Workers’ Compensation Status: Does It Affect Orthopaedic Surgery Outcomes? A Meta-Analysis

Introduction

Previous reviews have demonstrated that patient outcomes following orthopaedic surgery are strongly influenced by the presence of Workers’ Compensation. However, the variability in the reviews’ methodology may have inflated the estimated strength of this association. The main objective of this meta-analysis is to evaluate the influence of Workers’ Compensation on the outcomes of orthopaedic surgical procedures.

Methods

We conducted a systematic search of the literature published in this area from 1992–2012, with no language restrictions. The following databases were used MEDLINE (Ovid), Embase (Ovid), CINAHL, Google Scholar, LILACS and Pubmed. We also hand-searched the reference sections of all selected papers. We included all prospective studies evaluating the effect of compensation status on outcomes in adult patients who had undergone surgery due to orthopaedic conditions or diseases. Outcomes of interest included disease specific, region specific and/or overall quality of life scales/questionnaires and surgeons’ personal judgment of the results. We used an assessment tool to appraise the quality of all included studies. We used Review Manager to create forest plots to summarize study data and funnel plots for the assessment of publication bias.

Results

Twenty studies met our eligibility criteria. The overall risk ratio for experiencing an unsatisfactory result after orthopaedic surgery for patients with compensation compared to non-compensated patients is 2.08 (95% CI 1.54–2.82). A similar association was shown for continuous data extracted from the studies using assessment scales or questionnaires (Standard Mean Difference = −0.70 95% CI -0.97- −0.43).

Conclusions

Among patients who undergo orthopaedic surgical procedures, those receiving Workers’ Compensation experience a two-fold greater risk of a negative outcome. Our findings show a considerably lower estimate of risk compared to previous reviews that include retrospective data. Further research is warranted to determine the etiological explanation for the influence of compensation status on patient outcomes.

Systematic Review Registration Number

CRD42012002121     

Does Work Affect Personality? A Study in Horses

It has been repeatedly hypothesized that job characteristics are related to changes in personality in humans, but often personality models still omit effects of life experience. Demonstrating reciprocal relationships between personality and work remains a challenge though, as in humans, many other influential factors may interfere. This study investigates this relationship by comparing the emotional reactivity of horses that differed only by their type of work. Horses are remarkable animal models to investigate this question as they share with humans working activities and their potential difficulties, such as "interpersonal" conflicts or "suppressed emotions". An earlier study showed that different types of work could be associated with different chronic behavioural disorders. Here, we hypothesised that type of work would affect horses' personality. Therefore over one hundred adult horses, differing only by their work characteristics were presented standardised behavioural tests. Subjects lived under the same conditions (same housing, same food), were of the same sex (geldings), and mostly one of two breeds, and had not been genetically selected for their current type of work. This is to our knowledge the first time that a direct relationship between type of work and personality traits has been investigated. Our results show that horses from different types of work differ not as much in their overall emotional levels as in the ways they express emotions (i.e. behavioural profile). Extremes were dressage horses, which presented the highest excitation components, and voltige horses, which were the quietest. The horses' type of work was decided by the stall managers, mostly on their jumping abilities, but unconscious choice based on individual behavioural characteristics cannot be totally excluded. Further research would require manipulating type of work. Our results nevertheless agree with reports on humans and suggest that more attention should be given to work characteristics when evaluating personalities.     

Does Human Migration Affect International Trade? A Complex-Network Perspective

This paper explores the relationships between international human migration and merchandise trade using a complex-network approach. We firstly compare the topological structure of worldwide networks of human migration and bilateral trade over the period 1960–2000. Next, we ask whether pairs of countries that are more central in the migration network trade more. We show that: (i) the networks of international migration and trade are strongly correlated, and such correlation can be mostly explained by country economic/demographic size and geographical distance; (ii) centrality in the international-migration network boosts bilateral trade; (iii) intensive forms of country centrality are more trade enhancing than their extensive counterparts. Our findings suggest that bilateral trade between any two countries is not only affected by the presence of migrants from either countries, but also by their relative embeddedness in the complex web of corridors making up the network of international human migration.     

