Hyperspectral Analysis for Discriminating Herbicide Site of Action: A Novel Approach for Accelerating Herbicide Research.

In agricultural weed management, herbicides are indispensable, yet innovation in their modes of action (MOA)-the general mechanisms affecting plant processes-has slowed. A finer classification within MOA is the site of action (SOA), the specific biochemical pathway in plants targeted by herbicides. The primary objectives of this study were to evaluate the efficacy of hyperspectral imaging in the early detection of herbicide stress and to assess its potential in accelerating the herbicide development process by identifying unique herbicide sites of action (SOA). Employing a novel SOA classification method, eight herbicides with unique SOAs were examined via an automated, high-throughput imaging system equipped with a conveyor-based plant transportation at Purdue University. This is one of the earliest trials to test hyperspectral imaging on a large number of herbicides, and the study aimed to explore the earliest herbicide stress detection/classification date and accelerate the speed of herbicide development. The final models, trained on a dataset with nine treatments with 320 samples in two rounds, achieved an overall accuracy of 81.5% 1 day after treatment. With the high-precision models and rapid screening of numerous compounds in only 7 days, the study results suggest that hyperspectral technology combined with machine learning can contribute to the discovery of new herbicide MOA and help address the challenges associated with herbicide resistance. Although no public research to date has used hyperspectral technology to classify herbicide SOA, the successful evaluation of herbicide damage to crops provides hope to accelerate the progress of herbicide development.

Nursing Gender Pay Differentials in the New Millennium.

BACKGROUND: The gender pay gap in the United States is an ongoing issue, affecting women in nearly all occupations. Jobs traditionally associated with men tend to pay better than traditionally female-dominated jobs, and there is evidence to suggest within-occupation gender pay differences as well. PURPOSE: We compared and contrasted gender wage disparities for registered nurses (RNs), relative to gender wage disparities for another female-dominated occupation, teachers, while controlling for sociodemographic factors. METHODS: Using data in the American Community Survey, we analyzed the largest U.S. random representative sample of self-identified RNs and primary or secondary school teachers from 2000 to 2013 using fixed-effects regression analysis. RESULTS: There is greater disparity between nurse pay by gender than in teacher pay by gender. In addition, the net return in wages for additional education is higher for school teachers (21.7%) than for RNs (4.7%). CONCLUSIONS: Findings support preferential wages for men in nursing, more so than for men in teaching. CLINICAL RELEVANCE: The substantial gender disparities are an indirect measure of the misallocation of resources in effective patient care.

Who will have Sustainable Employment After a Back Injury? The Development of a Clinical Prediction Model in a Cohort of Injured Workers.

Purpose Our objective was to develop a clinical prediction model to identify workers with sustainable employment following an episode of work-related low back pain (LBP). Methods We used data from a cohort study of injured workers with incident LBP claims in the USA to predict employment patterns 1 and 6 months following a workers' compensation claim. We developed three sequential models to determine the contribution of three domains of variables: (1) basic demographic/clinical variables; (2) health-related variables; and (3) work-related factors. Multivariable logistic regression was used to develop the predictive models. We constructed receiver operator curves and used the c-index to measure predictive accuracy. Results Seventy-nine percent and 77 % of workers had sustainable employment at 1 and 6 months, respectively. Sustainable employment at 1 month was predicted by initial back pain intensity, mental health-related quality of life, claim litigation and employer type (c-index = 0.77). At 6 months, sustainable employment was predicted by physical and mental health-related quality of life, claim litigation and employer type (c-index = 0.77). Adding health-related and work-related variables to models improved predictive accuracy by 8.5 and 10 % at 1 and 6 months respectively. Conclusion We developed clinically-relevant models to predict sustainable employment in injured workers who made a workers' compensation claim for LBP. Inquiring about back pain intensity, physical and mental health-related quality of life, claim litigation and employer type may be beneficial in developing programs of care. Our models need to be validated in other populations.

