Acute kidney injury and workload in a sample of California agricultural workers.

BACKGROUND: Kidney damage is associated with an increased workload in high ambient temperatures and may represent a pathway to chronic kidney disease of unknown origin in agricultural workers. We tested the associations of workload and heat with acute kidney dysfunction in California agricultural workers. METHODS: We recruited a convenience sample of 471 agricultural workers from 29 farms in California during two summer harvest seasons. The sustained 3-minute maximum workload was estimated using accelerometer data collected from Actical monitors and individual heat load through elevations in core body temperature. Acute kidney injury (AKI) was defined by a change in serum creatinine of ≥0.3 mg/dL or ≥1.5 times the preshift creatinine over the course of the work shift. Associations between AKI and workload were modeled using logistic regression, controlling for demographic, physiologic, and occupational variables. RESULTS: Of the total, 357 workers (75.8%) had accelerometer readings in the moderate workload category, 93 (19.7%) had readings in the vigorous category. 177 (36%) had elevations of core body temperature ≥1°C; 72 workers (14.9%) demonstrated evidence of AKI after a single day of agricultural work. The workload category was associated with an increased adjusted odds of AKI (1.92; 95% confidence interval, 1.05-3.51). Piece-rate work was also associated with increased adjusted odds of AKI (3.02; 95% CI, 1.44-6.34). CONCLUSIONS: Heavy occupational workload and piece-rate work were associated with acute effects on the renal health of agricultural workers. This indicates that occupations requiring high physical effort put workers at risk for AKI, possibly independent of ambient and core body temperature. Changes to agricultural practices may reduce the risk of renal disorders for these workers.

Impacts of weather, work rate, hydration, and clothing in heat-related illness in California farmworkers.

BACKGROUND: The primary aim of this study was to investigate the effects of work rate, hydration status, and clothing on core body temperature (CBT) on California farmworkers. METHODS: Two hundred and eighty-seven farmworkers were recruited in Summer 2015, with 259 participants having sufficient data for analysis. We collected CBT, ambient temperature, work rate, body weight loss, and clothing worn by each participant throughout the work day and demographic data from a questionnaire. RESULTS: Multiple regression with CBT as the outcome was used to determine the adjusted associations between CBT, environmental heat load, and worker characteristics. The multivariate regression model showed statistically significant associations of CBT with work rate (ß = .006, 95% CI [0.004, 0.009]) and wet-bulb globe temperature (ß = .03, 95% CI [0.017, 0.05]). CONCLUSION: Results suggest that among our population workload is the primary modifiable risk factor for heat-related illness. As expected, the ambient temperature was also associated with higher risk.

Physical activity and common tasks of California farm workers: California Heat Illness Prevention Study (CHIPS).

Farm workers are at risk of heat related illness (HRI), but their work rates that contribute to HRI have not been objectively assessed. The CHIPS study collected accelerometer data and characterized the physical activity of major farm tasks. Demographic information, work characteristics, and accelerometer data were collected from 575 farm workers in California. Each participating worker contributed measurements over one work shift. An Actical accelerometer was attached securely to a belt worn at the hip. Data were collected at one-minute intervals throughout the work shift. A total of 13 major work-task categories were defined. The mean physical activity counts per minute (cpm) and percentage of the shift spent at moderate and/or vigorous levels of activity were described for each task. Multiple linear regression models were constructed to determine the worker and environmental characteristics contributing to the physical activity level. Mean levels of physical activity ranged from 700 cpm (workers who carry produce) to a low of 150 cpm "ground pruners" who tend low-level plants, with an overall mean of 345 cpm or "light" activity (2 to ≤3 metabolic equivalents). The environmental temperature was the major factor associated with physical activity. A 10°C increase in the median temperature reduced the mean cpm by 135 (95% CI = 87, 193). Age and the tasks of sorting, ground pruning, and harvesting low-level crops were also negatively and independently associated with mean cpm. Incentivized (piece rate) pay, multi-task work, and irrigator work were positively associated with cpm. An interaction was found between piece rate and sex. Men's activity significantly increased (p < 0.001) by a mean of 95 cpm, (95% CI = 38.3, 150.7) if they were paid by the piece, but there was a non-significant association with women's activity level. Workers conducting multiple tasks, irrigators, men, and those earning incentivized (piece rate) pay had higher adjusted mean physical activity levels and are likely at increased risk of heat-related illness on hot days.