Do Active Surveillance and Contact Precautions Reduce MRSA Acquisition? A Prospective Interrupted Time Series

Background

Consensus for methicillin-resistant Staphylococcus aureus (MRSA) control has still not been reached. We hypothesised that use of rapid MRSA detection followed by contact precautions and single room isolation would reduce MRSA acquisition.

Methods

This study was a pre-planned prospective interrupted time series comparing rapid PCR detection and use of long sleeved gowns and gloves (contact precautions) plus single room isolation or cohorting of MRSA colonised patients with a control group. The study took place in a medical-surgical intensive care unit of a tertiary adult hospital between May 21^st 2007 and September 21^st 2009. The primary outcome was the rate of MRSA acquisition. A segmented regression analysis was performed to determine the trend in MRSA acquisition rates before and after the intervention.

Findings

The rate of MRSA acquisition was 18.5 per 1000 at risk patient days in the control phase and 7.9 per 1000 at-risk patient days in the intervention phase, with an adjusted hazard ratio 0.39 (95% CI 0.24 to 0.62). Segmented regression analysis showed a decline in MRSA acquisition of 7% per month in the intervention phase, (95%CI 1.9% to 12.8% reduction) which was a significant change in slope compared with the control phase. Secondary analysis found prior exposure to anaerobically active antibiotics and colonization pressure were associated with increased acquisition risk.

Conclusion

Contact precautions with single room isolation or cohorting were associated with a 60% reduction in MRSA acquisition. While this study was a quasi-experimental design, many measures were taken to strengthen the study, such as accounting for differences in colonisation pressure, hand hygiene compliance and individual risk factors across the groups, and confining the study to one centre to reduce variation in transmission. Use of two research nurses may limit its generalisability to units in which this level of support is available.     

How Does Cilium Length Affect Beating?

The effects of cilium length on the dynamics of cilia motion were investigated by high-speed video microscopy of uniciliated mutants of the swimming alga, Chlamydomonas reinhardtii. Cells with short cilia were obtained by deciliating cells via pH shock and allowing cilia to reassemble for limited times. The frequency of cilia beating was estimated from the motion of the cell body and of the cilium. Key features of the ciliary waveform were quantified from polynomial curves fitted to the cilium in each image frame. Most notably, periodic beating did not emerge until the cilium reached a critical length between 2 and 4 μm. Surprisingly, in cells that exhibited periodic beating, the frequency of beating was similar for all lengths with only a slight decrease in frequency as length increased from 4 μm to the normal length of 10–12 μm. The waveform average curvature (rad/μm) was also conserved as the cilium grew. The mechanical metrics of ciliary propulsion (force, torque, and power) all increased in proportion to length. The mechanical efficiency of beating appeared to be maximal at the normal wild-type length of 10–12 μm. These quantitative features of ciliary behavior illuminate the biophysics of cilia motion and, in future studies, may help distinguish competing hypotheses of the underlying mechanism of oscillation.     

Language Acquisition: When Does the Learning Begin?

Language acquisition is quite sophisticated by four months of age. Two cues that babies use to discriminate their language from another are the stress patterns of words and visual cues inherent in language production.     

Does Early Psychosocial Stress Affect Mate Choice?

