing labral tears are currently the biceps load I and II, pain provocation of Mimori, and the internal rotation resistance strength tests.

Cartilage, Articular↗

Interrelationships between pain, disability, general health, and quality of life and associations with work-related and individual factors: a study among workers on sickness absence for 2 to 6 weeks for musculoskeletal complaints.

STUDY DESIGN: A cross-sectional study. OBJECTIVES: To measure interrelationships among pain, functional disability, general health, and overall quality of life for workers on sickness absence for 2 to 6 weeks due to musculoskeletal complaints, and to assess the impact of work-related and individual characteristics on these different health dimensions. The results of this study will contribute to a better understanding of the relationship between health and functional disability. SUMMARY OF BACKGROUND DATA: When choosing a patient-based outcome measure, different health dimensions must be considered. For musculoskeletal complaints, four health dimensions are important: pain, disability, general health, and overall quality of life. Improvement at one dimension does not necessarily correlate with better health on another dimension. Moreover, correlations between different dimensions may be influenced by individual and environmental factors. However, it is not known whether these factors influence different health dimensions differently. METHODS: A total of 218 workers on sickness absence for 2 to 6 weeks due to musculoskeletal complaints completed a questionnaire on four different health dimensions and work-related and environmental factors. RESULTS: Moderate correlations (r < 0.50) among measures of pain, disability, general health, and quality of life were found. These health dimensions were not influenced by work-related physical and psychosocial workload, suggesting no impact of recall bias in studies for work-related musculoskeletal complaints. Self-perceived ability to return to work within 6 weeks explained 21% to 26% of the outcomes on pain and disability and contributed less to the generic measures of health. CONCLUSION: Within a population of workers on sickness absence for 2 to 6 weeks, specific dimensions of pain and disability seem to be more appropriate measures of health than generic instruments of general health and quality of life.

Adult↗

Patterns of care for low back pain in a working population.

STUDY DESIGN: A prospective longitudinal study with 1-year follow-up. SUMMARY OF BACKGROUND DATA: Little is known about the consequences of having back pain and the patterns underlying the decisions to use medical care. OBJECTIVES: The aim of this study is to describe care utilization for low back pain (LBP) and to investigate which factors determine use of care for LBP. METHODS: We used a self-administered questionnaire to collect data on individual, health-related, and work-related factors and the type of medical care sought among 529 employees of nursing homes and homes for the elderly in the Netherlands. Logistic regression models were used to present associations between aforementioned factors and care utilization for LBP. RESULTS: A large proportion of the working population was afflicted with LBP, and only one third sought care. Individuals who use care had more intense pain, chronic pain, and functional limitations. Patients' characteristics varied among the different type of health care providers. Well-known work-related risk factors for the occurrence of LBP did not determine use of care for workers with LBP. CONCLUSIONS: Care utilization due to LBP was associated with severity and nature of back pain. Patients' characteristics vary among the different type of health care providers, but work-relatedness of LBP seems similar across all providers.

Adolescent↗

Prevalence, incidence, and recurrence of low back pain in scaffolders during a 3-year follow-up study.

STUDY DESIGN: Prospective cohort study. OBJECTIVE: To describe the natural history of low back pain by its prevalence, incidence, and recurrence during a 3-year period and identify risk factors for cumulative incidence and recurrence of low back pain in scaffolders. SUMMARY OF BACKGROUND DATA: Although some studies have described prevalence, incidence, or recurrence of low back pain, few studies have assessed two or more of these outcome measures simultaneously. Furthermore, little is known about the association between individual, physical, psychosocial, and health-related risk factors and cumulative incidence and recurrence of low back pain in scaffolders. METHODS: Between 1998 and 2001, a cohort of 288 scaffolders (response 85%) completed a questionnaire at baseline and at three yearly follow-ups during 3 years. RESULTS: At baseline 60% of the study population had had an episode of low back pain in the past 12 months of which 22% was of chronic nature. During follow-up, the yearly incidence of low back pain varied between 20% and 28%, while yearly recurrence rates were 64% to 77%. Only few workers consistently reported the presence (20%) or absence (26%) of low back pain each year. Weak significant associations were present for the following: age 35 to 44 years, moderate general health, high strenuous arm movements, and body mass index with the cumulative incidence of low back pain. Significant associations were found between high manual handling of material and high job demand and low job control and the cumulative recurrence of low back pain, while moderate general health only showed a weak significant association with this outcome measure. CONCLUSIONS: Low back pain was a dynamic process with high rates for incidence, recurrence, and recovery. General health and work-related physical and psychosocial factors influenced both the incidence and recurrence of low back pain. The incidence and recurrence of low back pain depend strongly on the recall period of low back pain and the time-window of investigation.