Registered Nurses: The Curious Case of a Persistent Shortage.

PURPOSE: To better understand the apparent persistent shortage of registered nurses (RNs), including both aggregate trends and cyclical responses. DESIGN: We examine the employment of RNs over variations in economic activity, employing national aggregate and unique micro-population data on nurses in Arizona. METHODS: These data, including our unique, ongoing survey of nurses in Arizona, enable a systematic examination of the cyclical demand for hospital care and institutional responses to that demand in the nursing market by employing multivariate regressions. FINDINGS: Demand for hospital nursing care increases rapidly during the early years of recessions, moderating as the economy improves. Hospitals initially employ more temporary nurses, then reduce temporary hires by shifting employed RNs from part time to full time while also adding RNs not previously employed in hospitals. The substitution of regularly employed RNs for temporary nurses reflects the need to reduce staffing costs to offset increases in uncompensated care. CONCLUSIONS: The increased supply of nurses came from delayed retirements, higher relative hospital wages (inducing nurses in other sectors to return to hospitals), and added-worker effects. Additional nursing hours were drawn from a pool of RNs who were not employed in health care. CLINICAL RELEVANCE: These results strongly suggest that correctly aligned incentives could reduce RN shortages without waiting for another recession.

Elevated Dihydrotestosterone is Associated with Testosterone Induced Erythrocytosis.

PURPOSE: Erythrocytosis is the most common dose limiting adverse effect of testosterone therapy but the mechanisms of testosterone mediated erythropoiesis remain unclear. In this study we examine risk factors for erythrocytosis associated with testosterone therapy. MATERIALS AND METHODS: A retrospective review was performed of 179 hypogonadal men on testosterone therapy at a single andrology clinic. Demographic data, testosterone therapy formulation and duration of treatment, and 5α-reductase inhibitor use were assessed. Serum dihydrotestosterone, total testosterone, free testosterone, follicle-stimulating hormone, luteinizing hormone, hematocrit and lipid levels were extracted, and changes during treatment were determined. Spearman's rank correlation was used to identify relationships between change in hematocrit and study variables. RESULTS: Of 179 patients 49 (27%) experienced a 10% or greater change in hematocrit and erythrocytosis (hematocrit 50% or greater) developed in 36 (20.1%) at a median followup of 7 months. Topical gels were used by 41.3% of patients, injectable testosterone by 52.5% and subcutaneous pellets by 6.1%. More men who experienced a change in hematocrit of 10% or greater used injectable testosterone than men with a change in hematocrit of less than 10% (65% vs 48%, p=0.035), and were less likely to be on a 5α-reductase inhibitor (2% vs 15%, p=0.017). Men with a change in hematocrit of 10% or greater had higher posttreatment dihydrotestosterone levels (605.0 vs 436.0 ng/dl, p=0.017) and lower luteinizing hormone and follicle-stimulating hormone levels than men with a change in hematocrit of less than 10%. Spearman's rank correlations yielded relationships between change in hematocrit and posttreatment dihydrotestosterone ρ=0.258, p=0.001) and total testosterone (ρ=0.171, p=0.023). CONCLUSIONS: Dihydrotestosterone may have a role in testosterone therapy related erythrocytosis and monitoring dihydrotestosterone levels during testosterone therapy should be considered. In men in whom erythrocytosis develops, 5α-reductase inhibitors may be therapeutic.

Impact of volatility reduction agents on dicamba and glyphosate spray solution pH, droplet dynamics, and weed control.