Early psychosocial stress (e.g., parental divorce, abuse) is conjectured to place individuals on a developmental trajectory leading to earlier initiation of sexual activity, earlier reproduction, and having more sex partners than those with less early psychosocial stress. But does it also affect an individual’s mate choice? The present study examined whether early psychosocial stress affects preferences and dislikes for opposite-sex faces varying in masculinity/femininity, a putative indicator of mate quality, in premenopausal women (58 with a natural cycle, 53 pill-users) and 196 men. No significant three-way interactions were found when women selected the most or least preferred face with participant group (natural cycle, pill), conception risk (low, high), and early psychosocial stress (low, high) as between-subjects factors. Early psychosocial stress did not affect men’s face preferences when selecting the most preferred face. However, men with high early psychosocial stress disliked masculine faces significantly more so than men with low early psychosocial stress. Overall it was concluded that early psychosocial stress does not affect mate choice with the exception that men with high early psychosocial stress were more likely to dislike masculine female faces. It was suggested that men with high early psychosocial stress may dislike masculine female faces because they have nothing to gain from associating with women with such faces.     

Does Ethnicity Affect Where People with Cancer Die? A Population-Based 10 Year Study

Background

Ageing is a growing issue for people from UK black, Asian and minority ethnic (BAME) groups. The health experiences of these groups are recognised as a ‘tracer’ to measure success in end of life patient-preferred outcomes that includes place of death (PoD).

Aim

To examine patterns in PoD among BAME groups who died of cancer.

Material and Methods

Mortality data for 93,375 cancer deaths of those aged ≥65 years in London from 2001–2010 were obtained from the UK Office for National Statistics (ONS). Decedent''s country of birth was used as a proxy for ethnicity. Linear regression examined trends in place of death across the eight ethnic groups and Poisson regression examined the association between country of birth and place of death.

Results

76% decedents were born in the UK, followed by Ireland (5.9%), Europe(5.4%) and Caribbean(4.3%). Most deaths(52.5%) occurred in hospital, followed by home(18.7%). During the study period, deaths in hospital declined with an increase in home deaths; trend for time analysis for those born in UK(0.50%/yr[0.36–0.64%]p<0.001), Europe (1.00%/yr[0.64–1.30%]p<0.001), Asia(1.09%/yr[0.94–1.20%]p<0.001) and Caribbean(1.03%/yr[0.72–1.30%]p<0.001). However, time consistent gaps across the geographical groups remained. Following adjustment hospital deaths were more likely for those born in Asia(Proportion ratio(PR)1.12[95%CI1.08–1.15]p<0.001) and Africa(PR 1.11[95%CI1.07–1.16]p<0.001). Hospice deaths were less likely for those born in Asia(PR 0.73 [0.68–0.80] p<0.001), Africa (PR 0.83[95%CI0.74–0.93]p<0.001), and ‘other’ geographical regions (PR0.90[95% 0.82–0.98]p<0.001). Home deaths were less likely for those born in the Caribbean(PR0.91[95%CI 0.85–0.98]p<0.001).

Conclusions

Location of death varies by country of birth. BAME groups are more likely to die in a hospital and less likely to die at home or in a hospice. Further investigation is needed to determine whether these differences result from patient-centred preferences, or other environment or service-related factors. This knowledge will enable strategies to be developed to improve access to relevant palliative care and related services, where necessary.     

Does Mutual Interference Affect the Feeding Rate of Aphidophagous Coccinellids? A Modeling Perspective

Mutual interference involves direct interactions between individuals of the same species that may alter their foraging success. Larvae of aphidophagous coccinellids typically stay within a patch during their lifetime, displaying remarkable aggregation to their prey. Thus, as larvae are exposed to each other, frequent encounters may affect their foraging success. A study was initiated in order to determine the effect of mutual interference in the coccinellids’ feeding rate. One to four 4^th larval instars of the fourteen-spotted ladybird beetle Propylea quatuordecimpunctata were exposed for 6 hours into plastic containers with different densities of the black bean aphid, Aphis fabae, on potted Vicia faba plants. The data were used to fit a purely prey-dependent Holling type II model and its alternatives which account for interference competition and have thus far been underutilized, i.e. the Beddington-DeAngelis, the Crowley-Martin and a modified Hassell-Varley model. The Crowley-Martin mechanistic model appeared to be slightly better among the competing models. The results showed that although the feeding rate became approximately independent of predator density at high prey density, some predator dependence in the coccinellid’s functional response was observed at the low prey—high predator density combination. It appears that at low prey densities, digestion breaks are negligible so that the predators do waste time interfering with each other, whereas at high prey densities time loss during digestion breaks may fully accommodate the cost of interference, so that the time cost may be negligible.     