Adult↗

Maternal and paternal risk factors for cryptorchidism and hypospadias: a case-control study in newborn boys.

Little is known on environmental risk factors for cryptorchidism and hypospadias, which are among the most frequent congenital abnormalities. The aim of our study was to identify risk factors for cryptorchidism and hypospadias, with a focus on potential endocrine disruptors in parental diet and occupation. In a case-control study nested within a cohort of 8,698 male births, we compared 78 cryptorchidism cases and 56 hypospadias cases with 313 controls. The participation rate was 85% for cases and 68% for controls. Through interviews, information was collected on pregnancy aspects and personal characteristics, lifestyle, occupation, and dietary phytoestrogen intake of both parents. Occupational exposure to potential endocrine disruptors was classified based on self-reported exposure and ratings of occupational hygienists based on job descriptions. Our findings indicate that paternal pesticide exposure was associated with cryptorchidism [odds ratio (OR) = 3.8; 95% confidence interval (95% CI), 1.1-13.4]. Smoking of the father was associated with hypospadias (OR = 3.8; 95% CI, 1.8-8.2). Maternal occupational, dietary, and lifestyle exposures were not associated with either abnormality. Both abnormalities were associated with suboptimal maternal health, a lower maternal education, and a Turkish origin of the parents. Being small for gestational age was a risk factor for hypospadias, and preterm birth was a risk factor for cryptorchidism. Because paternal pesticide exposure was significantly associated with cryptorchidism and paternal smoking was associated with hypospadias in male offspring, paternal exposure should be included in further studies on cryptorchidism and hypospadias risk factors.

Adult↗

Different risk factors for musculoskeletal complaints and musculoskeletal sickness absence.

OBJECTIVES: The aim of this study was to investigate whether individual, work-related physical and psychosocial risk factors involved in the occurrence of musculoskeletal complaints also determine musculoskeletal sickness absence. METHODS: This cross-sectional study used a self-administered questionnaire to collect data on individual and work-related risk factors and the occurrence of musculoskeletal complaints and musculoskeletal sickness absence among 373 employees of laundry-works and dry-cleaning establishments (response rate 87%). Logistic regression models were used to determine associations between risk factors and the occurrence of musculoskeletal complaints and sickness absence due to these complaints. RESULTS: Both work-related physical and psychosocial factors showed strong associations with low-back pain and upper-extremity complaints. Work-related physical factors did not influence sickness absence, whereas psychosocial factors showed some associations with sickness absence. Sickness absence was associated with The Netherlands as the country of birth [odds ratio (OR) 0.3, 95% confidence interval (95% CI) 0.2-0.6], and female workers had an episode of sickness absence due to low-back pain less often (OR 0.5, 95% CI 0.3-0.9), but more often due to upper-extremity complaints (OR 2.2, 95% CI 1.14.5). CONCLUSIONS: Work-related physical and psychosocial factors largely determine the occurrence of low-back pain and upper-extremity complaints, whereas individual factors predominantly determine whether persons with these musculoskeletal complaints take sick leave.

Adolescent↗

Work-related risk factors for the incidence and recurrence of shoulder and neck complaints among nursing-home and elderly-care workers.

OBJECTIVES: This study assessed the differences and similarities in the incidence and recurrence of shoulder and neck complaints with respect to work-related physical, psychosocial, and personal risk factors. METHODS: A prospective cohort study was carried out among 769 workers of nursing homes and homes for the elderly. At baseline, a questionnaire was used to collect data on personal characteristics, physical workload, psychosocial workload, and the presence of shoulder and neck complaints. After 1 and 2 years, follow-up data were collected on shoulder and neck complaints. Generalized estimation equations were used for analyzing risk factors for the participants with at least one follow-up measurement available (N=556, 72%). RESULTS: In the multivariate model, adjusted for age and gender, obesity [odds ratio (OR) 2.12, 95% confidence interval (95%CI) 1.23-3.65] was related to the incidence of shoulder complaints. The incidence of neck complaints was increased for obesity (OR 1.81, 95% CI 1.07-3.05), work in awkward postures (OR 1.76, 95% CI 1.11-2.78), and poor or fair general health (OR 1.53, 95% CI 1.02-2.31). The recurrence of both shoulder and neck complaints was associated with chronic complaints at baseline (shoulder: OR 1.91, 95% 1.36-2.67; neck: OR 1.71, 95% 1.14-2.55) but not with work-related risk factors. CONCLUSIONS: The results suggest that there are differences in risk factors for the incidence and recurrence of shoulder and neck complaints.

Adult↗

Risk factors for sickness absence because of low back pain among scaffolders: a 3-year follow-up study.