BACKGROUND: Regulations in 2021 required the addition of a volatility reduction agent (VRA) to dicamba spray mixtures for postemergence weed control. Understanding the impact of VRAs on weed control, droplet dynamics, and spray pH is essential. RESULTS: Adding glyphosate to dicamba decreased the solution pH by 0.63 to 1.85 units. Across locations, potassium carbonate increased the tank-mixture pH by 0.85 to 1.65 units while potassium acetate raised the pH by 0.46 to 0.53 units. Glyphosate and dicamba in tank-mixture reduced Palmer amaranth control by 14 percentage points compared to dicamba alone and decreased barnyardgrass control by 12 percentage points compared to glyphosate alone 4 weeks after application (WAA). VRAs resulted in a 5-percentage point reduction in barnyardgrass control 4 WAA. Common ragweed, common lambsquarters, and giant ragweed control were unaffected by herbicide solution 4 WAA. Dicamba alone produced a larger average droplet size and had the fewest driftable fines (% volume < 200 µm). Potassium acetate produced a larger droplet size than potassium carbonate for Dv0.1 and Dv0.5 . The addition of glyphosate to dicamba decreased droplet size from the entire spray droplet spectrum (Dv0.1 , Dv0.5 , Dv0.9 ). CONCLUSION: A reduction in spray pH, droplet size, and weed control was observed from mixing dicamba and glyphosate. It may be advisable to avoid tank-mixtures of these herbicides and instead, apply them sequentially to maximize effectiveness. VRAs differed in their impacts on spray solution pH and droplet dynamics, but resulted in a minimal negative to no impact on weed control. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

A modified measure of health care disparities applied to birth weight disparities and subsequent mortality.

We describe how a modified Gini index serves as an improved method of estimating health care disparities. The method, although general, is applied to an example of birth weight disparities and to their effect on subsequent mortality. The method provides the between-group results obtainable from current methods (i.e. how Hispanics generally fare relative to non-Hispanic Whites) but adds measures of within-group disparities (i.e. which specific Hispanics experience the greatest disparate treatment). Our application to birth weights and receipt of prenatal care, which may provide an upper bound because of omitted variables, shows that the time-of-birth disparities are associated with increased infant mortality within the first year of life.

Endometrial cancer surgery in Arizona: a statewide analysis of access to care.

OBJECTIVES: To investigate access to surgical care for endometrial cancer in Arizona. METHODS: The Arizona HealthQuery (AZHQ) data warehouse with claims information on over 7 million patients in Arizona was searched using the International Classification of Disease (ICD-9) codes and Current Procedural Terminology (CPT) codes for endometrial cancer surgery from 2005 to 2008. Coordinates were gathered for patients and hospital to determine the distance traveled, race, insurance and annual caseload per hospital/surgeon were collected. Distance traveled was local (< 50 miles) or distant (≥ 50 miles) and served as the primary independent variable. Secondary variables included age, race, insurance, surgeon annual volume, and hospital annual volume. Logistic regression for distance traveled was performed for insurance coverage, race, hospital volume, and surgeon volume and expressed as an odds ratio. RESULTS: There were 1532 endometrial cancer surgeries performed at 67 hospitals by 242 surgeons in 15 counties. Most (61%) were performed by high-volume surgeons. Approximately 1 in 5 (19%) of patients traveled greater than 50 miles. Medicare insured patients were twice (OR=2.07, 95% CI=1.38-3.13) and Medicaid patients were three times (OR=3.41, 95% CI=1.89-6.15) as likely to travel over 50 miles. No significant difference was found between uninsured and privately insured patients (OR=0.87, 95% CI=0.45-1.68). Patients were more likely to travel to a high volume facility (OR 2.39, 95% CI=1.26-4.51). Hispanics (OR=2.72, 95% CI=1.72-4.32) and Native Americans (OR=8.60, 95% CI=3.43-21.52) were more likely to travel compared to Caucasians. CONCLUSION: In Arizona significantly different patterns of care are seen for endometrial cancer surgery based upon insurance coverage, race, surgeon and hospital. Patients travel farther to a high-volume hospital and high-volume surgeon. Hispanics or Native Americans travel farther for care when compared with Caucasians. Patients on government funded insurance plans travel farther for care than patients covered by private insurance or those lacking insurance.

