Vitamin D levels and deficiency with different occupations: a systematic review.

BACKGROUND: Vitamin D deficiency is prevalent worldwide, but some groups are at greater risk. We aim to evaluate vitamin D levels in different occupations and identify groups vulnerable to vitamin D deficiency. METHODS: An electronic search conducted in Medline, Embase, the Cochrane Central Register of Controlled Trials, and CINAHL Plus with Full Text generated 2505 hits; 71 peer-reviewed articles fulfilled the inclusion criteria. Occupations investigated included outdoor and indoor workers, shiftworkers, lead/smelter workers, coalminers, and healthcare professionals. We calculated the pooled average metabolite level as mean ± SD; deficiency/insufficiency status was described as % of the total number of subjects in a given category. RESULTS: Compared to outdoor workers, indoor workers had lower 25-hydroxyvitamin D (25-(OH)D) levels (40.6 ± 13.3 vs. 66.7 ± 16.7 nmol/L; p < 0.0001). Mean 25-(OH)D levels (in nmol/L) in shiftworkers, lead/smelter workers and coalminers were 33.8 ± 10.0, 77.8 ± 5.4 and 56.6 ± 28.4, respectively. Vitamin D deficiency (25-(OH)D < 50 nmol/L), was high in shiftworkers (80%) and indoor workers (78%) compared to outdoor workers (48%). Among healthcare professionals, medical residents and healthcare students had the lowest levels of mean 25-(OH)D, 44.0 ± 8.3 nmol/L and 45.2 ± 5.5 nmol/L, respectively. The mean 25-(OH)D level of practising physicians, 55.0 ± 5.8 nmol/L, was significantly different from both medical residents (p < 0.0001) and healthcare students (p < 0.0001). Nurses and other healthcare employees had 25-(OH)D levels of 63.4 ± 4.2 nmol/L and 63.0 ± 11.0 nmol/L, respectively, which differed significantly compared to practising physicians (p = 0.01), medical residents (p < 0.0001) and healthcare students (p < 0.0001). Rates of vitamin D deficiency among healthcare professionals were: healthcare students 72%, medical residents 65%, practising physicians 46%, other healthcare employees 44%, and nurses 43%. Combined rates of vitamin D deficiency or insufficiency (25-(OH)D < 75 nmol/L) were very high in all investigated groups. Potential confounders such as gender and body composition were not consistently reported in the primary studies and were therefore not analyzed. Furthermore, the descriptions of occupational characteristics may be incomplete. These are limitations of our systematic review. CONCLUSIONS: Our review demonstrates that shiftworkers, healthcare workers and indoor workers are at high risk to develop vitamin D deficiency, which may reflect key lifestyle differences (e.g. sunlight exposure). This may help target health promotion and preventive efforts.

Back schools for the treatment of chronic low back pain: possibility of benefit but no convincing evidence after 47 years of research-systematic review and meta-analysis.

Back schools are interventions that comprise exercise and education components. We aimed to systematically review the randomized controlled trial evidence on back schools for the treatment of chronic low back pain. By searching MEDLINE, Embase, and Cochrane Central as well as bibliographies, we identified 31 studies for inclusion in our systematic review and 5 of these for inclusion in meta-analyses. Meta-analyses for pain scores and functional outcomes revealed statistical superiority of back schools vs no intervention for some comparisons but not others. No meta-analysis was feasible for the comparison of back schools vs other active treatments. Adverse events were poorly reported so that no reliable conclusions regarding the safety of back schools can be drawn, although some limited reassurance in this regard may be derived from the fact that few adverse events and no serious adverse events were reported in the back school groups in the studies that did report on safety. Overall, the evidence base for the use of back schools to treat chronic low back pain is weak; in nearly a half-century since back schools were first trialled, no unequivocal evidence of benefit has emerged.

"Decision-critical" work: a conceptual framework.

"Safety-sensitive" workers, also termed "safety-critical" workers, have been subject to fitness to work assessments due to concerns that a performance error may result in worker injury, injury to coworkers or the general public, and/or disruption of equipment, production or the environment. However, there exists an additional category of "decision-critical" workers, distinct from "safety-sensitive" workers, in whom impairment may impact workplace performance, relationships, attendance, reliability and quality. Adverse consequences in these latter areas may not be immediately apparent, but a potential "orbit of harm" nevertheless exists. Workplace consequences arising from impairment in "decision-critical" workers differ from those in "safety-sensitive" personnel. Despite their importance in the occupational context, "decision-critical" workers have not previously been differentiated from other workers in the published literature, and we now outline an approach to fitness to work assessment in this group.