STUDY DESIGN: A prospective cohort study was conducted. OBJECTIVE: To find risk factors for short-term ( 14 days) sickness absence because of low back pain among scaffolders. SUMMARY OF BACKGROUND DATA: Although some studies have described the relation between work-related risk factors for musculoskeletal disease and sickness absence, little is known about the role of individual, physical, and psychosocial factors and different end points of low back pain as risk factors for sickness absence among scaffolders. METHODS: Between 1998 and 2001, 222 scaffolders and 66 supervisors (response rate, 86%) completed a questionnaire at baseline. In addition, data on sickness absence were collected from absence records. RESULTS: At baseline, 60% of the study population had experienced an episode of low back pain in the 12 months preceding the investigation, 37% of which were of chronic nature. During the follow-up period, 34% of the population had been on sick leave for at least one episode of low back pain. The risk factors for sickness absence less than 2 weeks were a high physical load from strenuous arm movements and severe low back pain. Workers with severe low back pain were at higher risk for sickness absence longer than 2 weeks. Psychosocial workload and individual characteristics did not predict the occurrence of sickness absence because of low back pain. CONCLUSIONS: Because work-related physical load was a risk factor for sickness absence less than 2 weeks and severe low back pain was a risk factor for sickness absence both shorter than and longer than 2 weeks, a focus on secondary prevention for scaffolders with severe low back pain is advised.

Absenteeism↗

Risk factors for musculoskeletal disorders among nursing personnel in Greek hospitals.

OBJECTIVES: To investigate the relationships between physical, psychosocial, and individual characteristics and different endpoints of musculoskeletal complaints of the lower back, neck and shoulders. METHODS: In this cross-sectional study a questionnaire survey was carried out among 351 nursing personnel (response 84%) in six general hospitals in Athens, Greece. A questionnaire was used on physical and psychosocial workload, need for recovery, perceived general health and (1) the occurrence of musculoskeletal complaints in the past 12 months, (2) chronic complaints during at least 3 months, and (3) complaints which led to sickness absence. In logistic regression analysis odds ratios (ORs) were estimated for all relevant risk factors. RESULTS: Self-reported factors of physical load were associated with the occurrence of back pain (OR=1.85), neck pain (OR=1.88), and shoulder pain (OR=1.87) but these factors were not associated with chronic complaints and musculoskeletal sickness absence. Physical load showed a trend with the number of musculoskeletal complaints with ORs of 2.47 and 4.13 for two and three musculoskeletal complaints, respectively. No consistent influence of psychosocial factors on complaints, chronicity, or sickness absence was observed. A perceived moderate general health was also a risk factor, and strongest associations were observed for sickness absence due to back pain (OR=2.03), neck pain (OR=8.31), and shoulder pain (OR=6.84). CONCLUSIONS: The handling of physical loads among nurses seems to put them at risk for the occurrence of musculoskeletal disorders. The development of these complaints into chronic complaints and associated sickness absence is strongly determined by perceived general health and almost not associated with work-related physical and psychosocial risk factors. When the influence of work-related risk factors on musculoskeletal health is being investigated, the general health status of individual workers should be taken into account.

Adult↗

Inhibin B: a novel marker of spermatogenesis.

Subfertility affects about 15% of all couples. Assessment of spermatogenesis has a central role in the evaluation of the subfertile couple. Classical markers of spermatogenesis, such as semen analysis, testicular biopsy and endocrine evaluation all have their diagnostic limitations. There is a clear need for accurate additional markers of spermatogenesis. Recently, the serum inhibin B level has emerged as a sensitive endocrine marker of spermatogenesis. This paper summarises the pros and cons of different markers of spermatogenesis, with specific focus on serum inhibin B. The serum inhibin B level has been shown to be associated with classical markers of spermatogenesis, particularly testicular histology, and to be the most accurate endocrine marker of spermatogenesis. A subnormal serum inhibin B level clearly reflects disturbed spermatogenesis. Before puberty, when no spermatogenesis takes place, inhibin B is a marker of testicular integrity. Clinical applications of serum inhibin B in childhood and adulthood are given, and a view on future directions and research is presented. The serum inhibin B level has proven to be valuable in the evaluation of spermatogenesis, and holds a promise for further research.

Biomarkers↗

Commentary: variability in workplace exposures and the design of efficient measurement and control strategies.

Kromhout et al.'s (1993) well-cited publication presented detailed information on statistical procedures to estimate the magnitude of exposure variability within and between workers, drawing from a large database on chemical exposures throughout industry. It convincingly demonstrated that the construct of homogeneous exposure groups often does not hold true and suggested ways to improve measurement strategies. The authors hit a rich vein of research, and many publications, not at least by the authors themselves, followed in the decade after publication. In recent years the principles of estimating the variation in exposure have been applied in new methods for optimization of sampling strategies, for compliance testing, for quantifying exposures in epidemiologic studies, and for identifying important sources of emissions and suggesting strategies for controlling exposures. Many occupational hygienists across the globe have adopted these new methods as powerful tools in their exposure assessment strategies.