Adjusting rehabilitation costs and benefits for health capital: the case of low back occupational injuries.

INTRODUCTION: Case-mix adjustments for treatment/rehabilitation costs and benefits of non-traumatic injuries, such as occupational back pain, are much more difficult than adjustments for traumatic injuries. We present a new method for adjusting for severity differences in the costs and benefits of treating occupational low back injuries. METHODS: Using initial post-injury differences in the health capital of prospective sample of 1,831 occupational related back pain patients, we combine survey data with workers' compensation claim files and medical billing information to adjust the costs and benefits of treatment using multivariate techniques. RESULTS: We find that large differences in the net benefits of treatment between the three lowest cost provider groups virtually disappear once adjustments are made for worker's health capital (injury severity) at entry into treatment. CONCLUSIONS: Once adjustments are made for initial health capital immediately after injury, the net benefits of treating occupational low back pain are virtually identical for physician only care, physician plus physical therapy care, and chiropractic care. Net benefits of care are lower for combined physician/chiropractic care, and lowest for all other forms of care (principally, treatment by orthopedic surgeons). Our method is readily adapted for comparisons among individual health care/occupational rehabilitation professionals or among group practices and other health care organizations.

Using innovation to assess nursing workforce in Arizona: a collaborative approach.

The process of using nurse license renewal data to generate the information needed to measure and project the supply of RNs, LPNs, and APNs in a state is described. The use of licensing applications as the foundation to which time-varying survey questions can be added offers a continuing record of the behavior of the nursing workforce for all nurses in a state workforce. A significant added benefit is this can occur at a fraction of the cost of a one-point-in-time survey of even a small sample of nurses. Other states could benefit from adopting a similar approach of collaboration between health care systems (e.g., hospital associations), boards of nursing, and academia. Such collaboration would allow nursing administrators and academia alike the ability to accurately predict nursing workforce needs, thus facilitating operational decision making and strategic planning.

Confirmation of herbicide resistance mutations Trp574Leu, ΔG210, and EPSPS gene amplification and control of multiple herbicide-resistant Palmer amaranth (Amaranthus palmeri) with chlorimuron-ethyl, fomesafen, and glyphosate.

Herbicide-resistant weeds, especially Palmer amaranth (Amaranthus palmeri S. Watson), are problematic in row-crop producing areas of the United States. The objectives of this study were to determine if chlorimuron-ethyl, fomesafen, and glyphosate applied separately and in mixtures control A. palmeri and confirm the presence of various genotypes surviving two- and three-way herbicide mixtures. Fifteen percent of A. palmeri treated with the three-way herbicide mixture survived. Mixing fomesafen with chlorimuron-ethyl or fomesafen with glyphosate to create a two-way mixture reduced A. palmeri survival 22 to 24% and 60 to 62% more than glyphosate and chlorimuron-ethyl alone, respectively. Previously characterized mutations associated with A. palmeri survival to chlorimuron-ethyl, fomesafen, and glyphosate Trp574Leu, a missing glycine codon at position 210 of the PPX2L gene (ΔG210), and 5-enolpyruvylshikimate-3-phosphase synthase (EPSPS) gene amplification; respectively, were present in surviving plants. However, 37% of plants treated with chlorimuron-ethyl did not contain heterozygous or homozygous alleles for the Trp574Leu mutation, suggesting alternative genotypes contributed to plant survival. All surviving A. palmeri treated with fomesafen or glyphosate possessed genotypes previously documented to confer resistance. Indiana soybean [Glycine max (L.) Merr] fields infested with A. palmeri possessed diverse genotypes and herbicide surviving plants are likely to produce seed and spread if alternative control measures are not implemented.

Fetal mechanisms in neurodevelopmental disorders.