Heat strain, volume depletion and kidney function in California agricultural workers.

BACKGROUND: Agricultural work can expose workers to increased risk of heat strain and volume depletion due to repeated exposures to high ambient temperatures, arduous physical exertion and limited rehydration. These risk factors may result in acute kidney injury (AKI). METHODS: We estimated AKI cumulative incidence in a convenience sample of 283 agricultural workers based on elevations of serum creatinine between preshift and postshift blood samples. Heat strain was assessed based on changes in core body temperature and heart rate. Volume depletion was assessed using changes in body mass over the work shift. Logistic regression models were used to estimate the associations of AKI with traditional risk factors (age, diabetes, hypertension and history of kidney disease) as well as with occupational risk factors (years in farm work, method of payment and farm task). RESULTS: 35 participants were characterised with incident AKI over the course of a work shift (12.3%). Workers who experienced heat strain had increased adjusted odds of AKI (1.34, 95% CI 1.04 to 1.74). Piece rate work was associated with 4.24 odds of AKI (95% CI 1.56 to 11.52). Females paid by the piece had 102.81 adjusted odds of AKI (95% CI 7.32 to 1443.20). DISCUSSION: Heat strain and piece rate work are associated with incident AKI after a single shift of agricultural work, though gender differences exist. Modifications to payment structures may help prevent AKI.

How Does Environmental Temperature Affect Farmworkers' Work Rates in the California Heat Illness Prevention Study?

OBJECTIVE: Estimate the association between environmental temperature (wet bulb globe temperature [WBGT]) and work rate over the course of a workday. METHODS: Repeated-measures regression was used to identify characteristics impacting work rate in a cross-sectional study of Latino farmworkers. Minute-by-minute work rate (measured by accelerometer) and WBGT were averaged over 15-minute intervals. RESULTS: Work rate decreased by 4.34 (95% confidence interval [CI], -7.09 to -1.59) counts per minute per degree Celsius WBGT in the previous 15-minute interval. Cumulative quarter hours worked (2.13; 95% CI, 0.82 to 3.45), age (-3.64; 95% CI, -4.50 to -2.79), and dehydration at the end of workday (51.37; 95% CI, 19.24 to 83.50) were associated with counts per minute as were gender, pay type (piece rate vs hourly) and body mass index ≥25 kg/m 2 . The effects of pay type and body mass index were modified by gender. CONCLUSION: Increased temperature was associated with a decrease in work rate.

Are Cal/OSHA Regulations Protecting Farmworkers in California From Heat-Related Illness?

OBJECTIVE: Determine compliance with and effectiveness of California regulations in reducing farmworkers' heat-related illness (HRI) risk and identify main factors contributing to HRI. METHODS: In a cross-sectional study of Latino farmworkers, core body temperature (CBT), work rate, and environmental temperature (WBGT) were monitored over a work shift by individual ingestible thermistors, accelerometers, and weather stations, respectively. Multiple logistic modeling was used to identify risk factors for elevated CBT. RESULTS: Although farms complied with Cal/OSHA regulations, worker training of HRI prevention and hydration replacement rates were insufficient. In modeling (AOR [95% CI]) male sex (3.74 [1.22 - 11.54]), WBGT (1.22 [1.08 - 1.38]), work rate (1.004 [1.002 - 1.006]), and increased BMI (1.11 [1.10 - 1.29]) were all independently associated with elevated CBT. CONCLUSION: Risk of HRI was exacerbated by work rate and environmental temperature despite farms following Cal/OSHA regulations.

Equity in veterans' mental health care: Veterans Affairs medical center clinics versus community-based outpatient clinics.