Air Pollutants, Occupational↗

Occupational characteristics of cases with asbestos-related diseases in The Netherlands.

OBJECTIVE: To describe the occupational background of cases with an asbestos-related disease and to present overall mesothelioma risks across industries with historical exposure to asbestos. METHODS: For the period 1990-2000, cases were collected from records held by two law firms. Information on jobs held, previous employers, activities performed and specific products used were obtained from patients themselves or next of kin. Branches of industry and occupations were coded and the likelihood of asbestos exposure was assessed. For each branch of industry, the overall risk of mesothelioma was calculated from the ratio of the observed number of mesothelioma cases and the cumulative population-at-risk in the period 1947-1960. In order to compare mesothelioma risks across different industries, risk ratios were calculated for the primary asbestos industry and asbestos user industries relative to all other branches of industry. RESULTS: In total, 710 mesotheliomas and 86 asbestosis cases were available. The average latency period was approximately 40 yr and the average duration of exposure was 22 yr. Ship building and maintenance contributed the largest number of cases (27%), followed by the construction industry (14%), the insulation industry (12%), and the navy and army, primarily related to ship building and maintenance (5%). In the insulation industry, the overall risk of mesothelioma was 5 out of 100 workers, and in the ship building industry, 1 out of 100 workers. The construction industry had an overall risk comparable with many other asbestos-using industries (7 per 10,000 workers), but due to its size claimed many mesothelioma cases. CONCLUSION: The majority of cases with asbestos-related diseases had experienced their first asbestos exposure prior to 1960. For cases with first asbestos exposure after 1960, a shift was observed from the primary asbestos industry towards asbestos-using industries, such as construction, petroleum refining, and train building and maintenance. Due to the long latency period, asbestos exposure from 1960 to 1980 will cause a considerable number of mesothelioma cases in the next two decades.

Adult↗

Model for the work-relatedness of low-back pain.

OBJECTIVES: This study aimed at developing a model for determining the work-relatedness of low-back pain for a worker with low-back pain using both a personal exposure profile for well-established risk factors and the probability of low-back pain if the worker were unexposed to these factors. METHODS: After a systematic review of the literature, the pooled prevalence of low-back pain in an unexposed population and the pooled odds ratio (OR) for each risk factor was calculated in a meta-analysis using a random effect model. An unbiased risk estimate for each risk factor was obtained by correcting the pooled OR for confounding by other risk factors. The probability of low-back pain was calculated with a logistic regression model. The input was (i) the age-dependent prevalence when not exposed and (ii) the unbiased risk estimates per risk factor of low and high exposure. The etiologic fraction was calculated to determine the level of work-relatedness. RESULTS: The pooled prevalence for low-back pain among unexposed subjects was 22%, 30%, and 34% for the <35-year, 35-to-45-year, and >45-year age categories, respectively. The pooled OR was 1.51 [95% confidence interval (95% CI) 1.31-1.74] for manual materials handling, 1.68 (95% CI 1.41-2.01) for frequent bending or twisting, 1.39 (95% CI 1.24-1.55) for whole-body vibration, and 1.30 (1.17-1.45) for job dissatisfaction. For high exposure to manual materials handling, frequent bending or twisting, and whole-body vibration, the pooled OR was 1.92, 1.93, and 1.63, respectively. CONCLUSIONS: The model is the first that estimates the probability of work-relatedness for low-back pain for a given worker with low-back pain seen by a general practitioner or an occupational health physician.

Humans↗

Sources of bias in studies among infertility clients.

An assumption in case-control studies is that forces of selection are the same for cases and controls. This may not be true for studies of male infertility among infertility clients. Earlier reproductive outcomes may introduce modification of risk behavior or differential referral. Selection bias might also occur when infertile males are compared with fertile males. Partners of sterile men are more likely to have "normal" fertility, while partners of a reference group of normozoospermic men tend to have a lower fertility potential. The latter may lead to overrepresentation of causes of reduced female fertility and introduce bias into estimates of risk factors shared by couples. The relation between cigarette smoking and semen quality was studied in a population of infertility clients from the Netherlands during 1995-1996. To reduce the potential for bias, this relation was studied first in a restricted population less aware of the type of infertility involved. The odds ratio of infertility with smoking was elevated in the restricted population as compared with the total population. Adjustment for smoking by the female partner increased the odds ratios for male smoking as well. These results indicate that bias may occur in clinic-based fertility studies because of different forms of selection.

Adult↗