Normal development of the central nervous system depends on complex, dynamic mechanisms with multiple spatial and temporal components during gestation. Neurodevelopmental disorders may originate during fetal life from genetic as well as intrauterine and extrauterine factors that affect the fetal-maternal environment. Fetal neurodevelopment depends on cell programs, developmental trajectories, synaptic plasticity, and oligodendrocyte maturation, which are variously modifiable by factors such as stress and endocrine disruption, exposure to pesticides such as chlorpyrifos and to drugs such as terbutaline, maternal teratogenic alleles, and premature birth. Current research illustrates how altered fetal mechanisms may affect long-term physiological and behavioral functions of the central nervous system more significantly than they affect its form, and these effects may be transgenerational. This research emphasizes the diversity of such prenatal mechanisms and the need to expand our understanding of how, when altered, they may lead to disordered development, the signs of which may not appear until long after birth.

Satisfaction with low back pain care.

BACKGROUND: By using a unique, prospective study of occupational back pain claims, we examined health-care satisfaction by provider type and its effect on return to work. PURPOSE: We estimated satisfaction differentials by provider type, decomposing overall satisfaction into two components: bedside manner and effectiveness of care. We also examined how health-care satisfaction affects the duration of jobless claims. STUDY DESIGN: The Arizona State University Healthy Back Study (HBS) is a prospective study of work-related back pain; 1,831 workers completed a baseline interview, with follow-up interviews at 1 month, 6 months, and 1 year. The HBS merged demographic and claim characteristics from the workers' compensation claim files with self-reported severity measures, measures of satisfaction, and postonset employment from worker interviews. OUTCOME MEASURES: Overall and detailed satisfaction with treatment and workers' compensation claim duration. METHODS: We performed a nonparametric descriptive analysis of satisfaction by provider type and used multivariate regressions to decompose overall satisfaction into component parts. The duration analysis links differentials in health care satisfaction to differences in claim durations. RESULTS: Workers treated by surgeons, chiropractors (DCs), or physical therapists are more satisfied with their health care than those treated by MDs. Workers are more concerned with the effectiveness of care than with the bedside manner of their provider. A one standard deviation improvement in satisfaction with the health-care provider reduces claim duration by about 25%. CONCLUSIONS: Satisfaction with health care has a significant impact on jobless spells and varies significantly between provider types.

Patterns of sick-leave and health outcomes in injured workers with back pain.

Little is known about the sick-leave experiences of workers who make a workers' compensation claim for back pain. Our objective is to describe the 1-year patterns of sick-leave and the health outcomes of a cohort of workers who make a workers' compensation claim for back pain. We studied a cohort of 1,831 workers from five large US firms who made incident workers' compensation claims for back pain between January 1, 1999 and June 30, 2002. Injured workers were interviewed 1 month (n = 1,321), 6 months (n = 810) and 1 year (n = 462) following the onset of their pain. We described the course of back pain using four patterns of sick-leave: (1) no sick-leave, (2) returned to worked and stayed, (3) multiple episodes of sick-leave and (4) not yet returned to work. We described the health outcomes as back and/or leg pain intensity, functional limitations and health-related quality of life. We analyzed data from participants who completed all follow-up interviews (n = 457) to compute the probabilities of transition between patterns of sick-leave. A significant proportion of workers experienced multiple episodes of sick-leave (30.2%; 95% CI 25.0-35.1) during the 1-year follow-up. The proportion of workers who did not report sick-leave declined from 42.4% (95% CI 39.0-46.1) at 1 month to 33.6% (28.0-38.7) at 1 year. One year after the injury, 2.9% (1.6-4.9) of workers had not yet returned to work. Workers who did not report sick-leave and those who returned and stayed at work reported better health outcomes than workers who experienced multiple episodes of sick-leave or workers who had not returned to work. Almost a third of workers with an incident episode of back pain experience recurrent spells of work absenteeism during the following year. Our data suggest that stable patterns of sick-leave are associated with better health.

Glyphosate resistance in Ambrosia trifida: Part 1. Novel rapid cell death response to glyphosate.