This study examined differences in structures and processes of mental health care at Veterans Administration (VA) primary care clinics, comparing VA medical center (VAMC) clinics to community-based outpatient clinics (CBOCs). A survey was conducted of nurse managers at 46 of 49 primary care clinics (23 VAMC clinics and 23 CBOCs) within a VA health care network in the south central United States. Integration of care and services overall was comparable between VAMC clinics and CBOCs. The service mix differed. Integrated CBOCs more often offered group therapy, medication management, and smoking cessation. Integrated VAMC clinics more frequently used written suicide protocols and depression screening. Distance to offsite specialty care and wait times for referrals were shorter for patients at VAMCs than at CBOCs. The provision of mental health care at CBOCs is comparable to that at VAMC clinics, although differences in patient access to offsite care indicate that full equity was not achieved at the time of the survey. Since 2000, the VA has initiated several programs to address this need.

Recruitment, Methods, and Descriptive Results of a Physiologic Assessment of Latino Farmworkers: The California Heat Illness Prevention Study.

OBJECTIVE: The California heat illness prevention study (CHIPS) devised methodology and collected physiological data to assess heat related illness (HRI) risk in Latino farmworkers. METHODS: Bilingual researchers monitored HRI across a workshift, recording core temperature, work rate (metabolic equivalents [METs]), and heart rate at minute intervals. Hydration status was assessed by changes in weight and blood osmolality. Personal data loggers and a weather station measured exposure to heat. Interviewer administered questionnaires were used to collect demographic and occupational information. RESULTS: California farmworkers (n = 588) were assessed. Acceptable quality data was obtained from 80% of participants (core temperature) to 100% of participants (weight change). Workers (8.3%) experienced a core body temperature more than or equal to 38.5 °C and 11.8% experienced dehydration (lost more than 1.5% of body weight). CONCLUSIONS: Methodology is presented for the first comprehensive physiological assessment of HRI risk in California farmworkers.

Disparities in use of antipsychotic medications among nursing home residents in Arkansas.

Pilot work was conducted to determine whether there were racial disparities in the use of second-generation antipsychotic medications in a sample of 2,717 residents of nursing homes in Arkansas in 2001. Chi square analysis and a logistic regression model were used to examine the relationship between residents' race and likelihood of receiving a second-generation antipsychotic. Other independent variables included in the model were age, gender, and the location of the nursing home. The results indicated racial disparities in use of second-generation antipsychotics among the nursing home residents, with African-American residents less likely to receive these medications than residents from other racial or ethnic groups.

Cage Versus Noncage Laying-Hen Housings: Respiratory Exposures.

The objective of this study was to compare the personal respiratory exposures of poultry workers in three different types of layer housing under commercial production conditions. Workers were randomly assigned to each of conventional cage, enriched cage, and aviary barns in a crossover repeated-measures design for three observation periods over the hens' lifetime. Inhalable and fine particulate matter (PM) and endotoxin in both size fractions were assessed by personal and area samplers over the work shift. Concentrations of inhalable PM, PM2.5 (PM with an aerodynamic diameter <2.5 µm), and endotoxin in both size fractions were higher in aviary than either the conventional or enriched barns. Geometric means (95% confidence intervals [CIs]) of inhalable PM and endotoxin for the aviary, conventional, and enriched barns were 8.9 (6.8-11.5) mg/m(3) and 7517.9 (5403.2-10,460.2) EU/m(3), 3.7 (2.8-4.8) mg/m(3) and 1655.7 (1144.6-2395.2) EU/m(3), 2.4 (1.8-3.3) mg/m(3) and 1404.8 (983.3-2007.0) EU/m(3), respectively. Area samplers recorded a lower mean inhalable PM concentration and higher PM2.5 concentration than personal samplers. Ammonia concentrations were low throughout three monitoring seasons. These findings show that the aviary barns pose higher respiratory exposures to poultry workers than either conventional or enriched barns.

Cage Versus Noncage Laying-Hen Housings: Worker Respiratory Health.