How Does Cellular Contact Affect Differentiation Mediated Pattern Formation?

In this paper, we present a two-population continuous integro-differential model of cell differentiation, using a non-local term to describe the influence of the local environment on differentiation. We investigate three different versions of the model, with differentiation being cell autonomous, regulated via a community effect, or weakly dependent on the local cellular environment. We consider the spatial patterns that such different modes of differentiation produce, and investigate the formation of both stripes and spots by the model. We show that pattern formation only occurs when differentiation is regulated by a strong community effect. In this case, permanent spatial patterns only occur under a precise relationship between the parameters characterising cell dynamics, although transient patterns can persist for biologically relevant timescales when this condition is relaxed. In all cases, the long-lived patterns consist only of stripes, not spots.     

Does Iodine Biofortification Affect Oxidative Metabolism in Lettuce Plants?

Plants produce low levels of reactive oxygen species (ROS), which form part of basic cell chemical communication; however, different types of stress can lead to an overexpression of ROS that can damage macromolecules essential for plant growth and development. Iodine is vital to human health, and iodine biofortification programs help improve the human intake through plant consumption. This biofortification process has been shown to influence the antioxidant capacity of lettuce plants, suggesting that the oxidative metabolism of the plant may be affected. The results of this study demonstrate that the response to oxidative stress is variable and depends on the form of iodine applied. Application of iodide (I⁻) to lettuce plants produces a reduction in superoxide dismutase (SOD) activity and an increase in catalase (CAT) and L-galactono dehydrogenase enzyme activities and in the activity of antioxidant compounds such as ascorbate (AA) and glutathione. This did not prove a very effective approach since a dose of 80 μM produced a reduction in the biomass of the plants. For its part, application of iodate (IO₃⁻) produced an increase in the activities of SOD, ascorbate peroxidase, and CAT, the main enzymes involved in ROS detoxification; it also increased the concentration of AA and the regenerative activities of the Halliwell–Asada cycle. These data confirm the non-phytotoxicity of IO₃⁻ since there is no lipid peroxidation or biomass reduction. According to our results, the ability of IO₃⁻ to induce the antioxidant system indicates that application of this form of iodine may be an effective strategy to improve the response of plants to different types of stress.     

Does Management for Duck Productivity Affect Songbird Nesting Success?

ABSTRACT Habitat management for ducks has significantly influenced prairies and wetlands used by other species. However, the effects of management on other species have not been clearly assessed. We present the first study to compare the nesting success of ducks with the productivity of coexisting passerines. We evaluated effects of cattle grazing, subdivision of fields, habitat edges, year, and vegetation structure on duck and songbird nesting success in 32 mixed-grass prairie fields in southern Alberta, Canada. Duck and songbird nesting success were not correlated. Duck nesting success was influenced by timing of grazing and vegetation structure, and tended to be higher in wetter years, whereas nesting success of most songbirds was not influenced by vegetation structure or grazing, and was sometimes higher in drier years. Local habitat management for ducks cannot be assumed to benefit songbirds. However, some management strategies, such as those that promote tall grass and short litter, might benefit both taxa.     

Does Anterior Impaction Affect Radiographic Outcomes of Pilon Fractures?