BACKGROUND: Glyphosate-resistant (GR) Ambrosia trifida is now present in the midwestern United States and in southwestern Ontario, Canada. Two distinct GR phenotypes are known, including a rapid response (GR RR) phenotype, which exhibits cell death within hours after treatment, and a non-rapid response (GR NRR) phenotype. The mechanisms of resistance in both GR RR and GR NRR remain unknown. Here, we present a description of the RR phenotype and an investigation of target-site mechanisms on multiple A. trifida accessions. RESULTS: Glyphosate resistance was confirmed in several accessions, and whole-plant levels of resistance ranged from 2.3- to 7.5-fold compared with glyphosate-susceptible (GS) accessions. The two GR phenotypes displayed similar levels of resistance, despite having dramatically different phenotypic responses to glyphosate. Glyphosate resistance was not associated with mutations in EPSPS sequence, increased EPSPS copy number, EPSPS quantity, or EPSPS activity. CONCLUSION: These encompassing results suggest that resistance to glyphosate in these GR RR A. trifida accessions is not conferred by a target-site resistance mechanism. © 2017 Society of Chemical Industry.

Glyphosate resistance in Ambrosia trifida: Part 2. Rapid response physiology and non-target-site resistance.

BACKGROUND: The glyphosate-resistant rapid response (GR RR) resistance mechanism in Ambrosia trifida is not due to target-site resistance (TSR) mechanisms. This study explores the physiology of the rapid response and the possibility of reduced translocation and vacuolar sequestration as non-target-site resistance (NTSR) mechanisms. RESULTS: GR RR leaf discs accumulated hydrogen peroxide within minutes of glyphosate exposure, but only in mature leaf tissue. The rapid response required energy either as light or exogenous sucrose. The combination of phenylalanine and tyrosine inhibited the rapid response in a dose-dependent manner. Reduced glyphosate translocation was observed in GR RR, but only when associated with tissue death caused by the rapid response. Nuclear magnetic resonance studies indicated that glyphosate enters the cytoplasm and reaches chloroplasts, and it is not moved into the vacuole of GR RR, GR non-rapid response or glyphosate-susceptible A. trifida. CONCLUSION: The GR RR mechanism of resistance is not associated with vacuole sequestration of glyphosate, and the observed reduced translocation is likely a consequence of rapid tissue death. Rapid cell death was inhibited by exogenous application of aromatic amino acids phenylalanine and tyrosine. The mechanism by which these amino acids inhibit rapid cell death in the GR RR phenotype remains unknown, and it could involve glyphosate phytotoxicity or other agents generating reactive oxygen species. Implications of these findings are discussed. The GR RR mechanism is distinct from the currently described glyphosate TSR or NTSR mechanisms in other species. © 2017 Society of Chemical Industry.

Risk of autistic disorder in affected offspring of mothers with a glutathione S-transferase P1 haplotype.

OBJECTIVE: To test whether polymorphisms of the glutathione S-transferase P1 gene (GSTP1) act in the mother during pregnancy to contribute to the phenotype of autistic disorder (AD) in her fetus. DESIGN: Transmission disequilibrium testing (TDT) in case mothers and maternal grandparents. SETTING: Autistic disorder may result from multiple genes and environmental factors acting during pregnancy and afterward. Teratogenic alleles act in mothers during pregnancy to contribute to neurodevelopmental disorders in their offspring; however, only a handful have been identified. GSTP1 is a candidate susceptibility gene for AD because of its tissue distribution and its role in oxidative stress, xenobiotic metabolism, and JNK regulation. PARTICIPANTS: We genotyped GSTP1*G313A and GSTP1*C341T polymorphisms in 137 members of 49 families with AD. All probands received a clinical diagnosis of AD by Autism Diagnostic Interview-Revised and Autism Diagnostic Observation Schedule-Generic testing. MAIN OUTCOME MEASURES: Association of haplotypes with AD was tested by the TDT-Phase program, using the expectation-maximization (EM) algorithm for uncertain haplotypes and for incomplete parental genotypes, with standard measures of statistical significance. RESULTS: The GSTP1*A haplotype was overtransmitted to case mothers (P = .01 [P = .03 using permutation testing]; odds ratio, 2.67 [95% confidence interval, 1.39-5.13]). Results of the combined haplotype and genotype analyses suggest that the GSTP1-313 genotype alone determined the observed haplotype effect. CONCLUSIONS: Overtransmission of the GSTP1*A haplotype to case mothers suggests that action in the mother during pregnancy likely increases the likelihood of AD in her fetus. If this is confirmed and is a result of a gene-environment interaction occurring during pregnancy, these findings could lead to the design of strategies for prevention or treatment.