The objective of this study was to compare respiratory health of poultry workers in conventional cage, enriched cage and aviary layer housing on a single commercial facility, motivated by changing requirements for humane housing of hens. Three workers were randomly assigned daily, one to each of conventional cage, enriched cage, and aviary housing in a crossover repeated-measures design for three observation periods (for a total of 123 worker-days, eight different workers). Workers' exposure to particles were assessed (Arteaga et al. J Agromedicine. 2015;20:this issue) and spirometry, exhaled nitric oxide, respiratory symptoms, and questionnaires were conducted pre- and post-shift. Personal exposures to particles and endotoxin were significantly higher in the aviary than the other housings (Arteaga et al., 2015). The use of respiratory protection was high; the median usage was 70% of the shift. Mixed-effects multivariate regression models of respiratory cross-shift changes were marginally significant, but the aviary system consistently posted the highest decrements for forced expiratory volume in 1 and 6 seconds (FEV1 and FEV6) compared with the enriched or conventional housing. The adjusted mean difference in FEV1 aviary - enriched cage housing was -47 mL/s, 95% confidence interval (CI): (-99 to 4.9), P = .07. Similarly, for FEV6, aviary - conventional housing adjusted mean difference was -52.9 mL/6 s, 95% CI: (-108 to 2.4), P = .06. Workers adopting greater than median use of respiratory protection were less likely to exhibit negative cross-shift pulmonary function changes. Although aviary housing exposed workers to significantly higher respiratory exposures, cross-shift pulmonary function changes did not differ significantly between houses. Higher levels of mask use were protective; poultry workers should wear respiratory protection as appropriate to avoid health decrements.

Particulate matter, endotoxin, and worker respiratory health on large Californian dairies.

OBJECTIVE: To assess respiratory exposures and lung function in a cross-sectional study of California dairy workers. METHODS: Exposure of 205 dairy and 45 control (vegetable processing) workers to particulate matter and endotoxin was monitored. Pre- and postshift spirometry and interviews were conducted. RESULTS: Geometric mean inhalable and PM2.5 concentrations were 812 and 35.3 µg/m3 versus 481.9 and 19.6 µg/m3, respectively, for dairy and control workers. Endotoxin concentrations were 329 EU/m3 or 1122 pmol/m3 and 13.5 EU/m3 or 110 pmol/m3, respectively, for dairy and control workers. In a mixed-effects model, forced vital capacity decreased across a work shift by 24.5 mL (95% confidence interval, -44.7 to -4.3; P = 0.018) with log10 (total endotoxin) and by 22.0 mL (95% confidence interval, -43.2 to -0.08; P = 0.042) per hour worked. CONCLUSIONS: Modern California dairy endotoxin exposures and shift length were associated with a mild acute decrease in forced vital capacity.

The impact of father absence on adolescent separation-individuation.

The authors compared separation-individuation and psychological separation from fathers of 25 adolescent boys who were living with both biological parents with that of 25 boys who were living with their biological mothers in homes in which the fathers did not reside. The results showed that the boys in the 2 groups did not differ on measures of separation-individuation and that the quality of the mother-son relationship mediated several of the assessed separation-individuation manifestations. The authors' initial data analysis with regard to psychological separation showed that boys who lived in homes in which the father was a nonresident were more separated on 2 of the 4 dimensions assessed; however, when controlled for quality of mother-son and father-son relationship, these differences were not significant. The frequency of father contact in homes in which the father did not reside was positively correlated with healthy separation but negatively correlated with functional, attitudinal, and emotional independence from the father. The results of the study support the importance of the quality of a child's relationship with his or her mother and father as a mediator of several dimensions of the separation-individuation process.

Mortality in the California Farmer Health Study cohort.