BackgroundThe outcomes of pilon fractures are multifactorial. Anterior articular impaction requires sagittal plane correction (anterior distal tibia angle (ADTA)) with articular reduction. However, there is a risk of avascular necrosis of the articular fragments and postoperative tibiotalar arthritis. The purpose of this study was to determine if the presence of anterior impaction affects radiographic alignment after definitive fixation.MethodsRetrospective cohort study of patients who underwent operative management for pilon fractures at two academic, level 1 trauma centers between September 2005-September 2016. Fractures were categorized as having anterior impaction or no anterior impaction after review of preoperative radiographic and computer tomography imaging. Patient demographics and postoperative time to union was recorded. Quality of reduction was measured using (ADTA) (degrees), lateral distal tibia angle (LDTA) (degrees), and lateral talar station (LTS) (millimeters) from postoperative radiographs. Statistical analysis compared fracture patterns with anterior impaction to those without.Results208 patients met inclusion criteria. 132 fractures (63.4%) were determined to have anterior impaction. Cohorts were similar in demographics and medical comorbidities (p>0.05). Mean ADTA, LTDA, and LTS for the anterior impaction group 83.5°, 89.7°, and 2.4mm versus 84.6°, 89.9°, and 2.0mm in the group without anterior impaction. Cohorts significantly differed in ADTA(p=0.01), but not LDTA(p=0.12) or LTS(p=0.44). No significant differences were found between cohorts with infection (>0.05), nonunion(p=0.76), unplanned reoperation(p=0.56), or amputation(p=0.34).ConclusionThis study demonstrated no significant differences in the coronal or sagittal plane alignment when comparing definitively fixed pilon fractures with and without anterior impaction. Additional studies are needed to evaluate the longterm clinical impact of failing to restore ADTA. Level of Evidence: III     

Does 900 MHZ GSM Mobile Phone Exposure Affect Rat Brain?

This study investigated the effects of cell phone exposure on the fatty acid composition in phospholipids, malondialdehyde concentration, p53 immune reactivity and histological structure of the rat brain. Sixteen Sprague-Dawley rats were divided into two groups of eight, sham and experimental (speech conditions). The rats were confined to Plexiglas cages, and cellular phone were placed 0.5 cm under the cages. For the experimental group, cellular phones were activated 20 minutes per day, 7 days a week, for 1 month. For the sham group, the cellular phones were placed beneath the cages with the phones turned off. The Whole Body Average SAR (rms) was 0.52 W/kg and 1 g averaged peak SAR (rms) 3.13 W/kg. The Mann-Whitney U-test was used for statistical comparisons of groups. Histological alteration and changes in brain phospholipid fatty acids composition were not observed in rat brains. Immunohistochemical staining of brain tissue shown that p53 immunoreactivity was not affected by cell phone exposure. Malondialdehyde concentration in exposed brains was significantly higher than sham (p < 0.05).     

Does Sex Affect 30-Day Mortality in Staphylococcus Aureus Bacteremia?

BackgroundSex-related differences in complications and mortality of infection were examined with conflicting results. Further studies are required to bring new light in this topic in Staphylococcus aureus infections.ObjectiveWe examined the outcomes of S. aureus infection in men and in women and whether sex-related differences were explained by underlying disorders, severity of disease, or clinical management.MethodsThis cohort study was conducted in a single center between 1988 and 2007. Patients with clinically significant S. aureus bacteremia were included. We compared 30-day all-cause mortality in men and women. We used multivariable logistic regression analysis to test whether sex was independently associated with mortality.ResultsOne thousand ninety-three patients were identified with S. aureus bacteremia. All-cause mortality at day 30 was 39.3% (508 of 1293 patients): 44.8% (238 of 531 patients) in women and 35.4% (270 of 762 patients) in men (P < 0.01). In a multivariate analysis, female sex was associated with higher mortality (odds ratio = 1.63; 95% CI, 1.07–2.47). The excess mortality in women was not explained by differences in demographic characteristic factors, background conditions, infection severity and management, or septic complications.ConclusionsWe found that women with S. aureus bacteremia had a greater risk of 30-day all-cause mortality than men, even when adjusting for other risk factors. However, we failed to explain this excess of mortality.