Ataxin-3 interactions with rad23 and valosin-containing protein and its associations with ubiquitin chains and the proteasome are consistent with a role in ubiquitin-mediated proteolysis.

Machado-Joseph disease is caused by an expansion of a trinucleotide CAG repeat in the gene encoding the protein ataxin-3. We investigated if ataxin-3 was a proteasome-associated factor that recognized ubiquitinated substrates based on the rationale that (i) it is present with proteasome subunits and ubiquitin in cellular inclusions, (ii) it interacts with human Rad23, a protein that may translocate proteolytic substrates to the proteasome, and (iii) it shares regions of sequence similarity with the proteasome subunit S5a, which can recognize multiubiquitinated proteins. We report that ataxin-3 interacts with ubiquitinated proteins, can bind the proteasome, and, when the gene harbors an expanded repeat length, can interfere with the degradation of a well-characterized test substrate. Additionally, ataxin-3 associates with the ubiquitin- and proteasome-binding factors Rad23 and valosin-containing protein (VCP/p97), findings that support the hypothesis that ataxin-3 is a proteasome-associated factor that mediates the degradation of ubiquitinated proteins.

It pays to be nice: employer-worker relationships and the management of back pain claims.

OBJECTIVE: To quantify the influence that workers' satisfaction with the firm's treatment of their disability claim and their health care provider has on workers' return to work (RTW) following onset of occupational LBP. METHODS: Using a prospective survey on back pain, medical treatment, and workers' satisfaction, we employ nonparametric and logistic analyses to see how satisfaction affects RTW. RESULTS: Workers' satisfaction with their employer's treatment of their disability claim is more important in explaining RTW than satisfaction with health care providers or expectations about recovery. Dissatisfied workers have worse return to work outcomes because they are more likely to have time lost claims and are more likely to have multiple spells of joblessness. CONCLUSIONS: Workers' RTW is more responsive to their satisfaction with how the firm treated their disability claim than with their satisfaction with the health care provider. Satisfaction of both types plays an important role in determining RTW.

Analysis of case-parent trios at a locus with a deletion allele: association of GSTM1 with autism.

BACKGROUND: Certain loci on the human genome, such as glutathione S-transferase M1 (GSTM1), do not permit heterozygotes to be reliably determined by commonly used methods. Association of such a locus with a disease is therefore generally tested with a case-control design. When subjects have already been ascertained in a case-parent design however, the question arises as to whether the data can still be used to test disease association at such a locus. RESULTS: A likelihood ratio test was constructed that can be used with a case-parents design but has somewhat less power than a Pearson's chi-squared test that uses a case-control design. The test is illustrated on a novel dataset showing a genotype relative risk near 2 for the homozygous GSTM1 deletion genotype and autism. CONCLUSION: Although the case-control design will remain the mainstay for a locus with a deletion, the likelihood ratio test will be useful for such a locus analyzed as part of a larger case-parent study design. The likelihood ratio test has the advantage that it can incorporate complete and incomplete case-parent trios as well as independent cases and controls. Both analyses support (p = 0.046 for the proposed test, p = 0.028 for the case-control analysis) an association of the homozygous GSTM1 deletion genotype with autism.