Western agriculture, in comparison with Midwestern and Eastern, is more diverse, with a drier climate, mild winters, and different exposures. This randomly selected cohort of 1947 Californian farmers confirmed the usual finding: a lower mortality rate than general population (by 50%). A low smoking prevalence and healthy worker effect are likely contributors. Although farmers were more likely to die from injuries and skin cancer, death was less likely from Alzheimer's and cerebrovascular diseases. Within the cohort, disability and persistent wheeze were associated with increased mortality. The 200 deaths were insufficient to determine the significance of rare diseases.

Guideline implementation and patient-tailoring strategies to improve medication adherence for schizophrenia.

OBJECTIVE: To determine the effectiveness of an intervention to promote medication adherence. METHOD: Data were collected for adults with exacerbation of schizophrenia who were treated at one of 6 U.S. Department of Veterans Affairs (VA) Medical Centers (VAMCs) in 3 regional VA networks (Veterans Integrated Service Networks [VISNs]) from March 1999 to October 2000. All 6 VAMCs received a basic guideline implementation strategy for medication management of schizophrenia using usual VA procedures. One VAMC within each VISN was randomly selected to receive an enhanced implementation strategy designed to promote guideline-concordant prescribing by physicians and medication adherence by patients. In the enhanced strategy, a research nurse worked with study participants to identify medication adherence barriers and to develop patient-specific strategies to overcome those barriers. Participants (N = 349) were interviewed at enrollment and 6 months later, using the Structured Clinical Interview for the Positive and Negative Syndrome Scale (PANSS), the Barnes Akathisia Rating Scale, and the Schizophrenia Outcomes Module (SCHIZOM). Medication adherence was measured via subjects' self-report, using the SCHIZOM, and from data abstracted from medical records. RESULTS: Participants were primarily male (94%) and nonwhite (69%, primarily African American) with a mean age of 46 years. Medication adherence at follow-up was modeled using logistic regression, controlling for adherence at baseline, demographic characteristics, PANSS total score, akathisia at baseline, family history of mental illness, and substance abuse. A logistic regression model for adherence at follow-up was significant (likelihood ratio = 52.72, df = 14, p < .0001). Patients enrolled at sites receiving the enhanced intervention were almost twice as likely to be adherent at follow-up. Those who were nonadherent at baseline were significantly less likely to be adherent at follow-up. In addition, adherence at follow-up was significantly greater at 2 of the VA networks as compared to the third network. CONCLUSIONS: These data suggest that a patient-centered strategy to identify and overcome barriers to adherence can improve adherence to antipsychotic medications.

The effectiveness of guideline implementation strategies on improving antipsychotic medication management for schizophrenia.

OBJECTIVES: To compare the effectiveness of a conceptually-based, multicomponent "enhanced" strategy with a "basic" strategy for implementing antipsychotic management recommendations of VA schizophrenia guidelines. METHODS: Two VA medical centers in each of 3 Veterans Integrated Service Networks were randomized to either a basic educational implementation strategy or the enhanced strategy, in which a trained nurse promoted provider guideline adherence and patient compliance. Patients with acute exacerbation of schizophrenia were enrolled and assessed at baseline and 6 months and their medical records were abstracted; 291 participants were included in analyses. Logistic regression models were developed for rates of: (1) switching patients from first-generation antipsychotics (FGA) to second-generation antipsychotics (SGA), and (2) guideline-concordant antipsychotic dose. RESULTS: Of participants prescribed FGAs at baseline, those at enhanced sites were significantly more likely than participants at basic sites to have an SGA added to the FGA during the study (29% vs. 8%; adjusted OR = 7.7; 95% CI: 2.0-30.1), but were not significantly more likely to be switched to monotherapy with an SGA (29% vs. 23%). Guideline-concordant antipsychotic dosing was not significantly affected by the intervention. CONCLUSIONS: The enhanced guideline implementation strategy increased addition of SGAs to FGA therapy, but did not significantly increase guideline-recommended switching from FGA to SGA monotherapy. Antipsychotic dosing was not significantly altered. The study illustrates the challenges of changing clinical behavior. Strategies to improve medication management for schizophrenia are needed, and must incorporate recommendations likely to emerge from recent research suggesting comparable effectiveness of SGAs and FGAs.