Reporting on work-related low back pain: data sources, discrepancies and the art of discovering truths.

Work-related pain is unique in the pain context as it is, in theory, tied to one or more workplace activities and is therefore preventable. Back pain is a leading cause of lost workplace productivity, absence from work and reduced quality of life. Aggregate estimates of the work-related contribution to the overall burden of back pain vary, which may reflect incomplete reporting, inconsistency in data collection and coding between studies and jurisdictions, or, alternatively, genuine differences between occupational groups and countries. It is therefore important for researchers, policy analysts and program development personnel in the fields of pain medicine and occupational medicine to have a thorough understanding of the appropriate use and inherent limitations of the data sources which report on this topic.

The occupational health of Santa Claus.

Previous publications in the field of Santa studies have not focused on health and safety issues arising from Santa's workplace activities. However, it should be acknowledged that unique occupational hazards exist for Santa Claus. Major occupational health issues affecting Santa are discussed, along with suggestions for future research directions.

What is the relationship between disease activity, severity and damage in a large Canadian systemic sclerosis cohort? Results from the Canadian Scleroderma Research Group (CSRG).

We studied the relationships between physician-assessed damage, severity and activity in a large, multicentre systemic sclerosis (SSc, scleroderma) cohort. We hypothesized that there is a relationship between disease activity and severity and damage, but that severity would be more strongly related to damage. A total of 520 SSc patients (87% women, mean age 56 years, mean 8.6 years disease duration, 39% diffuse SSc) were studied. The correlations between physician's global assessments of damage, activity and severity were determined overall and in a subset of early, diffuse SSc (n = 74). The mean (SD) patient global health score was 3.6 (2.4) on a 0-10 scale. Physician-rated severity, activity and damage were 2.8 (2.2), 2.3 (2.0), and 3.4 (2.4) respectively. Damage was more strongly related to severity (r = 0.744, P < 0.001) than activity (r = 0.596, P < 0.001). Damage was not related to disease duration (r = 0.046, P = 0.3). In early diffuse SSc, the correlations were: damage and severity 0.771 (P < 0.001), damage and activity 0.596 (P < 0.001), severity and activity 0.809 (P < 0.001). The relationships vary in the overall cohort versus the early diffuse SSc subset where activity, severity and damage appear more strongly related. Thus, the exact nature of the relationship between damage, activity and severity will depend upon the characteristics of the population studied.

Data linkage to estimate the extent and distribution of occupational disease: new onset adult asthma in Alberta, Canada.

BACKGROUND: Although occupational asthma is a well recognized and preventable disease, the numbers of cases presenting for compensation may be far lower than the true incidence. METHODS: Workers' Compensation Board (WCB) claims for any reason 1995-2004 were linked to physician billing data. New onset adult asthma (NOAA) was defined as a billing for asthma (ICD-9 code of 493) in the 12 months prior to a WCB claim without asthma in the previous 3 years. Incidence was calculated by occupation, industry and, in a case-referent analysis, exposures estimated from an asthma specific job exposure matrix. RESULTS: There were 782,908 WCB eligible claims, with an incidence rate for NOAA of 1.6%: 23 occupations and 21 industries had a significantly increased risk. Isocyanates (OR 1.54: 95% CI 1.01-2.36) and exposure to mixed agricultural allergens (OR = 1.59: 95% CI 1.17-2.18) were related to NOAA overall, as were exposures to cleaning chemicals in men (OR = 1.91:95% CI 1.34-2.73). Estimates of the number of cases of occupational asthma suggested a range of 4% to about half for the proportion compensated. CONCLUSIONS: Data linkage of administrative records can demonstrate under-reporting of occupational asthma and indicate areas for prevention.

Assembly of aligned linear metallic patterns on silicon.

In order to harness the potential of block copolymers to produce nanoscale structures that can be integrated with existing silicon-based technologies, there is a need for compatible chemistries. Block copolymer nanostructures can form a wide variety of two-dimensional patterns, and can be controlled to present long-range order. Here we use the acid-responsive nature of self-assembled monolayers of aligned, horizontal block copolymer cylinders for metal loading with simple aqueous solutions of anionic metal complexes, followed by brief plasma treatment to simultaneously remove the block copolymer and produce metallic nanostructures. Aligned lines of metal with widths on the order of 10 nm and less are efficiently produced by means of this approach on Si(100) interfaces. The method is highly versatile because the chemistry to manipulate nanowire composition, structure and choice of semiconductor is under the control of the user.